Emerging Technologies
for Biosolids Management
EPA 832-R-06-005 SEPTEMBER 2006
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Emerging Technologies
for
Biosolids Management
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Emerging Technologies for Biosolids Management
EPA 832-R-06-005
September 2006
Produced under U.S. EPA Contract No. 68-C-02-111
Prepared by the Parsons Corporation
Fairfax, Virginia
Technical review was provided by professionals with experience in biosolids management.
Technical reviewers of this document were:
Michelle Hetherington and Michael Moore, Orange County Sanitation District, Fountain Valley,
California
Robert Pepperman, Environmental Group Services, White Marsh, Maryland
Timothy G. Shea, CH2M Hill, Herndon, Virginia
Lori Stone, National Biosolids Partnership, Alexandria, Virginia
Robert Reimers, Tulane University, New Orleans, Louisiana
Paul Rom, Black & Veatch, Chicago, Illinois
Recycled/Recyclable
Printed with vegetable-based ink on paper that contains a minimum of 50 percent post-
consumer fiber content chlorine free.
Electronic copies of this handbook can be downloaded from the
U.S. EPA Office of Wastewater Management web site at:
www.epa.gov/owm
Biosolids Management
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Emerging Technologies
Preface
The U.S. Environmental Protection Agency (U.S. EPA) is charged by Congress with
protecting the nation's land, air, and water resources. Under a mandate of environmental
laws, the Agency strives to formulate and implement actions leading to a balance between
human activities and the ability of natural systems to support and sustain life. To meet
this mandate, the Office of Wastewater Management (OWM) provides information and
technical support to solve environmental problems today and to build a knowledge base
necessary to protect public health and the environment well into the future.
This publication has been produced under contract to the U.S. EPA by Parsons Corporation
and provides information on the current state of development as of the publication date.
It is expected that this document will be revised periodically to reflect advances in this
rapidly evolving area. Except as noted, information, interviews and data development
were conducted by the contractor. It should be noted that neither Parsons nor U.S. EPA
has conducted engineering or operations evaluations of the technologies included. Some
of the information, especially related to embryonic technologies, was provided by the
manufacturer or vendor of the equipment or technology and could not be verified or
supported by full-scale case study. In some cases, cost data were based on estimated
savings without actual field data. When evaluating technologies, estimated costs, and
stated performance, efforts should be made to obtain current information.
The mention of trade names, specific vendors, or products does not represent an actual
or presumed endorsement, preference, or acceptance by the U.S. EPA or the Federal
government. Stated results, conclusions, usage, or practices do not necessarily represent
the views or policies of the U.S. EPA.
Biosolids Management iii
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Emerging Technologies September 2006
iv Biosolids Management
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Emerging Tedmolenies
Contents
Page
Executive Summary ES-1
1. Introduction and Approach 1-1
1.1 Introduction 1-1
1.2 Approach 1-2
1.2.1 Information Collection and New Process Identification 1-3
1.2.2 Initial Screening Technologies 1-4
1.2.3 Development of Technology Summary Sheets 1-11
1.2.4 Evaluation of Technologies 1-11
1.3 Guidance Document Format and Use 1-13
1.4 Chapter References 1-14
2. Conditioning 2-1
2.1 Introduction 2-1
2.2 Technology Assessment 2-1
3. Thickening 3-1
3.1 Introduction 3-1
3.2 Technology Assessment 3-1
4. Stabilization 4-1
4.1 Introduction 4-1
4.2 Technology Assessment 4-1
5. Dewatering 5-1
5.1 Introduction 5-1
5.2 Technology Assessment 5-1
6. Thermal Conversion 6-1
6.1 Introduction 6-1
6.2 Technology Assessment 6-1
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Contents
Page
7. Drying 7-1
7.1 Introduction 7-1
7.2 Technology Assessment 7-1
8. Other Processes 8-1
8.1 Introduction 8-1
8.2 Technology Assessment 8-1
9. Research Needs 9-1
9.1 Introduction 9-1
9.2 Research Needs 9-1
9.2.1 Analysis and Reduction of Risk Associated with Certain Beneficial Use
Practices 9-2
9.2.2 Utilization of the Potential of Biosolids to Yield Energy 9-2
9.2.3 Improved Operation, Performance and Efficiency of Biosolids Treatment
Processes 9-3
9.2.4 Research Needs 9-3
9.2.5 Chapter References 9-3
Appendix A A-1
A.1 Introduction A-1
A.2 Trade Associations A-1
vi Biosolids Management
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Emerging Technologies
List of Tables
Page
Table 1.1 Summary of Biosolids Technologies 1-6
Table 1.2 Descriptive Evaluation Criteria 1-12
Table 2.1 Conditioning Technologies - State of Development 2-1
Table 3.1 Thickening Technologies - State of Development 3-1
Table 4.1 Stabilization Technologies - State of Development 4-1
Table 5.1 Dewatering Technologies - State of Development 5-2
Table 6.1 Thermal Conversion Technologies -State of Development 6-2
Table 7.1 Drying Technologies - State of Development 7-1
Table 8.1 Other Processes - State of Development 8-1
Table 9.1 Research Needs Technologies: State of Development 9-2
List of Figures
Page
Figure 1.1 Summary of Wastewater Solids Management in the U.S 1-2
Figure 1.2 Flow Schematic for Guide Development 1-3
Figure 2.1 Evaluation of Innovative Conditioning Technologies 2-2
Figure 3.1 Evaluation of Innovative Thickening Technologies 3-2
Figure 4.1 Evaluation of Innovative Stabilization Technologies 4-2
Figure 5.1 Evaluation of Innovative Dewatering Technologies 5-2
Figure 6.1 Evaluation of Innovative Thermal Conversion Technologies 6-2
Figure 7.1 Evaluation of Innovative Drying Technologies 7-2
Figure 8.1 Evaluation of Other Innovative Processes 8-2
Biosolids Management
VII
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Emerging Technologies
List of Abbreviations
ABR anaerobic baffled reactor
AGF anoxic gas flotation
ATAD autothermal thermophilic aerobic digestion
ASCE American Society of Civil Engineers
AWWA American Water Works Association
BOD biochemical oxygen demand
BTU British thermal unit
CBFT3 Columbia biosolids flow-through thermophilic treatment
CFR Code of Federal Regulations
CIP capital improvement program
COD chemical oxygen demand
cP centipoise
CWMP comprehensive wastewater management plan
DAFT dissolved air flotation thickening
DC direct current
DCWASA District of Columbia Water and Sewer Authority
EPRI Electric Power Research Institute
ERS energy recovery system
FELL Focused Electrode Leak Locator
g/ac/day gallon per acre per day
gpcd gallon per capita per day
gpd gallon per day
GTI Gas Technology Institute
HAPs hazardous air pollutants
HIMET high methane process
IEUA Inland Empire Utilities Agency
JWPCP Joint Water Pollution Control Plant
kg kilogram
kWh kilowatt-hour
MFP master facilities plan
VIM
Biosolids Management
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Emerging Technologies
List of Abbreviations
MGD million gallons per day
MLSS mixed liquor suspended solids
MSO molten salt oxidation
NOAA National Oceanic and Atmospheric Administration
NPDES National Pollutant Discharge Elimination System
OCS oxygen combustion system
O&M operation and maintenance
OWM Office of Wastewater Management
POTW publicly owned treatment works
PSI pound per square inch
RHOX reheat and oxidize process
RP recycling plant
SRF State Revolving Fund
SRT solids retention time
SSDML sewage sludge digestion and metal leaching
SW southwest
SWSSD Southwest Suburban Sewer District
TPAnD temperature-phased anaerobic digestion
tpd ton per day
U.S. United States
U.S. EPA U.S. Environmental Protection Agency
USDA U.S. Department of Agriculture
VAR vector attraction reduction
VS volatile solids
VSR volatile solids reduction
WEF Water Environment Federation
WERF Water Environment Research Foundation
WWTF wastewater treatment facility
WWTP wastewater treatment plant
Biosolids Management
IX
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Emerging Technologies September 2005
Biosolids Management
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2006 Emerging Technologies
Executive Summary
Biosolids (sewage sludge) are the nutrient-rich organic materials resulting from treatment
and processing of wastewater residuals. U.S. Environmental Protection Agency (U.S.
EPA) estimates that the publicly owned wastewater treatment works (POTW) generate
over 8 million tons (dry weight) of sewage sludge annually. Figure 1.1 summarizes how
this material is managed. The technologies in this document help reduce the volume of
residuals, and produce biosolids that can be used, help improve soil fertility and tilth, while
decreasing the use of inorganic fertilizers, and promote the conservation of energy.
This document provides information regarding emerging biosolids management
technologies organized into three categories based on their stage of development:
Embryonic - Technologies in the development stage and/or tested at laboratory or
bench scale. New technologies that have reached the demonstration stage overseas, but
cannot yet be considered to be established there, are also considered to be embryonic
with respect to North American applications.
Innovative - Technologies meeting one of the following qualifications: (1) have been
tested at a full-scale demonstration site in this country; (2) have been available and
implemented in the United States (U.S.) for less than 5 years; (3) have some degree
of initial use (i.e. implemented in less than twenty-five utilities in the U.S;. and (4) are
established technologies overseas with some degree of initial use in the U.S.
Established - Technologies widely used (i.e. generally more than 25 facilities throughout
the U.S.) are considered well established.
The document also provides information on each technology—its objective, its description,
its state of development, available cost information, associated contact names, and
related data sources. For each innovative technology, this document further evaluates with
respect to various criteria, although it does not rank or recommend any one technology
over another. Research needs are also identified to help guide development of innovative
and embryonic technologies and improve established ones.
References
U.S. EPA. Office of Solid Waste. Biosolids Generation, Use, and Disposal in the United
States. EPA 530-R-99-009 (1999).
Biosolids Management ES-1
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Emerging Technologies September 2005
ES-2 Biosolids Management
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Introduction and Approach
Wastewater treatment processes produce residuals, also called sewage sludge, as a
by-product of the treatment processes. Biosolids are the nutrient-rich organic materials
resulting from the treatment and processing of these residuals. U.S. EPA estimates that
the publicly-owned wastewater treatment works generate over 8 million tons (dry weight)
of sewage sludge annually. Figure 1.1 summarizes how this material is managed. The
technologies in this document help reduce the volume of residuals, produce biosolids
that can be used, help improve soil fertility and tilth, while decreasing the use of inorganic
fertilizers, and promote the recovery of energy.
To meet the challenge of keeping progress in wastewater pollution abatement ahead
of population growth, changes in industrial processes, and technological developments,
U.S. EPA is providing this document to make information available on recent advances
and emerging techniques. The goal of this document is straightforward—to provide a
guide for persons seeking information on innovative and embryonic biosolids treatment
technologies. The guide lists processing technologies, where available assesses their
merits and costs, and provides sources forfurthertechnological information. This document
is intended to serve as a tool for wastewater facility owners and operators. It should
be noted that neither Parsons nor U.S. EPA has conducted engineering or operations
evaluations of the technologies included. The information provided is from the vendors
and/or practitioners; no detailed verification of vendors' claims has been undertaken.
Biosolids Management
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Emerging Technologies
September 2006
Other Disposal
1%
Landfilled
17%
Land
Application
Incinerated
22%
Other Beneficial
Use
7%
Advanced
Treatment
12%
Figure 1.1 - Summary of Wastewater Solids Management in the U.S.
(Source: U.S. EPA 1999)
Emerging technologies typically follow a development process that leads from laboratory
and bench-scale investigations to pilot studies and, subsequently, to initial use or "full-scale
demonstrations" before the technology is considered established. Not all technologies
survive the entire development process. Some fail in the laboratory or at pilot stages; others
see limited application in the field, but poor performance, complications, or unexpected
costs may cause them to lose favor. Even technologies that become established may
lose favor in time, as technological advances lead to obsolescence. In short, technologies
are subject to the same evolutionary forces present in nature; those that cannot meet
the demands of their environment fail, while those that adapt to changing technological,
economic, and regulatory climates can achieve long-standing success and survival in the
market.
1.2 Approach
To develop this guide, the investigators sought information from a variety of sources,
identified new technologies, prepared cost summaries, and evaluated technologies
deemed to be innovative.
1-2
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'-.
Emerging Technologies
This method is described below and in Figure 1.2.
Collect Information
Identify Process
No Further Action
Embryonic or Innovative
Prepare Process
Summary Sheets
No Further Action
Innovative
Prepare Process
Evaluation Matrix
Figure 1.2 Flow Schematic for Guide Development
1.2.1 Information Collection and New Process Identification
Information collection on new technologies provided the foundation for subsequent work.
To identify new biosolids processing technologies, investigators gathered information
from a variety of sources, including the following:
Published Literature -An extensive literature review was performed to identify new
technologies, and to evaluate their performance and applications. Specifically, the review
focused on relevant Water Environment Federation (WEF) and American Society of Civil
Engineers (ASCE) conference proceedings, as well as other publications from these and
other organizations.
"Gray" Literature - Vendor-supplied information, Internet research, and consultants'
technical reports were the primary sources of gray literature.
1-3
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Emerging Technologies 2006
Technical Associations - Investigators contacted a variety of professional and
technical associations in the United States, including members of WEF, to identify
emerging wastewater treatment technologies.
Interviews and Correspondence - Individuals known to the project investigation
team, including consultants, academics, and municipal wastewater treatment plant owners
and operators, were consulted.
Technologies identified through searches of the above sources were screened to determine
their classification as described below.
1.2.2 Initial Screening Technologies
This project focuses on emerging technologies that appear to be viable, but have not yet
been accepted as established processes in the United States. Specific screening criteria
used to define the state of development for processes are described in the following
paragraphs. This screening resulted in:
25 Embryonic Technologies
31 Innovative Technologies
Embryonic - These technologies are in the development stage and/or have been tested
at laboratory or bench scale. New technologies that have reached the demonstration stage
overseas, but cannot yet be considered to be established there, are also considered to be
embryonic with respect to North American applications.
Innovative - Technologies that meet one of the following criteria were classified as
innovative:
• They have been tested as a full-scale demonstration;
• They have been available and implemented in the United States for less than five
years;
• They have some degree of initial use (i.e. implemented in less than 25 municipalities
throughout the United States); or,
• They are established technologies from overseas.
Established-In most cases, these processes are used at more than 25full-scalefacilities
in North America; but there are some exceptions based upon specific considerations. The
established category may include technologies that are widely used although introduced
more recently in North America. In some cases, an established technology such as
Anaerobic Digestion may have been modified or adapted resulting in a new, innovative
technology such as Thermally Phased Anaerobic Digestion. Due to the extensive number
of established technologies and variations in each technology, established technologies
are only listed. None are described in depth in this document and Technology Summary
sheets are not provided for established technologies.
1 -4 Biosolids Management
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Emerging Technologies
The focus of this document is on Innovative Technologies along with some coverage of
Embryonic Technologies as well. Early in the development process (laboratory stage),
data are usually insufficient to prove or disprove technology viability at full scale; available
information on these embryonic technologies is presented in this document. Technologies
on the other end of the developmental scale, those defined as established in North
America, are excluded from the detailed assessments on the assumption that they are
proven, although still relatively new.
The differentiation between technologies established in Europe or Asia and those that
have reached similar status in the United States can be critical since technologies have
been applied successfully in other countries have not always flourished here. Because the
viability of imported technologies is not guaranteed, established processes from overseas
are classified as innovative technologies for this project unless they have been proven in
North American applications.
Some technologies fall into a "gray area" between the embryonic and innovative categories.
Technologies that fall into this category are incorporated into the innovative category. The
screening assessment is summarized in Table 1.1.
Biosolids Management 1 -5
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Emerging Technologies
September 2006
Table 1.1 - Summary of Biosolids Technologies
Chapter 2 Conditioning
Established
Chemical Conditioning
Heat Conditioning
Innovative
Cell Destruction
Chemical (Microsludge™)
Ultrasonic
Embryonic
Cell Destruction Biological (BIODIET®)
Electrocoagulation
Enzyme Conditioning
•
•
•
•
•
•
•
•
Chapter 3 Thickening
Established
Centrifuge
Flotation Thickening
Gravity Belt Thickening
Gravity Thickening
Rotary Drum Thickening
Innovative
Flotation Thickening -Anoxic Gas
Membrane Thickening
Recuperative Thickening
•
•
•
•
•
•
•
•
•
•
Embryonic
Metal Screen Thickening
•
•
1-6
Biosolids Management
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Emerging Technologies
Table 1.1 - Summary of Biosolids Technologies (Contd)
Chapter 4 Stabilization
Established
Aerobic Digestion
Autothermal Thermophilic Aerobic Digestion (ATAD)
Alkaline Stabilization
Advanced Alkaline Stabilization
Anaerobic Digestion
Dual Digestion
Two-Stage Mesophilic
Composting
Pasteurization
Solidification
Synox
Innovative
Aerobic Digestion
Aerobic/Anoxic
Anaerobic Digestion
Anaerobic Baffled Reactor (ABR)
Columbia Biosolids Flow-Through - Thermophilic Treatment
(CBFT3)
High Rate Plug Flow (Bio Terminator 24/85)
Temperature Phased Anaerobic Digestion (TPAND)
Thermal Hydrolysis (CAMBI Process)
Thermophilic Fermentation (ThermoTech11
Three-Phase Anaerobic Digestion
Two-Phase-Acid/Gas Anaerobic Digestion
Vermicomposting
Embryonic
Aerobic Digestion
Simultaneous Digestion and Metal Leaching
Biosolids Management
1-7
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Emerging Technologies
September 2008
Table 1.1 - Summary of Biosolids Technologies (Contd)
Anaerobic Digestion
Ozone Treatment
Ferrate Addition
Disinfection
Irradiation
Neutralizer®
Chapter 5 Dewatering
Established
Belt Filter Press
Centrifuge
Chamber Press
Drying Beds
Auger-Assisted
Natural Freeze-Thaw
Vacuum-Assisted
Vacuum Filters
Innovative
Drying Beds
Quick Dry Filter Beds
Electrodewatering
Metal Screen Filtration
Inclined Screw Press
Textile Media Filtration
Bucher Hydraulic Press
DAB™ System
Geotube® Container
Embryonic
Electro Dewatering
Electroacoustic
Electroosmotic
1-8
Biosolids Management
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Enigg
Table 1.1 - Summary of Biosolids Technologies (Contd)
Membrane Filtration
Membrane Filter Press
Textile Media Filtration
Simon Moos
Tubular Filter Press
Thermal Conditioning and Dewatering
Mechanical Freeze-Thaw
•
•
•
•
•
•
•
•
•
•
Chapter 6 Thermal Conversion
Established
Combustion
Fluidized-Bed Furnace
Multiple-Hearth Furnace
Oxidation
Wet Air Oxidation
Innovative
Combustion
Reheat and Oxidize (RHOX)
Oxidation
Supercritical Water Oxidation
Vitrification
Minergy
•
•
•
•
•
•
•
Embryonic
Combustion
Molten Salt Incineration
Oxygen Enhanced Incineration
Fuel Production
Gasification
Sludge-to-Oil
SlurryCarb™
•
•
•
•
•
•
•
•
•
•
Biosolids Management
1-9
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Emerging Technologies
2006
Table 1.1 - Summary of Biosolids Technologies (Contd)
Oxidation
Deep-Shaft Wet Air Oxidation (VERTAD™)
Plasma Assisted Sludge Oxidation
Vitrification
Melting Furnace
•
•
•
•
•
•
•
Chapter 7 Drying
Established
Direct Drying
Flash Drying
Indirect Drying
Innovative
Belt Drying
Direct Microwave Drying
Flash Drying
Fluidized Bed Drying
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Embryonic
Chemical Drying
Multiple Effect Drying
Carver-Greenfield (Not a viable technology)
•
•
•
•
•
Chapter 8 Other Processes
Innovative
Cannibal Process
Lystek
Injection into Cement Kiln
•
•
•
•
•
•
•
•
•
•
•
* Potential Benefits require confirmation on a case-by-case basis. May enhance existing facilities, replace existing
facilities, or offer an alternative choice for new facilities. For existing facilities, analysis of invested costs to date
must be considered.
1-10
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Emerging Technologies
1.2.3 Development of Technology Summary Sheets
Technologies defined as embryonic or innovative are summarized on an individual
Technology Summary sheet. Each process includes the following information:
Objective - Description of the goal of the technology.
State of Development - Where and how the technology has been applied (i.e.
laboratory study, demonstration scale, full scale, etc.).
Description -A brief overview of the technology.
Comparison to Established Technologies-A brief comparison to established
technologies that serve the same function in biosolids management.
Available Cost Information -An approximate range of capital and operation and
maintenance (O&M) (on an annual basis) costs, and assumptions made in developing
them. Annual O&M costs typically include labor, equipment replacement and/or parts,
energy, and chemicals. For many of the technologies, sufficient information was not
available for detail annual costs so general values are presented.
Contact Names- Names, addresses, and telephone numbers of contacts (vendors
and practitioners) with additional information on the technology.
Key Words for Internet Search - Words used to enhance Internet searches for
more information.
Data Sources - References used to compile the technology summary.
1.2.4 Evaluation of Innovative Technologies
Technologies defined as innovative in the initial screening were subjected to a detailed
evaluation presented in tabular format. Each technology was evaluated with respect to
the descriptive and comparative criteria described below. Descriptive criteria include:
State of Development - Describes the stage of development for each technology,
ranging from demonstration stage to full-scale operations.
Applicability - Qualitatively assesses where the technology is designed to be
used.
Beneficial Use - Describes the potential for the technology to produce a
biosolids product suitable for beneficial use (e.g. agriculture, construction, or power
generation).
Biosolids Management 1-11
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Emerging Technologies
Potential Benefits - Considers the benefits gained (e.g., capital or operational
savings, reduces odor, produces Class A biosolids, etc.) from implementation of the
technology.
Designations for each descriptive criterion are presented in Table 1.2.
Table 1.2 Descriptive Evaluation Criteria
State of Development
Applicability
Beneficial Use
Potential Benefits
B
P
I
0
D
N
I
F
S
L
A
C
P
C
0
V
A
M
F
R
Bench scale
Pilot scale
Full-scale industrial applications, with demonstration or pilots for
municipal sewage sludge
Full-scale operations overseas
Full-scale demonstration in North America
Full-scale operations in North America
Industrywide
Few plants
Primarily small plants
Primarily large plants
Agriculture
Construction
Power
Low or lower capital costs
Low or lower annual costs
Reduces solids or produces thicker product Concentrations
Produces Class A biosolids
Reduces odors
Produces high nutrient fertilizer
Beneficial use (nonagricultural)
Comparative criteria are general attributes that the technology may possess relative to
attributes of established technologies in the same category (e.g., conditioning etc.), for
the same criteria. The innovative technologies may be rated positive, neutral or negative
compared to expectations for established technologies. These criteria include:
Impact on Other Processes - Describes the degree to which the existing facilities
will be disturbed.
Complexity- Considers the construction method and operation of the technology.
Air Emission - Considers the potential for air emissions including odor.
Beneficial Use - Considers the potential to produce a product that allows for more
beneficial use options.
1-12 Biosolids Management
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September 2006 Emerging Technologies
Energy - Considers the potential to directly produce power or to produce a product
that has characteristics that make it suitable for energy generation.
Footprint - Considers the requirement for land to support the construction of the
technology at full-scale.
Environmental - Considers other factors associated with the technology that may
produce environmental impacts or enhance environmental conditions.
The criteria and ratings were applied to each innovative technology and the results are
presented in matrixformat. Where available information was insufficient to rate a technology
fora criterion, no rating is given. The project team and reviewers assessed each technology
based on the limited information gathered and their collective judgment, experience, and
opinions. Results of the evaluation are presented in subsequent chapters.
1.3 Use
The majority of the document is divided into chapters based upon general technologies.
One chapter is dedicated to each of the following categories:
Conditioning (Chapter 2)
Thickening (Chapter 3)
Stabilization (Chapter 4)
Dewatering (Chapter 5)
Thermal Conversion (Chapter 6)
Drying (Chapter 7)
Other Processes (Chapter 8)
Each chapter overviews the technology included, discusses the state of development
for each, presents an evaluation matrix for innovative and embryonic technologies,
and concludes with a Technology Summary sheet for each innovative and embryonic
technology.
The technology summaries and evaluation matrices are the cornerstones of each chapter,
giving a broad overview of the innovative technologies. Neither the summaries nor the
matrices should be considered definitive technology assessments. Rather, they should
be considered stepping stones to more detailed investigations.
The final chapter, Chapter 9, discusses research needs related to biosolids
management.
This document should be updated from time to time. Technologies were reviewed in mid-
2006.
Biosolids Management 1-13
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Emerging Technologies
September 2006
1.4 Chapter References
U.S. EPA. Office of Solid Waste. Biosolids Generation, Use, and Disposal in the United
States. EPA 530-R-99-009 (1999).
U.S. EPA. Office of Water. Clean Watersheds Needs Survey 2000 Report to Congress.
EPA832-R-03-001 (2003)
1-14
Biosolids Management
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H :,.;:< ^^Re-
Conditioning processes enhance biosolids characteristics for subsequent processing.
This chapter focuses on the latest developments in conditioning technologies.
Table 2.1 summarizes the state of development of conditioning technologies.
Recent technology innovations in the area of conditioning now include electro-coagulation,
ultrasonic disintegration, and enzyme addition as well as a combination of conditioning
processes. These processes aim at modifying the organic and inorganic characteristics
of biosolids critical to other following processes. Conditioning is typically linked to other
processes and the purpose of conditioning is based upon the goals of these other
subsequent processes. Often the results achieved by conditioning are seen in the
subsequent processes rather than the conditioning process itself.
Figure 2.1 includes an evaluation of the emerging technologies identified in this report.
Summary sheets for each innovative and embryonic technology are provided at the end
of this chapter.
Table 2.1 - Conditioning Technologies—State of Development
Chemical Conditioning
Heat Conditioning
Cell Destruction
« Chemical (MicroSludge™)
« Ultrasonic
Cell Destruction
« Biological (BIODIET®)
Electrocoagulation
Enzyme Conditioning
Biosolids Management
2-1
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Emerging Technologies
Figure 2.1 - Evaluation of Innovative Conditioning Technologies
Chemical Cell Destruction
(MicroSludge™
Ultrasonic Cell Destruction
B = Bench scale
D = Full-scale demonstrations in North
America
I = Full-scale industrial applications, with
demonstrations or pilots for municipal
sewage sludge
0 = Full-scale operations overseas
N = Full-scale operations in North America
P = Pilot
F = Few plants
I = Industrywide
L = Primarily large plants
S = Primarily small plants
A = Produces Class A biosolids
C = Capital savings
0 = Operational/maintenance savings
F = Produces high-nutrient fertilizer
M = Minimizes odors
R = Provides beneficial use (nonagricultural)
V = Sludge volume reduction
A = Agriculture
C = Construction
N/A = Not Applicable
P = Power
A Positive feature
0 Neutral or mixed
T Negative feature
2-2
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September 2006
Emerging Technologies
Technology Summary
Chemical Cell Destruction (MicroSludge™)
Objective:
Destroy the cell membranes of microbes in waste
activated sludge to increase the performance of
anaerobic digestion. Increase the amount of biogas
generated from anaerobic digestion of biosolids.
State of Development: Innovative
The first full-scale MicroSludge™ chemical biocell destruction
demonstration was conducted at the Chilliwack Wastewater
Treatment Plant (WWTP) near Vancouver, Canada in 2004. A
second full-scale demonstration started at the Los Angeles County
Sanitation Districts Joint Water Pollution Control Plant in October
2005. Neither is currently operating.
Description:
TWaste-activated sludge from the secondary clarifier enters a central unit where caustic chemicals (NaOH) are added. The mixture
is held for one hour to weaken cell membranes and significantly lower viscosity. As described by the developer of MicroSludge™,
the technology employs an industrial-scale high-pressure homogenizer or "cell disrupter" to provide an enormous and sudden
pressure drop to lyse the bacterial cells in the sludge. The processed sludge is liquefied, mixed with primary sludge, and
anaerobically digested to produce stabilized biosolids and biogas.
The central unit of the process is a high-pressure cell disrupter that subjects waste-activated sludge to a large abrupt pressure
drop. The sludge in the cell disruption valve is accelerated up to 300 meters per second (1,000 feet per second) in approximately
2 microseconds. The sludge then impinges on an impact ring, disrupting the cell membranes, and liquefying the waste-activated
sludge.
Comparison to Established Technologies:
Similar to conventional chemical conditioning only in that chemicals are added to the solids with the goal of breaking
cellular bonds. The caustic additive is not similar to chemicals traditionally used such as ferrous or aluminum salts.
Available Cost Information:
Approximate Capital Cost: $1.7 million to $2 million
Approximate O&M Costs: $68 to $119 per dry ton of activated sludge
The above range, provided by the vendor, is for a MicroSludg™ System 50 capable of processing approximately
50,000 U.S. gallons of thickened waste-activated sludge per day. According to the vendor, larger systems would cost
proportionately less per dry ton to operate. These costs do not include installation costs.
The operating cost estimate, again provided by the MicroSludge™ vendor, includes electricity, chemicals, and maintenance.
The above O&M cost estimate is for processing activated sludge to a range of 4 - 7% total solids. The estimate assumes
electricity is purchased at $0.07/kilowatt-hour and chemicals costs are $0.21/pound. Electricity is the largest single
operating cost contributor. Power consumption between
500 - 1,000 kWh/ton dry solids is required for this process.
Vendor Name(s):
Paradigm Environmental Technologies, Inc.
200,1600 West 6th Avenue
Vancouver, BC
Canada V6J1R3
Phone: 604-742-0360
Website: www.paradiamenvironmental.com
Practitioner(s):
The following were sites of technology demonstration but are not
current practitioners:
Chilliwack Wastewater Treatment Plant
8550 Young Road
Chilliwack, British Columbia V2P 8A4
Joint Water Pollution Control Plant, Los Angeles County
Sanitation Districts
Carson, CA
Biosolids Management
2-3
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Emerging Technologies
September 2006
Technology Summary
Chemical Cell Destruction (MicroSludge™) (Contd)
Key Words for Internet Search:
MicroSludge™, anaerobic digestion, cell lysis, chemical pretreatment, volatile solids reduction, sludge, biosolids
Data Sources:
Rabinowitz, B. and R. Stephenson "Full-Scale Demonstration of Waste-Activated Sludge Homogenization at the Los
Angeles County Joint Water Pollution Control Plant." Proceedings of the WEF/AWWA Joint Residuals and Biosolids
Management Conference, Cincinnati, Ohio, (12-15 March 2006).
Paradigm Environmental Technologies, Inc. (2006). Personal e-mail communication with Director of Marketing, Filipe
Figueira, on 12 May 2006.
2-4
Biosolids Management
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September 2006
Emerging Technologies
Ultrasonic Cell Destruction
Objective:
Increase the rate at which anaerobic digestion of solids
occurs; improve sludge settling; facilitate denitrification,
promote recovery of biogas for energy production.
Technology Summary
State of Development: Innovative
The full-scale technology has been used at the Bad Bramstedt
Sewage Works, Germany, in Kavlinge, Sweden (2002) and at
Mangere Wastewater Treatment Plant, New Zealand (2005).
Description:
Acoustic waves are applied to solids prior to digestion to attain extremely high pressures and temperatures within the biosolids.
This results in the implosion of gas bubbles, which produces shear stresses that break up surfaces of bacteria, fungi, and other
cellular matter. Different disintegration objectives can be achieved using either high- or low-frequency waves. The vendor claims
that the process has been shown to increase cell disruption, reduce anaerobic digestion time, reduce sludge quantity and raise
biogas production. Typically, this process is applied to waste activated solids, not primary solids.
Comparison to Established Technologies:
Ultrasonic disintegration is meant to enhance traditional anaerobic digestion by increasing the rate office and cell
disintegration. Since hydrolysis can be a rate-limiting factor in anaerobic digestion, the claim is that ultrasonic disintegration
increases the digestion rate, volatile suspended solids concentration, and gas production.
Available Cost Information:
Approximate Capital Cost: $265,000
Approximate O&M Costs: $10,000 - $20,000 per year
Capital cost is based on a 5 - 8 million gallon per day facility treating 30% of the sludge produced per day. Operation
and maintenance costs derived from a test plant in Riverside, southern California. Operation and maintenance cost
assumptions include supervision, parts, and power. Current energy prices will significantly impact power-related expenses.
Vendor Name(s):
EIMCO® Water Technologies
2850 S. Decker Lake Drive
Salt Lake City, UT 84119
Phone: 801-526-2342
Fax:801-526-2910
E-mail: info@eimcowater.com
Sonico LLC (North America)
3020 Old Ranch Parkway, Suite 180
Seal Beach, CA 90740
Phone: 562-314-4231
Practitioner(s):
The following was the site of a demonstration system but is not a
current practitioner:
Orange County Sanitation District
P.O. Box 8127
Fountain Valley, CA 92728-8127
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Ultrasonic Cell Destruction (Contd)
Key Words for Internet Search:
Ultrasonic cavitation, ultrasonic disintegration, Sonolyzer, biosolids, sludge
Data Sources:
Vendor-supplied information
2-6
Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Biological Cell Destruction (BIODIET®)
Objective:
Promote biological disintegration of organic matter in
organic sludges to water and carbon dioxide, thereby
reducing sludge volume.
State of Development: Embryonic
This technology is primarily marketed in Japan for highly organic
industrial (i.e. food processing) sludges. Currently marketed as
BIODIET®.
Description:
Activated sludge is diverted from the settling tank to a vessel where a chemical agent is added. The agent has strong oxidizing
power, causing the cell walls of the bacteria to become weak and breakdown. The processed bacteria are then returned to the
activated sludge unit where they decompose into carbon dioxide and water. The BIODIET® process is intended for organic sludges
only; volume reduction will be impacted by the amount of inorganic material in the sludge.
Comparison to Established Technologies:
Not similar to any established technologies.
Available Cost Information:
Approximate Capital Cost: Not available
Approximate O&M Costs: Detailed information is not available but the vendor's website presents anecdotal information
showing a cost savings of over 50% using BIODIET® compared to conventional methods of
managing industrial waste.
Vendor Name(s):
Plant Engineering Division
Kankyo Engineering Company, Ltd.
1-9-8 Higashikanda, Chiyoda-ku
Tokyo 101-0031 Japan
Phone: 81-3-3862-1611
Fax:81-3-3862-1617
E-mail: aeneral(5)k-ena.co.ip
Practitioner(s):
No practitioner at this time.
Key Words for Internet Search:
BIODIET®, Japanese wastewater treatment, sludge
Data Sources:
Japanese Advanced Environment Equipment. BIODIET®. Global Environment Centre Environmental Technology Database
NETT21.(2002).
T. Hagino, S. Gohda, H. Yoshida. "A Sludge-Thickening-Dehydrating System Featuring Single Polymer Conditioning" The
Abstract of Ebara Engineering Review. (1999).
Vendor-supplied information.
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Electrocoagulation
Objective:
Increase the rate at which anaerobic digestion of solids
occurs; improve sludge settling; facilitate denitrification,
promote recovery of biogas for energy production.
State of Development: Embryonic
Electrocoagulation has been used for mining and metals industry
applications since the 1900s. The wastewater treatment plant
at the Vancouver Shipyards (British Columbia) has been using
electrocoagulation for 4 years to successfully remove heavy
metals and emulsified oils. The system does not, however, remove
antifreeze or solvents, nor can it treat soluble biochemical oxygen
demand (BOD) and other organic constituents of sewage.
Powell Water Systems, Inc. markets electrocoagulation technology
for domestic wastewater treatment and claims anywhere from
85 to 99.99% removal of several wastewater constituents, including
heavy metals, phosphates, fats and oils, insoluble BOD, and Total
Coliforms.
Description:
Electrocoagulation uses an electrical current to dissolve a sacrificial anode and thereby introduce chemically reactive aluminum
into the wastewater stream. These positively charged aluminum ions are attracted to the very fine negatively charged ions and
particles in suspension. The resulting agglomerations of particulates increase in size until they no longer remain in suspension.
Simultaneously, gases formed by hydrolysis form very fine bubbles that associate with the particulates and buoy them up to the
surface of the treated wastewater for removal by flotation.
Comparison to Established Technologies:
Not similar to any established technologies
Available Cost Information:
Approximate Capital Cost: $451,000 (500 gpd system) $1,520,000 (3,000,000 gpd system)
Approximate O&M Costs: $678 per day (500 gpd system) $2,791 per day (3,000,000 gpd system)
Capital cost estimates are for the Powell electrocoagulation unit only, and they do not take into account additional
construction costs that may be necessary to install the unit. Operation and maintenance costs include electricity, labor,
replacement blades, and maintenance.
Vendor Name(s):
Powell Water Systems, Inc.
19331 Tufts Circle
Centennial, CO 80015-5820
Phone: 303-627-0320
Fax:303-627-0116
E-mail: scottpowelKgjpowellwater.com
Website: www.powellwater.com
Practitioner(s):
Vancouver Shipyards Co. Ltd.
North Vancouver, B.C.
Canada V7P 2R2
Phone: 602-988-6361
Fax: 604-990-3290
Email: info(S).vanship.com
2-8
Biosolids Management
-------
September 2006
Emerging Technologies
Technology Summary
Electrocoagulation (Contd)
Key Words for Internet Search:
Electrocoagulation, conditioning, dewatering, biosolids, sludge.
Data Sources:
Stephenson, R., B. Tennant, D. Hartle, G. Geatros. "Vancouver shipyards treat emulsified oily wastewater using
electrocoagulation." Watermark Newsletter of the British Columbia Water & Waste Association. (2003).
Vendor-supplied information.
Biosolids Management
2-9
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Emerging Technologies
September 2006
Technology Summary
Enzyme Conditioning
Objective:
Degrade organic material to increase the dewaterability
of biosolids and, in some cases, to reduce odors and
aid in digestion processes.
State of Development: Embryonic
Enzymes have shown promising results in breaking down fats and
oils in meat industry pretreatment facilities, as well as in reducing
odors, solvents, and chemical oxygen demand (COD) in aeration
tanks, lagoons, and biosolids digesters. There has also been
research with promising results showing significant increase in
percent solids from conventional dewatering of enzyme-treated
solids.
Description:
Mixtures of enzymes, specialized nutrients (i.e. humic acids, amino acids) and often aerobic and anaerobic bacteria cultures are
added to thickening and digestion systems that produce enzymes specially engineered to degrade organic materials converting
them into carbon dioxide and water. Reported advantages include limited damage to biological treatment systems and cost savings
as the enzymatic reaction will continue to occur over several days.
Comparison to Established Technologies:
Enzyme destruction of cells is not similar to any established processes.
Available Cost Information:
Approximate Capital Cost: $31 per pound of enzyme solution
Approximate O&M Costs: Not available
The manufacturer of Enviro-Zyme® recommends various amounts of solution depending on the amount of sludge to be
treated. For example, 1 pound is needed to treat 1 to 5 tons of sludge, 2 pounds are required for 6 to 25 tons of sludge, and
soon.
Vendor Name(s):
Eco-Cure, Inc.
1525 Casa Buena Drive Suite D
Corte Madera, CA 94925
Phone:415-924-8450
Email: jimkritchevertgjvahoo.com
Website: www.eco-cure.com
Envoguard
298 Kings Mill Rd York, PA 17403
Phone: (800) 297-8266
Email: infotgjenvoauard.com
Website: www.envoquard.com
Enviro-Zyme® International, Inc.
P.O. Box 169
Stormville, NY 12582
Phone: 800-882-9904
E-mail: info@envirozvme.com
Practitioner(s):
See websites for practitioners:
www.eco-cure.com/enzymeinfodert.htm
2-10
Biosolids Management
-------
September 2006
Emerging Technologies
Technology Summary
Enzyme Conditioning (Contd)
Vendor Name(s) (Contd):
Vendor Name(s):
The Moorhead Group, Inc
108 Don Lorenzo Court
Aptos, CA 95003
Phone 831-685-1148
Fax 831-685-1259
info(S)moorheadgroup.com
www.moorheadgroup.com
NRP, Inc.
2948 N. W. 60th Street
Fort Lauderdale, FL 33309
Phone: 954-970-7773
Fax: 954-970-7778
hschure(5)nrp-inc.com
www.nrp-inc.com
Suez
www.suez.com
Western Bio-Tec Services
1265 W. 16th Street
Long Beach, CA 90813-1381
Phone: 949-456-0058
Email: westernbiotec(5)aol.com
Website: www.westernbiotec.com
Key Words for Internet Search:
Enviro-Zyme, enzyme conditioning, odorants, ACE, Agricycle Catalyst Enzyme, WESBAC, Biolysis-e.
Data Sources:
Vendor-supplied information.
Dursun, D., AAyol, S.K. Dentel. "Pretreatment of Biosolids by Multi-Enzyme Mixtures Leads to Dramatic Improvements in
Dewaterability." Proceedings of the WEF Residuals and Biosolids Management Conference 2006: Bridging to the Future,
Cincinnati, OH (12-14 March 2006).
Toffey, William E., Matthew Higgins. "Results of Trials and Chemicals, Enzymes and Biological Agents for Reducing
Odorant Intensity of Biosolids." Proceedings of the WEF Residuals and Biosolids Management Conference 2006: Bridging
to the Future, Cincinnati, OH (12-14 March 2006).
Biosolids Management
2-11
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Thickening
The goal of thickening is to increase the concentration of solids. Thickening enhances
treatment processes that follow such as stabilization, dewatering, and drying. This chapter
focuses on the latest developments in thickening technologies.
Table 3.1 summarizes the state of development of thickening technologies.
Recent technology developments in this area focus on various methods to increase solids
concentrations such as anoxic gas flotation, membrane thickeners and recuperative
thickeners. These technologies can help reduce chemicals and increase the efficiency
of subsequent processes such as digestion. Some odor reduction during thickening also
has been recognized.
Figure 3.1 includes an evaluation of the innovative technologies identified in this report.
Summary sheets for each innovative and embryonic technology are provided at the end
of this chapter.
Table 3.1 - Thickening Technologies—State of Development
Centrifuge
Flotation Thickening
Gravity-Belt Thickening
Gravity Thickening
Rotary Drum Thickening
Flotation Thickening
« Anoxic Gas
Membrane Thickening
Recuperative Thickening
Metal Screen Thickening
Biosolids Management
3-1
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Emerging Technologies
Figure 3.1 - Evaluation of Innovative Thickening Technologies
Flotation Thickening - Anoxic Gas
e
e
e
Membrane Thickening
C,0,V
N/A
e
e
e
Recuperative Thickening
C,0,V
N/A
e
e
e
e
B = Bench scale
D = Full-scale demonstrations in North
America
I = Full-scale industrial applications, with
demonstrations or pilots for municipal
sewage sludge
0 = Full-scale operations overseas
N = Full-scale operations in North America
P = Pilot
F = Few plants
I = Industrywide
L = Primarily large plants
S = Primarily small plants
A = Produces Class A biosolids
C = Capital savings
0 = Operational/maintenance savings
F = Produces high-nutrient fertilizer
M = Minimizes odors
R = Provides beneficial use (nonagricultural)
V = Sludge volume reduction
A = Agriculture
C = Construction
N/A = Not Applicable
P = Power
Positive feature
0 Neutral or mixed
T Negative feature
3-2
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September 2006
Emerging Technologies
Flotation Thickening - Anoxic Gas
Objective:
Thicken contents of an anaerobic digester to reduce
volume of solids to dewater and transport. Increase
digester capacity.
Technology Summary
State of Development: Innovative
The technology was used for over a year at the Salmon Creek Plant
in Burien, King County, Washington. Volatile solids were increased
from approximately 50% to 71%; resulting in a 34% reduction in
volume of solids to be hauled off site. In addition, odors from the belt
presses and the amount of polymer required for dewatering were
both reduced. Plant operations, which used to experience frequent
foaming incidents, improved; there were no foaming incidents while
the technology was employed. The process is also used to treat dairy
and potato processing wastes in the U.S.
Description:
This totally-enclosed process involves separating and thickening solids removed from anaerobic digestion using digester gas to
float solids which are removed and returned to the digester. The technology is typically employed as an enhancement to existing
conventional digesters. Solids are concentrated to 6 -10%. All gases are discharged back to the anaerobic digester or to a biofilter.
Comparison to Established Technologies:
Similar to Dissolved Air Flotation Thickening (DAFT), however, uses digester gas instead of air.
Available Cost Information:
Approximate Capital Cost: $7.50 per dry Ib (at 6-8% solids, or $1.90 per gallon) processed per day
Approximate O&M Costs: $8.00 per dry ton of biosolids processed for polymer
Capital costs include associated equipment (saturator, controls, polymer feed, inlet/outlet pumps) and will vary with the
surface loading rate to the separators. The quoted costs are based on processing 200 pounds of dry solids per square foot
per day. According to the vendor, each gallon processed per day through an AGF will reduce feed through digester by 1.5 to
2.0 gallons per day.
Operational costs include a polymer requirement of 4 pounds per dry ton of biosolids processed at $2.00 per pound.
However, total polymer use may decrease.
Cost information supplied by vendor.
Vendor Name(s):
Environmental Energy Engineering Company
6007 Hill Road NE
Olympia,WA98516
Phone: 360-923-2000
E-mail: dennis@makingenergy.com
www.makinqenerqy.com
Practitioner(s):
The following hosted a demonstration project but is not a current
practitioner:
Southwest Suburban Sewer District (SWSSD)
Salmon Creek Wastewater Treatment Plant
431 Ambaum Blvd. SW
Burien, WA 98166
Phone: 206-244-2202
Fax: 206-433-8546
E-mail: millercreekWWTPtajaol.com
Biosolids Management
3-3
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Emerging Technologies
September 2006
Technology Summary
Flotation Thickening - Anoxic Gas (Contd)
Key Words for Internet Search:
Anoxic gas flotation, AGF, biosolids, Salmon Creek WWTP, King County Washington
Data Sources:
King County Applied Wastewater Program. "AGF -Anoxic Gas Flotation." Demonstration project evaluation. (2000).
Burke, D.A. "Application of AGF (Anoxic Gas Flotation) Process." Environmental Energy Company. (2000) Vendor-supplied
information
Burke, D.A "Producing Exceptional Quality Biosolids through Digestion, Pasteurization, and Redigestion". Biosolids 2001:
Building Public Support Conference Proceedings Water Environment Federation/AWWA/CWEA Joint Residuals and
Biosolids Management Conference. (2001).
3-4
Biosolids Management
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September 2006
Emerging Technologies
Membrane Thickening
Objective:
Thickening of waste-activated sludge.
Technology Summary
State of Development: Innovative
Membrane thickeners are operating in several locations throughout
the U.S. Full-scale facilities are in use in Dundee, Michigan and
Fulton County, Georgia among other locations.
Description:
A basin with suspended biomass and a membrane system that provides a barrier for the solid-liquid separation. These membranes
can be used in an aerobic environment to achieve separation of liquid from biomass. Anaerobic environments have plugged
membranes too quickly in tests. Therefore, aerobic environments are needed for oxygen mixing. Thickening to over 4% solids has
been reported. Flux through the membrane is reduced to half the value for membranes used in activated sludge basins.
The different types of membranes are described as modular and they are of the following types: tubular, hollow-fiber, spiral wound,
plate and frame, and pleated cartridge filters.
Comparison to Established Technologies:
Similar to MBRs for wastewater treatment. Membranes for thickening require a smaller footprint than many established
thickening technologies.
Available Cost Information:
Approximate Capital Cost: $125,000 for a one-train system with two cassettes.
Approximate O&M Costs: Not provided by vendor.
Vendor Name(s):
Enviroquip, Inc.
2404 Rutland Drive, Suite 200
Austin, TX
Phone:512-834-6019
Website: www.enviroquip.com
Infilco Degremont - U.S. Headquarters
P.O. Box 71390
Richmond, VA 23255-1390
8007 Discovery Drive
Richmond, VA 23229-8605 USA
Phone: (804) 756-7600
Website: www.infilcodegremont.com/membrane
filtration.html
Mitsubishi International Corporation
333 South Hope Street West, Suite 2500
Los Angeles, CA 90071
Phone:213-687-2853
Website: www.micusa.com
Practitioner(s):
Village of Dundee Wastewater Treatment Plant
596 E Main St
Dundee, Ml48131-1208
Phone: 734-529-3001
Fulton County Public Works Department
Cauley Creek Water Reclamation Facility
141 Pryor Street, Suite 6001
Atlanta, GA 30303
Phone: 404-730-7442
www.co.fulton.ga.us/public works projects/index new pubwksl.
html
See www.zenon.com/resources/case studies/wastewater/ for
additional practitioners.
Biosolids Management
3-5
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Emerging Technologies
September 2006
Technology Summary
Membrane Thickening (Contd)
US Filter/MEMCOR
4116 Sorrento Valley Blvd.
San Diego, CA 92121
Contacts for regional offices that provide information on MEMCOR are
available at
www.usfilter.com/en/Product+Lines/Memcor Products/Contacts/memcor us
contacts.htm
Veolia Water Solutions & Technologies
L'Aquarene
1 place Montgolfier
94417, Saint Maurice
France
Phone:+33 (0)1 45 11 5555
Website: www.veoliawater.com
Zenon Environmental Services, Inc.
3239 Dundas Street West
Oakville, Ontario
Phone: 905-465-3030
Fax: 905-465-3050
Website: www.zenon.com
Key Words for Internet Search:
Membrane thickening, biosolids membrane treatment, sludge separation
Typical membrane unit
Data Sources:
Metcalf and Eddy. Wastewater Engineering Treatment and Reuse. 4th Edition. (2003).
Vendor-supplied information.
Overview of the Cauley Creek WRF
Fulton County, GA
MBR Technology at Cauley Creek WRF
Fulton County, GA
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Biosolids Management
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September 2006
Emerging Technologies
Recuperative Thickening
Objective:
Reduce biosolids volume, enhance biosolids
destruction and gas production; reduce dewatering and
beneficial use/disposal costs.
Technology Summary
State of Development: Innovative
Recuperative thickening was the subject of a full-scale test at the
Spokane, Washington, Advanced Wastewater Treatment Plant from
September 2000 to May 2001. Two benefits were reported in the
study: (1) Use of existing dissolved air flotation capacity allowed
implementation with essentially no capital cost; (2) Co-thickening with
waste-activated sludge showed no increase in thickening labor or
power costs. Polymer use increased for thickening and decreased
for dewatering. Recuperative thickening of 25% of the digesting
solids increased solids retention time in the anaerobic digesters from
15.7 days to 24.0 days. Anaerobic digestion volatile solids reduction
increased from 50% to 64%. Recuperative thickening did not affect
effluent quality.
Description:
Digested biosolids are removed from the anaerobic digestion process, thickened, and returned to the anaerobic digestion process.
Anoxic gas flotation is one type of recuperative thickening process, and it is described earlier in this chapter.
Comparison to Established Technologies:
Technology allows for the use of existing biosolids process equipment and does not have the additional capital costs
associated with other'.innovative technologies that [equire greater capital investments.
Available Cost Information:
Approximate Capital Cost: Not provided by vendor.
Approximate O&M Costs: Not provided by vendor.
Capital and operations and maintenance cost estimates will vary depending on what thickening equipment currently exists
at a treatment facility. According to the Spokane study, the net result was a net reduction of polymer requirements by 15%
with an annual savings of $28,000. Biosolids production (wet weight) was reduced 22% with a resultant annual savings of
$85,000. There is no specific equipment to be purchased.
Vendor Name(s):
Not applicable (procedural variation not requiring
specific equipment)
Practitioner(s):
The following hosted a demonstration project but is not a current
practitioner:
Spokane Advanced Wastewater Treatment Plant
4401 North A.L. White Parkway
Spokane, WA 99205
Phone: 509-625-4600
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Recuperative Thickening (Contd)
Key Words for Internet Search:
Recuperative thickening/thickener, anaerobic digestion
Data Sources:
Reynolds, D.T., M. Cannon, T. Pelton. "Preliminary Investigation of Recuperative Thickening for Anaerobic Digestion.1
WEFTEC Paper. (October 2001).
3-8
Biosolids Management
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September 2006
Emerging Technologies
Metal Screen Thickening
Objective:
This equipment performs conditioning and thickening in
one basin
Technology Summary
State of Development: Embryonic
According to Ebara Corporation, a pilot test was conducted in a
24-hour operation biosolids treatment facility for a period of about 1
year. Test results indicated a sludge treatment rate of about 200 kg
dissolved solids per hour.
Description:
This system employs a set of slit screens with 1-millimeter openings. The screens are installed in a mixing tank. Sludge is thickened
by cross-flow filtration through the screens. According to the vendor, this system is designed to prevent clogging (which often
occurs with simple screening under atmospheric pressure) with low differential pressure through the submerged screens.
Comparison to Established Technologies:
Not similar to any established technologies.
Available Cost Information:
Approximate Capital Cost: Not provided by vendor.
Approximate O&M Costs: Not provided by vendor.
Vendor Name(s):
Not applicable (procedural variation not requiring
specific equipment)
Practitioner(s):
The following hosted a demonstration project but is not a current
practitioner:
Spokane Advanced Wastewater Treatment Plant
4401 North A.L. White Parkway
Spokane, WA 99205
Phone: 509-625-4600
Key Words for Internet Search:
Recuperative thickening/thickener, anaerobic digestion
Data Sources:
Reynolds, D.T., M. Cannon, T. Pelton. "Preliminary Investigation of Recuperative Thickening for Anaerobic Digestion."
WEFTEC Paper. (October 2001).
Biosolids Management
3-9
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Stabilization
Biosolids are stabilized to reduce pathogens, eliminate offensive odors and inhibit, reduce
or eliminate the potential for putrefaction that leads to odor production. Stabilization also
reduces attraction to vectors. Stabilization processes may produce Class A or Class B
biosolids, depending on the level and type of stabilization provided. This chapter focuses
on the latest developments in stabilization technologies.
Table 4.1 summarizes the state of development of stabilization technologies.
Recent technology developments in this area include several adaptations to the anaerobic
digestion process. Temperature-Phase Anaerobic Digestion (TPAnD), Two-Phase Acid/
Gas, and Three-Phase Anaerobic Digestion are included as innovative technologies.
Figure 4.1 includes an evaluation of the innovative technologies identified. Summary
sheets for each innovative and embryonic technology are provided at the end of this
chapter.
Table 4.1 - Thickening Technologies—State of Development
Aerobic Digestion
• Autothermal Thermophilic
(ATAD)
Alkaline Stabilization
Advanced Alkaline Stabilization
Anaerobic Digestion
» Dual Digestion
« Two-Stage Mesophilic
Composting
Pasteurization
Solidification
Synox
Aerobic Digestion
» Aerobic/Anoxic Digestion
Anaerobic Digestion
* Anaerobic Baffled Reactor
« Columbus Biosolids Flow-Through
« Thermophilic Treatment
« High-Rate Plug Flow (BioTerminator 24/85)
* Temperature Phased Anaerobic Digestion
« Thermal Hydrolysis (CAMBI Process)
« Thermophilic Fermentation (ThermoTech™)
« Three-Phase Anaerobic Digestion
» Two-Phase Acid Gas Anaerobic Digestion
Vermicomposting
Aerobic Digestion
« Simultaneous Digestion and
Metal Leaching
Anaerobic Digestion
» Ozone Treatment
Disinfection
» Ferrate Addition
« Irradiation
• Neutralized
Biosolids Management
4-1
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Emerging Technologies
Figure 4.1 - Evaluation of Innovative Thickening Technologies
Aerobic/Anoxic Digestion
D
C,0,V
N/A
Enhances aerobic
digestion
Anaerobic Baffled Reactor (ABR)
D
C,0,V
N/A
e
e
e
e
e
e
Columbus Thermophilic Treatment
(CBFT3)
C,0,V
e
e
Retrofits to produce
Class A
High-Rate Plug Flow BioTerminator
24/85
C,0,V
N/A
Requires screening and
degritting
Temperature-Phased Anaerobic
Digestion
C,0,V
Thermal Hydrolysis
(CAMBI Process)
D
C,0,V
N/A
e
e
Odor issues
Thermophilic Fermentation
(ThermoTech™)
C,0,V
N/A
e
e
Three-Phase Anaerobic Digestion
C,0,V
e
e
Two-Phase Acid/Gas Anaerobic
Digestion
C,0,V
Low capital cost
Vermicomposting
C,0,V
B = Bench scale
D = Full-scale demonstrations in North
America
I = Full-scale industrial applications, with
demonstrations or pilots for municipal
sewage sludge
0 = Full-scale operations overseas
N = Full-scale operations in North America
P = Pilot
F = Few plants
I = Industrywide
L = Primarily large plants
S = Primarily small plants
A = Produces Class A biosolids
C = Capital savings
0 = Operational/maintenance savings
F = Produces high-nutrient fertilizer
M = Minimizes odors
R = Provides beneficial use (nonagricultural)
V = Sludge volume reduction
A = Agriculture
C = Construction
N/A = Not Applicable
P = Power
A Positive feature
0 Neutral or mixed
T Negative feature
4-2
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September 2006
Emerging Technologies
Aerobic/Anoxic Digestion
Objective:
Improve denitrification and enhance aerobic digestion.
Technology Summary
State of Development: Innovative
Full-scale aerobic/anoxic operation has been evaluated at treatment
plants in Castle Rock, Colorado; Paris, Illinois; and Clyde, Ohio. In
each case, the result was nearly complete nitrification and the ability
to maintain approximately neutral pH values, enhanced digestion,
near-complete nitrification, and nitrogen removal.
Description:
Aerators in an aerobic digester cycle on and off so that denitrification occurs under the anoxic conditions produced when the
aerators are turned off. Aerobic/anoxic digestion results in denitrification, which can provide approximately neutral pH that enhances
nitrification, aerobic digestion, and nitrogen removal. Effective pathogen destruction is also observed. Aerobic/anoxic operation
at several facilities has allowed the facilities to maintain approximately neutral pH values, enhanced digestion, near-complete
.n|trifira|pn^andnjfrqgenrempya!.
Comparison to Established Technologies:
Similar to aerobic/anoxic wastewater treatment nutrient removal technologies. Aerobic/anoxic sludge digestion has been
shown to improve sludge dewaterability, filtrate quality, and pH control compared to aerobic digestion alone.
Available Cost Information:
Approximate Capital Cost: Process involved conversion of existing facilities. Vendor does not have unit capital costs.
Approximate O&M Costs: Not provided by the vendor.
Vendor Name(s):
Enviroquip, Inc.
2404 Rutland Drive, Suite 200
Austin, TX 78758
Phone: 512-834-6000
Fax:512-834-6039
Practitioner(s):
Plum Creek Wastewater Authority
4255 N US Highway 85
Castle Rock, CO 80108
Phone:303-688-1991
Fax:303-688-1992
Key Words for Internet Search:
Aerobic-anoxic, biosolids, sludge
Data Sources:
Daigger, G.T. and E. Bailey. "Improving Digestion by Prethickening, Staged Operation, and Aerobic-Anoxic Operation: Four
Full-Scale Demonstrations." Water Environment Research. (May/June 2000).
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Anaerobic Baffled Reactor (ABR)
Objective:
Reduce sludge production by encouraging anaerobic
biological degradation of the primary sludge in the
primary treatment tank.
State of Development: Innovative
A full-scale pilot plant at Orange County Sanitation District was used
to evaluate the performance of an ABR in Southern California. Full-
scale prototypes have been constructed in the United Kingdom.
The appropriateness of the ABR for on-site primary sanitation in low-
income communities in South Africa also has been evaluated.
Description:
An anaerobic baffled reactor (ABR) consists of alternating hanging and standing baffles that compartmentalize the reactor and
force liquid flow up and down from one compartment to the next. The compartmentalized design separates the solids retention time
from the hydraulic retention time, making it possible to anaerobically treat wastewaters at short retention times (4-10 hours).
Comparison to Established Technologies:
Similar to baffled wastewater treatment basins used as a sequence of complete mix reactors. ABR systems have been
shown to provide higher resilience to hydraulic and organic shock loads, longer biomass retention times, and lower sludge
yields than other high rate anaerobic treatment systems. According to Orange County Sanitation District, volatile solids
reduction was not clear from the test data. High BOD in effluent was observed.
Available Cost Information:
Approximate Capital Cost: $400,000 to retrofit a 4-MGD rectangular primary clarifier with ABR
Approximate O&M Costs: $10,000 per year
Costs are expected to vary based on rectangular versus circular retrofit.
Vendor Name(s):
Atkins Water
3020 Old Ranch Parkway
Suite 180
Seal Beach, CA 90740
Phone: (562) 314-4231
Email: rupert.kruqertajatkinsqlobal.com
Practitioner(s):
The following hosted a pilot project but is not a current
practitioner:
Orange County Sanitation District
10844 Ellis Avenue
Fountain Valley, CA 92708-7018
Phone:(714)962-2411
Email: forinformation(5)ocsd.com
Key Words for Internet Search:
Anaerobic Baffled Reactor, ABR, volatile solids reduction, biosolids
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Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Anaerobic Baffled Reactor (ABR) (Contd)
Data Sources:
Foxon, K.M., S. Pillay, T. Lalbahdur, N. Rodda, F. Holder and C.A. Buckley. "The anaerobic baffled reactor (ABR): An
appropriate technology for on-site sanitation." Water SA 30:5 (2004)
44-50.
Kruger, R. and J. Brown. "Large-scale pilot trial of anaerobic baffled reactor: Assessment of key performance parameters
and cost-benefit analysis of full-scale retrofit." Proceedings of the WEF/AWWA Joint Residuals and Biosolids Management
Conference, Nashville, Tennessee. (17-20 April 2005)
Gas Outlets
Sample Ports
Inlet
ABR installation. Photo courtesy
of Atkins Water, 2006.
Outlet
Schematic of ABR unit (Foxon, et al., 2004)
Tank 1
Tank 2
Tank 3
rr
flow
baffles
/
XV
Tank 4
Cross-section of ABR (Kruger and Brown, 2005)
Sludge blanket
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Columbus Biosolids Flow-Through Thermophilic Treatment (CBFT3)
Objective:
Low-cost way for converting from Class B to Class A
biosolids production.
State of Development: Innovative
Columbus Water Works (CWW), Georgia, completed a pilot-scale
study of CBFT3 in June 2003 which showed successful production
of Class A biosolids at digestion temperatures of 53°C > 6 days and
60°C for 30 minutes with a very specific treatment train. This has
received site-specific approval for Class A biosolids production. In
addition, testing for Helminth and viruses continue.
Description:
The CBFT3 design consists of a conventional, complete-mix, continuous-feed thermophilic anaerobic digester followed by a long,
narrow plug-flow reactor. Mesophilic digestion is then used to minimize odors in the final product. The construction of a plug-flow
reactor prototype was completed in February 2004, and ongoing studies are testing its effectiveness. Estimates indicate that the
CBFT3 conversion process could save from $0.6 million for a 5 MGD plant up to $19 million for a 200 MGD plant. Patent rights of
this process were given to the Water Environment Research Foundation (WERF) in 2005.
Comparison to Established Technologies:
An improved process from conventional anaerobic digesters potentially capable of yielding Class A biosolids.
Available Cost Information:
Approximate Capital Cost: $12,000,000 (for a 90 MGD facility)
Approximate O&M Costs: Not available.
Capital cost estimate is based on construction loan for the South Columbus Water Resource Facility, Georgia. Maintenance
activities are completed on an "as-needed" basis, a minimum of once annually.
Vendor Name(s):
Developed by the Columbus Water Works with:
Brown and Caldwell
4700 Lakehurst Court, Suite 100
Columbus, OH 43016
Phone:(614)410-6144
Fax:(614)410-3088
Practitioner(s):
Columbus Water Works
1421 Veterans Parkway, P.O. Box 1600
Columbus, GA 31901
Phone: 706-649-3400
Fax: 706-327-3845
Email: mailbox(g)cwwqa.orq
Website: www.cwwqa.org
Key Words for Internet Search:
Columbus Biosolids Flow-Through Thermophilic Treatment, CBFT3, Columbus Water Works
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Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Columbus Biosolids Flow-Through Thermophilic Treatment (CBFT3) (Contd)
Data Sources:
Esters, K. "Columbus Water Works honored for technique that turns human waste into safe fertilizer." Water Industry News.
(22 February 2005).
Water Environment Research Federation (WERF). "Columbus Retrofits Plants to Achieve Low-Cost Class A Biosolids."
Compiled by Roy Ramani in WERF Progress Newsletter-Vol 15: Issue 3. (Summer 2004)
Willis, J. and P. Schafer. "Upgrading to Class A Anaerobic Digestion: Is Your Biosolids Program Ready to Make the Move?"
Public Works Magazine. (1 January 2006).
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
High-Rate Plug Flow BioTerminator 24/85
Objective:
Reduce total suspended solids of feed sludge by 85%
in 24 hours. Generate methane that can be recovered
and used for energy
State of Development: Innovative
Pilot studies of the BioTerminator system have been conducted at
wastewater treatment plants in Daphne, Alabama; Galveston, Texas;
Baton Rouge, Louisiana; and Fort Smith and Little Rock, Arkansas.
Based on pilot study results, the BioTerminator appears to achieve
exceptional total and volatile solids destruction. The first full-scale
application of the BioTerminator technology is scheduled to be
installed at the Daphne, Alabama WWTP in 2007.
Description:
The BioTerminator 24/85 anaerobic digester consists of a plug flow insulated tank with a patented arrangement of baffles. The
tanks are rectangular in shape with a maximum capacity of 10,000 gallons.
A plant requiring more than the 10,000 gallon feed capacity would need to employ multiple reactors. Prior to entering the tank,
the sludge may need to be screened and/or degritted, and will have to be heated to 35°C (95°F). For some sludges, a minimal
amount of carbon supplement, typically sugar, is added as a microbial stimulant. For mixed primary and secondary sludges,
sodium bicarbonate is fed if necessary to maintain proper pH.
A portion of the methane generated by the process is used to preheat the sludge (<25%, depending on climate) and the rest may
be flared or used to recover energy value. Additional descriptions of the various system components are provided in Burnett
(2005).
Comparison to Established Technologies:
According to the vendor, the BioTerminator requires much shorter retention time and achieves a greater reduction in total
solids in comparison to a well-operated conventional anaerobic digester. Studies are underway to support these claims.
Available Cost Information:
Approximate Capital Cost: $1.2 million for first 10,000 gpd reactor and equipment skid
$400,000 for subsequent two reactors, if added
Approximate O&M Costs: $15,000/year for chemicals and $4,000/year electricity
Recoverable energy value of methane, if used, would offset O&M costs
Vendor Name(s):
Shaw Environmental & Infrastructure, Inc.
17 Princess Road
Lawrenceville, NJ 08648
Phone: 609-895-5340
Practitioner(s):
Information on practitioners is available at
www.bioterminator.com/casestudies.phtml.
Key Words for Internet Search:
Anaerobic digester, volatile solids, mesophilic, plug flow, solids reduction, BioTerminator
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Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
High-Rate Plug Flow BioTerminator 24/85 (Contd)
Data Sources:
Burnett, C. "Pilot test results of the BioTerminator high-rate plug flow anaerobic digester." Proceedings of the WEF/AWWA
Joint Residuals and Biosolids Management Conference, Nashville, Tennessee. (17-20 April 2005).
The website www.totalsolidsolution.com provides information on this technology although this company is no longer a
vendor for the BioTerminator system.
Also visit www.shawwatersolutions.com.
lOTerminator
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Temperature-Phased Anaerobic Digestion (TPAnD)
Objective:
Improve the quality of biosolids by combining
thermophilic and mesophilic anaerobic digestion.
State of Development: Innovative
The Western Lake Superior Sanitary District in Duluth, Minnesota
uses the TPAnD system to process solids resulting from the
treatment of 40 mgd of wastewater. The technology is also used at
Madison, Wl and in Orange County and Los Angeles in CA.
Blue Plains Advanced Wastewater Treatment Plant is planning to
construct an egg-shaped TPAnD digester facility. The results of
studies performed by Virginia Tech comparing a TPAnD system, a
two-stage thermophilic system, and two mesophilic conventional
digesters recommended that DC WASAcontinue to pursue TPAnD
as a process option for their new anaerobic digestion facility.
Description:
Temperature-phased anaerobic digestion (TPAnD), also referred to as thermophilic/mesophilic digestion, is a promising process
option for the wastewater treatment facilities due to its higher performance and ability to control product odor. The process employs
thermophilic (>55°C) conditions in the first phase of digestion followed by mesophilic (35°C) conditions in the second phase of
digestion.
Comparison to Established Technologies:
A combination of thermophilic digestion and mesophilic digestion processes. By their combined use, the performance is
enhanced over either individual process.
Available Cost Information:
Approximate Capital Cost: $4,700,000
Approximate O&M Costs: Not available.
Capital cost is based on the 2004 estimated cost to install a new 2,465 m3 temperature-phased anaerobic digester,
associated piping upgrades, and upgrades to a secondary digester at the Ravensview Water Pollution Control Plant in
Kingston, Ontario.
Vendor Name(s):
Not applicable
Practitioner(s):
Western Lake Superior Sanitary District
2626 Courtland St.
Duluth, MN 55806
218-722-3336
Website: www.wlssd.com
Key Words for Internet Search:
Anaerobic digestion, temperature phased, Blue Plains wastewater
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Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Temperature-Phased Anaerobic Digestion (TPAnD) (Contd)
Data Sources:
J.L. Richards & Associates, Ltd. Ravensview WPCP Secondary Treatment and Capacity Upgrades Class EA Update.
Technical Memo No. 5 - Biosolids Management Upgrades. Prepared for Utilities Kingston. (May 2004).
Inman D.C., S. Murthy, P. Schafer, P. Schlegel, J. Webb, J.T. Novak. "A comparative study of two-stage thermophilic, single-
stage mesophilic, and temperature-phased anaerobic digestion." Proceedings of the WEF 2005 Residuals & Biosolids
Specialty Conference, Nashville, Tennessee. (17-20 April 2005).
Water Environment Federation Residuals and Biosolids Committee. "High-Performance Anaerobic Digestion (White
Paper)". Water Environment Federation, Alexandria, Virginia. (January 2004)
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Thermal Hydrolysis (CAMBI Process)
Objective:
Biosolids mass reduction; increased production of
biogas.
State of Development: Innovative
This process was used full scale in 2002 at the Nigg Bay Wastewater
Treatment Plant in Aberdeen, Scotland, and is installed at additional
wastewater treatment facilities across Europe, Australia and Japan.
In Europe, it is also used by pulp manufacturers.
Description:
Prior to digestion, sludge is dewatered to 15%-20% solids and fed through a hydrolysis vessel. The process involves the oxidation
of sludge under elevated temperature (approximately 320°F) and pressure (approximately 100 psi). Under these conditions,
pathogens are destroyed and cell structures in the sludge breakdown, releasing energy-rich compounds.
Following hydrolysis, sludge is fed to an anaerobic digester where it readily breaks down, resulting in high volatile solids destruction
(approximately 65%) and increased biogas production compared to conventional anaerobic digestion.
Odor issues need to be addressed for this process
Comparison to Established Technologies:
Similar to established technology by Zimpro Wet Air Oxidation process. Increased biogas production from hydrolyzed
sludge.
Available Cost Information:
Approximate Capital Cost: $6,000,000
Approximate O&M Costs: $360 per dry ton treated
Capital and O&M costs are for the installation and 2000-2001 estimated operational costs of the CAMBI process at the
5 MGD Hamar Wastewater Treatment Plant, Norway. Operational costs include operating the treatment plant, disposal of
waste biosolids, personnel costs, overhead costs, depreciation, and interest. The Hamar plant accepts biosolids from other
treatment plants.
Vendor Name(s):
RDP Technologies, Inc.
2495 Boulevard of the Generals
Norristown, PA 19403
Phone:610-650-9900
E-mail: pchristv(S)rpdtech.com
Practitioner(s):
North of Scotland Water Authority
Denburn House
25 Union Terrace
Aberdeen, Scotland AB10 1NN
Phone: 845-743-7437
For additional practitioners see
www.cambi.com/sludae frame.asp
Key Words for Internet Search:
Thermal hydrolysis, CAMBI Process, biosolids, sludge
Data Sources:
Stevens, D., Kelly, J., Listen, C., Oemeke, D. Biosolids Management in England and France. Water, 29(1):56-61. The
Journal of the Australian Water Association. (2002).
Wilson, S. Panter, K. (2002). Operating Experience of Aberdeen CAMBI Thermal Hydrolysis Plant Proceeding of CIWEM/
AQUA Enviro 7th European Biosolids and Organic Residuals Conference. (November 2002).
Vendor-supplied information
4-12
Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Thermophilic Fermentation (ThermoTech™)
Objective:
Converts sewage sludge and residuals into fertilizer-
grade product by thermophilic fermentation process.
State of Development: Innovative
ThermoMaster™ plants in Canada convert food wastes into a high-
protein animal feed supplement and wastewater treatment sludges
into fertilizer material. This technology is not being actively marketed
by the vendor at this time.
Description:
ThermoTech™ is a microbial organic waste digestion technology originally developed to create animal feed supplement from
relatively high-solids-content food wastes. The process has been modified for wastewater sludge and materials with a lower solids
content. In the ThermoMaster™ process, autoheated aerobic digestion is operated at a relatively short residence time of 30 hours
to maximize single-cell protein production using the influent waste material as a substrate. The solids from the digestion process
are then dried and pelletized.
Limited information was available on this technology as the vendor is no longer focusing its efforts on marketing this technology.
Comparison to Established Technologies:
Fermenting provides a number of benefits over established technologies, including a 20% increase in protein content and
minimal energy requirements (as the process creates its own heat). Residuals are transformed into salable products in less
time and with smaller space requirements.
Available Cost Information:
Approximate Capital Cost: $15,000,000 - $50,000,000 for a 400-tpd facility
Approximate O&M Costs: Not available.
Vendor Name(s):
ThermoTech™ Technologies
204-195 County Court Boulevard
Brampton, Ontario L8E 5V9 Canada
Phone: 905-451-5522 or 561-2662
Fax:905-451-5833
Practitioner(s):
No practitioner at this time.
Key Words for Internet Search:
ThermoTech™, ThermoMaster™, waste digestion, autoheated aerobic digestion
Data Sources:
Glenn, Jim. "Nutrient Niches: Marketing Food Residuals As Animal Feed." Biocycle. (April 1997) 43-50.
PR Newswire. "ThermoTech™ Ventures, Inc. Signs US Dollars 200 Million Commitment to Secure Long-Term Debt
Financing to Build and Operate ThermoMaster Mark II Plants." (2 March 1999).
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Three-Phase Anaerobic Digestion
Objective:
Increase dewaterability, produce Class A biosolids for
direct land application, increase biogas production, and
reduce odors.
State of Development: Innovative
Three-phase anaerobic digestion was implemented full scale at the
Inland Empire Utilities Agency (IEUA) Regional Water Recycling
Plant No. 1 (RP-1) in San Bernardino County, California, in
November 2000.
Description:
This anaerobic digestion system operates using three phases. The first phase is a volatile fatty acid digester operating at a
temperature of 35°C. The second is an anaerobic thermophilic gas digester operating in the range of 50°C to 56°C. The third
phase is not heated but remains above 35°C. IEUA received U.S. EPA's approval for Class A Biosolids per Alternative 4 of CFR
503. The following operating parameters apply:
• Phase 1-Minimum HRTof 2 days (monthly average) at temperatures greater than 35°C;
• Phase 2-Minimum HRT of 14 days (monthly average) at temperatures greater than 50°C;
• Phase 2-Minimum HRT of 10 days (daily minimum) at temperatures greater than 55°C;
• Phase 3-Minimum HRT of 4 days (monthly average) at temperatures greater than 35°C.
Comparison to Established Technologies:
Three-phase anaerobic digestion reportedly results in improved pathogen destruction and very high volatile solids reduction
and gas production as compared to single stage anaerobic digestion.
Available Cost Information:
Approximate Capital Cost: Not available.
Approximate O&M Costs: $60 per wet ton treated
Operational and maintenance costs for IEUA include chemicals, labor, miscellaneous materials, power used, natural gas
consumed, and power that was generate in its RP-1 facility (a credit). O&M costs do not include laboratory or monitoring
costs, collection system or pretreatment costs, any administrative costs, contract labor or professional fees and services.
JBJAestjmatedJt.sayec| $270,000 in energy costs dunn^
Vendor Name(s):
None identified.
Practitioner(s):
Inland Empire Utilities Agency
Recycling Plant 1 (RP-1)
2450 E. Philadelphia Avenue
Ontario, California 91761
Phone:909-993-1800
Fax: 909-947-2598
City of Tacoma Wastewater Management
2101 Portland Avenue
Tacoma, WA 98421
Key Words for Internet Search:
Three-phase anaerobic digestion, thermophilic digestion, Inland Empire Utilities Agency, IEUA, biosolids
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Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Three-Phase Anaerobic Digestion (Contd)
Data Sources:
Lee, S.A., D.D. Drury, C.A. Baker, J.S. Bowers, R.H. Nienhuis. "Three-Phase Thermophilic Digestion Disinfects Biosolids."
Biosolids Technical Bulletin. Water Environment Research Federation. Vol. 8: No. 6. (2003).
Salsali H.R., and W.J. Parker. "An Evaluation of 3 Stage Anaerobic Digestion of Municipal Wastewater Treatment Plant
Sludges." Proceedings of the WEF Residuals and Biosolids Management Conference 2006: Bridging to the Future,
Cincinnati, OH (12-14 March 2006).
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Two-Phase Acid/Gas Anaerobic Digestion
Objective:
Increase methane production and shorten biosolids
digestion time.
State of Development: Innovative
Patented process developed by Dr. Samnabuth Ghosh during his
tenure at Gas Technology Institute (GTI, also known as Institute of
Gas Technology). It has been in operation for more than 10 years
at a 12 MGD wastewater treatment plant in DuPage County, Illinois.
The treatment generates sufficient methane to power a 1.5 mega
watt generator.
Full-scale projects are either installed or underway in Denver, Dallas,
Hampton Roads and Baltimore.
Description:
Two-phase anaerobic digestion utilizes an acid stage and a gas stage to break down biosolids. Hydrolysis reactions along with
acidification and acetification occur in the acid phase digester where the pH is in the range of 5.5 to 6.0 because of the volatile fatty
acid fermentation. The second (gas) stage is where high quality (>650 BTU per cubic foot) methane gas production occurs.
The two-phase anaerobic digestion process (called the HIMET or high-methane process) is based on physically separating two
different groups of bacteria into two separate tanks and maximizing their growth by maintaining optimum conditions in each tank
for that particular group of bacteria. The first group, the acidogenic bacteria, is grown in the acid phase digester where the pH is in
the range of 5.5 to 6.0 because of the volatile fatty acid fermentation. The second group, the methanogenic bacteria, is grown in the
methane digester where the pH is naturally much higher and where residence time can be between 7-10 days, depending upon
the waste characteristics. The acidogenic bacteria will not thrive in the methane reactor as most of its feed material is used in the
acid digester; the methanogenic bacteria cannot thrive in the acid digester as the retention time is top short and the pH is top low
Comparison to Established Technologies:
This process is similar to fermentation processes. According to one vendor, upsets in conventional anaerobic digesters
are often attributable to the methanogenic bacteria, which are difficult to grow and are sensitive to overloads. Two-phase
digestion is resilient to changes in feed volume and composition because the acidogenic bacteria are hardy and do well
under extreme loading conditions. It is also; claimed that the technologyminimizes or eliminates; foaming problems.
Available Cost Information:
Approximate Capital Cost: Not available.
Approximate O&M Costs: Not available.
Vendor Name(s):
Vendor Name(s):
GTI
1700 S. Mount Prospect Road
DesPlaines, IL60018
Phone: 847-768-0500
Fax: 847-768-0501
E-mail: environscienceandtech@aastechnoloav.orci
Practitioner(s):
Woodridge - Greene Valley Wastewater Facility
7900 South Route 53
Woodridge, IL 60517
Email: Kbuoy@dupageco.org
Phone: 630-985-7400
Website: www.dupaaeco.ora/publicworks/
Key Words for Internet Search:
Two-phase anaerobic digestion, two-stage anaerobic digestion, biosolids, sludge
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September 2006
Emerging Technologies
Technology Summary
Two-Phase Acid/Gas Anaerobic Digestion (Contd)
Data Sources:
Kelly, H.G. Emerging Technologies in Biosolids Treatment. Dayton & Knight Ltd., West Vancouver, Canada. (2003).
GTI. "HI MET-A Two-Stage Anaerobic Digestion Process for Converting Waste to Energy." Company website:
www.qastechnoloqv.org. (September 2004).
DuPage County, Illinois, Department of Public Works website. (2005). Woodridge-Greene Valley Wastewater Facility.
Available online at www.dupaqeco.org/publicworks/qeneric.cfm7doc id=880.
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Vermicomposting
Objective:
Achieve pathogen reduction, produce a land
application-quality compost from biosolids.
State of Development: Innovative
In July 2004, the first full-scale vermicomposting facility in the
United States was commissioned for the township of Granville,
Pennsylvania. This facility, which treats approximately 70 dry tons
annually, processes aerobic digested biosolids.
Description:
Earthworms, added to biosolids, break down organic material and produce a fine-grained castings, considered by some to have
greater value as a soil amendment than traditional composts. Generally operated in a semi-continuous flow. The earthworms stay
in the bed with no need to restock regularly; generally, the worm population is self regulating and will increase to the point where
available food and space constrain further expansion. The process must be monitored for such parameters as moisture content
and temperature but is not labor-intensive. Flow of solids into the system is then adjusted to optimize living conditions for the
worms. The castings are known to contain plant growth regulators and other substances that make them an effective form of bio-
fertilizer and bio-pest control agent.
A full-scale demonstration in Orange County, Florida, showed greater reduction of indicator pathogens in biosolids composted
with, versus without, the addition of worms. The Manure Management Program, Cornell University, is currently researching
vermicomposting of animal manure.
Comparison to Established Technologies:
Vermicomposting involves earthworms and microorganisms working together. In contrast to conventional aerobic
composting, it does not involve a thermophilic stage to achieve stabilization. As with other non-enclosed composting
technologies, vermicomposting does have a fairly large footprint similar to aerated static pile composting.
Available Cost Information:
Approximate Capital Cost: $1,600,000
Approximate O&M Costs: $495,000
Vendor Name(s):
Vermitech USA Inc.
100 Helen Street
Lewistown, PA 17044
Phone: 717-994-4885
Website: www.vermitech.com
Email: shaun.ankers(5).vermitech.com
Practitioner(s):
Township of Granville
Junction Wastewater Treatment Facility
100 Helen St.
Lewistown, PA 17044
Email: lcraig(5).granville-twp.orq
Phone:717-242-1838
Key Words for Internet Search:
Vermicomposting, vermiculture, municipal waste, biosolids, sludge
4-18
Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Vermicomposting (Contd)
Data Sources:
Eastman, Bruce R. "Achieving Pathogen Stabilization Using Vermicomposting". Biocycle Journal of Composting.
(November 1999). 62-64.
Slocum, Kelly. "Pathogen Reduction in Vermicomposting." Worm Digest. Issue 23. (1999).
Vendor-supplied information
Granville Township, PA Vermicomposting facility
(Photo courtesy of Granville Township)
Biosolids Management
4-19
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Emerging Technologies
September 2006
Technology Summary
Simultaneous Digestion and Metal Leaching (SSDML)
Objective:
Increase the pathogen reduction and metals solubility
during the digestion process.
State of Development: Embryonic
A 2003 pilot-scale study found that the SSDML process was
successful in obtaining acidity and oxidation-reduction potential
levels within a sludge bioreactor that were greater than necessary
for solubilization of toxic metals. Nutrient levels (N, P, K) in the
decontaminated sludge were preserved throughout the process. The
study also found the process to be effective in reducing odors and
indicator bacteria in the sludge.
Description:
The simultaneous sewage sludge digestion and metal leaching (SSDML) process involves the addition of elemental sulfur to
biosolids during aerobic digestion. After several days, the pH of the mixture is very low (about 2), which is conducive to increasing
the solubility of toxic metals within the biosolids.
Comparison to Established Technologies:
Not similar to other established technologies.
Available Cost Information:
Approximate Capital Cost: Not available.
Approximate O&M Costs: Not available.
Vendor Name(s):
Institut National de Recherche Scientifique
Universite du Quebec
2700 rue Einstein
C.P. 7500
Sainte-Foy, Quebec G1V 4C7
Phone:418-654-2617
E-mail: tvaai(5)inrs-ete.uauebec.ca
Practitioner(s):
No practitioner at this time
Key Words for Internet Search:
Metals leaching, SSDML, aerobic digestion, biosolids, sludge
Data Sources:
Blais, J., N. Meunier, G. Mercier, P. Drogui, and R.D. Tyagi. "Pilot Plant Study of Simultaneous Sewage Sludge Digestion
and Metal Leaching." Journal of Environmental Engineering. 130:5 (2004) 516-525.
4-20
Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Anaerobic Digestion with Ozone Treatment
Objective:
Break down organic matter in biosolids to increase the
effectiveness of anaerobic digestion.
State of Development: Embryonic
The Vranitsky and Lahnsteiner (2002) laboratory-scale study found
that the average degradation rate of organic matter increase to 65%,
as compared to 45% in a conventional (non-ozonated) system. The
study also showed an increase in biogas production of 30%^40%
due to the added biological disintegration from the ozone addition.
The achieved removal rate of carbon and nutrients decreased, but
remained within regulatory requirements.
Description:
Anaerobically digested biosolids are diverted from the digester to a reaction tank where they are exposed to low levels of ozone.
One experiment by Vranitsky and Lahnsteiner (2002) showed that only 0.06 g of ozone per gram of dissolved solids was necessary
to destroy the biological activity of the digested biosolids. The ozonated biosolids are then sent to the thickening tank and then
back to the digester where they are mixed with both ozonated and non-ozonated biosolids. The biosolids either exit the digester to
be dewatered, or they are again diverted back to the ozone reactor. The ozone generation is based on corona discharges that are
capable of transforming molecular oxygen into ozone.
Comparison to Established Technologies:
Not similar to other established technologies.
Available Cost Information:
Approximate Capital Cost: Not available.
Approximate O&M Costs: $1700 per million gallons treated
Operational cost estimate is based on a model wastewater treatment plant treating approximately 5 million gallons per day
using an ozonation plant unit capable of producing 42.3 pounds of ozone per hour.
Vendor Name(s):
American Air Liquide
2700 Post Oak Blvd., Suite 1800
Houston, TX 27056
Phone: 800-820-2522
Website: www.us.airliauide.com
Key Words for Internet Search:
Ozone treatment, ozonation, biosolids, sludge
Practitioner(s):
No practitioner at this time
Data Sources:
Vranitsky, R., J. Lahnsteiner. "Sewage sludge disintegration using ozone -a method of enhancing the anaerobic
stabilization of sewage sludge." Proceedings of the European Biosolids and Organic Residuals Workshop, Conference and
Exhibition. (2002).
European Environmental Press. "Europe: Using Ozone to Reduce Sludge." (2005)
Water and Wastewater.com. Available online at
www.waterandwastewater.com/www services/news center/publish/article O0540.shtml. March 31.
Vendor-supplied information
Biosolids Management
4-21
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Emerging Technologies September 2005
Technology Summary
Ferrate Addition
Objective: State of Development: Embryonic
Stabilization and disinfection of wastewater solids as Pilot-scale investigation was conducted using solids from a
well as enhancement of biosolids products increasing Washington DC area wastewater treatment plant.
beneficial use potential.
Description:
Ferrate is a powerful oxidizing chemical with a higher reactivity than traditional oxidants. As a liquid, ferrate can be injected into
the process stream without the addition of special mixing equipment. One study by the USDA showed dosing dewatered solids
with ferrate inactivated 99.9% of E. coli. The resulting pH of the disinfected solids is generally between 12 and 13 depending on
dose. Ferrates also have been shown to have an affinity to react with sulfides, mercapitans and alkyl amines, all odor-producing
compounds common in wastewater solids.
Comparison to Established Technologies:
Depending on use of the ferrate, the process can be compared to various processes where a chemical is added to
wastewater solids to increase the potential for beneficial use.
Available Cost Information:
Approximate Capital Cost: Not provided by the vendor.
Approximate O&M Costs: Ferrate liqujd is available for approximately $2 per pound
Vendor Name(s): Practitioner(s):
Ferrate Treatment Technologies, LLC No practitioner at this time.
6432 Pine Castle Blvd, Unit #2C
Orlando, FL 32809
Phone: 407-857-5721
Fax:407-826-0166
E-mail: calig(5).ferrate.biz
Website: www.ferratetreatment.com
Key Words for Internet Search:
Ferrate, biosolids, sludge
Data Sources:
Chao, A. Quality Improvement of Biosolids by Ferrate (VI) Oxidation of Offensive Odour Compounds." IWA Publishing
Journal Online at www.iwaponline.com/wst/03303/wst033030119.htm. 8 August 2006.
Kim, H. P. Millner, V. Sharma, L. McConnell, A. Torrents, M. Ramirez, C. Peot. "Ferrate: Nature's Most Powerful Oxidizer:
It's Potential As a Disinfection Treatment for Thickened Sludge." Research Notes published at
www.ars.usda.gov/research/publications/publications.htm7SEQ NO 115=190364. 8 August 2006.
Reimers, R.S., V.K. Sharma, S.D. Pillai, and D.R. Reinhard. "Application of Ferrates in Biosolids and Manure Management
with Respect to Disinfection and Stabilization." WEF/AWWA Joint Residuals and Biosolids Management Conference 2005,
Nashville, Tennessee (17-20 April 2005).
4-22 Biosolids Management
-------
September 2006 Emerging Technologies
Technology Summary
Objective: State of Development: Embryonic
Biosolids disinfection Beta and gamma irradiation have been tested for at least 20 years
based on the promise of their low space requirement; however,
to date irradiation methods have not been implemented on a
continuous full-scale basis at any wastewater treatment plants in the
United States.
Description:
Irradiation destroys organisms by altering the colloidal nature of cell protoplasm. Gamma rays are high-energy photons produced
by certain radioactive elements; beta rays are electrons accelerated in velocity by electrical potentials in the vicinity of 1 million
volts. Both types of radiation destroy pathogens; however, the effectiveness of beta radiation is dependent on the dose. A dose of
1 megarad or more at 2°C will reduce pathogenic viruses, bacteria, and helminthes to below detectable levels. Lower doses may
successfully reduce bacteria and helminth ova but not viruses. Gamma rays from isotopes such as 60Cobalt and 137Cesium (at
1 megarad at 20°C) can penetrate substantial thicknesses and are easier to expose to sludge. Beta rays have limited penetration
ability and therefore are introduced by passing a thin layer of sewage sludge under the radiation source. Because these processes,
when used alone, do not reduce nuisance odors and the attraction of vectors, they are considered supplementary to typical
stabilization and pathogen treatment processes.
Comparison to Established Technologies:
Low space requirement is an advantage irradiation offers. However, irradiation does not "stabilize" sludge to satisfy vector
attraction reduction (VAR) requirements of U.S. EPA. An alternate approach is to incorporate the biosolids material into the
soil within 8 hours, or lime can be added, an established method of vector attraction management.
Available Cost Information:
Approximate Capital Cost: Not available.
Approximate O&M Costs: Not available.
Vendor Name(s): Practitioner(s):
No vendors at this time No practitioner at this time.
Key Words for Internet Search:
Ferrate, biosolids, sludge
Data Sources:
Pennsylvania Department of Environmental Protection. Training Course. "Biosolids - Characteristics and Treatment."
(1998). Available online at www.dep.state.pa.us/dep/biosolids/traininq/index.htm
Biosolids Management 4-23
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Emerging Technologies
September 2006
Technology Summary
Objective:
Disinfection of wastewater solids.
State of Development: Embryonic
The process has been tested in the laboratory on aerobically
digested, anaerobically digested and raw solids. It has also been pilot
tested at the Lagoon Wastewater and Sludge Facility, St. Thomas,
U.S. Virgin Islands. Research has demonstrated the reduction of
fecal coliforms and viral densities to below detectable limits and the
viability of helminth eggs to 0%. The process has been tested on
both raw and digested solids.
Description:
Neutralizer® is a sequenced batch process. First, chlorine dioxide is added to solids as they are fed into a mixing tank. Continuous
mixing is provided during this initial two-hour contact time. Next, sulfuric acid is added to acidify the solids to a pH of between 2.3
to 3.0. Then sodium nitrite (which converts to nitrous acid at this pH) is added to the tank. The tank is completely filled to eliminate
head space. The pressure in the tank builds to between 15 and 25 psig due to the acidification of the solids and generation of
nitrous acid gas. The material is held for another two hour period with continuous mixing. After the two hour period, the pH of the
material can be adjusted to create a biosolids favorable for beneficial use.
Comparison to Established Technologies:
Similar to Synox process but uses chlorine dioxide and nitrous acid instead of ozone. Chlorine dioxide is less expensive
and more reliable than ozone.
Available Cost Information:
Approximate Capital Cost: varies with application; contract vendor for specific cost information
Approximate O&M Costs: varies wjth application; contract vendor for specific cost information
Vendor Name(s):
BioChem Resources
3540 Agricultural Center Drive
St. Augustine, FL 32092
Phone: 904-607-2223
Fax: 904-607-9224
E-mail: ws@biochemresources.com
Practitioner(s):
No practitioner at this time.
Key Words for Internet Search:
Neutralizer®, biosolids, sludge
Data Sources:
Reimers, R.S., L.S. Pratt-Ward, H.B. Bradford, F.P. Jussari and W. Schmitz. "Development of the Neutralizer® Process for
Disinfection and Stabilization of Municipal Wastewater Residuals." WEF/AWWA Joint Residuals and Biosolids Management
Conference 2006, Cincinnati, Ohio (12-14 March 2006).
4-24
Biosolids Management
-------
Dewatering
Dewatering removes water from biosolids making them easier and less expensive to
transport, dry, compost, or incinerate. Dewatering is most often accomplished by drying
beds or a physical process that separates water from the solids via presses or centrifuges.
Often chemicals are used to enhance the processes. This chapter focuses on the emerging
dewatering technologies.
Table 5.1 summarizes the state of development of dewatering technologies.
Physical separation techniques have dominated the practice of dewatering for decades.
Recent advancements in dewatering use electricity rather than, or in combination with,
mechanical devices. Electroacoustical, electroosmotic, and electrodewatering are three
such processes. Membrane and tubular filter presses have had some reported success in
overseas dewatering applications; however, these technologies have yet to gain popularity
in the United States. Two more dewatering systems, DAB and Simon Moos, may be
promising technologies for small wastewater treatment plants and septage dewatering
applications.
Figure 5.1 includes an evaluation of the innovative technologies identified. Summary
sheets for each innovative and embryonic technology are provided at the end of this
chapter.
Biosolids Management
5-1
-------
Emerging Technologies
Table 5.1 - Dewatering Technologies—State of Development
Belt Filter Press
Centrifuge
Chamber Press
Drying Beds
« Auger-Assisted
s Natural Freeze-Thaw
« Vacuum-Assisted
Vacuum Filters
Drying Beds
s Quick Dry Filter Beds
Electrodewatering
Metal Screen Filtration
« Inclined Screw Press
Textile Media Filtration
« Bucher Hydraulic Press
« DAB™ System
s Geotube® Container
Electrodewatering
s Electroacoustic
« Electroosmotic
Membrane Filtration
« Membrane Filter Press
Textile Media Filtration
Simon Moos
« Tubular Filter Press
Thermal Conditioning and Dewatering
« Mechanical Freeze-Thaw
Figure 5.1 - Evaluation of Innovative Dewatering Technologies
Quick Dry Filter Beds
C,0,V
N/A
Electrodewatering
B,P
V
N/A
e
e
e
e
Inclined Screw Press
V,R
N/A
Bucher Hydraulic Press
0
N/A
DAB™ System
C,0
N/A
e
e
e
Similar to thickening
Geotube® Container
C,0,V
N/A
B = Bench scale
D = Full-scale demonstrations in North
America
I = Full-scale industrial applications, with
demonstrations or pilots for municipal
sewage sludge
0 = Full-scale operations overseas
N = Full-scale operations in North America
P = Pilot
F = Few plants
I = Industrywide
L = Primarily large plants
S = Primarily small plants
A = Produces Class A biosolids
C = Capital savings
0 = Operational/maintenance savings
F = Produces high-nutrient fertilizer
M = Minimizes odors
R = Provides beneficial use (nonagricultural)
V = Sludge volume reduction
A = Agriculture
C = Construction
N/A = Not Applicable
P = Power
Positive feature
0 Neutral or mixed
T Negative feature
5-2
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September 2006
Emerging Technologies
Quick Dry™ Filter Beds
Objective:
Drying biosolids to a higher solids percentage -
30%-60% dry cake
Technology Summary
State of Development: Innovative
Drying beds with a difference in the drainage system and under bed
construction.
Description:
The Quick Dry filter bed process consists of a series of pipes laid on the base of a bed to provide drainage and to presaturate water
to enter the bed before the sludge is applied. These pipes are then covered with 20-25 mm rock. A honeycomb grid is placed on
the base rock, filled with 10-15 mm rock and covered with a final layer of sand to complete the bed. The Quick Dry process also
includes a flocculation system (RapidFloc Mixer), an in-line polymer preparation system that injects polymer into the flocculation
device, and a self-contained harvesting unit.
Deskins Quick Dry filter bed is based on rapid gravity drainage with further water removal by natural solar evaporative processes.
The Quick Dry media prevents compaction of the filtering media in conventional sand drying beds. Saturation of the bed forces
out any air that has been trapped in the filter media and allows the sludge to flow evenly across the bed surface to achieve
maximum distribution. When the underdrain is opened, a vacuum or siphoning effect is created and causes the rapid dewatering
of the sludge. Along with this cracking or "opening up" of the sludge occurs and allows air to circulate around the cake and further
increase drying. Around 90% of the water will exit in 12 hours and the sludge will continue to drain while it is on the bed. Results of
several trials produced a cake of 45%-60% dry.
Comparison to Established Technologies:
Compares favorably with mechanical dewatering systems such as a belt filter press or centrifuge. Performs better than
existing drying beds. Dewaters solids to greater than 50% within 5-7 days on a footprint about 30% of the size of standard
drying beds.
Available Cost Information:
Approximate Capital Cost: Not provided by vendor.
Approximate O&M Costs: Not provided by vendor.
Vendor Name(s):
F D Deskins Company, Inc.
23 Fairway Drive
Alexandria, Indiana 46001
Phone: 765-724-7878
Fax: 765-724-7267
E-mail: deskins(5).netdirect.net
Practitioner(s):
McAllen Public Utilities
4001 N Bentsen Road
McAllen, TX 78504-9790
City of Casey
108 Main Street
Casey, IL 62420
Biosolids Management
5-3
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Emerging Technologies
September 2006
Technology Summary
Quick Dry™ Filter Beds (Contd)
Key Words for Internet Search:
Deskins, Quick Dry filter bed, polymer mixing, floe
Data Sources:
Evans, Anthony. Biosolid Reduction and the Deskin Quick Dry Filter Bed. Australia Water Industry Operators Association
Annual Conference Proceedings (220) www.wioa.orq.au/conf papers/02/paper10.htm
Fraser, Ross. Latest Advance in Solids Dewatering.
Deskins Quick Dry Filter Bed
Polymer Preparation Unit
Rapid Flocculation Mixer
Dried Solids Harvesting Unit
5-4
Biosolids Management
-------
September 2006
Emerging Technologies
Electrodewatering
Objective:
Enhance conventional dewatering using electric
current.
Technology Summary
State of Development: Innovative
Electrodewatering has been attempted by a variety of groups
since the 1920s. A bench-scale demonstration was conducted by
the Electric Power Research Institute (EPRI). An electroacoustic
dewatering process using electric and ultrasonic fields that improved
water removal over a conventional belt filter press by approximately
8% was demonstrated. Until recently, very little work has been
done to develop a suitable system capable of meeting full-scale
requirements, or to optimize such a system.
Description:
A direct current (DC) voltage is applied to the biosolids mixture. The application of the current in the initial stages of dewatering
causes particles to migrate to the electrode of opposite charge (i.e., electrophoresis). Once a cake is formed, electroosmosis
occurs as ions migrate to the appropriate electrode to compensate for particle charges. Electrodewatering can be combined
with conventional filter presses. According to a recent study by the Water Environment Research Foundation (WERF), the cost
benefit of electrodewatering is likely to be greatest for sludge that does not respond well to traditional pressure filtration. The study
demonstrated that the novel electrodewatering technique is applicable to a wide range of sludges and indicated that performance
might be limited for sludges with high conductivities.
Comparison to Established Technologies:
Not similar to any established technologies. May be combined with filter presses to enhance the thickening of highly
conductive sludges.
Available Cost Information:
Approximate Capital Cost: Approximately $5.25 million to retrofit 30 belt filter presses.
Approximate O&M Costs: $5,100 -$24,200 per dry ton
Operation and maintenance costs include electricity ($70-$140 per dry ton), labor ($9-$29 per dry ton), and maintenance
($5,000-$24,000 per dry ton). Cost savings anticipated over conventional dewatering costs.
Vendor Name(s):
Waste Technologies of Australia
Environmental Biotechnology CRC Pty Ltd
Suite G01 Bay 3 Locomotive Workshop
Australian Technology Park
Everleigh NSW 1430
Phone: +61 (0) 2 9209 4963
Website: www.wastetechnoloqies.com
Practitioner(s):
Electric Power Research Institute (EPRI)
3412 Hillview Avenue
Palo Alto, CA 94304
Phone:800-313-3774
E-mail: askeprKgjepri.com
Website: www.epri.com
Biosolids Management
5-5
-------
Emerging Technologies
September 2006
Technology Summary
Electrodewatering (Contd)
Key Words for Internet Search:
Electrodewatering, EPRI, biosolids, sludge
Data Sources:
Electric Power Research Institute (EPRI). "Emerging Environmental Technologies: An Analysis of New Treatment
Technologies for the California Energy Commission." Palo Alto, California, California Energy Commission, Sacramento,
California. 1007411. (2003).
Water Environment Research Foundation (WERF). "Demystifying the Dewatering Process: New Techniques and
Technologies Shed Light on a Complex Process." WERF Progress Newsletter. WERF, Alexandria, Virginia. (April 2006).
Available online at: www.werf.us/press/sprinqQ6/dewaterinq.cfm.
Vendor-supplied information.
5-6
Biosolids Management
-------
September 2006
Emerging Technologies
Inclined Screw Press
Objective:
Provide cost-effective dewatering with simplified
operations and lower polymer usage.
Technology Summary
State of Development: Innovative
The City of Old Town, Maine installed the first permanent inclined
screw press in the United States in 2003 as part of a major plant
upgrade. In the first year of operation, the inclined screw press
successfully met its design criteria and demonstrated that it is a
viable and cost-effective dewatering option. Inclined screw presses
have since been installed in Utah and other installation projects are
underway.
Description:
Liquid sludge (mixture of primary and secondary solids at 114 to 2%) is pumped to a flocculation reactor. A polymer is introduced
through a dosing ring in the feed sludge line and is mixed with the sludge in a static inline mixer.
Flocculated sludge overflows into an inclined screw (-20°) rotating inside a stainless steel, wedge wire screen (200 micron). As the
sludge is advanced up the rotating screw, filtrate flows out through the screen. The frictional force at the sludge/screen interface
coupled with increased pressure caused by the outlet restriction produces the dewatered sludge cake. The screw flights are
provided with a brush for continuous internal cleaning of the screen. The screen basket is also cleaned periodically with spray water
from the outside. Spray bars rotate around the basket, but within the enclosure of the press.
A lower and wider section of the basket serves as predewatering zone where free water drains by gravity. A second section of the
basket with a reduced diameter serves as a pressure zone. Here the sludge is compressed between narrowing flights of the screw.
The pressure in the pressure zone is controlled by the position of a cone at the discharge end of the basket. The dewatered sludge
is driven through a gap between the cone and the basket. The dewatered sludge cake (at about 20% to 25% solids) drops on a
conveyor or directly into a dumpster.
Two or three screw presses can be installed in parallel, with a single feed pump, polymer station, and flocculation reactor.
Comparison to Established Technologies:
The slow rotational speed results in less noise, vibration and overall wear, reducing anticipated long-term maintenance
costs. The unit is constructed of stainless steel and is fully enclosed, reducing the corrosion potential and assisting with
containing odors and improving working conditions. In addition, the operation of the unit is fully automated, reducing
operational costs as compared to more traditional technologies.
Available Cost Information:
Approximate Capital Cost: Not Available
Approximate O&M Costs: Not available
Vendor Name(s):
Huber Technology, Inc.
9805 North Cross Center Court, Suite H
Huntersville, NC 28078
Phone:704-949-1010
Fax:704-949-1020
www.huber-technoloqy.com
Practitioner(s):
City of Old Town
Pollution Control Facility
150 Brunswick Street
Old Town, Maine 04468
Phone: 207-827-3970
Fax: 207-827-3964
Biosolids Management
5-7
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Emerging Technologies
September 2006
Technology Summary
Inclined Screw Press (Contd)
Key Words for Internet Search:
Inclined screw press, dewatering, biosolids, sludge, City of Old Town Maine
Data Sources:
Atherton, P.C., R. Steen, G. Stetson, T. McGovern, and D. Smith. "Innovative biosolids dewatering system proved a
successful part of the upgrade to the Old Town, Maine water pollution control facility." Proceedings of the 2005 WEFTEC:
The Water Quality Event, Washington, DC. (30 October - 2 November 2005) 6650-6665.
Schematic of Incline Screw Press.
Image courtesy ofHuber Technology, Inc., 2006
Installed incline screw press at Old Town Water Pollution
Control Facility. (Atherton et al, 2005)
5-8
Biosolids Management
-------
September 2006
Emerging Technologies
Bucher Hydraulic Press
Objective:
Increase cake solids content in biosolids with
lower energy requirements than typical dewatering
processes.
Technology Summary
State of Development: Innovative
The Bucher hydraulic de-juicing press was tested side-by-side
with the existing belt filer presses on digested biosolids as well
as digested manure at the Inland Empire Utilities Agency (IEUA)
Regional Plant Number 1 (RP-1). The press was also tested at
the Big Bear Area Regional Wastewater Authority for dewatering
undigested oxidation ditch sludge.
The Bucher press is widely used in Europe and North America in
food and beverage processing applications. Industrial-scale trials
of hydraulic press sludge dewatering also have been conducted at
solids treatment plants in Switzerland and Germany.
Description:
The Bucher press is a hydraulic dejuicing press consisting of a cylinder and a moving piston that squeezes the sludge allowing
the water to pass through several filter elements made of porous cloth material. The sludge cake is retained inside the cylindrical
shell. After the sludge enters the cylinder, it is continuously squeezed by the piston, thereby achieving a high degree of mechanical
dewatering. Filtrate can be collected and discharged to the wastewater system.
Comparison to Established Technologies:
Side-by-side testing results with a belt filter press indicated that a hydraulic press can improve the biosolids and manure
cake solids content by more than 25% compared to the belt filter press. The chemical conditioning requirements for the
hydraulic press were similar to the belt filter press.
Available Cost Information:
Approximate Capital Cost: Not provided by vendor.
Approximate O&M Costs: Not provided by vendor.
Vendor Name(s):
Atkins Water
3020 Old Ranch Parkway, Suite 180
Seal Beach, CA 90740
Phone: 562-314-4231
Email: rupert.kruqer@atkinsalobal.com
Practitioner(s):
The following tested the technology but is not a current
practitioner.
Inland Empire Utilities Agency
Recycling Plant 1
2450 E. Philadelphia Avenue
Ontario, California 91761
Phone:909-993-1800
Fax: 909-947-2598
Biosolids Management
5-9
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Emerging Technologies
September 2006
Technology Summary
Bucher Hydraulic Press (Contd)
Key Words for Internet Search:
Hydraulic press, dewatering, sludge
Data Sources:
Kolisch G., M. Boehler, F.C. Arancibia, D. Pinnow, W. Krauss. "A new approach to improve sludge dewatering using a semi-
continuous hydraulic press system." Water Science Technology, 52:10-11(2005) 211-8.
Soroushian, R, Y. Shang, E.J. Whitman, and R. Roxburgh. "Biosolids and manure dewatering with a hydraulic de-juicing
press." Proceedings of the WEF/AWWA Joint Residuals and Biosolids Management Conference, Cincinnati, Ohio
(12-15 March 2006).
Hopper / fr-ish
sludge purnp
Bucher Hydraulic Press. (Soroushian et. al, 2006)
5-10
Biosolids Management
-------
September 2006
Emerging Technologies
DAB™ System
Objective:
Provide low-cost, low-maintenance dewatering.
Technology Summary
State of Development: Embryonic
More than 20 DAB™ systems are operating around the world; seven
are located in Quebec. Several are operating in Sweden, where
the technology originated. DAB™ system installed at the Bowhouse
Wastewater Treatment Works in Scotland has been operating
successfully for 7 years.
Description:
The DAB™ dehydration unit consists of a conical gravity flow filtration-drainer mechanism that separates sludge liquids and solids,
removing most of the free water from the sludge and producing a 90% solids product. The drainer consists of a double-walled
cylinder of fine mesh filter medium on a stainless steel frame.
The mechanism is immersed in flocculated sludge. The filtrate flows by gravity in the space between the medium. Additional
batches of flocculated sludge are added to the cone. The extra weight compresses the sludge at the base of the silo, increasing
solids concentration. The filter medium is kept clean by an internal high-pressure jet system. Batches can be added several times a
day, and thickened sludge withdrawn from the base of the tank. Depending on climate, it is not necessary to install the DAB™ unit
in a I
Comparison to Established Technologies:
Similar to an Imhoff tank with a vacuum filtration step to further reduce the water content of the solids.
Available Cost Information:
Approximate Capital Cost: $150,000 for a 10-m3 unit to $175,000 for a 25-m3 unit.
Approximate O&M Costs: $8-$12 per m3 of sludge treated.
A 10-m3 unit can dehydrate up to 130 m3/day (34,000 gal/day) of septic tank sludge, a 25 m3 unit can treat up to
240 m3/day (63,000 gal/day). Note: costs vary with currency conversion rate; consult with vendor for current cost
information. Construction and installation requires 2 to 3 months.
Vendor Name(s):
GSI Environment
855 Pepin
Sherbrooke, Quebec J1L 2P3
Phone:819-829-2717
Fax:819-829-2717
E-mail: sherbriiie@qsienv.ca
Practitioner(s):
No practitioner at this time.
Scottish Water
P.O. Box 8855
Edinburgh, Scotland EH106YQ
www.scottishwater.co.uk
Key Words for Internet Search:
DAB™ dewatering, GSI Environmental Quebec, biosolids, sludge.
Data Sources:
Vendor-supplied information
Rand, Chris (Editor). "East of Scotland Water cuts treatment costs." Published online in Engineeringtalk by Simon-Hartley
at www.enqineerinqtalk.com/news/sim/sim102.html. (21 August 2000).
Biosolids Management
5-11
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Emerging Technologies
September 2006
Technology Summary
Geotube® Container
Objective:
Provide on-site, low-maintenance, cost-effective
dewatering.
State of Development: Innovative
Geotextile tubes have been used in the past to contain and dewater
dredge materials from shipping harbors. Studies in California,
Georgia, Ohio, and New Hampshire have shown improved
dewatering of fine grained sewage sludge, successful containment of
odors during dewatering, reduction in effluent suspended solids, and
cost savings resulting from the use of Geotube® containers.
Description:
Geotube® brand geotextile tubes are comprised of high-strength polypropylene fabric and are fabricated to the project's
requirements. The tube is filled by a pumping system conveying sludge material. The geosynthetic tube retains fine-grain fill
material while allowing effluent water to permeate through the tube wall. With the addition of a chemical conditioning agent (i.e.,
a polymer), excess water drains from the Geotube® container through the geotextile resulting in effluent that is, according to the
manufacturer, clear and safe enough to be returned to the plant. Volume reduction within the container allows for repeated filling.
After the final cycle of filling and dewatering, retained fine grain materials continue to consolidate by desiccation because residual
water vapor escapes through the geotextile. The dried biosolids are removed from the tube when retained solids meet dryness
goals.
Comparison to Established Technologies:
A recent study of a Geotube® installation at a Midwestern WWTP stated that, compared to the previous year's belt press
operations, the Geotube® dewatering system required little to no operation and maintenance time. A belt press or centrifuge
requires full-time monitoring and constant adjusting with fluctuating influent conditions. However, if sufficient time is not
available for a Geotube® system to dewater stored biosolids, a mechanical dewatering technique may be required. With a
belt filter press, biosolids are open to the air where they can release odors or spill off the belt, and belt presses are often
noisy. The closed-loop Geotube system reduces odors, the potential for spills, and general biosolids handling. Geotube®
systems can be run through all seasons as long as the polymer delivery lines do not freeze. Mechanical dewatering
systems are often in climate-controlled buildings and freezing is not an issue.
Available Cost Information:
Approximate Capital Cost: Approximately $0.03/gallon of biosolids for the first 150,000 gallons. Includes one 60-ft-cir-
cumference by 100-ft-long Geotube® container, a polymer make-down system, 1,350 pounds
of polymer, bench testing, and technical assistance during start-up.
Approximately $0.02/gallon of biosolids for 250,000 gallons more. A more shear-resistant
polymer and an additional 60-ft by 100-ft Geotube® container were added to the system
described above for the subsequent 250,000 gallons of biosolids.
Approximate O&M Costs: Not Available.
Excavation, transportation, and disposal of dried solids were not included in calculation of project costs, as these costs
would fluctuate depending on the percent solids in the containers and final mass disposed of at the landfill.
5-12
Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Geotube® Container (Contd)
Vendor Name(s):
Miratech
A Division of Ten Gate Nicolon
3680 Mount Olive Road
Commerce, Georgia 30529
Phone:706-693-1897
Fax:706-693-1896
Website: www.qeotubes.com
Practitioner(s):
Saticoy Sanitary District
1001 Partridge Drive, Suite 150
Ventura, CA 93003-0704
Phone: 805-658-4605
City of Cambridge WWTP
Cambridge, OH
Phone: 740-432-3891
The vendor's website includes case studies for several
practitioners.
Key Words for Internet Search:
Geotube containers, geotextiles, thickening and dewatering, polymers, biosolids, sludge
Data Sources:
Mastin, B.J. and G.E. Lebster. "Dewatering with Geotube® Containers: A Good Fit For A Midwest Wastewater Facility?"
Proceedings of the WEF/AWWA Joint Residuals and Biosolids Management Conference, Cincinnati, Ohio.
(12-15 March 2006).
Miratech™ Division, Ten Gate Nicolon. 2006. Company website, www.qeotubes.com.
WaterSolve, LLC. 2006. Company website, www.qowatersolve.com/qeotube.htm.
Geotube* Container at Cambridge WWTP after
being filled with 250,000 gallons of biosolids.
(Mastin and Lebster, 2006).
The phases of Geotube9 Container operation. Image from Watersolve, LLC, 2006.
Biosolids Management 5-13
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Emerging Technologies
September 2006
Technology Summary
Electroacoustic Dewatering
Objective:
Enhance dewatering of biosolids by combining
electrical fields and ultrasound waves.
State of Development: Embryonic
Batelle Laboratories has conducted bench-scale studies on
electroacoustical dewatering, and as a result have designed a
commercial prototype belt filter press.
Description:
The combination of electrical fields and ultrasound waves has been shown to enhance dewatering. The electrical field allows for
increased electrophoresis and electroosmosis, and the acoustical force of the ultrasound waves help maintain electrical continuity
throughout the biosolids. It has also been shown in bench-scale studies that the ultrasonic waves decrease specific energy
consumption, increase the filtration rate, and reportedly help keep the cathode clean.
Comparison to Established Technologies:
Tests of the prototype on four different types of wastewater sludges showed solid contents were increased by 3.4% to
10.4%loverconventionaldewatering, with fin
Available Cost Information:
Approximate Capital Cost: Not available
Approximate O&M Costs: $19 to $27 per ton of dry solids
Operational cost estimate is based on the energy costs for a bench-scale study by Batelle Laboratories.
Vendor Name(s):
OilTrap Environmental
(markets Electro-Pulse)
2775 29th Avenue SW
Tumwater, WA98512
Phone: 360-943-6495
Fax:360-943-7105
E-mail: support (Sjoiltrap. com
Practitioner(s):
No practitioner at this time.
Key Words for Internet Search:
Electroacoustic dewatering, Electro-Pulse, electrodewatering, biosolids, sludge
Data Sources:
Abu-Orf, M., Muller, C.D., Park, C., and Novak, J.T. "Innovative Technologies to Reduce Water Content of Dewatered
Municipal Residuals." Journal of Residuals Science & Technology. 1:2 (2001) 83-91.
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Biosolids Management
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September 2006
Emerging Technologies
Electroosmotic Dewatering
Objective:
Enhance conventional dewatering using electric
current.
Technology Summary
State of Development: Embryonic
This phenomenon has been successfully used in the ceramics
industry for product dewatering, as well as in the construction
industry for soil dewatering at building foundations. Researchers
have used this process on a bench scale to dewater a variety
of agricultural products, including animal manure, without the
drawbacks of thermal water removal.
Description:
This technology uses an imposed electric field to force ionic particles in a biosolids mixture to migrate to their attractive electrodes.
Comparison to Established Technologies:
Not comparable to established technologies.
Available Cost Information:
Approximate Capital Cost: Not available
Approximate O&M Costs: Not available
Vendor Name(s):
Not available
Practitioner(s):
The following tested this technology but is not a current
practitioner.
Electric Power Research Institute (EPRI)
3412 Hillview Avenue
Palo Alto, CA 94304
Phone:800-313-3774
E-mail: askepri(5)epri.com
Key Words for Internet Search:
Electroosmotic dewatering, electrodewatering, biosolids, sludge.
Data Sources:
Electric Power Research Institute (EPRI). "Emerging Environmental Technologies: An Analysis of New Treatment
Technologies for the California Energy Commission." Palo Alto, California. California Energy Commission, Sacramento,
California. 1007411. (2003)
Biosolids Management
5-15
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Emerging Technologies
September 2006
Technology Summary
Membrane Filter Press
Objective:
Increases percent of solids in biosolids cake.
State of Development: Embryonic
According to one vendor of membrane filter press technology, their
press has been used in the following industries: chemical processing,
Pharmaceuticals, food product and ingredient manufacturers, wine
and juice producers, industrial waste dewatering and recycling.
Description:
Membrane filter presses operate on what the manufacturer calls the "variable chamber principle." The liquid biosolids are pumped
into a chamber. The clear filtered liquid passes through the filter cloth against a drainage surface built into the plate, just like on
a conventional filter press. Once the filtration step has been completed, the flexible membrane, or diaphragm, is inflated with
pressurized fluid, typically water, thereby compressing the formed filter cake. The final cake discharge volume is reduced in the
process.
Comparison to Established Technologies:
Not comparable to established technologies.
Available Cost Information:
Approximate Capital Cost: Not available
Approximate O&M Costs: Not available
Vendor Name(s):
Komline-Sanderson Engineering Corp.
12 Holland Avenue
Peapack, NJ 07077
Phone: 800-225-5457
Fax: 908-234-9487
E-mail: info(5)komline.com
Practitioner(s):
No practitioner at this time.
Key Words for Internet Search:
Membrane filter press, biosolids sludge
Data Sources:
Vendor-supplied information
5-16
Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Objective:
On-site dewatering for septic tanks and small
wastewater treatment plants.
State of Development: Embryonic
According to the manufacturer, the Simon Moos technology has
been successfully demonstrated to pump and dewater septic tanks,
grease traps, wastewater treatment plants, and various types of
industrial sludge.
Description:
The Simon Moos System consists of a dewatering container and a built-in or a separate pump and dosing plant. Dewatering of
sludge is achieved by the injection of polymer into the sludge as it is being pumped by the sludge pump or pressed through the
cyclone of the system's pump and dosing plant into the dewatering container. During this operation, polymer amounts are adjusted
to achieve the best sludge flocculation possible. Once separated, the water flows through a special set of filter nets installed inside
the container and out drain ports located on each side of the container. Solids remain inside the container until accumulation
requires dumping and disposal.
Comparison to Established Technologies:
Not comparable to established technologies.
Available Cost Information:
Approximate Capital Cost: Not provided by vendor
Approximate Capital Cost: Not provided by vendor
Vendor Name(s):
Simon Moos MaskinfabrikA/S
Kallehave 33, Horup
DK-6400 Sonderborg, Denmark
Phone: +45 74 41 0 51
Fax: +45 74 41 52 08
E-mail: MWtSjsimonmoos.com
Practitioner(s):
Nyk0bing Falster Wastewater Treatment Plant
Denmark
Key Words for Internet Search:
Simon Moos, mobile dewatering, biosolids, sludge.
Data Sources:
Vendor-supplied information
Biosolids Management
5-17
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Emerging Technologies
September 2006
Technology Summary
Tubular Filter Press
Objective:
Dewater and thicken inorganic sludges.
State of Development: Embryonic
The tubular filter press has primarily been used for dewatering
of mining waste waters. One pilot study showed that chromium
discharge to the environment in mine wastewater could be nearly
eliminated by concentrating the pollutants in the dried cake. The
tubular filter press also has been used to treat drinking water in
South Africa.
Description:
Sludge is pumped at a high velocity through a series of tube-shaped filter presses constructed of proprietary fabric. Cake from the
tube walls is then dislodged by a roller cleaning and the cake, in the form of flakes, is simultaneously transported out of the tubes,
drained, and conveyed to a collection hopper.
Comparison to Established Technologies:
Not comparable to established technologies.
Available Cost Information:
Approximate Capital Cost: Not available
Approximate O&M Costs: Not available
Vendor Name(s):
Explochem
P.O. Box 400
Ferndale, 2160, Gauteng, South Africa
Phone: +27 11 888-3926
Fax:+27 11 888-3942
E-mail: micheleb(5)explochem.co.za
Practitioner(s):
No practitioner at this time.
Key Words for Internet Search:
Tubular filter press, South African wastewater treatment, biosolids, sludge
Data Sources:
Coopman's, E.P.A., H.P. Schwarz, M.J. Pryor. "The dewatering of a mining sludge containing hexavalent chromium using a
tubular filter press - a South African development." Water Supply. 1:5-6 (2001) 371-376.
Vendor-supplied information.
5-18
Biosolids Management
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September 2006
Emerging Technologies
Mechanical Freeze-Thaw
Objective:
Increase the dewaterability of sludge without chemical
additives.
Technology Summary
State of Development: Embryonic
Pilot-scale demonstrations of nonmechanical freeze/thaw drying
beds have been successful in New York State. The mechanization of
the process in order to speed up the freeze/thaw cycles is still being
studied.
Description:
In freeze-thaw dewatering, the sludge is frozen using commercially available freezer equipment. The frozen sludge is crushed
and allowed to thaw naturally. Freezing alters the chemical bonds between the solids in the sludge and the water, making the
sludge more easily dewatered. The conditioned sludge is then processed using conventional sludge dewatering equipment.
Conditioning the sludge increases the amount of water that can be removed from the sludge. Testing has shown this technology to
be particularly successful with inorganic (e.g., alum and ferric iron) sludges.
Comparison to Established Technologies:
Similar to drying beds with refinements (addition of freezer equipment) which improves sludge dewatering.
Available Cost Information:
Approximate Capital Cost $250,000 - $1,500,000
Approximate O&M Costs: $26,000 - $960,000
The total installed cost of a freeze/thaw system is directly related to the amount of ice produced each day for use in
the freezing process. Fewer freezer plates will reduce the installation cost. Properly maintained residuals freezing and
refrigeration systems can be expected to provide many more years of service than the typical 10-year period assumed
for economic evaluation. Frequently, annual maintenance costs are estimated as a percentage of total plant equipment
cost, which has generally proven to be realistic and reasonable values. The above ranges of capital and O&M costs were
estimated for residuals production ranging from 2,500 to 40,000 gallons per day. This process is typically more cost-
effective in cooler climates where natural freezing may occur.
Vendor Name(s):
Not available
Practitioner(s):
The following tested the technology but is not a current
practitioner.
Electric Power Research Institute
3420 Hillview Avenue
Palo Alto, CA 94304
Phone: 650-855-2000
Key Words for Internet Search:
Freeze-thaw dewatering, mechanical freeze-thaw, biosolids, sludge
Data Sources:
Energy Power Research Institute (EPRI). Mechanical Freeze/Thaw and Wastewater Residuals: Status Report. Palo Alto,
California. TR-112063 (1998)
EPRI. Mechanical Freeze/Thaw and Freeze Concentration of Water and Wastewater Residuals: Status Report. Palo Alto,
California. WO-671002. (2001)
Biosolids Management
5-19
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Thermal Conversion
Thermal conversion processes are used to significantly reduce volume by oxidizing the
organic matter in the biosolids. Some treatment plants that use thermal conversion lower
their energy costs by recovering energy as a part of these processes.
Table 6.1 summarizes the state of development of thermal conversion technologies.
In the past, thermal conversion of wastewater residuals has often been equated with
incineration. However in recent years, some industries and municipalities have shown
interest in creating a usable product, such as fuel from their thermal conversion processes.
Four emerging thermal conversion technologies featured in this chapter—gasification,
melting furnace, sludge-to-oil and supercritical water oxidation—aim to produce a
usable end product. Both the reheat and oxidize (RHOX) process and oxygen-enhanced
incineration have improved conventional incineration by making it more efficient and/
or reducing air emissions. Molten salt oxidation has been used primarily for industrial
applications where the wastewater residuals are hazardous, or in areas where biosolids
must be destroyed.
Figure 6.1 includes an evaluation of the innovative technologies identified. A summary
sheet for each innovative and embryonic technology is provided at the end of this
chapter.
Biosolids Management
6-1
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Emerging Technologies
Table 6.1 - Thermal Conversion Technologies—State of Development
Combustion
« Fluidized-Bed Furnace
• Multiple-Hearth Furnace
Oxidation
« Wet Air Oxidation
Combustion
• Reheat and Oxidize (RHOX)
Oxidation
• Supercritical Water Oxidation
Vitrification
• Minergy
Combustion
« Molten Salt Oxidation
• Oxygen-Enhanced Incineration
Fuel Production
« Gasification
• Sludge-to-Oil
• SlurryCarb™
Oxidation
• Deep-Shaft Wet Air Oxidation (VERTAD™)
« Plasma Assisted Sludge Oxidation
Vitrification
« Melting Furnace
Figure 6.1 - Evaluation of Innovative Thermal Conversion Technologies
Reheat and Oxidize (RHOX)
Supercritical Water Oxidation
P,0
V,A
Minergy
V,R
e
e
B = Bench scale
D = Full-scale demonstrations in North
America
I = Full-scale industrial applications, with
demonstrations or pilots for municipal
sewage sludge
0 = Full-scale operations overseas
N = Full-scale operations in North America
P = Pilot
F = Few plants
I = Industrywide
L = Primarily large plants
S = Primarily small plants
A = Produces Class A biosolids
C = Capital savings
0 = Operational/maintenance savings
F = Produces high-nutrient fertilizer
M = Minimizes odors
R = Provides beneficial use (nonagricultural)
V = Sludge volume reduction
A = Agriculture
C = Construction
N/A = Not Applicable
P = Power
A Positive feature
0 Neutral or mixed
T Negative feature
6-2
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September 2006
Emerging Technologies
Reheat and Oxidize (RHOX)
Objective:
Decrease fuel usage and air emissions from biosolids
incineration furnaces.
Technology Summary
State of Development: Innovative
The first RHOX installation at a wastewater treatment plant used
a shell and tube heat exchanger to preheat the scrubbed gasses
on their way to the afterburner. This unit, located in Willow Grove,
Pennsylvania, has operated for almost 10 years.
Description:
Hot (1,500°F) afterbumed gases are passed down through a bed of ceramic forms. In doing so, the heat content of the gas is
transferred to the ceramic mass and the gas is cooled (to about 250°F) for discharge to the atmosphere. Cold, dust-free gas from
the afterburner pollution control equipment is passed up through another bed of ceramic forms, which has previously been heated
with afterburner gas. Here, the cold gas is preheated to a temperature approaching the afterburner requirement by extracting
the heat previously stored in the mass of ceramic forms. A small quantity of fuel is burned in the afterburner to reach the required
temperature. The hot and cold gases pass back and forth through two or more beds to achieve preheating and cooling.
Comparison to Established Technologies:
Technology designed to reduce emissions. Not similar to any other established technology.
Available Cost Information:
Approximate Capital Cost: Not available
Approximate O&M Costs: Not available
Vendor Name(s):
Chavond-Barry Engineering Corporation
400 County Road 518, P.O. Box 205
Blawenburg, NJ 08504
Phone: 609-466-4900
Fax:609-466-1231
Practitioner(s):
Upper Moreland Hatboro Joint Sewer Authority
2875 Terwood Road
Willow Grove, PA
Additional practitioners are available from the vendor.
Key Words for Internet Search:
RHOX process, sludge, biosolids, reheat, oxidize
Data Sources:
Vendor-supplied information
Biosolids Management
6-3
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Emerging Technologies
September 2006
Technology Summary
Supercritical Water Oxidation
Objective:
Reduce the volume of biosolids using the physical
properties of water.
State of Development: Innovative
Application of the process in industrial and wastewater treatment
facilities is ongoing. The first two units were installed at the Harlingen,
Texas, wastewater treatment facility in July 2001 for use in a pilot
study.
Description:
Water is heated and pressurized above the critical point [374°C and 3,191 pounds per square inch (psi)] and the solubility of
organic substances and oxygen into water is significantly increased. Supercritical water oxidation technology takes advantage of
this characteristic to completely decompose organic substances. This technology produces a high-quality effluent and is capable of
producing Class A biosolids. Supercritical water oxidation also may be referred to as "hydrothermal oxidation."
Comparison to Established Technologies:
Not similar to established technologies.
Available Cost Information:
Approximate Capital Cost: $3,500,000
Approximate O&M Costs: $160—$295 per dry ton
Capital and O&M costs are for the system installed at the Harlingen Water Works System wastewater treatment facility in
July 2001. O&M costs include seven major components: oxygen (55.3%), natural gas (12.5%), labor-operators (12.4%),
electrical (8%), solids disposal (6%), maintenance (5%), and expendable chemicals (0.5%).
Vendor Name(s):
HydroProcessing LLC
3201 Longhorn Blvd., Suite 101
Austin, TX 78758
Phone: 512-339-9981
E-mail: info(S)hvdroprocessina.com
Practitioner(s):
The following was the site of a demonstration facility but is not
currently a practitioner:
Harlingen Water Works System
134 East Van Buren
Harlingen, TX 78550
Phone:956-430-6100
Fax: 956-430-6111
www.hwws.com
Key Words for Internet Search:
Supercritical water oxidation, SCWO, biosolids, sludge
Data Sources:
Bartholomew, R. Conversion of Biosolids: An Innovative Alternative to Sludge Disposal. Pennsylvania Department of
Environmental Protection. (October 2002).
Kelly, H.G. Emerging Technologies in Biosolids Treatment. Dayton & Knight Ltd., West Vancouver, Canada. (2003)
6-4
Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Objective:
Convert biosolids into construction material and
industrial feed stocks that are inert and marketable.
State of Development: Innovative
Minergy's GlassPack® Demonstration Unit in Winneconne,
Wisconsin, built in 2000, is a 12-dry-tons-per-day commercial-scale
system available to demonstrate Minergy's GlassPack® technology.
Solids from several wastewater treatment plants have been
processed at the facility on trial bases. There are operational systems
using pulp and papermill sludges.
Description:
Minergy gives the following description of the three-zone operation of the GlassPack vitrification system:
Zone 1 Melting and Combustion. Feedstock that has been predried to approximately 90% solids or more is injected along with
air or synthetic air into the Zone 1 chamber. In this zone, the organic component of the sludge is completely combusted, liberating
a significant amount of heat energy. In a closed-loop oxygen-enhanced application, this energy release results in temperatures of
approximately 2,400° to 2,700°F. At these high temperatures, the mineral (ash) component of the feedstock melts to form a pool of
molten glass at the bottom of the Zone 1 chamber. The high-temperature environment provides very high destruction efficiencies of
any organic compounds that may be contained in the feedstock.
Zone 2 Phase Separation. Phase separation of the molten glass and exhaust gas occurs by gravity draining the molten glass from
Zone 1 through a drain port on the bottom of the Zone 2 chamber. The molten material drops into a quench tank and is cooled into
the glass aggregate product. The exhaust gas is directed out of Zone 2 through a refractory-lined duct into Zone 3.
Zone 3 Gas Cooling. The exhaust gas from Zone 2 is 2,400°F to 2,700°F and is cooled through dilution mixing with lower
temperature gases obtained external to the melter. Reducing the temperature offers two important cost-saving advantages.
This system can eliminate refractory-lined ductwork exterior to the melter and can cool carry over particulate below its softening
point, thus eliminating ductwork fouling. The temperature of the Zone 3 exit gas is dependent on the selection of heat recovery
technology, but is typically in the range of 700° to 1,400°F. Higher exit gas temperature can provide for higher efficiencies in heat
recovery systems.
Comparison to Established Technologies:
Similar to the Melting Furnace, an innovative technology. Minergy claims the GlassPack® process eliminates the need
to co-fire fuel to achieve vitrification and provides significant environmental air emissions improvement over current
combustion technologies due to the closed-loop design. In contrast to traditional incineration-type techniques, ash disposal
is not necessary because the final end product is a glass aggregate that has many uses including sandblasting grit, roofing
shingle granules, and asphalt paying.
Available Cost Information:
Approximate Capital Cost: $104,000
Approximate O&M Costs: $97,000
Cost estimates are for 7.5-ton-per-day glassification unit coupled to a thermal dryer with a minimum size of 20 dry tons per
day. Estimates are from a cost analysis performed for Eastern Municipal Water District, California, and assume a 20-year
life cycle and the costs associated with providing adequate facilities for this time period.
Vendor Name(s):
Minergy Corporation
1512 S. Commercial Street
Neenah,Wl 54956
Phone:(920)727-1919
E-mail: infotgjminerqv.com
www.minerqy.com
Practitioner(s):
Minergy Corporation Vitrification Technology Center
200 Tower Road
Winneconne, Wl 54986
Minergy Corp. Fox Valley Glass Aggregate Plant
231 Millview Drive
Neenah,Wl 54956
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Minergy (Contd)
Key Words for Internet Search:
Vitrification, Minergy, glassification, GlassPack®, biosolids, sludge
Data Sources:
Baudhuin, T, T. Carroll, and R. Paulson. 2005. Vitrification: A Sustainable Biosolids Management Alternative. Proceedings of
the WEFTEC: The Water Quality Event, Washington, D.C.
(30 October - 2 November 2005) 659-666.
Kilian, R.E., A.C. Todd, A.K. Wason, M. Luker, J. Jannoni, J.D. Wall. (2003). "How to Put One Egg in Multiple Baskets."
EMWD's Regional Biosolids Management Approach Makes Sense. Proceedings of the WEF/AWWA/CWEA Joint Residuals
and Biosolids Management Conference, Baltimore, Maryland, USA. (19-22 February 2003).
Vendor website
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Biosolids Management
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September 2006
Emerging Technologies
Molten Salt Incineration
Objective:
Eliminate or reduce biosolids volume.
Technology Summary
State of Development: Embryonic
This treatment system is favored for wastes contaminated with both
chlorinated organics and heavy metals such as cadmium, chromium,
zinc, etc. Industrial applications of this technology have been in use
on a small scale since the 1950s.
Description:
The Molten Salt Oxidation (MSO) process uses a sparged liquid bed of alkaline salt contained in a reaction vessel. The process
is based on the catalytic action of alkaline molten salts for the oxidation of organic materials. The molten salt bed acts as a heat
transfer and reaction media. Sufficient heat is liberated by the oxidation reaction to maintain the molten salt bed at a temperature of
900°to1,000°C.
Comparison to Established Technologies:
Not similar to established technologies.
Available Cost Information:
Approximate Capital Cost: Not available
Approximate O&M Costs: $1,1507metric ton treated (Australian dollars)
Generally, the cost of treatment with this technology is relatively high because of the high capital cost of the equipment, the
labor requirements, and the high energy cost. The cost per ton depends on the feed rate of the contaminant to the furnace.
The above O&M cost estimate was provided for hazardous waste sludges at a feed rate of 1,000 kilograms per hour, and
it does not include effluent treatment costs, residuals and waste shipping costs, handling and transport costs, analytical
costs, and site restoration costs.
Vendor Name(s):
None identified
Key Words for Internet Search:
Molten salt oxidation, sludge
Practitioner(s):
No practitioner at this time.
Data Sources:
CMPS&F Environmental. Appropriate Technologies for the Treatment of Scheduled Wastes. Review Report Number 4.
(November 1997)
Biosolids Management
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Emerging Technologies
September 2006
Technology Summary
Oxygen-Enhanced Incineration
Objective:
Improve the performance of biosolids and industrial
sludge furnaces.
State of Development: Embryonic
Praxair, Inc., claims successful operations in both municipal and
industrial incineration applications with its Oxygen Combustion
System (DCS).
Description:
A small amount of oxygen is added through an annulus around the fuel tube of the furnace to promote flame stability and consistent
destruction efficiency during variations in feed material. Typical temperatures with air combustion are about 3,000°F (1,649°C),
whereas temperatures with conventional oxygen-enriched systems can rise to 5,000°F (2,760°C), thereby reducing incomplete
combustion.
Comparison to Established Technologies:
Reaches higher temperatures than conventional oxygen-enriched furnaces.
Available Cost Information:
Approximate Capital Cost: Not provided by vendor.
Approximate O&M Costs: Not provided by vendor.
Vendor Name(s):
Praxair, Inc.
39 Old Ridgebury Road
Danbury, CT 06810
Phone: 716-879-4077
Fax:716-879-2040
www.praxair.com
Practitioner(s):
No practitioner at this time.
Key Words for Internet Search:
Praxair, oxygen-enhanced incineration, oxygen injection, biosolids, sludge.
Data Sources:
Vendor-supplied information.
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Biosolids Management
-------
September 2006
Emerging Technologies
Technology Summary
Objective:
Reduce the volume of biosolids and produce gas that
can be used to generate electricity.
State of Development: Embryonic
Recovery of biomass-derived gas for use as a fuel source has
been used for industrial, wood and agricultural wastes in the United
States for more than 50 years. It was used for production of coal
gas for over 200 years. However, gasification of biosolids is a new
application and there are no full-scale facilities operating in the
United States. Industrial sludges have been successfully gasified at
facilities in the United States. In 2002, the Balingen Sewage Works,
Germany, started operation of a sewage sludge gasification plant
as a demonstration study. Since 2004, it has been operating as a
full-scale facility.
Waste to Energy Limited (United Kingdom) has patented a
gasification system for the production of electricity. The company
conducted a demonstration project with Anglian Water in the
United Kingdom, and reports having an agreement with Kwikpower
International to build biosolids gasification plants in Morocco.
Description:
The gasification process converts sludge or biosolids into a combustible gas, referred to as synthesis gas, or "syngas," which can
be recovered. While incineration fully converts the input waste into energy and ash, gasification heats the material under controlled
conditions, deliberately limiting the conversion so that combustion does not take place directly. Syngas can be used as a fuel to
generate electricity and heat. The fuel value of Syngas is not typically as high as that of digester gas, perhaps 60% of digester gas
energy values.
The gasification process takes place in two steps: pyrolysis and partial combustion. Pyrolysis is the degradation of biosolids in
the absence of air, into a gas and a black, carbon-rich substance called "char." In the second reaction, the char is gasified by
partial combustion in the presence of oxygen or air to produce the syngas described above. Due to the concentrating effect of the
constituents in the original biosolids, the remaining char will require disposal, probably in a landfill.
Comparison to Established Technologies:
Similar to pyrolysis of other organic substances such as coal gasification.
Available Cost Information:
Approximate Capital Cost: Not provided by the vendor
Approximate O&M Costs: Not provided by the vendor
Studies have shown that gasification is technically feasible, but project costs are typically higher than conventional
alternatives and not based on any full-scale operations. Data on true capital cost and operating costs for "real-world"
applications are unavailable. Vendor-supplied literature suggests one kilogram of waste will typically produce one kilowatt
of electricity and two kilowatts of heat. At this time, no full scale facilities are operating in the United States to verify these
claims in actual operations.
Biosolids Management
6-9
-------
Emerging Technologies
September 2006
Technology Summary
Gasification (Contd)
Vendor Name(s):
Waste to Energy Limited
Borley Green
Sudbury, England C0107AH
Phone:+44 1787 373007
Fax:+44 1787 373535
E-mail: info(5)waste-to-enerqv.co.uk
www.wastetoenerqy.co.uk
US Centrifuge
4011 Championship Drive
Indianapolis, IN 46268
Phone: 800-899-2040
www.uscentrifuqe.com
KopfAG
Stutzenstrasse 6
72172Sulz-Bergfelden
Germany
www.kopf-ag.de
info@kopf-aq.de
Practitioner(s):
Anglian Water
P.O. Box 770
Lincoln, England LN5 7WX
Phone:+44 1522 341922
www.anqlianwater.co.uk
Key Words for Internet Search:
Sewage sludge, gasification, waste-to-energy, bioenergy.
Data Sources:
KMK Consultants Limited. City of Toronto Biosolids and Residuals Master Plan. In association with Black & Veatch Canada.
(September 2004).
Gasification Technologies Council website, www.qasification.org
Water Environment Federation, Bioenergy from Wastewater Treatment - A Clean, Affordable Energy Source. Alexandria, VA
(2006).
Vendor-supplied information
6-10
Biosolids Management
-------
September 2006
Emerging Technologies
Sludge-to-Oil
Objective:
Produce a commercially marketable oil product from
biosolids.
Technology Summary
State of Development: Embryonic
ThermoEnergy Corporation, in conjunction with another contractor,
operated a 5-MGD sludge-to-oil demonstration project in Colton,
California, for two years. The project closed in November 2000 and
the vendor is focusing on other technologies.
Enersludge™ process was built at the Subiaco WWTP, Perth,
Australia, in 1999. It operated for 4 months before being shut down
when the oil product was deemed unsuitable for diesel engines.
Description:
This technology uses an enhanced pyrolysis process that through specified pressures and catalysts can produce lightweight oils of
varying viscosities.
One such process is the ThermoFuel process marketed by ThermoEnergy Corporation in Little Rock, Arkansas. The company
claims ThermoFuel allows wastewater treatment plant operators to meet all water quality standards, produce a product that meets
Class A biosolids standards, and improve process efficiency at a lower cost without increasing the size of the plant.
Comparison to Established Technologies:
Not similar to established technologies.
Available Cost Information:
Approximate Capital Cost: $3,000,000
Approximate O&M Costs: Not available
Capital cost estimate is based on the approximate cost of the 5-MGD Colton, California, demonstration project described
above.
Vendor Name(s): Practitioner(s):
ThermoEnergy Corporation No practitioner at this time.
323 Center Street, Suite 1300
Little Rock, AR 72201
Phone: 501-376-6477
E-mail: technoloav(5)thermoenerav.com
Key Words for Internet Search:
Sludge-to-oil, biosolids-to-oil, ThermoEnergy, ThermoFuel
Data Sources:
Kelly, H.G. Emerging Technologies in Biosolids Treatment. Dayton & Knight Ltd., West Vancouver, Canada. (2003)
Vendor-supplied information.
Biosolids Management
6-11
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Emerging Technologies
September 2006
Technology Summary
SlurryCarb™ Process
Objective:
Convert biosolids into a renewable fuel. For a dried
product, a drying process must be added.
State of Development: Embryonic
Construction is scheduled to start in 2006 on a 675 wet tons per
day facility in Rialto, California, that will incorporate the SlurryCarb™
process plus biosolids drying. The dried product from the facility,
scheduled to begin full-scale operations in 2008, is intended to be
used as fuel by a cement kiln. It is estimated that the facility will
produce 140 dry tons of product per day.
Description:
Cake of between 20 and 30% solids are first macerated to create a feedstock of particles of less than 1/2 inch. The
macerated solids are pressurized to above the saturated steam pressure, heated to approximately 450°F (232°C) and then
fed to a reactor where temperature and pressure are maintained. The elevated pressure and temperature cause the cells to
rupture and release carbon dioxide gas. This "carbonization" step causes the solids to lose their affinity for water. Following
this carbonization step, the material is put through a centrifuge to separate off the liquid filtrate. Trace contaminants are
removed from the filtrate and the purified water is recycled to the slurry preparation phase of the process or discharged.
The carbonized material can then be dewatered to greater than 50% solids. The dewatered product can either be managed
directly as slurry or further dried. The vendor reports plans to use the final product as a fuel supplement in operations such
as cement manufacturing and pulverized coal boilers.
Comparison to Established Technologies:
The SlurryCarb™ process operates at a lower temperature and pressure, and for a shorter reaction time, than pyrolysis.
It produces an energy-rich carbon product, but no gases or oils like pyrolysis. The SlurryCarb™ process also operates
at a lower temperature and pressure, and for a shorter reaction time than typical wet air oxidation, and no air is added
to partially oxidize the organics in the biosolids. SlurryCarb™ also differs from the Carver-Greenfield® process in that the
SlurryCarb™ process does not add anything to the biosolids and does not evaporate water. However, if a dried product is
necessary, evaporative drying would have to be added. Drying will probably be required due to very limited use for a
50% solids slurry.
Available Cost Information:
Approximate Capital Cost: Not provided by the vendor
Approximate O&M Costs: Not provided by the vendor
Vendor Name(s):
EnerTech Environmental, Inc.
675 SeminoleAve., Suite 207
Atlanta, GA 30307
Phone: 404-355-3390
Fax: 404-355-3292
Email: slurrvcarbtgjenertech.com
Website: www.enertech.com
Practitioner(s):
City of Rialto
Public Works Department
335 W. Rialto Avenue
Rialto, CA 92376
Phone: 909-820-2608
Email: publicworks(5).rialtoca.qov
6-12
Biosolids Management
-------
September 2006
Emerging Technologies
Technology Summary
SlurryCarb™ Process (Contd)
Key Words for Internet Search:
SlurryCarb™, biosolids, sludge, carbonization, renewable fuel
Data Sources:
EnerTech Environmental, Inc. Company Information Packet: The SlurryCarb™ Process. (2006) Available at
www.enertech.com.
EnerTech Environmental, Inc. "Converting Biosolids to a Usable Fuel: The Emerging Technology of Biosolids Carbonization
-The Rialto Regional Biosolids Facility." Presentation to CIWMB, (12 May 2005).
Kearney, R.J. and K.M. Bolin. "Using the New SlurryCarb™ Process Prior to Drying: How to Save Money and Achieve
Permanent Recycling of Biosolids." Proceedings of the WEF/AWWA Joint Residuals and Biosolids Management
Conference, Cincinnati, Ohio. (12-15 March 2006).
Slimy Preparation
Hre received, and if required.
i3Tv:i:er5d to ::>c: solids Tbis becomeE
me feed sluiry for rite process.
Biosolidi at 20°r iolids
Step 5: Detvatering
Excess moisture ii removed from :ae
carbonized produce to form a sinnr fasi
and dewatered uiecianciaLly TO 50° o.
Aiso. carbonized produce may be
to rejnm'e Trace
: Filtrate Recycle
Trjce CDLKauiLLaiit; Jiie cliLorides.
Dissolved solids. BOD, COD. are
removed from SJcra^e utilizmg a
LiEb-iLear membiane :ecliro!o=y.
Sludge from :JT precre^bjaeiLt::
addei :o [be fuel pioduci-
Step 7: Combustion
The carbonized slurry fuel ss cried.
peLle-.zed or kept in slurry form and
transported and Transported to tie
cu=.ioLLier to re u:;l:zed of:"-=-tte
Steo 2: Slurry Pre^m izntion
Feed il'.irn' ;i coutLU'.ioMiLy jiEiitrizei v.::b
pump TO ia3m;au: li^Tiid conditions \vhei
heated.
. be pteiE-nrized iLr.tr>' i=. trousbt to
Temperanie :iuou=jlL ieat excnauEe T.v:±
reaction products 3nl an external iieat source.
4: Reaction
la reacTor cxysen sronp= from
the lob'd sl'.Tjry are removed ••'•.
carbon dioxjde gas snd cilorin-
ated orsanics sre decomposed
to ioltible salts.
SlurryCarb™ process flow diagram from EnerTech Environmental, Inc. (2005)
Biosolids Management
6-13
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Emerging Technologies
September 2006
Technology Summary
Deep-Shaft Wet Air Oxidation (VERTAD™)
Objective:
Increases energy efficiency and produces Class A
biosolids.
State of Development: Embryonic
The last trial of this technology related to biosolids was at King
County's Renton Wastewater Treatment Plant, Washington.
Description:
Deep-Shaft Wet Air Oxidation is an autothermophilic aerobic digestion process that treats sludge in a subsurface
autothermophilic reactor that is 250-350 feet deep. The VERTADTM vendor's website describes three reactor zones that
function as follows:
Oxidation Zone: The top of the shaft where the sludge digestion takes place.
Mixing Zone: Feed sludge and air are introduced in this zone. Air provides oxygen and mixing. Solids separation is through
flotation thickening.
Saturation Zone: Stabilized biosolids removed from the reactor flow through the saturation zone where high temperature
and long residence time occur."
High oxygen transfer efficiency promotes rapid digestion of sludge. Pathogen-free Class A biosolids are produced in four
days. Thickened biosolids can be dewatered to 30%-35% solids and reduced polymer usage. Offgas is separated and
treated in a fixed-film biofilter.
Comparison to Established Technologies:
Similar to vertical reactors that have been used for wastewater treatment for 25 years. VERTAD™ has a small footprint and
is largely underground. Therefore they are less visible than surface tankage.
VERTAD™ achieves 40% volatile solids (VS) reduction in 4 days in comparison to conventional anaerobic digestion
systems that require up to 30-day retention times for a 55% VS reduction.
Available Cost Information:
Approximate Capital Cost: Capital cost lower than conventional autothermal thermophilic aerobic digestion (ATAD) plant
of similar size.
Approximate O&M Costs: Not Available
Low energy requirements: 1.27 kW.hr/kg VS destroyed
Low polymer requirements: 14lb/ton
Vendor Name(s):
NORAM Engineering and Construction, LTD
Suite 400-200 Granville Street
Vancouver BCV6C1S4
Phone:604-681-2030
Fax:604-683-9164
www.noram-enq.com
Practitioner(s):
The following was the site of a trial facility but is not currently a
practitioner:
Technology Assessment and Resource Recovery
King County
201 South Jackson Street
Mail Stop: KSC-NR-0512
Seattle, WA 98104
Phone:(206)684-1255
Fax: (206) 684-2057
6-14
Biosolids Management
-------
September 2006
Emerging Technologies
Technology Summary
Deep-Shaft Wet Air Oxidation (VERTAD™) (Contd)
Key Words for Internet Search:
VERTAD™, deep-shaft, wet air oxidation, biosolids
Data Sources:
Vendor-supplied information.
Thickened \
Sludge /
CompfMiOf
*r ^>
-------
Emerging Technologies
September 2006
Technology Summary
Plasma Assisted Sludge Oxidation
Objective:
Significant volume reduction through combustion.
State of Development: Embryonic
The process was pilot tested by LTEE, Hydro-Quebec's research
facility, for approximately 2 years using industrial, municipal, and
farming feedstocks.
Description:
Plasma assisted sludge oxidation uses a rotary oven operating at between 600° and 700°C at atmospheric pressure. The oven
is equipped with an air plasma arc torch. The plasma arc generates ultraviolet radiation and ionic radicals to sustain oxidation.
A plasma plume is used to catalyze oxidation of wet sludges at relatively low temperatures. The vendor claims low operating
temperatures result in high combustion efficiency. Feed solids can have a solids content as low as 20% but operating efficiencies
are directly related to the solids content. The process results in an ash to be used or disposed. Combustion can reach autothermal
operation if feed solids have a high enough energy value [estimated at 20,000 millijoules per dry ton (mJ/dry ton)].
Comparison to Established Technologies:
Not similar to established technologies.
Available Cost Information:
Approximate Capital Cost: Not available
&M Costs: Not aailab le
Vendor Name(s):
Fabgroups Technologies, Inc.
1100 St. Amour
St. Laurent, Quebec, Canada H4S 1J2
Phone: 514-331-3712
Fax: 514-331-5656
Email: tmulhern@fabciroups.com
Practitioner(s):
No practitioner at this time.
Key Words for Internet Search:
Plasma assisted oxidation, biosolids, sludge
Data Sources:
Mulhern, T. and M. Bacon. "Full Scale Demonstration of Plasma Assisted Sludge Oxidation." Proceedings of the 2006 WEF
Residuals and Biosolids Management Conference, Cincinnati, Ohio. (12-15 March 2006).
6-16
Biosolids Management
-------
September 2006
Emerging Technologies
Melting Furnace
Objective:
Reduce the volume of biosolids and industrial wastes
by heating them to extremely high temperatures while
producing potentially usable by-products.
Technology Summary
State of Development: Embryonic
Full-scale melting furnaces have been in operation in Japan for more
than 20 years. This is primarily due to the lack of available space for
land application or surface disposal of municipal biosolids. Similar
melting furnaces have been used to melt industrial sludges as well.
As of 2003, the Ebara Corporation was operating two small plants
using the Meltox technology that had been in operation for nearly
4 years. In addition, the Ministry of Housing and Local Government
in Malaysia decided in 2003 to construct a large TwinRec thermal
waste treatment plant for municipal waste.
Description:
The Ebara Corporation of Japan has developed the Meltox (called TwinRec in Europe) biosolids melting and ash
incineration technology. This process melts biosolids at temperatures exceeding 1,300°C and produces a marketable
by-product. The furnace is fluidized bed gasification unit comprising a vertical primary combustion chamber, an inclined
secondary combustion chamber, and a slag outlet section. Biosolids are blown into the furnace with compressed air, where
they are incinerated and melted during a spiral descent. A plate at the outlet maintains a steady flow of slag, which is cooled
by water or air before discharge. Flue gas is separated and treated to reduce odors and sulfur oxide (S0x) emissions. The
slag can be used in various ways, such as for filling material, tiles for pavement and roads, interlocking blocks, terrazzo
tiles, and other construction materials.
Comparison to Established Technologies:
Similar to fluidized bed furnace except that it can operate at higher temperatures. Similar to innovative vitrification furnace.
Available Cost Information:
Approximate Capital Cost: Not available
Approximate O&M Costs: Not available
Vendor Name(s):
Ebara Corporation
1-6-27, Konan, Minato-ku
Tokyo, 108-8480 Japan
Phone: +81-3-5461-5585
Fax:+81-3-5461-5784
Website: www.ebara.ch
Practitioner(s):
A list of practitioners using Ebara Corporation melting furnace
technologies in Asia is available online at:
www.ebara.ch/twinrec.php?n=1
Key Words for Internet Search:
Melting furnace, biosolids, sludge, Meltox
Data Sources:
Selinger, A., S. Steiner, K. Shin. "TwinRec Gasification and Ash Melting Technology - Now also established for Municipal
Waste." 4th Int'l Symposium on Waste Treatment Technologies. Ebara Corporation, Zurich. (2003)
Japanese Advanced Environment Equipment. Meltox Sludge Melting System. Global Environment Centre Environmental
Technology Database NETT21. (2002)
Vendor-supplied information.
Biosolids Management
6-17
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-------
•,< I;-" v5vV;t1;."*'•:'"V".~<
f:'.''i ,'.•.•'.'. ;;'":'•'
:.;, ^''"'^1'
"
Drying
The objective of the drying process is to remove water from biosolids producing a relatively
high percent solids, and to reduce weight and volume of the biosolids. This is usually
accomplished with either a direct or indirect heat source. Drying can produce marketable
products that meet Class A standards. It also dramatically reduces transportation costs if
long distance hauling is involved.
Table 7.1 summarizes the state of development of drying technologies. This table includes
three innovative heat-drying technologies. Belt, flash, and microwave drying all have been
successfully operated in Europe and pilot-tested in the United States.
Figure 7.1 includes an evaluation of the innovative technologies identified. Summary
sheets for each technology categorized as innovative or embryonic technology are
provided at the end of this chapter.
Table 7.1 - Drying Technologies—State of Development
Direct Drying
Flash Drying
Indirect Drying
Belt Drying
Direct Microwave Drying
Flash Drying
Fluidized Bed Drying
Chemical Drying
Multiple Effect Drying
« Carver-Greenfield (case studies have shown technology to
be not viable in the United States. No technology summary is
provided.)
Biosolids Management
7-1
-------
Emerging Technologies
Figure 7.1 - Evaluation of Innovative Drying Technologies
Belt Drying
Direct Microwave Drying
D
C,0,V,A,R
A,P
Flash Drying
B,P
C,0,V,A,R
A,P
Centrifuge and drying
process in one.
Fluidized Bed Drying
0
C,0,V,A,R
A,P
e
e
e
e
B = Bench scale
D = Full-scale demonstrations in North
America
I = Full-scale industrial applications, with
demonstrations or pilots for municipal
sewage sludge
0 = Full-scale operations overseas
N = Full-scale operations in North America
P = Pilot
F = Few plants
I = Industrywide
L = Primarily large plants
S = Primarily small plants
A = Produces Class A biosolids
C = Capital savings
0 = Operational/maintenance savings
F = Produces high-nutrient fertilizer
M = Minimizes odors
R = Provides beneficial use (nonagricultural)
V = Sludge volume reduction
A = Agriculture
C = Construction
N/A = Not Applicable
P = Power
. Positive feature
0 Neutral or mixed
' Negative feature
7-2
-------
September 2006
Emerging Technologies
Belt Drying
Objective:
Drying of biosolids to 90% or more solids.
Technology Summary
State of Development: Innovative
A BioCon® dryer has been in operation at the Bronderslev WWTP
in Denmark since 1995. The first operating US facility will be Mystic
Lake, Minnesota.
A HUBER KULT® dryer for wastewater sludge is under construction
in Germany. There is also a HUBER KULT® dryer in operation in
Germany for drying water treatment plant residuals.
Description:
This technology is composed of two or more slow moving belts in series with air supplied through or around the belts. Dewatered
sludge is spread in a thin layer on the first belt to maximize surface area. Preheated air is either blown through the belts or pumped
into the area surrounding the belts.
In the BioCon® dryer, temperatures ranges from 350°F at its hottest down to 175°F as the biosolids complete the drying process.
The residence time in the dryer is more than 60 minutes, thereby exceeding Class A pathogen reduction requirements. An add-on
process called the Energy Recover System (ERS), uses the fuel value of the dried product to generate energy used in the drying
process.
Comparison to Established Technologies:
The BioCon® dryer is operated at a low negative pressure to minimize odor and dust generation often associated with
biosolids drying technologies.
Available Cost Information:
Approximate Capital Cost: Not provided by the vendor.
Approximate O&M Costs: Not provided by the vendor.
Vendor Name(s):
Kruger, Inc.
401 Harrison Oaks Blvd., Suite 100
Gary, NC 27513
Phone:919-677-8310
Fax: 919-677-0082
Huber Technology
9805 North Cross Center Court
Suite H
Huntersville, NC 28078
Phone:704-949-101
Website: www.huber-technoloqy.com
Practitioner(s):
Mystic Lake, Minnesota
Biosolids Management
7-3
-------
Emerging Technologies
September 2006
Technology Summary
Belt Drying (Contd)
Key Words for Internet Search:
BioCon, ERS, Huber Technology KULT®, biosolids, sludge, drying
Data Sources:
Frewerd, B. "Harnessing the Power of Biosolids." Published by Kruger Inc., a division of Paris-based Veolia Water Solutions
& Technologies. (2006).
Vendor websites.
Air/Air Heat
Exchanger
BioCon9 Process Flow Diagram (Frewerd, 2006).
BioCon9 ERS Unit
(Photo courtesy of Kruger USA).
KULT® dryer schematic
(Huber Technology website 8 August 2006).
7-4
Biosolids Management
-------
September 2006
Emerging Technologies
Direct Microwave Drying
Objective:
Remove excess water from waste activated sludge and
reduce pathogens.
Technology Summary
State of Development: Innovative
Burch BioWave® is in use in Ireland and Fredericktown, Ohio. Anew
installation will be on line in Zanesville, Ohio, in fall 2006.
Description:
Burch BioWave® is a patented continuous flow process that uses a duel-fueled microwave system to remove water and pathogens
from dewatered sludge. The process utilizes a high-efficiency multi-mode microwave system specifically designed to remove
moisture. Microwaves vibrate water molecules and the resulting friction heats the water. BioWave® uses heated air forced through
the biosolids to evaporate the moisture released by the microwaves. The air is heated by either natural gas, liquified petroleum gas
(LPG), or digester gas.
The equipment comes in various sizes, each with the ability to dry a certain throughput of material. The process is completely
automated and can dry biosolids with an initial moisture content of 85% to a final product with 10% moisture content. Tests show
100% pathogen kill without any change in nutrient content.
Comparison to Established Technologies:
Established drying technologies use natural gas as fuel and rely on convection to heat solids from the outside in along
with a loss of energy to the environment. In microwave drying, all the materials are heated simultaneously and the heat is
tne
Available Cost Information:
Approximate Capital Cost: $800,000 for system capable of processing 1 dry ton per day
Approximate O&M Costs: Not provided by the vendor.
Equipment provided in cost includes stainless steel applicator unit, four 100-kilowatt microwave transmitters, control panel,
250,000-BTU gas burner, standard aluminum wave guides, operator training and 1 -year system warranty.
Maintenance cost are low because there are no moving parts. Electricity is more than 90% of the energy used. System is
80% energy efficient.
Vendor Name(s):
Burch Hydro, Inc.
17860 An kneytown Road
Fredricktown, OH43019
Phone: 800-548-8694
Website:
www.burchbiowave.com/sections/process/index.asp
Practitioner(s):
Fredericktown, Ohio.
Biosolids Management
7-5
-------
Emerging Technologies
September 2006
Technology Summary
Direct Microwave Drying (Contd)
Key Words for Internet Search:
Burch BioWave®, microwave dryer, biosolids
Data Sources:
Vendor-supplied information.
Burch Bio Wave® dryer installed
7-6
Biosolids Management
-------
September 2006
Emerging Technologies
Flash Drying
Objective:
Drying of biosolids to 90% or more solids.
Technology Summary
State of Development: Innovative
The Centridry® flash drying process was evaluated in King County,
Washington, where it reduced the water content of 20% dewatered
solids to 60%-70% solids. However, product testing indicated that
for best usability, the product should also be composted, which
significantly increases costs. This project was completed in the
summer of 2001 and King County does not anticipate any further
testing on this process. Centridry® units have been in operation in
Europe since 1993.
Description:
Liquid biosolids combined with polymer are pumped into a centrifuge where conventional mechanical dewatering takes place. The
dewatered biosolids reach a minimum of 25% dry solids, and are discharged into the thermal stage as a fine-grained spray.
The biosolids particles are instantly dried upon entering the thermal cyclone chamber in order to prevent them from sticking to the
walls of the chamber. The particles are then entrained and conveyed in the sweep gas, and exit the chamber in a matter of seconds
during which time the sludge granules are dried and the temperature of the conveying gas is dramatically reduced. The pneumatic
conveying and drying process continues during the relatively short transport time to a cyclone where the product particles are
separated and discharged via a rotary valve to the stockpile.
The sweep gas, drawn through the system via the main ventilator fan, is reheated in the hot gas generator before re-entering the
dryer loop. Excess gas vapors in the system are drawn off by a small blower, treated in a venturi scrubber to remove residual
quantities of fine dust and volatile components, and discharged for odor treatment.
Comparison to Established Technologies:
Similar to other drying processes; however CentriDry® does not require biosolids to be dewatered prior to entering the unit.
Available Cost Information:
Approximate Capital Cost: Not provided by the vendor.
Approximate O&M Costs: Not provided by the vendor.
Vendor Name(s):
Euroby Limited
Columbia House, Columbia Drive
Worthing, West Sussex BN13 3HD
Phone: +01-903-69-44-00
E-mail: sales@.eurobv.com
Website: www.eurobv.com/centridv.htm
Practitioner(s):
Severn Trent Water STW
Worksop, UK
Key Words for Internet Search:
Centridry®, centrifuge drying, biosolids, sludge
Data Sources:
King County Department of Natural Resources. Regional Wastewater Services Plan -Annual Report. Wastewater
Treatment Division. (December 2001).
Vendor-supplied information
Biosolids Management
7-7
-------
Emerging Technologies
September 2006
Technology Summary
Fluidized Bed Drying
Objective:
Provide a safer, more reliable, more flexible technology
for drying digested/undigested municipal biosolids to
Class A levels.
State of Development: Innovative
Three plants in Europe are currently operating using this technology.
It is used in other industrial applications in the U.S.
Description:
Mechanically dewatered wet cake is pumped from storage directly into the fluidized bed dryer, where it comes in contact with
already-dry granules, building larger granules. The process is done entirely within the fluid bed itself without the need for recycling/
blending/classifying steps. It is also accomplished within an inert closed loop. Only a minimal amount of gas is exhausted for
treatment. All heating is done via indirect means with heat exchanger surfaces (tubes) immersed in the fluidized layer of solids in
the dryer. Heating configuration is extremely flexible and can be accomplished with energy derived from natural gas, digester gas,
steam, waste heat, and other sources. The end product is >90% dry solids, dust free, mechanically stable, and can be used in land
application or as a fuel and mineral source in cement kilns.
Comparison to Established Technologies:
Not similar to any established biosolids management technologies. This process is established for drying pellets, powders,
and granules in the chemical and pharmaceutical industries.
Available Cost Information:
Approximate Capital Cost: Approximately $750,000 per ton of water per day evaporated.
Approximate O&M Costs: Approximately 65 to 75 kWh per ton of water evaporated.
Maintenance costs approximately 3% per year.
Figures are approximate and depend largely on equipment arrangement and structure for the equipment to be located, and
the amount of wet cake and dry granule storage, which is included. The thermal energy requirement is approximately 1,250
to 1,300 BTU per pound of water evaporated. Technology is best suited for plants in the 5 to 500+ MGD range, but is cost
competitive at lower capacities as well.
Vendor Name(s): Practitioner(s):
Andritz-Ruthner, Inc. No practitioners of this technology for wastewater solids in the
1010 Commercial Boulevard, South U.S. were identified. However, vendors can provide information
Arlington, TX 76001 on practitioners in other industries.
Phone: 817-419-1704 Fax: 817-419-1904
E-mail: peter.commerford(5)andritz.com
Website: www.andritz.com
Schwing America, Inc.
Material Handling Division
5900 Centerville Road
St. Paul, MN 55127
Phone: 651-429-0999 Fax: 651-653-5481
E-mail: cwanstrom(5)schwing.com
Website: www.schwina.com
7-8
Biosolids Management
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September 2006
Emerging Technologies
Technology Summary
Fluidized Bed Drying (Contd)
Key Words for Internet Search:
Fluid bed dryer, biosolids, sludge
Data Sources:
Vendor-supplied information and websites
Biosolids Management
7-9
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Emerging Technologies
September 2006
Technology Summary
Chemical Drying
Objective:
Solids are dried through chemical reaction. The dried
product is mixed with nutrients to enhance the fertilizer
value of the final product.
State of Development: Embryonic
There are no installation or pilot facilities of this technology operating
in the U.S.
Description:
In the chemical drying process, ammonium salts or anhydrous ammonia and concentrated organic acids are mixed with dewatered
biosolids. The organic acids (e.g., sulfuric acid, phosphoric acid) react with the ammonia in an extremely exothermic reaction.
Sulfates and phosphates are produced in the reaction between the acid and the ammonia. The heat and pressure from the reaction
sterilize the biosolids and complete the drying process. The reaction of the biosolids with the ammonium salts produces a hard
granular material. As with other drying processes, the granular material can be combined with plant nutrients to further raise the
nutritive value of the product.
Comparison to Established Technologies:
Vendor claims indicate a final product similar to that produced by other drying technologies that is suitable for beneficial use
(provided feed solids are of acceptable quality).
Available Cost Information:
Approximate Capital Cost: < $ 4M for a 22 ton (25% solids) per day facility
< $10M for a 100 ton (25% solids) per day facility
Approximate O&M Costs: Not provided by the vendor.
Vendor Name(s):
VitAG, LLC.
2111 Forest View Road
Aiken, SC 29803
Phone: 239-398-6127 Fax: 803-652-2009
E-mail: Jburnham1(g)aol.com
Unity Envirotech, LLC
1119 Burgundy Circle
Pennsburg, PA 18077
Phone: 215-262-5233 Fax: 904-819-9224
E-mail: RTuttleUFC@aol.com
Practitioner(s):
No practitioner at this time.
Key Words for Internet Search:
VitAG, Unity, biosolids, sludge, chemical drying
Data Sources:
Vendor-supplied information
7-10
Biosolids Management
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Other Processes
This chapter focuses on other processes that do not fit clearly into one of the other
categories in this report.
Table 8.1 summarizes the state of development of other processes. Two of the technologies
presented in this chapter are designed to significantly reduce either the volume or
pathogen content of biosolids without all of the steps required by conventional methods.
The Cannibal® process uses bacteria developed specifically to degrade biosolids' organic
matter. The Lystek process uses heat and chemicals to produce a liquid biosolids product
that is suitable for land application and meets Class A requirements. Use of biosolids as
a fuel in cement kilns is also addressed.
Figure 8.1 includes an evaluation of the innovative technologies identified. Summary
sheets for each process are provided in this chapter.
Table 8.1 - Other Processes—State of Development
Cannibal® Process
Lystek Process
Injection in Cement Kiln
N/A
Biosolids Management
8-1
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Emerging Technologies
Figure 8.1 - Evaluation of Other Innovative Processes
Cannibal® Biosolids Destruction
Process
C,0,V
e
e
e
Lystek Thermal/Chemical Process
C,0,A
N/A
e
e
Injection in Cement Kiln
C,0,V,R
B = Bench scale
D = Full-scale demonstrations in North
America
I = Full-scale industrial applications, with
demonstrations or pilots for municipal
sewage sludge
0 = Full-scale operations overseas
N = Full-scale operations in North America
P = Pilot
F = Few plants
I = Industrywide
L = Primarily large plants
S = Primarily small plants
A = Produces Class A biosolids
C = Capital savings
0 = Operational/maintenance savings
F = Produces high-nutrient fertilizer
M = Minimizes odors
R = Provides beneficial use (nonagricultural)
V = Sludge volume reduction
A = Agriculture
C = Construction
N/A = Not Applicable
P = Power
Positive feature
0 Neutral or mixed
T Negative feature
8-2
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September 2006
Emerging Technologies
Technology Summary
Cannibal® Biosolids Destruction Process
Objective:
Biosolids volume reduction without digestion,
thickening, dewatering or polymer addition
State of Development: Innovative
A1 MGD sequential batch reactor wastewater treatment plant
in Georgia began using the Cannibal solids reduction process in
October 1998. The plant has purged solids once in five years to
relieve the plant of extremely fine inert material buildup. The plant
removed 8,000 pounds of wasted biosolids using the process
between January 2000 and September 2003. Favorable results also
have been realized at other full-scale operations within the United
States. This process also has been successful at the Alpine Cheese
Factory in Holmes County, Ohio, and has been the subject of bench-
scale research at Virginia Polytechnic Institute and State University.
Description:
A portion of sludge from the main treatment process is pumped to a sidestream bioreactor where the mixed liquor is converted from
an aerobic-dominant bacterial population to a facultative-dominant bacterial population. Aerobic bacteria are selectively destroyed
in this sidestream reactor while enabling the facultative bacteria to break down and use the remains of the aerobes and their
byproducts.
Mixed liquor from the bioreactor is recycled back to the main treatment process. There, the facultative bacteria, in turn, are out-
competed by the aerobic bacteria and subsequently broken down in the alternating environments of the aerobic treatment process
and the sidestream bioreactor.
Trash, grit and other inorganic materials are removed from the process by a patented solids separation module on the return sludge
line. All of the return sludge is pumped through this module and recycled back to the main treatment process. Only a portion of this
flow is diverted to the sidestream bioreactor for the selection and destruction process.
Comparison to Established Technologies:
Not similar to any established technology
Available Cost Information:
Approximate Capital Cost: Not available
Approximate O&M Costs: Not available
According to the vendor, a 1.5 MGD WWTP could recognize an approximate net operating cost savings of $245,600 using
the Cannibal process.
Vendor Name(s):
Envirex Products
1901 S. Prairie Ave.
Waukesha,WI53189
Phone:262-521-8570
Fax: 262-547.4120
E-mail: RoehlM(5)usfilter.com
website: www.usfilter.com
Practitioner(s):
Alpine Cheese Factory, Inc.
1504 US 62
Wilmont, OH 44689
Phone: 330-359-5454
Fax: 330-359-5049
Biosolids Management
8-3
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Emerging Technologies
September 2006
Technology Summary
Cannibal® Biosolids Destruction Process (Contd)
Key Words for Internet Search:
Cannibal® process, biosolids, sludge
Data Sources:
Sheridan, J. and B. Curtis. "Casebook: Revolutionary Technology Cuts Biosolids Production and Costs." Pollution
Engineering. 36:5 (2004).
Novak, J.T., D.H. Chon, B-A. Curtis, M. Doyle. "Reduction of Sludge Generation using the Cannibal® Process: Mechanisms
and Performance." Proceedings of WEF Residuals and Biosolids Management Conference 2006: Bridging to the Future."
Cincinnati, OH (12-14 March 2005).
Vendor-supplied information
8-4
Biosolids Management
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September 2006
Emerging Technologies
Lystek Thermal/Chemical Process
Objective:
Biosolids treatment and processing technology for
production of high solids and pathogen-free product for
beneficial use.
Technology Summary
State of Development: Innovative
The process has been successfully demonstrated at a full-scale
pilot facility at the Guelph Wastewater Treatment Plant in Ontario,
Canada. It was able to produce a Class A biosolids of 12 to 15%
solids. The product was stored without any change in product quality.
Description:
The Lystek process is a propriety sequenced batch operation where heat is applied and chemicals added to the feed solids in
controlled conditions. Retention times are relatively short and the system can be fully automated to control the relevant parameters:
pH, temperature and time. The resultant product is 12%-15% solids with a viscosity of < 1,500 cP (>2,000,000 cP of the feed) and
is compatible with standard equipment used for land application. The resulting material retains the pump-ability needed to reduce
the costs of biosolids handling, storage, transport and land application. The process has been shown to achieve the specifications
required for Ontario NMA Class B biosolids and U.S. EPA Class A biosolids.
Comparison to Established Technologies:
Similar to digestion processes that use additives and heat to reduce pathogens.
Available Cost Information:
Approximate Capital Cost: $1,000,000 - $1,250,000
Approximate O&M Costs: $120 - $145 per dry metric ton
Capital cost estimates for the Lystek system are for a generic WWTP producing approximately 4,000 dry tons biosolids per
year, and do not take into account any additional modification costs that may be necessary to integrate the Lystek system
to the existing wastewater treatment plant. The cost will also depend on the nature of the biosolids produced by the plant.
Operation and maintenance costs include material and energy
Vendor Name(s):
Lystek International, Inc.
107-279 Weber Street North
Waterloo, Ontario N2J 3H8
Canada
Phone:519-880-2170
Fax:519-747-8125
E-mail: infotgjlvstek.com
Website: www.lvstek.com
Practitioner(s):
City of Guelph Wastewater Services
530 Wellington Street
Guelph, Ontario N1H3A1
Phone:519-837-5629
E-mail: connie.mcdonald@quelph.ca or wastewater@quelph.ca
Key Words for Internet Search:
Lystek, biosolids, sludge
Data Sources:
Singh, A, F. Mosher, O.P. Ward, W. Key. "An advanced biosolids treatment and processing technology for beneficial
applications of high solids and pathogen-free product." 3rd Canadian Organic Residues and Biosolids Management
Conference, Calgary. (1-4 June 2005).
Biosolids Management
8-5
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Emerging Technologies
September 2006
Technology Summary
Injection in Cement Kiln
Objective:
The objective for the wastewater treatment plant is
cost effective, environmentally sound management
of biosolids. The objective from the standpoint of the
cement kiln is to reduce emission of nitrogen oxides
(NOx) and/or fuel usage.
State of Development: Innovative
The technology is currently used for managing dewatered biosolids
from a few wastewater treatment plants in California. It is also used
to manage dried biosolids in a facility in Union Bridge, Maryland.
A pilot study was conducted at the Maryland facility in 2004 and
operation of the full scale facility began in 2006 under the terms of a
six-month test fire permit. Heidelberg Cement (the parent company
of Lehigh Cement, the owner of the Maryland facility) has been using
this technology in Europe for a number of years
Description:
Biosolids are injected into cement kilns at different locations depending on the purpose of the biosolids. Biosolids can be used to
reduce NOx emission and can serve as an alternate fuel source.
In reducing NOx emissions, the ammonia present in the biosolids reacts with oxygen to form nitrogen and water. In this application,
dewatered biosolids are injected into the process at a point where temperatures are between 1600 and 1700° F (870 - to 930° C),
typically, where the exhaust gases leave the kiln. This application is appropriate for preheater/pre-calciner kilns because in these
plants, the target temperature range occurs at a location where it is feasible to inject the biosolids. In kilns of other designs the ideal
temperature range occurs within the rotating portion of the kiln, an area where injecting the biosolids is not feasible. In addition
to providing the means for the chemical reaction, the introduction of the biosolids at the point where exhaust gases leave the kiln
also creates less favorable conditions for NOx formation by lowering the gas temperature. Through many years of operation,
Mitsubishi's Lucerne Valley Cushenberry Plant in California has found that with a commercial injection rate of approximately 10
tons of dewatered biosolids per hour results in a small increase in electric load. That facility has also tested for increase in carbon
monoxide and hazardous air pollutants (HAPs). There was no significant increase in HAPS. There were some notable increase in
carbon monoxide emission but emissions remained below acceptable levels of 550 ppm.
Where biosolids are used to augment fossil fuels, dried biosolids (greater than 90% solids) are fed into the calciner combustion
zone of the cement manufacturing process. During the initial pilot testing at the Lehigh Cement facility, the biosolids were mixed
with the pulverized coal fuel. However, NOx emissions increased slightly with the use of biosolids at the Maryland facility, believed
to be the result of increase rate of combustion. Currently, alternate feed locations are being investigated in an effort to reduce
NOx emission while maximizing the use of biosolids. Testing of other emissions showed slight decrease in carbon monoxide, total
hydrocarbons and sulfur dioxide.
In both applications there are no addition residuals to manage; ash is bound in the cement product and has been found to be
compatible with the raw materials used in cement manufacture. However, adequate fan capacity must be provided to deal with
steam vapor resulting from the use of biosolids in both applications. The vapor is more of a concern when the feed biosolids have
lower percent solids.
Comparison to Established Technologies:
Not similar to any established technology.
8-6
Biosolids Management
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Emerging Technologies
Technology Summary
Injection in Cement Kiln (Contd)
Available Cost Information:
Approximate Capital Cost: Not applicable to biosolids generator; capital investment is made by cement kiln operator/
owner.
Approximate O&M Costs: Cost varies regionally; tipping fees of less than $5 per ton (wet) were quoted in the literature
but will be influenced by the percent solids of the biosolids
Vendor Name(s):
Operators of cement kilns that have accepted biosolids
include:
Lehigh Cement
7600 Imperial Way
Allentown, PA18195
Phone:610-366-4636
Email: emortontgjhtcnam.com
Mitsubishi Cement Corporation
5808 State Highway 18
Lucerne Valley, CA
Phone: 760-248-737
Practitioner(s):
Joint Water Pollution Control
24501 S Figueroa Street
Carson, CA
Synagro-Baltimore LLC
Key Words for Internet Search:
Cement kiln biosolids injection
Data Sources:
Battye, R., S. Walsh, J. Lee-Greco. NOx Control Technologies for the Cement Industry, Final Report. (2000).
Kahn, Robert. "Biosolids Injection: A New Technology for Effective Biosolids Management," Undated.
Morton, Edward L. "A Sustainable Use for Dried Biosolids." Undated.
Cement Industry Environmental Consortium website, www.cieconline.net.
Vendor-supplied information.
Lehigh Cement plant in Union Bridge, Maryland.
(Photo courtesy of Lehigh Cement. 2006.)
\lanagetnent
8-7
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Research
In order to reclassify any technology which is considered to be innovative or embryonic,
additional research and field demonstration projects are necessary. This chapter focuses
on specific technologies that may have a significant impact on biosolids treatment and
management, and the relevant research needs in these areas.
Sound, sustainable biosolids management is based upon controlling and influencing the
quantity, quality and characteristics of biosolids in such a way that negative impacts to
the environment are avoided and beneficial uses are optimized. It is recognized that
each wastewater treatment facility in the United States faces unique circumstances
resulting in a variety of applicable biosolids management strategies. Biosolids treatment
technologies are used to achieve beneficial use to the greatest extent possible.
Table 9.1 identifies research needs for especially promising technologies in biosolids
treatment. Beneficial use can take advantage of the soil conditioning and fertilizing
properties of this material or it may include gas and energy production. Substantial
scientific research will enable the beneficial use of biosolids to continue to expand by
reducing the uncertainties and data gaps on the potential effects of biosolids exposure
to human health. Research is used to determine whether current practices need to
be altered. Emerging and innovative technologies can provide new cost-efficient and
effective solutions to biosolids management. Some steps towards completing scientific
research include: "development and standardization of sampling and analytical methods,
investigation of contaminant fate/transport and exposure routes, potential human health
effects, risk assessment determinations; evaluation of improvements that may be needed
in operational practices, technologies, and management practices for biosolids treatment
and reuse." (WERF, 2002).
Biosolids Management
9-1
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Emerging Technologies
September
Table 9.1 - Research Needs Technologies: State of Development
Conditioning
Thickening
Stabilization
Dewatering
Thermal
Conversion
Drying
None
None
Temperature-Phased
Digestion
Two-Phase
Digestion
Ferrate Addition
Neutralize!-®
None
RHOX Process
Gasification
Sludge-to-Oil
Supercritical Water
Oxidation
SlurryCarb™
Deep-Shaft Wet Air
Oxidation
Belt Drying
Direct Microwave
Drying
Flash Drying
Fluidized Bed Drying
Chemical Drying
Cannibal®
Lystek
None.
None.
Confirm solids reduction and gas production.
Determine SRT needed vs. conventional anaerobic digestion.
Identify operating problems - Thermophile Heating/Heat Recovery.
Confirm solids reduction and gas production.
Determine SRT needed vs. conventional anaerobic digestion.
Identify operating problems.
Confirm performance, costs and viable operating parameters.
Confirm performance, costs and viable operating parameters.
None.
Document improvement in plant capacity and decrease in emissions.
Determine impact on capital and operating costs.
Conduct testing at several locations.
Document improvements in plant capacity and decrease in emissions.
Determine impact on capital and operating costs.
Conduct testing at several locations.
Document improvements in plant capacity and decrease in emissions.
Determine impact on capital and operating costs.
Conduct testing at several locations.
Document improvements in plant capacity and decrease in emissions.
Determine impact on capital and operating costs.
Conduct testing at several locations.
Document improvements in plant capacity and decrease in emissions.
Determine impact on capital and operating costs.
Conduct testing at several locations.
Document improvements in plant capacity and decrease in emissions.
Determine impact on capital and operating costs.
Determine capital and operating costs.
Identify operating problems/confirm performance.
Determine capital and operating costs.
Identify operating problems/confirm performance.
Determine capital and operating costs.
Identify operating problems/confirm performance.
Determine capital and operating costs.
Identify operating problems/confirm performance.
Confirm performance, costs and viable operating parameters.
Document improvements in performance.
Determine impact on capital and operating costs.
Document improvements in performance.
Determine impact on capital and operating costs.
9-2
Biosolids Management
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2006 Emerging Technologies
Generally, research and technical issues can be grouped into three areas:
(1) Analysis and reduction of risk associated with beneficial use practices;
(2) Utilization of the potential of biosolids to yield energy; and,
(3) Improved operation, performance, and efficiency of biosolids treatment
processes.
9.2.1 Analysis and Reduction of Risk Associated with Certain Beneficial Use
Practices
Fundamental research in this area relates to:
• Standardization of sampling and analytical methods for contaminants to assure
the use of the best measurement methods for particular microbial and chemical
contaminants. This standardization should also state the best time and place for
sampling.
• Standardization of risk assessment measures and methods for chemicals and
pathogens. Risk assessment allows for the evaluation of operational improvement
practices and technologies. This evaluation would differ from most plant efficiency
evaluations by focusing on the treatment practices and the protections they offer
to human and environmental health.
• Fate and transport of the contaminants during biosolids management practices.
• Emerging chemical contaminants and pathogens, as well as on exposure
measurements and routes. The potential health risks and effects should be
addressed to determine the adverse effects of the emerging contaminants.
• Resolution of issues that affect the acceptability of Class B biosolids to continue
in the future.
• Reactivation of fecal conforms in centrifuge dewatered solids, anaerobically
digested biosolids.
9.2.2 Utilization of the Potential of Biosolids to Yield Energy
Fundamental research in this area relates to:
• Research on technologies that can generate or increase the quantity of energy
from the production of biosolids by-products and gases.
• Utilization of process-generated gas to provide energy to offset at least some of
the energy requirements of wastewater and biosolids treatment technologies.
Biosolids Management 9-3
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Emerging Technologies September 2006
9.2.3 Improved Operation, Performance and Efficiency of Biosolids Treatment
Processes
• Optimization of the application of chemicals for dewatering and their impact on the
quality of the final product.
• Assessment of the odor potential from biosolids stabilization and dewatering
techniques and advances to mitigate odor emissions.
• New technologies for the production of artificial soils and fertilizer components or
products.
• Emergence of high temperature, high-volume solids destruction technologies.
• Improvements in energy efficiency, particularly the use of heat exchangers and
heat recovery.
9.2.4 Research Needs
The technologies are arranged by type, noting the recommended focus of the investigations
for each.
Selection of the technologies and their research needs is based upon an assessment of
the process summaries and evaluations in the previous chapters. Criteria used to select
the technologies include applicability, judgment about critical assessments needed to
promote the technology to the next level of development, promise for further development
and current interest in the technology.
9.2.5 Chapter References
Water Environment Research Foundation (WERF) (2002).
www.werf.org/funding/researchplan.cfm
WERF (1999) Biosolids Management Evaluation of Innovative Processes.
9-4 Biosolids Management
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Great Lakes By-products Management Association
15743 Hagenderfer Road, Plain City, OH 43064
Phone: 866-309-7946
Web: http://glbma.org
Mid-Atlantic Biosolids Association
Web: http://www.mabiosolids.org
National Biosolids Partnership
601 Wythe Street, Alexandria, VA 22314
Phone: 703-684-2400
Web: http://www.biosolids.org
North East Biosolids & Residuals Association
P.O. Box422Tamworth, NH 03886-0422
Phone: 603-323-7654
Web: http://www.nebiosolids.org
Northwest Biosolids Management Association
201 S. Jackson St Seattle, WA 98104-3855
Phone:206-684-1145
Web: http://www.nwbiosolids.org
Water and Wastewater Equipment Manufacturers Association (WWEMA)
P.O. Box 17402, Washington, D.C. 20041
Phone:703-444-1777
Web: http://www.wwema.org
Water Environment Federation
601 Wythe Street, Alexandria, VA 22314-1994
Phone: 703-684-2452
Web: http://www.wef.org
Biosolids Management
A-1
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Emerging Technologies September 2006
Water Environment Research Foundation
635 Slaters Lane, Suite 300, Alexandria, VA 22314
Phone: 703-684-2470
Web: http://www.werf.org
Air and Waste Management Association
One Gateway Center, 3rd Floor, 420 Fort Duquesne Blvd.
Pittsburgh, PA 15222-1435
Phone: +1-800-270-3444
Web: http://www.awma.org/
National Association of Clean Water Agencies
1816 Jefferson Place, NW Washington D.C. 20036
Phone: 202.833.2672
Web: http://www.nacwa.org/
A-2 Biosolids Management
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