PB85-165744
   Emerging Technology Assessment of
   Phostrip  a/0, and Bardenpho Processes for
   Biological Phosphorus Removal
  Weston  (Roy P.), Inc., West Chester,  PA
  Prepared  for

  Environmental  Protection Agency, Cincinnati,  OH
  Feb 85
Department of Commerce
   Technical Information Service

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                                            EPA/600/2-85/008
                                            February 1985
     EMERGING TECHNOLOGY ASSESSMENT OF

   PHOSTRIP, A/0, AND BARDENPHO PROCESSES

     FOR BIOLOGICAL PHOSPHORUS REMOVAL
               Weston,  Inc.
          Designers-Consultants
    West Chester, Pennsylvania  19380
       EPA Contract No.  68-03-3055
            Project Officer
              E. F. Barth
      Wastewater Research Division
 Water Engineering Research  Laboratory
         Cincinnati,  Ohio 45268
WATER ENGINEERING RESEARCH LABORATORY
  OFFICE OF RESEARCH AND DEVELOPMENT
      £?S?SIAL PROTECTION AGENCY
       CINCINNATI,  OHIO  45268

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                                   TECHNICAL REPORT DATA
                            (f lease read Instructions on the reverse before completing)
1. REPORT NO.

  EPA/600/2-85/008
             3. RECIPIENT'S ACCESSION NO,
                         Ife&ZM/ML
4. TITLR AND SUBTITLE

 EMERGING TECHNOLOGY  ASSESSMENT OF PHOSTRIP,  A/0, AND

 BARDENPHO PROCESSES  FOR BIOLOGICAL PHOSPHORUS REMOVAL
             5. REPORT DATE

                February 1985
             6, PERFORMING ORGANIZATION CODE
7. AUTHOR(S(

  Weston, Inc.
                                                            8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
  Weston, Inc.
  Weston Way
  West Chester, PA  19380
             10. PROGRAM ELEMENT NO.

                 CAZBTB	
             II. CONTRACT/GRANT NO.

               Contract No. 68-03-3055
12. SPONSORING AGENCY NAME AND ADDRESS
  Water  Engineering Research Laboratory--Cin.,OH
  Office of Rese&rch and  Development
  U.S.  Environmental Protection Agency
  Cincinnati, OH 45268	
             13. TYPE OF REPORT AND PERIOD COVERED

             Final-Jimo lOR^-Sont  19Q4
             14. SPONSORING AGENCY CODE
              EPA/600/14
IS. SUPPLEMENTARY NOTES
   Project Officer;   E.  F.  Barth       Telephone -  (513)  684-7641
  , Present Contact:   James F. Kreissl	(513 S  684-7611
16, ABSTRACT
 An  engineering evaluation of three proprietary processes for biological  removal of
 phosphorus from municipal wastewater was conducted.   The report presents for each
 process:     Technology Description;
               Technology Evaluation;
               Development Status;
               Equivalent Technologies Comparison;
               Assessment of National Impact;
               Cost Considerations; and
               Recommendations.
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.IDENTIFIERS/OPEN ENDEP TERMS
                           c. COSATI Field/Group
  Phosphorus removal
  Anoxic
  Anaerobic
  Aerobi c
  Cost
  Biological processes
  Activated sludge
  Nutrient control
   13B
18. DISTRIBUTION STATEMENT


 RELEASE TO PUBLIC
19. SECURITY CLASS {ThisReportl
 UNCLASSIFIED
21. NO. OF PAGES

       116
20. SECURITY CLASS fTlris page!
 UNCLASSIFIED
                           22. PRICE
BB4 e..n
                                    IS OBSOLETE

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                                  DISCLAIMER


     "The information  In this  document  has  been  funded  wholly or  in  part
by the  United  States  Environmental  Protection  Agency  under   Contract  No.
68-03-3055 to  Weston,  Inc.   It has been  subject to  the Agency's  peer  and
administrative review,  and  it  has  been  approved  for  publication as  an  EPA
document.  Mention of trade  names  or commercial products does not constitute
endorsement or recommendation for use."

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                                  FOREWORD

     The U.S. Environmental Protection Agency is charged by Congress with
protecting the Nation's land, air, and water* systems.  Under a mandate of
national environmental laws, the agency strives to formulate and implement
actions leading to a compatible balance between human activities and the
ability of natural systems to support and nurture life.  The Clean Water
Act, the Safe Drinking Water Act, and the Toxics Substances Control Act
are three of the major congressional laws that provide the framework for
restoring and maintaining the integrity of our Nation's water, for pre-
serving and enhancing the water we drink, and for protecting the environ-
ment from toxic substances.  These laws direct the EPA to perform research
to define our environmental problems, measure the impacts, and search for
solutions.

     The Water Engineering Research Laboratory is that component of EPA's
Research and Development program concerned with preventing, treating, and
managing municipal and industrial wastewater discharges; establishing
practices to control and remove contaminants from drinking water and to
prevent its deterioration during storage and distribution; and assessing
the nature and controllability of releases of toxic substances to the air,
water, and land from manufacturing processes and subsequent product uses.
This publication is one of the products of that research and provides a
vital communication link between the researcher and the user community.

     The innovative and alternative technology provisions of the Clean
Water Act of 1977 (PL 95-217} provide financial incentives to communities
which use wastewater treatment alternatives that reduce costs or energy
consumption over conventional systems.  Some of these technologies have
been only recently developed and are not in widespread use in this country.
In an effort to increase awareness of the potential benefits of such alter-
natives and to encourage their implementation where applicable, the Water
Engineering Research Laboratory has initiated this series of Emerging Tech-
nology Assessment reports.  This document discusses the applicability and
economic feasibility of utilizing biological processes for the control of
phosphorus for municipal wastewater treatment.

                                       Francis T. Mayo, Director
                                       Mater Engineering Research Laboratory
                                    m

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                            ABSTRACT
    This technology assessment addresses three proprietary proc-
esses (namely PhoStripf &/o, and Bardenpho) for biological phos-
phorus removal from municipal wastewaters. These processes are
used as alternatives to the conventional method of treatment by
activated sludge with chemical addition for phosphorus precipi-
tation, The objective of this report is primarily to provide
guidance to those individuals involved with reviewing new proc-
esses as part of the Innovative and Alternative Technology pro-
gram.

    PhoStrip, &/Q, and Bardenpho processes were all developed
in the early 1970"s based on the ability of the biological sys-
tem to provi.?^ enhanced or the so called "luxury" uptake, which
involves the mechanism of phosphorus release by microorganisms
under anaerobic conditions, followed by cellular phosphorus up-
take under aerobic conditions. These three systems are different
with respect to their specific process design and to their abil-
ity to provide phosphorus removal, as well as various degrees of
nitrogen removal. The PhoStrip process employs sidestream (i.e.,
a portion of the return sludge) treatment in an anaerobic con-
tact tank where biologically-bound phosphorus is released to the
aqueous medium, and the supernatant liquor is treated with lime
to precipitate inorganic phosphorus as calcium hydroxyapatite.
Both the A/0 and Bardenpho processes involve mainstream  (influ-
ent flow plus sludge recycle) anaerobic treatment to pre-condi-
tion the system for phosphorus removal via waste activated
sludge.

    The A/0 process can be designed for phosphorus removal with-
out nitrification by use of anaerobic/oxic stages, or for phos-
phorus removal with nitrification by use of anaerobic/anoxic/ox-
ic stages plus additional internal mixed liquor recycle  from the
oxic to the anoxic stage. The Bardenpho system is a five-stage
(anaerobic/anoxic/aeration/anoxic/reaeration) process designed
to provide both phosphorus and total nitrogen removal.

    The development status of these processes  (including a list
of pilot studies and full-scale installations), process  theory,
capabilities, and design considerations are addressed in this
report.
                                IV

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     Related capital, O&M, and total present worth costs for
these three processes, as well as for baseline technology of
coventional activated sludge  (one, two, or three-stage system
depending on the degree of nitrogen removal required) with alum
addition, were estimated to provide a reasonable basis for
alternative comparison.  Based on these estimates and assump-
tions of the tote L present worth costs, the three proprietary
processes are found to be cost-effective and particularly
applicable under the following conditions:

      •   PhoStrip process for effluent residual total phos-
          phorus for large treatment plants.

      *   A/O process for effluent residual total phosphorus
          at all plant sizes.

      »   Modified A/O process for effluent residual total
          phosphorus oE 2 mg/L and 1 rag/L ammonia nitrogen
          at all plant sizes.

      •   Bardenpho process for effluent residual total phos-
          phorus of 2 mg/L and total nitrogen of about 3 mg/L
          at all plant sizes.

     Market potential for these three processes (based on a
needs survey in the U.S.), and their costs and energy impacts
are addressed in the report.  Further research and development
efforts and potential areas for process modifications are also
identified.

     Appendix C contains the response of the three proprietary
firms to this report.

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                              CONTENTS
 Foreword
 Abstract
 Figures.
 Acknowledgements  .....        .......  ....... V111
                             *"**••«••»••  .....   ix

     1.  Technology Description ........  .               •,
            Introduction. .....******   7
                                      ..
            Technology descriptions . '. '. '.
               PhoStrip process ......
               A/O process (anaerobic/oxic)
               Bardenpho process. ....
     2.   Technology Evaluation .......
            Process theory. . . ....... *•-.....   y
            Process capability and limitations." III.*""*  i?
            Design considerations ....... ....   *  *  14
               PhoStrip process .....    **•••*•-.  J.
               A/0 process. . . .....  .."[.*  ......  tfi
               Bardenpho process ......  II!!!]**"  YJ
            Operations and maintenance considerations . I       20
     3.   Development Status ...........    ° • •  •  •  ^"
            PhoStrip process.  .....  I  I  I  ..... *  *  *  ^
            A/O process .  .......  !  I  I  I  ***""""   of
            Bardenpho process .....  I  "  *  *  .......   po
     4.   Comparison with Equivalent  Technologies!  Ill*"*   33
            Equivalent conventional  concept  ...            *   •a-i
            Cost comparison .  ......  ...*******   ^f
            Energy  requirements  .  .....  .........   ^
     5.   Assessment of National  Impact.  ..."  *  ......   c?
            Market  potential ..........  Ill**""   51
            Costs and  energy  impacts.  ..  I  I  I  I  """***   ct
            Risk assessment  .........  I  I  *  "  *  *  *  *   cc
     6.   Recommendations.  ..  .....  III!  ......  *   c^
            Future  research and development efforts  I  "  "  *  *   sfi
            Process/ technology modifications   ......  .*  *   57

References  ...........
Appendices                     «...  .....  .  .....   59


    A.   - Cost and energy analysis — assumptions.  ...       66
    a.  - Lost comparison and energy analysis  .            *   ji
    C.  - Response of proprietary firms.  .
                               VI

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                             FIGURES

Number                                                      page

   1     PhoStrip Process Flow Diagram ...........   4

   2 (a)  A/0 Process Plow Diagram for Phosphorus Removal . .   6

   2(b)  A/O for Phosphorus Removal with Nitrification/De-
          nitrifieation	   6

   3     Baraenpho Process Flow Diagram. ..... 	   8

   4     Biological Phosphorus and BOD Removal Due to
          Anaerobic-Aerobic Contacting (Adapted from
          Reference 17)	 .  10

   5(a)  Capital Cost Comparison — Case 1:  Phosphorus Re-
          moval (Effluent TP = 1 mg/L) ...........  43

   5 (b)  O&M cost comparison —- Case 1:  phosphorus Removal
          (Effluent TP = 1 mg/L)	  44

   6(a)  Capital Cost Comparison — case 2:  Phosphorus Re-
          moval (Effluent TP = 2 mg/L) ...........  45

   6(b)  O&M cost Comparison — Case 2;  Phosphorus Removal
          {Effluent TP = 2 mg/L)	 .  46

   7 (a)  Capital Cost Comparison -- Case 3:  Phosphorus Re-
          moval and Nitrification (Effluent TP = 2 mg/L,
          NH3-N = 1 mg/L)  .................  47

   7(b)  O&M cost comparison — Case 3;  Phosphorus Removal
         and  Nitrification (Affluent TP = 2 mg/L, NH^-N » I
          mg/L).	  7 ...  48

   8(a)  Capital Cost Comparison — case 4:  Phosphorus Re-
          moval i Nitrification, and Denitrification (Effluent
          TP = 2 mg/L, TN = 3 mg/L)   ............  49

   8(b)  O&M Cost Comparison -- Case 4:  Phosphorus Removal,
          Nitrification, and Denitrification (Effluent TP =
          2 mg/L,  TN = 3 mg/L) ...............  50
                               VII

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                              TABLES

Number                                                      Page

   1     PhoStrip Process — Pilot and Full-Scale Plant
          Operations Data. .....  	 , 	  22

   2     A/0 Process — Pilot and Full-Scale Plant Opera-
          tions Data .............. 	  25

   3     Bardenpho Process — Pilot and Full-Scale Plant
          Operations Data. .....  	 . 	  29

   4     Alternative Cases Evaluated Under Technology As-
          sessment of Biological Phosphorus Removal.  ....  34

   5     Summary of Cost Comparison — Case 1:  Phosphorus
          Removal (Effluent TP = 1 mg/L)	37

   6     Summary of Cost Comparison -- Case 2:  Phosphorus
          Removal (Effluent TP = 2 mg/L)  ..........  38

   7     Summary of Cost Comparison — Case 3:  Phosphorus
          Removal and Nitrification (Effluent TP = 2 nig/L,
          HH3-N = 1 mg/L)	39

   8     Summary of Cost Comparison — Case 4:  Phosphorus
          Removal and Nitrification/Denitrification (Efflu-
          ent TP = 2 ag/L, TN =* 3 mg/L)	 .  40

   9     Summary of Least Cose Alternatives.	41


  10     Summary of Energy Requirements in 10  kwh/year. . .  42

  11     Facilities Designed to Provide Advanced Waste-
          water Treatment (AWT) for all States and U.S.
          Territories	  52

  12     National Dollar Needs for Changes in Existing
          Treatment Plants and for Construction of New Ad-
          vanced Wastewater Treatment (AWT) Facilities ...  54
                               Vlli

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                         ACKNOWLEDGEMENTS
    This report was prepared by Dr. Larry Y. H. Lin of Roy F.
Weston, Inc. and reviewed by Dr. M. Ramanathan, Anthony J.
DeFalco, and Glenn M. Johnson from the technical aspect.

    The cooperation of the U.S. EPA Municipal Environmental Re-
search Laboratory staff throughout the preparation of this re-
port is gratefully acknowledged. We are indebted to Mr. Gary R.
Lubin, who served as Project Officer during this effort, for his
coordination and guidance in completing this assignment. Partic-
ular appreciation is extended to Mr. Edwin F. Barth who provided
a detailed review of this report as well as numerous comments
and valuable input.

    The technical assistance provided by the following persons
was appreciated in preparing the technology description and de-
velopment status of the three proprietary biological phosphorus
removal processes:

    •   Biospherics Incorporated - Dr. Gilbert V. Levin
                                   Mr. Tony Kish

    9   Air Products and Chemicalsf Inc. - Dr. David J. Krichten
                                           Dr. Sun-Nan Hong

    •   EIMCO Process Machinery Division
        of Envirotech Corp. - Mr. David DiGregorio

    •   Dr. H. David Stensel (University of Utah)

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                            SECTION 1

                      TECHNOLOGY DESCRIPTION
INTRODUCTION

    For the past two decades, phosphorus has been recognized as
a major limiting factor (along with nitrogen) in the control of
eutrophication due to excessive algae and aquatic vegetative
growth in streams and lakes. In response to this effect, pollu-
tion control agencies have instituted stringent limitations
controlling nutrient discharge into receiving waters.  Examples
are the Great Lakes regions, the Florida Tampa Bay region,  Lake
Tahoe, and the Chesapeake Bay area (1). Typical effluent stand-
ards have been 1 mg/L and 3 mg/L for phosphorus and total nitro-
gen, respectively. Less stringent requirements are also adopted
in various localities to meet water quality standards.

    Since the early 1970's, chemical precipitation with either
alum, ferric chloride, or lime has been the widely used as  a
demonstrated technology for phosphorus removal (2). Where possi-
ble, steel mill waste pickle liquor has provided a relatively
inexpensive chemical source for phosphorus precipitation, al-
though it may also contain other undesirable heavy metals.  The
disadvantages of chemical precipitation treatment for phospho-
rus removal are chemical costs, chemical handling and storage
requirements, increased sludge production, and related sludge
handling and disposal costs.

    Prior to the present application of specifically designed
biological phosphorus removal systems, a series of studies  and
full-scale plant observations on biological phosphorus removal
had been reported. In 1955, Greenburg et al. (3) proposed that
activated sludge could take up phosphorus at a level beyond its
normal microbial growth requirements. Srinath et al. (4) report-
ed in 1959 that soluble phosphorus in mixed liquor (aqueous
phase) decreases rapidly to below 1 mg/L under varying condi-
tions of aeration. However, Levin and Shapiro (5) in 1965 were
the first to associate excess biological phosphorus removal, now
called "luxury uptake,*1 with anaerobic/aerobic sequencing of
biological treatment systems, which is currently the accepted
mechanism. This led to intensive studies of the possible appli-
cation of this phenomenon for removal of phosphorus in activated

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sludge plants  16,  7,  8,  9, 10). It appeared that all the plants
that successfully  removed phosphorus were high-rate, non-nitri-
fying, plug-flow type activated sludge plants. By the early
1970's, three distinct proprietary biological phosphorus removal
processes had been developed; namely, the PhoStrip process by
Levin et al.  {11,  12, 13), the Bardenpho process by Barnard of
South Africa  (14,  15), and the A/0 process by Air Products and
Chemicals, Inc.  (16,  17). These three commercial biological
phosphorus removal processes are currently patented and marketed
in the United States  by  the following companies:

    •   PhoStrip - Biospherics, Inc.

    •   A/O - Air  Products and Chemicals, Inc.

    •   Bardenpho  - EIMCO Process Machinery Division of
        Envirotech Corporation

    In addition to the three major proprietary processes dis-
cussed in this report, a number of other modifications to the
biological phosphorus removal system have been proposed. They
include:

    •   The UTC (University of Capetown)  process described
        by Siebritz, Ekama and Marais (18)  for application
        to wastewaters with relatively high total Kjeldahl
        nitrogen to chemical oxygen demand (TKN/COD) ra-
        tios.

    •   The "safe" design optimization approach proposed by
        Mulbarger  and Prober (19), which can be various
        combinations of primary chemical treatment, anaero-
        bic and aerobic contacting as in the A/0, PhcStrip
        with lime addition, and metal salts addition in the
        aeration basin for polishing phosphorus to low lev-
        els.

    •   The biological phosphorus removal with "roughing"
        chemical treatment proposed by Stensel (1), which
        is a modified anaerobic contactor design similar
        to a combination of the Bardenpho or A/O with the
        PhoStrip system.

    These modified processes can be applicable to certain spe-
cific cases; however, they are not included in the technical as-
sessment within this report due to the complexity of the subject
and their limited available development data.

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    The Clean Water Act (PL 95-217} mandated that an analysis
and evaluation of innovative and alternative technologies be
conducted during the development of federally-funded wastewater
management projects (21, 22}. This requirement, administered
through the U.S. Environmental Protection Agency's (EPA)  Con-
struction Grants Program, has encouraged the development of
several new treatment processes having potential for applica-
tion in municipal wastewater treatment practice. In order to as-
sess the status of development and the capabilities of these
"emerging" technologies, EPA has initiated a series of technol-
ogy assessments for evaluating these processes. This technology
assessment report is prepared to evaluate the three patented
processes for biological phosphorus removal, which are currently
gaining in acceptance and applications.

TECHNOJJOGY DESCRIPTIONS

PhoStrip Process

    The PhoStrip process was first proposed by Gilbert Levin in
1965 (5, 6) and is currently marketed by Biospherics, Inc. This
process is an activated sludge process that takes advantages of
"luxury" phosphorus uptake and anaerobic phosphorus release. A
schematic flow diagram of the PnoStrip process is presented in
Figure 1. This process differs from conventional activated
sludge in that a portion of the return sludge is subjected to
"phosphorus stripping" by holding  the sludge under anaerobic
conditions in a stripper tank. The solids retention time  (SET)
in this tank typically ranges from 8 to 12 hours. During this
anaerobic period, phosphorus is released and is elutriated from
the sludge in the stripper tank with a stream that is low in
phosphorus content. This stream may either be the overflow from
the chemical treatment tank  (reactor clarifier) as is shown in
Figure 1, or primary effluent. The phosphorus-rich overflow
from the stripper tank passes continuously to the chemical
treatment tank where lime is added for phosphorus precipitation.-

    Because of the flexibility of  the percent of return sludge
that can be subjected to anaerobic conditions for different
detention times in the stripper tank, a wide range of phos-
phorus removal can be achieved. Control of the side-stream
permits phosphorus removal to be divided between stripper super-
natant and waste activated sludge  (13).

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Influent
  CO)
              Primary
              Sludge
                                                  Direct Sludge Recycle
                                                     (0,2 to 0.50)
Phosphorus-
  Enrichecf
  Sludge
(0.2 Co 0.3QJ
                               Effluent
                         Waste
                    fci  Activated
                         Sludge
                                                                                       Anaerobic
                                                                                      Phosphorus
                                                                                        Stripper
                                                                               L« c -- ElubiaUon from any oft
                                          _.   -  ,
                                          Chemical \
                                           Sludge
                                                                          Stripper
                                                                          Underflow
                                                                         (0.1 to 0.2Q)
                    (a) Stripper Underflow Recycle
                    (b) Primary Effluent
                    {ci Reactor - Clarifier Supernatant
                             Figure 1.   PhoStrip process flow diagram.

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A/0 Process (Anaerobic/Oxic)

    The A/O process was developed by Air Products and Chemicals,
Inc. for the removal of phosphorus and/or nitrogen from wastewa-
ter (16, 17). The A/0 process is a single-sludge, suspended
growth system that can combine anaerobic, anoxic-S and aero-
bic sections in sequence. Figure 2(a) is a schematic represen-
tation of the A/O process for phosphorus removal. The process
can be designed for phosphorus removal with or without nitrifi-
cation and denitrification. All sections are partitioned into
several hydraulic stages to approach plug-flow and prevent back-
mixing. Typically, for removal of phosphorus, three anaerobic
stages are followed by three or more aerobic or oxic stages.
Recycled sludge from the secondary clarifier is mixed with
either raw wastewater or primary effluent in the anaerobic
section so that there is "sorption" of BOD by the organisms,
with accompanying phosphorus release necessary for biological
phosphorus removal. The anaerobic section is covered and equip-
ped with mechanical mixers for mixing but not aeration.

    The oxic stage, essential for the metabolism of BOD and up-
take of the phosphorus released in the anaerobic stage, may be
aerated with either air or oxygen. Phosphorus is removed from
the system in the waste sludge, which may contain 4- to 6-per-
cent phosphorus by dry weight. Effluent phosphorus concentra-
tions are dependent on sludge wasting, which in turn is control-
led by the plant's operating solids residence time (SRT) .

    When necessary, nitrification can be accomplished in the
oxic section by operation at a properly selected solids resi-
dence time and organic loading suitable for growth of nitri-
fying bacteria. When denitrification is further required,  the
anoxic section is included between an anaerobic and oxic sec-
tion as shown in Figure 2(b). The anoxic section is deficient
in dissolved oxygen, but chemically-bound oxygen in the form of
nitrate or nitrite is introduced by recycling nitrified mixed
liquor from the oxic section back to the anoxic section.
     term "anaerobic" refers to environments that have no
 measurable concentrations of either dissolved oxygen or oxi-
 dized nitrogen in the form of nitrate or nitrite; "anoxic"
 refers to environments that have no dissolved oxygen, but can
 have oxidized nitrogen present.

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Influent or (Q) _
Primary Effluent
i
^ 	
1
1
1
I
(
I
1
1
1
1 1 I
I | I
! i
1 1
1 I I
Anaerobic 1 Qxic



• 	 j*1 1 uiai
                                    Sludge Recycle
                                                                                Effluent
                                                                   Waste Aciivated Sludge
                                                                     (Phosphorus-Rich)
 i   Figure 2(a).  A/O process flow diagram for phosphorus removal.
  Influent or     (Q)
Primary Effluent
                                    Internal Recycle
                                         (20)
                                Sludge Recycle
                                                                              Effluent
                                                                  Waste Activated Sludge
                                                                    {Phosphorus-Rich}
Figure 2{b).  A/O for phosphorus removal with nilriftcation/deniirification.

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Bardenpho process

    The Bardenpho process was first Investigated in Pretoria,
South Africa by Jaraes Barnard in the early 1970 "s (14). Barden-
pho stands for Barnard-denitr ification-phosphorus,  an activated
sludge process designed to accomplish both biological phosphorus
uptake and nitrogen removal. The process is patented by the
South African inventions Development Corporation and licensed to
Envirotech corporation for marketing in the United States. The
Bardenpho process is very similar to the previously described
&/O processf except there is an additional anoxic and a reaera-
tion section at the tail end.

    As shown in Figure 3, two anoxic stages are used to accom-
plish high levels of biological nitrogen removal by denitrifi-
cation. An anaerobic stage is added ahead of the original four-
stage Bardenpho nitrogen removal system to create anaerobic-aer-
obic contacting conditions necessary for biological phosphorus
uptake. Return activated sludge, separated from the clarifier,
is mixed with the influent wastewater prior to the anaerobic
contactor, which is to initiate luxury phosphorus uptake by
first releasing phosphate. Mixed liquor from the anaerobic con-
tactor then flows into the first anoxic denitrification zone
where it is mixed with an internally recycled mixed liquor from
the aerobic nitrification zone. In the first anoxic denitrifica-
tion zone, nitrate is reduced to nitrogen gas using soluble or-
ganic matter in the wastewater as a carbon source.  The mixed
liquor then flows into the aerobic nitrification zone where lux-
ury phosphorus uptake, ammonia oxidation, and additional BOD re-
moval occurs. Following the aerobic nitrification zone, a second
anoxic zone provides additional denitrification, which is de-
signed to remove additional nitrate and minimize nitrate feed-
back to the anaerobic contactor. The reaeration zone provides
oxidation of remaining ammonia and raises dissolved oxygen
levels for effluent discharge.

    Phosphorus is removed from the system in the waste sludge,
which may contain 4- to 6-percent phosphorus by dry weight.
Depending on the relative amounts of phosphorus, BOD, and ni-
trogen in the influent, low levels of phosphorus (less than 1
mg/L) can be achieved in the effluent. For weaker wastewaters
or high influent phosphorus concentrations, a small amount of
chemicals, such as alum or ferric salts, are added to polish
the effluent phosphorus to below 1 mg/L, if required. Because
of the liquid detention times and SET required for  nitrification
and denitrification, a relatively high-quality effluent in terms
of BOD, suspended solids, and ammonium nitrogen concentrations
is possible. The resultant SET provides an aerobically-stabi-
lized sludge that has been disposed of without further stabili-
zation (1).

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                               Internal Recycle
                                    WO)
Influent
               Anaerobic
   Anoxic  I     Aeration
(Devitrification)  (Nilrificalion)
                                                     Anoxic
                                                            Reaeralion
                                       Sludge Recycle
                                                                                    Waste Activated Sludge
                                                                                      (Phosphorus-Rich)
                        Figure 3.   Bardenpho process flow diagram.

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                            SECTION 2

                      TECHNOLOGY EVALUATION
PROCESS THEORY

    Phosphorus in raw wastewaters exists in three forms: ortho-
phosphate  {£04), poly-phosphate  ^307)i and organic phos-
phorus (47). The ortho-phosphorus can be readily assimilated by
microorganisms, and the poly- and organic phosphorus forms are
usually hydrolyzed by microorganisms to the ortho form. Phos-
phorus is an important element for microorganisms due to its use
in energy transfer and for cell components such as phospholip-
ids, tmcleotides, and nucleic acids. The amount of phosphorus
removed due to sludge wasting may be in the range of 10 to 30
percent of the influent amount for typical secondary treatment
employing the activated sludge process.

    The phoStrip, A/O, and Bardenpho processes were all develop-
ed in the early 1970's by utilizing essentially the same mechan-
ism of enhanced biological phosphorus removal  (or the so-called
"luxury" uptake} in activated sludge systems, which is created
by cyclic stressing of the system to anaerobic (i.e., absence of
molecular oxygen, nitrate, or nitrite) and aerobic conditions.
This mechanism takes advantage of the fact that phosphorus is
released by microorganisms under anaerobic (starved) conditions
and subsequently incorporated to a higher cellular content
(luxury) under aerobic conditions.

    Tne biological phosphorus and BOD removal due to anaerobic-
aerobic contacting in the A/0 process is depicted in Figure 4.
The A/0 process initially mixes the full forward influent and
recycle sludge under anaerobic conditions to influence selec-
tion of microbial population favoraole to such phosphorus re-
moval mechanism  (17). Phosphorus is removed from the system
through wasting of activated sludge that is rich in phosphorus
content. The phosphorus levels in the waste activated sludge
from the A/0 process typically reach 4 to 6 percent by dry
weight, as compared to 2 to 3 percent in conventional activated
sludge.

-------
Influent •
             r_ _ _ Return Sludge
                  Anaerobic
Aerobic
                                                                            ToCfarifier
           c



           1
           4-*

           CD
           O

           O
           O

           CO
           3
           h*
           O

           •§.
           in
           O

           0-


           O

           O
                          Space Time


         Figure 4.  Biological phosphorus and BOD removal due to anaerobic

                    aerobic contacting (Adopted from Ref. 17).
                                         10

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    In the case of  the  PhoStrip process, a portion of the  return
activated sludge  is routed  to  an  "anaerobic  stripper" tank where
the microorganisms  release  soluble phosphorus. The stripper tank
supernatant, which  is only  a fraction of the  total wastewater
flow, needs proportionally  lower  amounts of  lime to precipitate
the phosphorus in this  flow. The  supernatant  and lime mixture
may then be routed  to the primary clarifier  or a separate  re-
actor-clarifier for removal of the precipitated sludge. "She
phosphorus-depleted sludge  from the stripper  is returned to the
aeration basin, where the microorganisms take up phosphorus un-
der aerobic conditions  (13). Part of the phosphorus is also re-
moved from the system through  the waste activated sludge route.
The relative amounts of phosphorus removed through the two exit
points can depend on wastewater characteristics (particularly
the relative concentrations of BOD and phosphorus in the influ-
ent) as well as design  and  operation of a specific system.

    In the Bardenpho process, Barnard (14)  found that higher-
level phosphorus  removal from wastewater occurred during aera-
tion of sludge that was subjected to anaerobic contacting! thus,
he added an anaerobic contacting  stage ahead of the four-stage
(anoxic-aeration-anoxic-reaeration) system originally devised
for nitrogen removal, Barnard also found that nitrates in  the
recycle flow to the anaerobic zone could prevent phosphorus re-
lease and reduce  the high levels  of phosphorus uptake in the
aerobic zone? thus,  the internal  recycle of mixed liquor from
the aerobic to the  anoxic zone (see Figure 3) to remove the ni-
trate is also important from the  standpoint of maintaining an-
aerobic conditions  in the first stage. As in the case of &/Q,
the full forward  influent flow and recycle sludge are subjected
to anaerobic treatment, and the phosphorus is removed from the
system through sludge wasting. Thus, of the three proprietary
systems, PhoStrip is a sidestream treatment process, while A/O
and Bardenpho are mainstream treatment processes.

    The anaerobic-aerobic staging apparently results in the se-
lection of a biological population that is capable of achieving
phosphorus removal.  The actual mechanism for the phosphorus
storage and release is not fully  known, nor is the basis for the
phosphorus removal  population selection. This is partly due to
the complexity of the many factors involved, and to the lack of
complete quantitative fundamental :>ialysis of the biological
phenomena. The following lists tn<* various empirical observa-
tions reported for  the occurrence of biological phosphorus re-
moval (1) :

    •   Phosphorus  release occurs under anaerobic contact-
        ing, with mixed liquor soluble phosphorus reported
        in the range of 20 to 40 mg/i».

-------
•   Phosphorus uptake occurs rapidly under subsequent
    aerobic conditions to produce low mixea liquor
    soluble phosphorus concentrations.

•   The increased phosphorus taken up appears to be
    stored as polyphosphates in the cell, or contained
    in volutin granules within the cell. The volutin
    granules contain lipidsf protein, RNA, and magne-
    sium, in addition to polyphosphates. volutin is
    used for nucleic acid synthesis and may be released
    as orthophosphate to meet metabolic requirements
    of the cell  (5, 48, 49, 50, 51).

•   The synthesis and degradation of poly-beta-hydroxy-
    butyrate  (PHB), which is an intracellular carbon
    storage product, can play a role in the biological
    phosphorus removal  (52 through 60}.

*   Acinetobactor  (a grain-negative, aerobic bacteria)
    has been "frequently found in biological phosphorus
    removal systems and is known to store polyphosphate
     (61, 50,  53, 54, 55). However, glucose is not as-
    similated by Ac inetobactor. Other types of poly-
    phosphate-storing bacteria, including certain gram-
    positive species, Aeromonas, pseuaomonas, and fac-
    ultative bacteria, have also been found to exist in
    biological phosphorus removal systems  (49, 62, 63).

*   Significant levels  (over 70 percent) of influent
    soluble BOD could be taken up by the microorgan-
    isms in the  initial anaerobic stage. Aeration-
    stage oxygen uptake rates are lower in anaerobic-
    aerobic systems than in conventional activated
    sludge systems. This can be due to  the accumulation
    of storage products such as PHB within the cells
    during the anaerobic stage, thereby extending the
    period of oxidation of the carbon source  {57, 58).

•   The presence of nitrates or oxygen  in  the anaero-
    bic stage will prevent phosphorus release and sub-
    sequent biological  phosphorus removal. Methods
    available to mitigate this effect include:

       Feeding high BOD strength wastewater to the sys-
       tem to rapidly deplete any dissolved oxygen.

       Avoiding  any recycling of nitrified effluent  or
       sludge containing nitrate back to  the anaerobic
       stage.

-------
         -  Proyiding removal of nitrate by separate-stage
            devitrification, if nitrification is also re-
            quired.


            Extending the period of anaerobic contacting, if
            necessary, to provide residence time for deni-
            trific
             trification.


 PROCESS CAPABILITY AND LIMITATIONS
 panaM  fc5ree pr?Priefcary Processes have been demonstrated as

 malfv loundTOV1^ ?ho*Phorus fr^ ^e 4 to 12 rag/L range nor-
 mally found in municipal wastewaters  (20)  down to the 1 to 2

       e?f?LS it0ta^ ?hosPhorus  <«»• " is important to con-
       effluent limitations in each specific case to determine

       S^11^0^3011 °f these P«*>««es. For exaJS^JSe
   «   t     3*d Plor/lda-TamPa Bay Region call for effluent
 limitations of 1 mq/L as TP, while some areas in South Africa
 have a standard of less than I mg/L of ortho-phSspSate

 A™*-  aS fi,    ce these Presses are often "marginal" in

 Sa/?Ua«nmefp1Ue?H qUalit? °f less than l  to 2 m
-------
    The A/O process can be used for phosphorus removal with or
without nitrification. Concentrations of total phosphorus in the
treated effluent are usually in the range of 1.5 to 3.0 mg/L
(see Table 2 in Section 3). Since significant amounts of efflu-
ent phosphorus are associated with the suspended solids, efflu-
ent filters would become necessary if total phosphorus at 1 mg/L
is to be met. It is possible that the A/0 process can be design-
ed also for denitrification. However, operations at Largo showed
that only partial denitrification was achieved. The capability
of the A/0 process to provide phosphorus removal, as well as
complete nitrificacation/denitrification, remains to be demon-
strated. It should be noted that phosphorus-rich waste activated
sludge is generated from the A/Q process. The sludge should be
further stabilized to remove degradable portions of volatile
solids by either aerobic or anaerobic digestion.  In particular,
when anaerobic digestion is used, the digested liquor would
contain high concentrations of phosphorus, and it should not be
returned to the front end of the A/0 system without chemical
treatment to precipitate the phosphorus. Air Products estimates
that for each 37,850 m3 (10 million gallons) of wastewater
treated, 1.0 to 1.5 tons (2,000 to 3,000 Ib) of lime are re-
quired for anaerobically-digested sludge, and 0.33 ton (660 lb)
of lime is required for aerobically-digested sludge (17).

    The Bardenpho process is applicable when removal of Doth the
phosphorus and total nitrogen is necessary. This process is not
normally used when only phosphorus removal is required. The cap-
ability of the Bardenpho process to consistently produce total
phosphorus of less than 2 mg/L, or soluble phosphate of less
than 1 mg/L as P, without supplemental mineral addition, remains
to be demonstrated (see Table 3 in Section 3). Effluent filters
would probably be needed if total phosphorus in the effluent is
to be reduced to less than 1 mg/L. Since solids residence time
(SRI) in the Bardenpho process is typically maintained near 20
days and can be as long as 40 days, the excess sludge wasted
from the system is reasonably well stabilized.

DESIGN CONSIDERATIONS

    Since PhoStrip, A/O, and Bardenpho are all proprietary proc-
esses, respective consultation from Biospherics, Air Products,
or EIMCO should be sought when designing a specific biological
phosphorus removal system. Typical design parameters and other
considerations important to each of the three processes are pre-
sented in the following paragraphs.
                                14

-------
PhoStrip Process

Brass--
       Influent BOD5 = ?o to 300 mg/L.
       Influent TP = 3 to 20 mg/L.
       Wastewater temperature =  10 to 30°C.
       Secondary clarifier NO3-N pius NOo-N = l t-n in
       ??£uo^
       Scours? detenti°" time in aeration basin = 1 to
       MLSS = 600 to  5,000 mg/L.
          PhoStrip design parameters  are as follows:
   •   Refer to Figure 1.
   *   t^ofa"?111 retUrn SlUdge flow to be treated  =  0.2
   *   t?mer-b|Ctnh?fPh°rUS friPPer sl^ge retention
       time -8  to 12 hours (elevated NO-,/NCH-N con-
       centrations require a 50 percent incrlase in SRT) .
   »   Stripper  SWD = 6.1 m (20 ft).
   •  Stripper  sludge blanket depth = 4.6  m {15 ft).
   •  Elutriation flow =  50  to 100 percent of the
      per feed  by one of  the  three sources:
                ef,o-
                ettluent e
        Reactor-clarifier overflow elutriation.
                       recycle to aeration basin - 0.1
                           15

-------
    •   Stripper supernatant to reactor-clarifier = 0.1 to
        0.2 Q.

    •   Reactor-clarifier overflow rate = 49 m3/m2/d
        (1,200 gpd/sq ft).

    •   Reactor-clarifier pH = 9.

    •   Lime dosage = 100 to 300 mg/L, depending on alka-
        linity concentration in stripper supernatant.

A/O Process

    Mr Products (17) has developed a bio-kinetic simulation
model that can predict the soluble phosphorus and BOD removal
performance of a treatment plant under a given set of condi-
tions. This model has been tested using the Largo A/0 pilot-
plant and full-scale plant data with good correlation.

    Typical design parameters for the two A/O systems (33) are
as fallows:
                                 BOD and p      BG0, p, and N
    Parameter                     removal         removal
Detention time, hrs
  Anaerobic stage                0.5-1.0           0.5-1.0
  Anoxic stage                     	             0.5-1.0
  Oxic stage                       1-3             3.5-6

F/M,
  kg BODs/day/kg MLVSS           0.2-0.6          0.15-0.25
  (Ibs BQD5/day/lb MLVSS)       {0.2-0.6)        (0.15-0.25)

MLVSS, mg/L                    2,000-4,000       3,000-5,000

Oxygen usage,
  kg O2/kg BODs removed            1.0               1.2
  (Ibs O2/lb BODs removed)         {1.0}             (1.2)

Return sludge flow, % of
influent Q                        10-30             20-50

Underflow concentration,
% solids                           2-4             1.5-3.0

Internal recycle, % of
influent Q                         	             100-300
                                16

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                                 BOD and P      BOD, P, and N
    Parameter                     removal         removal


Minimum D.O.  (oxic stage) »
                                   2. 0               2.0
Sludge wasted,
  kg/kg BOD5 removed             0.5-0.8           0.3-0.6
  (Ibs/lb BOD 5 removed)          (0.5-0.8)         (0.3-0.6)

Mixing energy (anaerobic) ,
  kw/1,000 m3                     10                10
  (hp/1,000 gal)                  (0.05)            (0.05)

Temperature, °C                    5-30              5-30


    Normally suggested formats for baffled staging of the A/O
system are three anaerobic stages , three anoxie stages, and
four oxic (aerobic) stages. The anoxie stages and the internal
recycle are used only if nitrogen removal (i.e., nitrification/
denitrification) is required. The anerobic and anoxie zones are
provided with mixers and covers to avoid exposure to the atmos-
phere. The size of the oxic stage depends on nitrification re-
quirements. Without oxidation of nitrogen, a hydraulic detention
time of 2 to 2.5 hours is recommended. With nitrification, the
oxic stages must be enlarged to 3.5 to 6 hours, depending on
nitrification rate and temperature. The final clarifiers are
normally designed at an overflow rate of 24.5 m^/m^/d (600
gpd/sq ft), with a desired sludge blanket depth of below 0.6 m
(2 ft) . Attention should be paid to possible phosphorus bleed-
back within the sludge blanket due to anaerobic conditions.  Use
of a hydraulic bottom sweep to rapidly remove the sludge can
help to mitigate phosphorus bleedback in this area.  Maximum
design return sludge recycle is 50 to 75 percent of influent
flow.

Bardenpho Process

    The Bardenpho process design approach must evaluate design
requirements for each of the five stages to accomplish phosphor-
us removal, nitrification, and denitrification. The detention
time in each of the five stages is affected by 8005 and total
nitrogen concentration, wastewater temperature, effluent re-
quirements, and sludge handling considerations. Typical design
detention times, based on influent flow, for the five stages,
are as follows:
                                17

-------
Stage
 11 plants in
 South Africa
[Reference 44)
  Range   &vg.
                             Detention  Hrae, hours
   Palmetto/
    Florida
(Reference 38)
 Design  Actual
   Kelownar
    Canada
(Reference 1)
   Design
Anaerobic
First Anoxie
Aeration
(Nitrification)
Second Anoxic
Heaeration
Total
0.6- 1.9 1.3
2.2- 5.2 3.2

6.7-19.0 11.2
2.2- 5.7 3.3
0.5- 1.6 1.1
12.2-33.4 20.1
1.0
2.7

4.7
2.2
1.0
11.6
1.4
3.8

6.6
3.0
1.4
16.2
2
4

9
4
2
21
    Sludge disposal considerations may affect the process de-
sign sizing. For example, many Bardenpho system designs, which
are based on achieving nitrification and denitrifieation, may
result in a final SRT that may be within the range of sludge
stabilization by aerobic digestion. In such cases, design SRT
values are increased by increasing the detention times of the
aeration tanks to achieve a stable sludge in addition to
nitrogen, BOD, phosphorus, and suspended solids removal  (1).

    The first step in the Bardenpho design is to review the fac-
tors that will determine the amount of biological phosphorus
removal. Phosphorus removal will therefore depend on the amount
of sludge wasted and the percent phosphorus content of the
sludge. The influent 6005 concentration and system SRT will
determine sludge production. The percent phosphorus in the
waste sludge may be affected by the anaerobic zone detention
time, as well as the influent soluble 6005 concentration. The
amount of nitrate or dissolved oxygen in the recycle streams to
the anaerobic zone must be minimal for effective phosphorus re-
moval. The sludge wasting techniques must also be evaluated to
maximize phosphorus removal from the system. Sludge processing
and wasting techniques that result in leaching of phosphorus
from the biological cells, and the subsequent return of this
leached phosphorus to the Bardenpho system, will reduce phos-
phorus removal efficiency. Bardenpho sludges have been wasted
to drying beds, applied on land, or thickened by dissolved air
flotation prior to dewatering to minimize phosphorus release
(1).
                                18

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    The first anoxic design follows a nitrogen balance performed
for the system. This balance determines the amount of nitrogen
oxidized by subtracting from the influent nitrogen, the nitro-
gen used for cell synthesis and the ammonium nitrogen in the ef-
fluent. Using a four to one internal recycle rate, two-thirds
of the ammonium nitrogen oxidized in the nitrification stage is
then directed to the first anoxic stage. The first anoxic stage
is designed for complete denitrification of the recycled ni-
trate t and its volume is a function of the MISS concentration
and specific denitrification rate (64) .

    The remaining nitrate is denitrified in the second anoxic
stage. The specific denitrification rate (64)  has been described
for this stage as a function of the endogenous respiration rate
of the mixed liquor. This will be a function of the system SET,
temperature, and active fraction of the mixed liquor suspended
solids. The volume for the second anoxic stage is then deter-
mined by the amount of nitrate that must be reduced, the specif-
ic denitrification rate, and the system MISS concentration.

    The first step in the nitrification stage design is the
selection of the necessary nitrification SRT as a function of
wastewater temperature. A minimal nitrification SRT predicted
by Knowles (65) may be used with a 2 or 3 safety factor multi-
plier depending on peak to average flow conditions expected.
The nitrification stage SRT is then determined using the follow-
ing equation;

                                  (MLSS) V
                           SRT  =         n
                              n   ₯  (&BQD) Q


where:

    SRTn   = Nitrification stage design SRT, day.

    MLSS   = Mixed liquor suspended solids, mq/L.

    Vn     =» Nitrification stage volume, m3 (million gallons).

    Yn     = Net system sludge yield based on overall system
             SRT, kg SS/kg BOD5 removed (Ibs SS/lb BODs
             removed).

    AsOD   = BOD removal in system, mg/L.

    Q      = Wastewater flow, m3/d  (mgd).

    The total  system SRT is based on all of the stages where
biological growth can occur, and not just the nitrification
stage. The net sludge yield includes cell synthesis and
endogenous decay.

                                19

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    Oxygen requirements for the nitrification aeration stage are
based on the amount of BOD removed, the net kg C>2/kg BOD5
removed (Ibs 02/lb BODs removed) based on the total system
SRT, and the oxygen required to oxidize the ammonium nitrogen
minus a credit for the equivalent oxygen available during ni-
trate reduction. The reaeration stage is designed both to strip
enmeshed nitrogen gas bubbles from the floe matrix and to raise
the mixed liquor dissolved oxygen concentration to at least 2
mg/L or higher as determined by effluent requirements.

    The above design approach may involve iterations until the
desired overall system SET is met with regard to sludge aerobic
stabilization needs. If the sludge is to be stabilized by addi-
tional steps or handled in a different manner, then the volume
of the stages will be determined only by nitrification and
denitrification needs (1).

    The anaerobic contact detention time is presently based on
experience. The importance of sufficient carbon for the removal
of nitrates has been stressed by Barnard (45)« It would appear
that at a CODrTKN ratio of above 10, there are no problems in
reducing the nitrates and inducing the removal of phosphorus.
Primary sedimentation could change this ratio, and the degree
of such removal must be determined. When there is sufficient
carbon, some form of high rate primary sedimentation may be
economical, and this has been applied in some plants. On the
other hand, if the wastewater is weak and there is insufficient
carbon to induce anaerobic conditions, provisions should be
made to bypass the primary clarifier and to pass only part of
the return sludge to the anaerobic zone, while bypassing the
remainder to the anoxic zone, provision of flow equalization
ahead of the system can also serve to avoid the short detention
time in the anaerobic contact zone during peak hydraulic flow.

OPERATIONS AND MAINTENANCE CONSIDERATIONS

    In general, the three proprietary processes for phosphorus
removal are not appreciably different from the equivalent con-
ventional activated sludge process with mineral addition. A
number of various mechanical problems have been experienced in
all three types of plants, which have caused either delay in
startup or interruptions in stable operation. These problems
are more related to mechanical design and selection of equip-
ment than to the process itself. However, process problems can
be induced due to mechanical problems. Therefore, higher stand-
ards of operator training and a greater theoretical knowledge
of the process on the part of operators than those for conven-
tional activated sludge plants are required. The Bardenpho proc-
ess is more complicated than PhoStrip or &/Q  (without nitrifi-
cation) from the process standpoint, since the former involves
both phosphorus and nitrogen removal. The relatively highly
skilled staff and large number of sample analyses required for
successful operation of a biological phosphorus removal system
could well be a major burden for some small plants  (44).

                                20

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                            SECTION 3

                        DEVELOPMENT STATUS
PHOSTRIP PROCESS

    Since the concept of the PhoStrip proce: i was devised in
1965 by Levin (5), many pilot studies and plant-scale demonstra-
tion tests had been conducted in the early 1970's to substanti-
ate the applicability of this process under various operating
conditions. In addition, over a dozen full-scale plants employ-
ing the PhoStrip process have been constructed, many of them in-
volving retrofitting of existing facilities.  Available pilot and
full-scale operations data from plante employing the PhoStrip
process are presented in Table 1. The results of the findings
from the available pilot tests and plant-scale data are summar-
ized below;

    •   The PhoStrip process is capable of producing ef-
        fluent quality with total phosphorus (IP) of 1
        mg/L, most of the time, without effluent filtra-
        tion.

    •   Excursion of total phosphorus above the 1 mg/L lev-
        el can happen due to high suspended solids dis-
        charged in the final clarifier effluent.  Seven of
        the plants shown in Table 1 include the use of ef-
        fluent filters to assure that the effluent TP of 1
        mg/L is met.

    •   The PhoStrip process is applicable to a wide range
        of activated sludge modes and various wastewater
        characteristics.

    •   The PhoStrip process requires less chemicals and
        produces less sludge than conventional mainstream
        treatment using lime addition for phosphorus re-
        moval*
                                21

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                          TABLE  1.   PHOSTKIP PROCESS — PILOT AND  FULL-SCALE PLANT OPERATIONS DATA
(O
NJ
Plant and location
District of Columbia
Seneca Falls, New York
Reno-Sparks, Nevada


Texas City, Texas
Brockton, Massachusetts

Union Carbide's Labora-
tory, Tonawanda, Hew York
Adrian, Michigan
Central Contra Costa
Sanitary District,
Walnut Creek, California
Design
flow
n>3/d
(mgd)
	
3,785
(1.0)
22,700
(6.0)
...
113,600
(30.0)
*-——
---
18,900
(5.0)
	
26,500
(7.0)

Actual
flow
nVd
(mgd)
	
3,400
(0.90)
21,900
(5.8)
...
89,300
(23.6)
• — >-
---
___
— -~
21,000
(5.6)

Influent
T-P Ortho-P
Status mg/lt mg/L
0.038 ra3/h (10 gph) 6.4 	
pilot test in 1972
Full-scale demonstra- 6,3 	
tion in 1973
Plant-scale test in 7,7 	
1974-1975
1.07 B3/h (4.7 8.4 	
gpra) , Phase 11
pilot-f»lant test in
1976
Started up in 1981j 6.3 —
mechanical problems
0.038 m3/h (10 gph) 7.9 	
pilot-plant test in
1976
1.04 m3/h (4,6 gpm) 8.7 	
pilot-plant test in
1976
Plant under construe- 	 	
tion
0.064 «3/h (0.28 12
gpm) pilot test in
1976
Started up in 1981j 4.5 	
temporary shutdown
after 5 months good
operation to replace
stripper feed pumps
0.45 m3/h (2 gpm) 10 	
pilot-plant operation
in 1981; Phase Id data
Effluent
T-P Ortho-P
mg/L mg/L References
0.92 0.45 41
0.55 — 12
liO 	 23, 24
0.8 24
0.75 	 25
0.7 — 24
1.0 — - 26
* -— 31
0.75 0.4 27
0.5* — 13, 31
1.0 0.2 28
       •Effluent filters used.

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                                                       TABLE 1.   (continued)
to
Plant and location
ftnthecst, New York






cacpentetsville, Illinois




Lansdale, Pennsylvania

Lititz, Pennsylvania


Little Patuxent, Maryland
(She Savage Plant)


Southdowns, New Xork

Texas City, fexas


Ithaca, New Jock

Ho Chester, New York

Tahoe/Truckee, Nevada

Design
flow
(rngd)
90,800
(24.0)





18,900
(5.0)



9,500
(2.5)
13,200
(3.5)

56,800
(15.0)


60,600
(16.0)
30,300
(8.0)

37,800
(10.0)
71,900
(19.0)
18,900
(5.0)
Actual
*i°w influent Effluent
mj/d r-p Ortho-p T-P Ortno-P
- * 	 31
_..
          *E£fluent  filters  used.

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    The PhoStrip process was marketed by Biosphericsf Inc. until
1974 when Union Carbide purchased the Levin patent. Biospherics
reacquired the PhoStrip rights in 1981, and is presently market-
ing the process at the following address:

                     Biospherics Incorporated
                        4928 Wyaconda  Road
                   Rockville,  Maryland  20852

                     Telephone: 301-770-7700

    The equipment used in the PhoStrip process includes concrete
or steel tanks, mixers, pumps, and lime feed facilities. These
are all conventional wastewater treatment facilities and are
available from many competitive equipment suppliers. However,
there have been many cases of mechanical difficulties observed
during startup. There  is need to provide a more reliable equip-
ment package, particularly  those related to transfer pumps, lime
handling facilities, and automatic control instrumentation.

A/0 PROCESS

    Since the &/O process was developed and patented by Air
Products and Chemicals, Inc. in the 1970's, a number of labora-
tory-scale and pilot-plant  tests have  been conducted, including
those at Bath, Pennsylvania? Washington, DC;  Allentown, Pennsyl-
vania? Rochester, New  York? and Largo, Florida. The only plant-
scale demonstration  facility existing  so far  is the  3.0-mgd
retrofitted portion  of the  plant at Largo, Florida, After com-
pleting pilot and plant-scale  A/0 studies, the City of Largo
decided to expand their entire 9-mgd  plant to 15 mgd. Full-scale
A/O plants for several municipalities  are currently  in the de-
sign stage or under  construction. Available data from pilot and
plant-scale operations employing the  A/O process are presented
in Table  2. The  results of  findings from the  pilot and plant-
scale  tests are  summarized  as  follows:

    *   Soluble  ortho-phosphorus can  be  reduced to less
         than  1 mg/L  by the  A/0 system without nitrifica-
         tion  in  a  relatively  short detention  time  (less
         than  4  hours).

    9   Data  from  the  Largo demonstration  plant showed  that
         the A/O  system with nitrification  produced effluent
         soluble  phosphorus  in excess  of  1  mg/L during the
         first four months,  but less  than 1 mg/L after  that
         period  of  acclimation. Ammonia nitrogen was  gener-
         ally  reduced to less  than  2 mg/L»  which indicated
         that  nitrification  was quite  effective. However,
         nitrate  and   nitrite  levels  in the treated
                                 24

-------
                            , TABLE 2.  A/0 PROCESS —  PILOT AND FULL-SCALE PLANT OPERATIONS DATA
        Plant  and location
Design  Actual
 flow    flow

(mgd)   (ngd)
                                                                           Influent
                  Effluent
                                                          Status
T-P
mg/L
                                            ortho-P
                                             mg/L
T-P
mg/L
Qrtho-P
   mg/L
                                                                                                          References
        Bath,  Pennsylvania
        Washington,  DC

        Allentown,  Pennsylvania



        Rochester,  New tork
K5
tn
        Largo,  Florida
   ___     	  11-21 liters <3-5.5    20.      	
                gal)  bench-scale
                laboratory tests;
                A/0 without nitrifi-
                cation (2.6 hours  de-
                tention)

   	     	  Pilot-plant data        	     3.4

   	     	  Pilot-plant data;  A/0 18,
                without nitrification
                (3.7  hours detention)

   __'_     	  2.8 m3 (750 gal)        	     2.23
                pilot plant;  A/0
                without nitrifica-
                tion  (2.0  hours deten-
                tion)

                A/0 with nitrifies-     	     4.1
                tion  (4.0  hours deten-
                tion)

           ___  2.8 m3 (750 gal)        	     5.83
                pilot plant;  A/o
                without nitrification
                (2.1  hours detention)

11,400  12,100  Demonstration plant;    8.9     	
  (3.0)    (3.2)  A/0 with nitrification
                (4.2  hours detention)/
                March 1980 perfo ma nee
                test  data

                City  operation; A/O     -—     - —
                without nitrification;
                February-June 1981 data

                City  operation; A/0     	     	
                with  nitrification;
                July  1981  - February
                1982  data
                          4.4    17
                          0.1    31

                          0.3    32



                  	     0.49   16,  17






                  	     0.3S   16,  17



                          1.03   17




                  1.85    0.51   17,  34,  35






                  1.3S    0.64   17



                  1.77    1.04   17 •

-------
TABLE: 2.   (continued)
Plant and location
Largo, Florida (continued)
patapsco Plant,
Baltimore, Maryland

Lancaster, Pennsylvania
to
0%
Huron, Michigan
Spr ingettsbiary , Pennsyl-
vania
liberty Lake, Washington
Cox Creek, Maryland
Titusville, Florida
Design Actual
flow flow
n3/d n)3/d
(mgd) (mgd)
56,800 	
(15.0)
	 	
265,000 	
(70.0)
34,000 	
(9.0)
79,500 	
(21.0)
90,800 	
(24.0)
56,800 	
(15. D)
7,600 	
(2.0)
56,800 	
U5.0)
22,700 	
(6.0)
Influent Effluent
T-P Ottho-P T-P Ortho-P
Status mg/L mg/L mg/L mg/L References
Plant expansion under 	 	 	 	 17, 36
construction
Pilot-plant in prog™ 	 	 	 • 	 36
ress
Retrofit selected but 	 -»- 	 	
not yet in design
Retrofit in design -~ -— 	 	 36
Plant in design 	 	 	 	
Plant in design 	 	 — — 	 36
Plant in design 	 	 	 	 36
Plant in design 	 	 	 	 36
Retrofit selected but • 	 	 • 	 	 36
not yet in design
Selected but not yet 	 	 	 -• — 3fr
in design

-------
        effluent were in the range of 8 to 10 mg/L,  which
        indicated that only partial denitrification  was at-
        tained.  The ability of the A/0 system to achieve a
        high degree of denitrification and to produce ef-
        fluent soluble phosphorus of less than 1 mg/L on a
        consistent basis remains to be demonstrated.

    •   The performance of the A/0 system is  dependent on
        the ratio of soluble BOD to phosphorus in the feed
        to the system! it will operate*best when the ratio
        is greater than approximately 10 to 1.

    •   Phosphorus removal performance remained relatively
        stable as operating temperature was decreased from
        15°C to 10°C,  and actually improved as operat-
        ing temperature was further decreased from 10°C
        to 5°C.

    •   The A/Q system produces a pnosphorus-rich (4.2 to
        6 percent by weight) excess sludge which must be
        further stabilized before final disposal.

    •   Concentrations of total phosphorus (i.e., soluble
        plus suspended form) in the A/0 effluent at  Largo
        were in the range of 1.3 to 2.0 mg/L. The phos-
        phorus concentrations were attributable to the
        total suspended solids (TSS)  in the clarifier ef-
        fluent.  (For example, if the TSS were 20 mg/L in
        the clarifier effluent and contained  5 percent of
        P, the phosphorus in these solids would amount to
        1.0 mg/L), Therefore, effluent filters will  be
        necessary if effluent limitations call for total
        phosphorus not to exceed 1 mg/L.

    9   Chemical treatment may be required to reduce the
        amounts of phosphorus contained in the internal
        sidestreams, particularly in the case of superna-
        tants from anaerobic digesters.

    Additional information on A/0 can be obtained from the fol-
lowing address;

                Environmental Products Department
                 Air Products and Chemicals,  Inc.
                             Box 538
                  Alientown,  Pennsylvania   18105

                     Telephone;   215-481-4911
                                27

-------
    The equipment used in the A/Q process includes concrete or
steel tanksf mixersf aerators, clarifiers, and pumps for recycle
and sludge handling. As in the case of the PhoStrip process,
these are all conventional facilities available from many equip-
ment suppliers.

BARDENPHQ PROCESS

    The original process developed by Barnard (14) in the early
1970's was a single-sludge, four-stage (anoxic-aeration-anoxic-
reaeration) system intended for nitrogen removal by biological
nitrification and denitrification. The modified Bardenpho proc-
ess is a five-stage system, with an anaerobic stage added ahead
of the original four-stage system for biological phosphorus re-
moval (see Figure 3). Over 30 wastewater treatment plants era-
ploying the Bardenpho process Cor both phosphorus and nitrogen
removal have been designed or operated in South Africa (44).
The first facility employing this process in the U.S. is the
5,300 m3/d (1.4 mgd) plant located in Palmetto, Florida. An-
other Bardenpho system, the 3,200 m3/d (0.85 mgd) plant in
Pluckemin, New Jersey, started operation in late 1982. The first
Bardenpho system in Canada is the 60,600 m3/d (6 mgd) facility
in Kelowna, British Columbia, which started operation in mid-
1982. Available pilot and full-scale operations data from plants
employing the Bardenpho process are presented in Table 3. The
results of findings from the pilot and plant-scale teats are
summarized as follows:

    •   Bardenpho is a promising process for removal of
        both phosphorus and nitrogen, although limited op-
        erating data from the existing plants show incon-
        sistencies in plant performance.

    •   Many plants in South Africa produce variable con-
        centrations of effluent phosphorus (see Table 3),
        possibly due to a combination of reasons, such as
        weak wastewater strength in the feed, high TKN-to-
        carbon ratio, and low plant flow relative to de-
        sign capacity.

    •   The capability of the process to consistently pro-
        duce total phosphorus of less than 2 rag/L, or
        ortho-phosphate of less than 1 mg/L as P, remains
        to be demonstrated. At Palmetto,  Florida, the
        average total phosphorus concentration during the
        period between April and September 1980 was 2.2
        mg/L after effluent filters. Addition of a small
        dose of alum was necessary to reduce the total
        phosphorus to 0.8 mg/L (1).
                                28

-------
                 TABLE 3.   BARDENPHO PROCESS -- PILOT AND FULL-SCALE PLANT OPERATIONS DATA
Plant and location
Palmetto, Florida









Kelowna, B.C., Canada


pluckemin, New Jersey

Daspoort, Pretoria,
South Africa
Alexandra Plant,
Johannesburg, South
Africa
Olifantsvlei Plant,
Johannesburg, South
Africa
Johannesburg, South
Africa
Goukoppies, South Africa




Northern Works, South
Africa
Design Actual
m3/d m3/d
(mgd) (mgd)
5,300 4,600
(1.4) (1.22)



4,100
(1.08)
3,785
(1.00)


60,600 	
(6.0) 	


3,200
(0.85)
.__
	 ---
	 	
__,
	 	

...


— — — — — —
Influent
T-P ottho-P
Status nig/k mg/L
Design detention 8.2
=11.6 hours; started
up in October 1979;
February-April 1980
operating data
April-September 1980 6.2 	
operating data
October 1981-Maech 7.6
1982 operating data
(with minimal alum
dosage added)
Design retention 	 —
- 21 hours; started up
in July 1982? first 6
weeks of operating data
Started up in late — —
1982
4.1 m3/h (18 gpm) 10.5 	
pilot plant 10. ---
Full-scale plant 6.7 	
modifications operat-
ing data
Full-scale plant 4.2 	
modifications operat-
ing data
Laboratory-scale 9 —
plant No. 1
laboratory-scale 6.6 	
plant No. 1 (MLSS =
2,700 mg/L)
Laboratory-scale 6.6 —
plant No. 2 (MLSS »
3,100 mg/L>
Laboratory-scale 7.1 —
plant No. 1 (MLSS =
1,300 mg/L)
Effluent
T-P Ortho-P
mg/L mg/L References
2.5* — - 37, 38, 39



2.2* --- 1

0.8* — 1



0.2* 1


1

1,0** 	 15, 40
1.5 — 41
0.3** 	 15, 42, 43
2.2** 	 IS, 42, 43
<1 — 41
1.7 — 41

1,1 — 41


6.4 41
 *Ef£luent filters used.
**Not specified as either total or ortho-phosphorus.

-------
                                            TABLE 3.   (continued)
Plant and location
Northern Hocks, South
Me lea (continued)



Secunda, South Africa



Roodepoort, South Africa

Vanderbi jlpark, South
Africa
Meyer town, South Africa

Standerton, South Africa

Benoni, South Aft lea

Klerksdorp, South Africa


Stilfontein, South Africa

Baviannpoort , South
Africa


Northern Works, Johannes-
burg, South Africa




Design
flow
m3/a
<«jd)
« M H-"




3,400
(0.9)


6, BOO
(1.8)
9,100
(2.4)
4,900
(1.3)
4,500
(1.2)
7,600
(2.0)
7,900
(2.1}

10,600
(2.8)
15,900
(4.2)


151,400
(40.0)




Actual
flow
mVa
(-«»a>
!-«.—




4,900
(1.3)


4,200
(l.l)
___
— — —
3,000
(0.8)
3,000
(0.8)
4,500
(1.2)
15,900
(4.2)

5,300
(1.4)
9,500
(2.5)


75,700
(20.0)




Influent Effluent
T-P Ortho-P T-P Ortho-P
Status mg/ti mg/t mg/L mg/t. References
Laboratory-scale 10. 	 	 < 1 41
plant So. 2 (MLSS •
2000 mg/L; primary
sludge added to
system)
Started up in October 	 3-10 	 1 1, 44
1976 (toxic and aero-
bic zones not physi-
cally separated)
Started up in March 13 — 9 — 1, 44
1978
Started up in October 	 2-7 	 2-7 1, 44
1979
Started up in April 9 	 --- 1-7 1, 44
1977
Started up in June 	 15 	 6-10 1, 44
1979
S tat ted up in August 10 	 7 	 1, 44
1979
Started up in Febru- 	 	 1** — - 1, 44
ary 1979 (no secondary
anoxic stage)
Started up in March 	 — 	 	 1, 44
1977
Started up in August 	 15 	 11 1, 44, 45
1979 j poor phosphorus
removal due to high
TKN/carbon ratio
Design detention 9.4 	 7.1 6.0 1, 44, 46
» 14 hoursf started up
in Hovember 1979; low
strength of feed from
primary effluent caused
poor phosphorus removal
 •Effluent filters used.
**Not specified as either total or ortho-phosphorus.

-------
                                                        TABLE 3.  (continued)
U>

Plant and location








Goudkoppies plant,
Johannesburg, South
Africa


RandEontain, South Africa

Indhoek, South Africa

Cape Flats, South Africa

Mitchell's Plain, South
Africa
Witbank, South Africa

Potchefstroom, South
Africa
Que Que, Zimbabwe

Umtall, Zimbabwe

, ,
E>9 jt I.SDIJ iry t SIIUDSOWG

Bulawayo, Zimbabwe

Design
flow
(mgd)








151,400
(40,0)



9, BOO
(2.6)
11,000
(2.9}
151,400
(40.0)
22,000
(5.8)
22,000
(5.8)
9,800
(2.6)
9,800
(2.6)
9,800
(2.6)
"} £ 'Sfin
J O r «3UU
(9.6)
9,800
(2.6)
Actual
flow Influent Effluent
n»3/d T-P Ortho-P T-E Ortho-P
(fflgd) Status mg/L mg/L mg/L mg/L
37,100 Primary sludge added 10 4.0 1.3 1.3
(9.8) to system during an
experimental period to
increase feed strength
and improve perform-
ance! experiment term-
inated to correct prob-
lems related to rag
98,400 Design detention 7.5 	 1.4 0.7
(26.0) = 14 hours; started
up in December 1977 j
1980-1981 operating
data
... ... ___ ... ___ ___
...
... ... __. 	 ___ 	
~ -
... ... ... ... ... .__
— ,
	 . ... ... , 	 . 	 „ . 	
—
_._ ... ... ... ... ...
...
... ... ... ... ...
	
..*,... ... ... ... ...
— .
... ___ ... 	 	 ___
. —

** — — . ..— .«w ... ...
-__
	 ___ ___ ___ ___ ___
...

References
46







1, 44, 46



1

1

1

1

1

1

1

1


1

1

            *Bffluent  filters used.
           **Kot  specified as either  total  or  ortho-phosphorus.

-------
    •   At the Palmetto plant, the polishing filters remove
        only 3 to 4 mg/L of suspended solids. The suspended
        solids concentrations in the clarifier effluent
        are very low (average of less than 5 mg/L)  before
        final filtration treatment, due to the very low
        sludge volume index (SVI)  and rapid sludge settling
        characteristics. This plant maintains a solids res-
        idence time (SRT) of approximately 20 days, which
        is in the low range of 20 to 40 days typically
        found in the Bardenpho process.

    •   Problems encountered during the start-up period at
        the Palmetto facility were related to the internal
        recycle pumps.  Without the internal recycle, efflu-
        ent nitrate concentrations exceeded 8 to 10 mq/L,
        which caused biological phosphorus removal to de-
        crease markedly to less than 50 percent. This was
        actually a mechanical problem rather than one re-
        lated to the process itself. Once the recycle pumps
        were operable,  the effluent nitrate concentration
        decreased and phosphorus removal improved.

    The Bardenpho process is marketed in the United States by
Envirotech at the following address:

                 EIMCO  Process Machinery Division
                     Envirotech Corporation
                      669 West Second South
                           P.O.  Box 300
                   Salt Lake City, Utah  84110

                     Telephone:  801-526-2000

    As in the case of the PhoStrip and A/0 processesf the equip-
ment used in the Bardenpho process includes the conventional fa-
cilities of concrete or steel tanks, mixers, aerators, clari-
fier s, and pumps.

-------
                            SECTION 4

             COMPARISON WITH EQUIVALENT TECHNOLOGIES
EQUIVALENT CONVENTIONAL CONCEPT

    Although the primary purpose of this evaluation is to com-
pare the costs for phosphorus removal, the PhoStrip, A/O, and
Bardenpho processes have different levels of applications with
respect to their capability to provide various degrees of BOD,
phosphorus, and nitrogen removal. Due to this complexity, these
three processes should not be compared with each other indis-
criminately- The conventionally-available phosphorus removal
methods primarily involve mineral addition with alum, ferric
chloride, or pickle liquor.

    The total costs involved for using ferric chloride are
slightly less than those for alumj however, iron and color con-
centrations in plant effluents treated with ferric chloride or
pickle liquor may become a concern on occasion. The costs in-
volved in using two-stage tertiary lime treatment are usually
higher than those for alum treatment, except in the case of very
large plants (see Reference 66, Pact Sheets 4.2.2 vs 5.1.1).
Furthermore, lime treatment generates more solids handling, as
well as potential precipitation and line freezing problems. For
aXo. of the above considerations, the conventional activated
sludge treatment (one, two, or three separate-stage systems, de-
pending on the degree of nitrogen removal involved), together
with alum addition, is assumed as the baseline technology for
cost comparison with the three proprietary phosphorus removal
processes. The alternative cases evaluated for costs and energy
requirements in this technology assessment report are depicted
in Table 4. Tne alternative cases included here are considered
to be among those more frequently encountered, but are not meant
to be exhaustive.

    It should be further noted that, in this model comparison,
it was assumed the PhoStrip process could produce effluent TP
of 1 rog/L, and that the A/O and Bardenpho processes could
produce effluent TP of 2 tng/L without effluent filters.
                                33

-------
                TABLE 4,  ALTERNATIVE CASES EVALUATED UNDER TECHNOLOGY ASSESSMENT
                          OF BIOLOGICAL PHOSPHORUS REMOVAL
    Alternative cases
                                      A                       B
                                  (Baseline)
                     Activated sludge with alum addition
                        1-Stage    2-Stage    3-Stage      PhoStrip
          A/O   Bardenpho
to
1,  Phosphorus removal
    (effluent TP = 1
    mg/L)

2.  Phosphorus removal
    (effluent TP = 2
    mg/L)

3.  Phosphorus removal
    and nitrification
    (effluent TP = 2
    mg/L,  NH3-N = 1
    mg/L)

4.  Phosphorus removal
    and nitrification/
    denitrification
    (effluent TP = 2
    mg/L,  TN = 3 mg/L)
                              1-A
                              2-A
                                         3-A
                                                    4-A
1-B
2-B
1-C
2-C
         3-C  (*}
                   4-D
    TP « Total phosphorus.
    TN = Total nitrogen.
    *  = Partial denitrif ication to TN - 10 mg/L in A/0 process per Largo,  Florida data.

-------
     The  related  sludge handling processes assumed  in the model
 are  as follows:

     *   Thickening  of  waste  activated  sludge by Dissolved
         Air  Flotation  (DAF)  for all plant sizes except
         1,892  m3/d  (0.5 mgd).

     *   Stabilization  of primary and waste activated sludge
         (except  the latter from Bardenpho) by aerobic di-
         gestion  for plants smaller than 37,850 m3/d (10
         mgd),  or anaerobic digestion for plants greater
         than 37,850 m3/d (10 ragd).

     •   Dewatering  of  stabilized sludge by sludge drying
         bed  for  plants smaller than 3,785 m3/d (1 mgd),
         or vacuum filtration for plants greater than 3,785
         mj/d (1  mgd).

     •   Sludge hauling (32 kin (10 miles) one way) and
         landfilling for  all plant sizes.

 COST COMPARISON

     For  each of  the alternatives indicated in Table 4,  costs
 were developed for  three plant sizes based on average design
 flow:

     1.    1,892  m3/d (  0.5 mgd)
     2.   18,925  mVd (  5p0 mgd)
     3.   189,250  m3/d (50.0 mgd)

     In each  case, costs were compared on a "total plant" basis
 since the various processes would generate different amounts of
 biological and inorganic solids, which affect sludge handling
 and  disposal costs.

     The  economic analysis of the three proprietary processes and
 baseline technologies  considered the initial investment cost
 (capital cost),  the annual operation and maintenance cost,  and
 the  present  worth cost of the total treatment system.  Cost  esti-
 mates developed  by  the U.S. EPA for evaluating innovative and
 alternative  technologies (66) were used as the primary  source
 for  estimating installed capital,  and annual operation  and  main-
 tenance costs  for most of the unit processes involved.  These
 cost estimates were supplemented with cost figures from Appendix
 H of the Areawide Assessment Procedures Manual (67) for the non-
 structural cost  components (e.g.,  influent pumping or lift  sta-
 tion, and miscellaneous structures such as control buildings,
 outfall sewer,  etc.). Cost curves for the A/O and Bardenpho
processes were not available in the literature;  therefore,  these
 costs were developed by WESTON based on preliminary concept de-
 sign of the facilities and in-house cost estimates.


                               35

-------
     All cost estimates were updated to reflect October 1982
construction costs  ( Eng ineeringNews_ Record Construction Cost
Index 3875).  The basic assumptions and procedures utilized in
estimating construction costs are summarized in Appendix A.

     The estimated  capital, O&M, and total present worth costs
for each of the alternative cases and different plant sizes are
presented in Tables B-l through B-12 in Appendix B.  Tables 5, 6,
1, and 8 show the summaries of cost comparison for equivalent
alternative cases.  A summary of least cost alternatives (based
on total present worth) is presented in Table 9.  The cost curves
for capital and total present worth costs for these alternatives
are depicted in Figures 5(a), 6{a), 7(a}f and 8(a).  The cost
curves for comparative o&M costs are presented in Figures 5(b),
6(b), 7(b)f and 8(b).

     It should be noted that site specific conditions will effect
changes in the relative costs of each of these alternative tech-
nologies and, therefore, these estimates are merely presented as
guidance to potential users to assist their cost-effective analyses
in terms of procedure and reasonable default values.  Also, no
consideration has been given to retrofit applications, which
greatly accentuate  the controlling nature of site specific con-
ditions.

ENERGY REQUIREMENTS

     An approach similar to that utilized for cost comparison was
used for estimating the energy requirements for the alternative
cases shown in Table 4.  The estimated energy requirements by
unit processes are presented in Tables B-13 through B-24 in Ap-
pendix B, and summarized in Table 10.  Those alternatives requir-
ing the least amount of energy are also denoted in Table 10,
                              36

-------
w
•j
                                TABLE 5.   SUMMARY OF COST COMPARISON1



                                               CASE 1

                                         PHOSPHORUS REMOVAL

                                       (EFFLUENT IP = 1 mg/L)
Plant size
Alternative
1-A
(Baseline)
1-B
1-C
Costs
Capital2, $
O&M, $/year
Total present worth,
Capital2, $
O&M, $/year
Total present worth,
Capital2, $
O&M, £/year
Total present worth,
1,892 m3/d
(0.5 mgd)
2,461,000
202,000
$ 4,501,000{*)
3,373,000
253,000
$ 5,928,000
2,990,000
210,000
$ 5,111,000
18,925 ni3/d
(5 mgd)
9,628,000
805,000
17,757,000(*)
11,182,000
690,000
18,150,000
11,763,000
775,000
19,589,000
189,250 m3/d
(50 mgd)
49,306,000
5,200,000
101,817,000
52,416,000
3,666,000
89,436,000(*)
56,319,000
4,212,000
98,853,000
          Alternative 1-A * One-stage activated sludge system with alum addition


          Alternative 1-B = PhoStrip,


          Alternative 1-C * A/O (4 hours total detention) with effluent filters.
               Tables B-lf B-2, and B-3 in Appendix B for breakdown of costs by unit
           processes.

          2ENR Construction Cost Index - 3875.


          (*)  Denotes least cost alternative.

-------
U)

00
                                TABLE  6,  SUMMARY  OF COST COMPARISON1



                                               CASE 2

                                         PHOSPHORUS REMOVAL

                                       (EFFLUENT TP = 2 mg/L)
Plant size
Alternative
2-A
(Baseline)
2-B
2-C
Costs
Capital2, $
O&M, $/year
Total present worth,
Capital2, $
O&M, $/year
Total present worth,
Capital2, $
O&M, $/year
1,392 m3/d
(0.5 mgd)
2,451,000
197,000
$ 4,440,000
3,373,000
253,000
$ -5,928,000
2,496,000
183,000
18,925 m3/d
(5 mgd)
9,602,000
774,000
17,418,000
11,182,000
690,000
18,150,000
9,600,000
641,000
189,250 m3/d
(50 mgd)
49,113,000
4,890,000
98,494,000
52,416,000
3,666,000
89,436,000
. 46,419,000
3,540,000
         Alternative 2-A = One-stage activated sludge  system  with  alum addition.


         Alternative 2-B = PhoStrip.


         Alternative 2-C = A/0  (4 hours total detention) .
              Tables B-4, B-5, and B-6 in Appendix B for breakdown of  costs by unit
          processes.                                                          J ""•*'-

         2ENR Construction Cost Index = 3875.


         (*)  Denotes least cost alternative.

-------
                               TABLE 7.  SUMMARY OF COST COMPARISON1
                                               CASE  3
                               PHOSPHORUS  REMOVAL AND  NITRIFICATION
                               (EFFLUENT  TP =  2 mg/L, NH3~N  =  1  mg/L)
U)
Plant size
Alternative
3 -A
(Baseline)
Costs
Capital2, $
O&M, £/year
Total present worth,
1,892 m3/d
(0.5 mgd)
2,990,000
227,000
$ 5,282,000
18,925 m3/d
(5 mgd)
11,376,000
854,000
20,000,000
189,250 m3/d
(50 mgd)
56,239,000
5,369,000
110,457,000
            3-C
Capital2, $            2,788,000
O&M, $/year              195,000
Total present worth, $ 4,757,OOQ(*;
10,596,000
   702,000
17,685,000(*)
52,501,000
 3,952,000
92,409,000(*}
         Alternative 3-A = Two-stage activated sludge system with alum  addition.

         Alternative 3-C » A/0  (6 hours total detention) for nitrification  and  partial
                           denitrification to TN = 10 mg/L.


         %ee Tables B-7, 8-8, and B-9 in Appendix B for breakdown of costs by  unit
          processes.
         2ENR Construction Cost Index = 3875.
          (*) Denotes least cost alternative.

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                      TABLE 8.  SUMMARY OF COST COMPARISON*

                                     CASE  4
              PHOSPHORUS  REMOVAL AND NITRIFICATIGN/DENITRIFICATION
                       (EFFLUENT TP = 2 mg/L, TN = 3 ITig/L)
Plant size
Alternative
4-A
(Baseline)
Costs
Capital2, $
O&M, 6/year
Total present worth,
1,892 m3/d
<0.5 ragd)
3,433rOQQ
274,000
$ 6,200,000
18,925 m3/d
(5 mgd)
12,913,000
1,112,000
24,142,000
189,250 m3/d
(50 ragd)
64,576,000
7,469,000
140,000,000
   4-D
Capital2, $            2,947,000     12,026,000     68,742,000
O&M, $/year              190,000        701,000       4,219,000
Total present worth, $ 4,866,000(*)  19,105,000(*} 111,347,000(*)
Alternative 4-A = Three-stage activated sludge system with alum addition.

Alternative 4-D = Bardenpho (16 hours total detention) .
     Tables B-10, B-ll, and B-12 in Appendix B for breakdown of costs  by  unit
 processes.
2EHR Construction Cost Index = 3875.

(*)  Denotes least cost alternative.

-------
          TABLE  9.   SUMMARY OF LEAST COST ALTERNATIVES1

Alternative2

1-A (Baseline)
1-B (PhoStrip}
1-C (A/0)
2-A (Baseline)
2-B (PhoStrip}
2-C (A/0)
3-A (Baseline)
3-C (A/0)
4-A (Baseline)
4-D (Bardenpho)

1,892 m3/d
(0,5 ragd)
(*)

._.
*••••««
	
(*)
— —— =
(*}
— — —
(*)
Plant size
18,925 m3/d
(5 mgd}
(*)

	

-__
{*)
_—
(*)
— —.«*.
(*)

189,250 ra3/d
(50 mgd)

/*)
\ r

•i- limn. •
(*}

(*)

(*}
^Based on total .presecLtjQrtb  costs.   \
     Table 4 for definition  of alternative.
                               41

-------
   TABLE 10.  SUMMARY OF ENERGY REQUIREMENTS1  IN  10 3 KWH/YEAR
Plant size
Alternative2

1-A
1-B
1-C
2-A
2-B
2-C
3-A
3-C
4-A
4-D

(Baseline)
(PhoStrip)
(A/0)
(Baseline)
(PhoStrip)
(A/0)
(Baseline)
(A/0)
(Baseline)
(Bardenpho)
1,892 m3/d
(0.5 mgd)
309(*5
353
364
309(*)
353
332
393(*)
440
417
383(*)
18,925 m3/d
(5
3,
3,
3,
3,
3,
3,
3,
3,
4,
3,
mgd)
171
146(*5
353
171
146
028(*>
815
758(*j
035
832(*»
189,250 m
(50
21,
20,
23,
21,
20,
20,
27,
26,
30,
32,
Vd
mgd)
950
960
489
950
960
389
902
453

(*>



(*)

(*)
002(*)
125

Isee Tables B-13 through B-24 in Appendix B for breakdown of
 energy requirements by unit processes.
%ee Table 4 for definition of alternatives.
                                42

-------
   1000
    900
    aoo<
    700
    as

    500'

    TO'

    300-
O  MO.
§   w

I   »•
g
CL.
5   20-
§   ,-
3   9"
1   8-
O   T.
   t.o.
        Legend
         One-Stage Activaled Sludge with Alum Addition (Baseline)
	PhoStrlp
.	A/O witti Effluent Fitters
                    i.	J.
                 	1  	1,11.
                                                   -1	L.
                                                              I  I  II.
                                                                                   J	L
                                                                                             '  	i 1-1
     0.1
                     3    .4   »  6 .7
                           05
3   *   '  6  7 t 9 •
       5         W
                                                                             '  60 708090
                                                                             SO        100

LLI I 1 i 1 I f
i 1
t.008 1,892

Flow, mgd
I i i i i i i i

:D,OQO
Flow, roVd

1 1 II
r - •" — ' — u
W.WI


1 1 1 1 1

109.000



— rj — -1 — i
189258

               Figure 5(a).  Capital cost comparison.
                              Case 1: Phosphorus removal (effluent TP = 1 mg/l).
                                                 43

-------
    «0
    90-
    60-

   ITO-
    eo-
    50-
    10-
     9-
0.
a
&

I    <-
O
O
5

?   tt.
§   os-
c
<   M-
    OS-
    OS-
   M-
   01-
                        LEGEND
                       — One-Stage Activaterf Sludge wift Afum Addition (Baselinei
                       — PhoStrip
                       — MO with Effluent Filters
                                                                       Annual
                                                                       OSM
                                                                       Costs
              -I	i—1—,	I f ,1.1
                                              J	1,  .1
                                                        4     8 7 « »'
                                                           S         10
                                                                                   M   40  I  a» 70S)SO
                                                                                          SO        100
      p  I  I I 111
                                                Flow, mgd

                                      1—I   I-LI IJ
                                                                J	1 	1	J 1,
                  I.CCO
                                                 tn.oco
                                                Flow,
                                                                                100 000
                                                                                        189550
              Figure S(b).  O&M cost comparison.
                             Case 1: Phosphorus removal (effluent TP = 1 mg/l).
                                               44

-------
   1005.
   SO.
   800-
   TO-
   HO.

   500'
   m-
a ' no-
's   »'
a,   »•
E   ro-
*
    50'

    «'

    30-
©

1  "
o
13
O   10.
—   9-
m   a*
o.
a   ;:
    5-
                       LEQEND
                       — One-Stage Activated Sludge with Alum Addition (Baseline)
                       — PhoStrip
                       — A/O
                                                               Total
                                                              Present
                                                              Worth
                                                                     Capital
                                                                      Costs
               J	L
                                	I  I I.
                                              -i	1	1—,1111
                                                                             J	L
                                -7-83.
                                                                              20    M   «
                                               Flow, tngd
                                                                                                   100
      II  I  tlllt
                          —T"
                           im
                                   i    i   i  i  i i  11
                                                                           .1	l	l	t i,,.
                   1,000
                                                  mow
                                               Flow, m»
—r*_
 U.M5
                                                                                 1WCOO
                                                                                          r
                                                                                         189250
               Figure 6(a).   Capital cost comparison.
                              Case 2: Phosphorus removal (effluent TP   2 mg/l).
                                                45

-------
 100-
 90,


" 70-



 50.

 40'


 30-



 29-
C5  *u"
f   9'
C   8'
£   T'
£   6-
a

5   3-
o

«8
O

3  to.
g  09.
<  OB-
   07-
   04.


   03-
                        LEGEND
                          One-Stage Activated Sludge with Alum Addition (Baseline)
               	,	PhoStrlp
                                                                    Annual
                                                                    O&M
                                                                    Costs
                               ' r i
                                            J_
                                                  _i	L
                                                                                 I   '
                                                                                          .1	1 1,1
     It—«.  I  I »
                        A  o^'7JJ«
                                           2     3

                                         Flow, mgd


                                   1  i  I  I  I I I
                                                                          »    30
                                                                           'ill
1 60 78»Sa]
50        100
                 I.OCO
                                                        VMS
                                                                              IOO.OCO
                                           Flow, rnVd
              Figure 6(b).  O&M cost comparison.
                            Case 2: Phosphorus removal (effluent TP  2 mg/l).
                                               46

-------
   tow
    900
    $00
    TOO
    MO
    SOB

    400

    300
   200
   too
    m
c   «
§
£   »
a.
3
o
o
a
"5
«
c
o
o
1
o
o
3
a
3
    20 -
                    LEGEND
                  	 Two-Stage Activated Sludge with Alum Addition (Baseline)
                  	A/O
'     ..f    I     I  I Il_
2     a    *  1  ft  ? e o
                                               Ji	L
                                                       	I... Ill,
                                                        8789"
                                                                                     I  111.
                                                                            30  «    60 708095
                                                                                  M        100

U_J_




1 1 1 1 1 .

JJTO


	 ,1 	 L

tm

Flow, mgd
1 'Mil1

10,030
Ffow, m3/t}

I
P
18,925


1 1 1 1 1 II 1

101000



— r1—
189250






     Figure 7(a).  Capital cost comparison.
                  Case 3: Phosphorus removal (effluent TP = 2 mg/1, NHs-N = 1 mg/1).
                                            47

-------
   IOC.
    90.
    80.
    10.
    W.



    40'


    30'



    20-
cs
>   10-
&   9>
flL   8-
«   ?-
~   6!
o
a   s<
"5
in   <•
c
_o
=   3-
O   2-
O

MS
O
"S
2   If.
E   OJ.
<   OB-
    07-
    06-

    05-
   01-
   01-
                    LEGEND
                    — Two-Stage AcMvaled Sludge with Alum Addition (Baseline)
                    — A/O
                                                                       Annual
                                                                       O&M
                                                                       Costs
                       —  | ~  -    i
                                             _L
                                                  -l_
                                                                                J	L
     0.1
3   4 ""  6 7 8  9 '
       5         JO
                                                                                        1  GO 708GW
                                                                                        50        100
      11   '  I  I  I I
                                                 Flow, mgd

                                        I  »  '«'!	,1
                                                                I    '   l  »  i  1 i i
                  1,000
                          1.192
                                                10,000

                                                 Flow, m'/d
                                                        "T
                                                        1US2S
                                                                              100,O)0
         Figure 7(b).  O&M cost comparison.
                       Case 3: Phosphorus removal (effluent TP = 2 mg/1, NH3-N = 1 mg/l).
                                               48

-------
   1000
    900
    BOO
    TOO
    600
    500

    400-

    300-
 S  200
 a
B
 o ' ion.
=  90'
1
o
I
o
o
1
a
(0
 1  «-
    20-
10.
s-
8-
I.
6'
5-
    3-
                       LEGEND
                      — Three-Stage Activated Sludge with Alum Addition (Baseline)
                      — Bardenpho
                   -I	'      '  '  ' '
                    .3   .4   '  6 J S 3 *
                                         -I	1	1	,  I  I 1 1
      M—'
                                    10
                                                   I    4   '  6  7 J 9 '
                                                          5         it
                                                Flow, mgd
                                                                        20    30
                                                                           i  ' i '
                                                                                      m n 80 90
                                                                                    »        100
                  1.000
                          1J89Z
                                            WOW     18
                                            Flow. m5/d
                                                                              1DO.OOO
           Figure 8(a).  Capital cost comparison.
                         Case 4: Phosphorus removal, nitrification and denitrification
                         (effluent TP - 2 mg/l, TN = 3 mg/i).
                                               49

-------
   100-
   90-
   80.

   70-

   60.

   50-
   30-
   20-
a  »•
o   9.

*   !'
a.   7.
e   5-
I
£   3-

5
a

o
O
   U
  -OJ»
   04-

   07-

   05-

   OS-
   03-
   92-
   0,1-
                       LE6END
                         Three-Stage Activated Sludge with Alum Addition (Baseline)
             	—— Barcfenpho
                                     Annual
                                      OSM
                                      Costs
                    '   '     I  ' J  '
                       I—	I	I 11...
                       t   '6789'
                          5        !0
                                                                                   1   I
                                                                                             J, I.J.
                                              Flow, fngd
                                                                                   M   40  ' 60 706090
                                                                                          SO        100
J	1—L..J	1.1	1,1	
                                                                     	I 	I	I  I  M I
                                                                                           JL
                                                                                                -M
                  1MO
                                                 10.000
                                                          \t$R
                                                                                100.000
                                                                                         169560
                                             Fiow. I
           Figure 8(b).   O&M cost
                          Case 4: Phosphorus removal, nitrification and denitrification
                          (effluent TP = 2 mg/l, TN «= 3 mg/l).
                                                50

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                            SECTION  5

                  ASSESSMENT OP NATIONAL IMPACT
MARKET POTENTIAL

    The needs for phosphorus and nitrogen removal in the United
States have been projected by  the U.S. EPA in the "1980 Needs
Survey for Conveyance and Treatment of Municipal Wastewater11
(68) under Category IIB - Advanced Wastewater Treatment (AWT).
The requirement for AWT generally exists where water quality
standards require removal of such pollutants as phosphorus,
ammoniaf nitrate, and other substances. In addition, this AWT
requirement exists where removal for conventional pollutants
(BOD, solids) exceeds the Advanced Secondary Treatment  (AST)
level, i.e., 95 percent or 10/10 mg/L. It should be noted that a
large number of plants designed for Advanced Secondary Treatment
(AST) also have the capability for removing phosphorus and am-
monia nitroqen.

    Table 11 summarizes the projected facilities designed to
provide advanced wastewater treatment (broken down into phos-
phorus, ammonia nitrogen, and total nitrogen removal) in the
U.S. for the years 1980 and 2000.

    It can be seen that the total wastewater flov; of facilities
requiring AWT is projected to increase five-fold from 2,840,000
m3/d (750 mgd) in the year 1982 to 15,500,000 m3/d (4,100
mgd) in the year 2000. Close to 60 percent of the total flow for
AWT would involve phosphorus removal, while removal of ammonia
nitrogen and total nitrogen would amount to 75 percent and 25
percent, respectively, of total AWT flow by the year 2000. The
number of plants designed for phosphorus removal under AWT is
projected to increase from 85 in the year 1980, to 263 in the
year 2000. The number of plants designed for ammonia nitrogen
removal under AWT is expected to increase from 116 in the year
1980, to 493 in the year 2000, while the corresponding number of
plants for total nitrogen removal is 35 and 118. The sizes of
these AWT plants range from less than 378 m3/d  (0.1 mgd) up to
189,250 m3/d (50 mgd), with the average size being near 19,000
m3/d (5 mgd) in 1980, and 30,000 m3/d (8 mgd) in 2000.
Therefore, the trend is toward building more large-size AWT
plants between 1980 and 2000 than those that currently exist.
From the data presented in Table 11, it appears that significant
                                51

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    TABLE  X.I.   FACILITIES  DESIGNED TO PROVIDE ADVANCED WASTEWATBR TREATMENT (AWT)  FOR ALL STATES AND U.S. TERRITORIES*'2





Facilities in
operation in 1980
Facilities to be
in operation in
2000
Increment from
1980 to 2000
Average plant
size in 1980
Average plant
size in 2000


Total
flow
1,000 mVd



% of
total
flow
48.8

75.1


80.9

~ „-

_.»-.



Number
of.
plants
35

118


83

-»_

•.~ —

Total N

Flow
1,000 m3/d
(ragd)
574
(152)
3,888
(1,027)

3,314
(875)
16.4
(4.3)
33.0
(8.7)


8 of
total
flow
20.1

24.8


25.9





      Reference 68, the "1980 Needs Survey."
2Does not include Advanced Secondary Treatment (AST)  plants, which are for removal of BOD/TSS to the range of 10/10  to
 24/24 mg/I», but also provide specific processes that remove phosphorus and/or ammonia in excess of the amounts  normally
 removed by secondary treatment.

-------
market potential exists for all three proprietary processes.
Specifically, the greatest market potential exists in the fol
lowing areas:

    *   Application of the PhoStrip process for phosphorus
        residual of 1 mg/L; for plant size above 19,000
        m3/d (5 mgd).

    •   Application of the A/0 process for phosphorus te-
        sidual of 2 mg/L; for all plant sizes.

    *   Application of the A/O process for phosphorus and
        ammonia nitrogen residuals of 1 and 2 mg/L, re-
        spectively; for all plant sizes.

    *   Application of the Bardenpho process for phosphorus
        and total nitrogen residuals of 2 and 3 mg/L, re-
        spectively,- for all plant sizes.
COSTS AND ENERGY IMPACTS

    The national dollar needs for upgrading/enlarging existing
treatment plants and for construction of new advanced wastewater
treatment (AWT) facilities are presented in Table 12 based on
the "1980 Needs Survey" (68). The total incremental costs of AWT
above the advanced secondary treatment (AST) level are estimated
at $830 million in 1980 dollars. It is noted that these costs
are for construction only and do not include costs for operation
and maintenance. From comparison of total present worth costs
presented in Tables 5 through 8, it can be seen that significant
cost savings can be realized when either the PhoStrip, A/0, or
Bardenpho process is used instead of the conventional (Baseline)
process. The potential cost savings tends to increase when the
plant size is  increased. For plant size in the range of 18,925
to 189,250 m3/d (5 to 50 mgd), savings in total present worth
costs are estimated to be in the range of 10 to 25 percent on a
total plant basis, depending on effluent requirements and the
type of alternative process used. Savings in energy are expected
to be less significant than in total present worth costs. As can
be seen from Table 10, energy savings through the use of the
three proprietary processes are generally less than 10 percent
on a total plant basis, but can be as high as 20 percent, da-
pending on the plant size, effluent requirements, and the type
of alternative process used.
                                53

-------
    TABLE 12.  NATIONAL DOLLAR NEEDS FOR CHANGES IN EXISTING
               TREATMENT PLANTS AND FOR CONSTRUCTION OP NEW
               ADVANCED WASTEWATER TREATMENT  (AWT) FACILITIES1
          Type
Number
  of
plants
Total
dollar
needs2,
in mil-
 lions
of 1980
dollars
    Changes in existing plants

        Planned changes by present design       251     335.6
        level of tertiary treatment for all
        facilities in operation in 1980

        Plants to be upgraded to tertiary
        treatment

        Plants to be enlarged and upgraded to
        tertiary treatment

    Sub-total

    New tertiary treatment facilities

    Total                                       461     829.2
16
11
278
183
10.3
49.7
395.6
433.6
      Reference 68, the "1980 Needs Survey."
2Incremental costs above advanced secondary treatment (AST).
                               54

-------
RISK ASSESSMENT

    All three proprietary biological phosphorus removal process-
es have been reasonably well developed. Generally, they are cap-
able of providing 1 to 2 mg/L of residual phosphorus. Therefore,
the risk involved in using any of these processes is not in its
complete failure/ but in its capability to meet a specific set
of effluent limitations. From available data presented in Tables
If 2, and 3, it can be seen that these processes can be margin-
al, at times, in meeting the total phosphorus concentrations of
1 mg/L or 2 mg/L. Conducting pilot tests to obtain data for ap-
plication in a specific case, prior to design, can minimize such
risk.

    Provision of additional facilities, such as the use of ef-
fluent filters and supplemental mineral addition, will further
reduce the risk of not meeting the effluent requirements. Howev-
er, such a provision would also reduce the benefit of cost sav-
ings that can be gained from the use of these alternative proc-
esses.
                                55

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                            SECTION 6

                         RECOMMENDATIONS


FURTHER RESEARCH AND DEVELOPMENT EFFORTS

    All three proprietary processes for biological phosphorus
removal are based on the basic mechanism that utilizes the an-
aerobic treatment to pre-condition the microorganisms for subse-
quent enhanced uptake of phosphorus under aerobic conditions.
Although significant data and experience have been obtained to
substantiate the validity of the fundamental concept, numerous
complex factors affecting the performance of the three different
versions of biological phosphorus removal systems are not yet
fully understood. Many researchers have raised a number of un-
answered questions and expressed needs for further research and
development, which have been put together in a perspective by
Irvine, Stensel, and Alleman (1). Some of the more important as-
pects of research needs, including those identified by numerous
researchers, as well as the opinions of the consultant, are
listed in the following:

    •   Basic studies involving organisms selection, phy-
        siological states, survival, and the direct impact
        of the anaerobic zone must be conducted before bi-
        ological phosphorus removal can be understood ful-
        ly.

    •   Current design of the anaerobic section in each of
        the three proprietary processes appears to be em-
        pirical, and there is a lack of rational basis for
        sizing the anaerobic stage. The A/O system employs
        a relatively short detention time in the anaerobic
        zone and requires a sufficiently high input of sol-
        uble substrate to ensure rapid formation of anaero-
        bic conditions. The Bardenpho system has a slightly
        longer detention time,  but, as in the case of A/O,
        it also requires the presence of soluble substrate
        to establish adequate anaerobic conditions. (Some
        of the failures associated with the Bardenpho sys-
        tem have been related to low COD:TKN ratios in the
        feed to the system.) On the other hand, the
        PhoStrip process employs a relatively long SRT in
        the anaerobic stripper, which allows for hydrolysis
                                56

-------
         of participate organics contained in the portion of
         recycle sludge subjected to anaerobic treatment.
         Furthermore,  introduction of dissolved oxygen and
         nitrate into  the anaerobic zone has been found to
         interfere with biological phosphorus release in all
         three proprietary processes. The quantitative ef-
         fects of these various factors on the sizing of the
         anaerobic tank need to be further delineated.

    *   The three biological phosphorus removal  processes
         are capable of producing effluent total  phosphorus
         of less than  2 mg/L; however,  effluent total phos-
         phorus  concentrations of 1 to  2 mg/L appear  in the
         marginal area that can hardly  be predicted with
         certainty.  The total phosphorus consists of  soluble
         phosphorus  as well as phosphorus associated  with
         t-.he suspended solids form.  The  soluble phosphorus
         in the  effluent is related to  the performance  of
         the process employed,  while  the phosphorus in  the
         solids  form is related to  the  settling characteris-
         tics  of  sludge maintained  in the  system.  Further
         research  is necessary  to develop a better basis  for
         predicting effluent  quality  under  various operating
        conditions and  wastewater  characteristics.

PROCESS/TECHNOLOGY MODIFICATIONS

All three processes discussed  in this document have been  well
developed  from the phosphorus  removal standpoint. Potential im-
provements or modifications  for each of  the three processes are
as EO1J.OWE:

    *   The Phostrip process has been applied in conjunc-
        tion with a two-stage activated sludge system to
        provide phosphorus and ammonia nitrogen removal
        Nevertheless,  the basis of design for necessary"
        modifications  in the PhoStrip process to  integrate
        with biological nitrification/denitrification
        treatment systems needs to be further developed,

    •    Some modifications in the A/O process, possibly in
        the area of internal sludge recycle and^more  appro-
        priate sizing  of the anaerobic/anoxic/aerobic
        stages,  may be necessary to demonstrate the capa-
        bility of this process to achieve more satisfactor,
        phosphorus removal and a higher degree of nitrifi-"
        cation/denitrification than currently available.
                               57

-------
Some modifications in the Bardenpho process may be
necessary to achieve more satisfactory performance
in phosphorus and total nitrogen removal, particu-
larly under the conditions of low CODrTKN ratio in
the feed to the system.

-------
                           REFERENCES

1. Irvine, R.L., H.D. Stensel, and J.E. Allanman. Summary Re-
   port i Workshop on Biological Phosphorus Removal  in Municipal
   Wastewater Treatment, Annapolis,  Maryland, June  22-24,
   1982. Sponsored by U.S. EPA, Municipal Environmental
   Research Laboratory, Cincinnati,  Ohio, September  1982.

2. U.S. EPA. Process Design Manual for Phosphorus Removal. EPA-
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3. Greenburg, A.E., G. Klein, and W.J. Kauffman. Effect of
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4. Srinath, E.G., C.A. Sastry, and S.C. Pillai. Rapid Removal
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5. Levin, G.V., and J. Shapiro. Metabolic Uptake of  Phosphorus
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6. Shapiro, J., G.V. Levin, and Z.G. Humberto. Anoxically In-
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7. Vacker, D., C,H. Connel, and W.N. Wells. Phosphate Removal
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8. Menar, A.B., and C. Jenkins. The  Pate of Phosphorus in Waste
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9. Milbury, W.F., D. McCauly, and C.H. Hawthorne. Operation of
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-------
10. Garber, W.F. Phosphorus Removal by Chemical and Biological
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11. Levin, G.V., G.J. Topol, A.G. Tarmy, and R.B. Samworth.
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12, Levin, G.V., G.J. Topol, and A.G. Tarnay. Operation of a
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13. Levin, G.V., D.L. Masse, and J.J. Kish, Biospherics, Inc.
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14. Barnard, J.L. Cut P and N Without Chemicals. Water and
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15. Refling, D.R., H.D. Stensel, D.E. Burns,  and J.L. Barnard.
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16. Krichten, D.J., D.M. Nicholas, and J.v. Galdiers. Phosphorus
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17. Hong, S.N., D.J. Krichten, K.S. Kisenbauer, and R.L. Sell. A
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    in Municipal Wastewater Treatment,  Annapolis, Maryland,
    1982.

18. siebritz, J.P., G.A. Ekama, and G.V.A. Marais.  A Parametric
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    cal Treatment Processes, International Association on Water
    Pollution Research, Pretoria,  South Africa, 1982.

19. Mulbarger,  M.C., and R. Prober. A Consultant's Perspective.
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    in Municipal Wastewater Treatment,  Annapolis, Maryland,
    1982.

-------
 20. Earth, E.F., and H.D. Stensel.  International  Nutrient  Con-
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 21. U.S. EPA. Innovative and Alternative Technology Assessment
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 22. Smith, J.M., J.J. McCarthy, and H.L. Longest. Impact of In-
     ?KVa^QD«,and Mternatl^e Technology in the United States in
     tne iyao s. U.S. EPA, Municipal Environmental Research Lab-
     oratory, Cincinnati, Ohio, 1980.

 23. Peirano, L.E. Low Cost Phosphorus Removal at Reno-Sparks,
     Nevada. Water Pollution Control Federation J  ,
     46(4) :568-5?4,  1§77.

 24. Drnevich, R.F.  Biological-Chemical Process for Removing
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     EPA, 1979.

 25. Peirano,  L.E. ,  D.B.  Henderson,  J.G.M.  Gonzales,  and E.F
     Davis.  Full-scale Experiences with the PhoStrip Process
     Presented at Post Conference Seminar on Phosphate Removal  in
     Biological Treatment Processes,  International Association  on
     Water  Pollution Research,  Pretoria,  South Africa,  1982.

 26. Campbell,  T L. ,  J.M.  Reece,  T.J. Murphy,  and  R.F.  Drnevich.
     Biological Phosphorus  Removal at Brockton,  Massachusetts
     New England  Water  Pollution  Control  Association  J.,  12(1);
     D-L — 73,  1978.

 27.  Drnevich,  R.F ,  and  L.C. Matsch.  A Process  for Simultaneous
     Phosphorus and Nitrogen  Removal.  Presented  at  the  51st  Annu-
     al  Conference of  the Water Pollution Control  Association,
     Anaheim,  California, 1978.

 28.  Miyamoto-Mills, J. , J. Larson, D.  Jenkins,  and W.  Owen   De-
     sign and Operation of  a  Pilot-Scale  Biological Phosphate Re-
     moval Plant at the Central Contra  Costa Sanitary District
     Presented at Post Conference Seminar on Phosphate  Removal in
     Biological Treatment Processes,  International  Association on
     Water Pollution Research, Pretoria,  South Africa,  19821

29.  Dedyo, J. , and R. Doan. Reduced Energy Usage with Biological

                    aater P°11Ufeion  Confci:o1 Federation J. ,
30. Roy F  Weston, Inc. I/A Technology Assessment Post Construc-
    tion Evaluation of Amherst, New York, PhoStrip Facility  EPA
    Contract No. 68-03-3055, U.S. EPA, Draft Report, 1983!

-------
31. Levin, G.V., Biospherics,  Inc.,  undated.

32. Galdieri, J.V. Biological  Phosphorus  Removal.  Chemical Engi-
    neering J., 86(28):34-35,  1979.

33. Air Products and  Chemicals,  Inc. Wastewater  Treatment  with
    Nutrient Removal,  the A/0  System.  Catalog  No.  210-101,  1981.

34. Hong, S.N., K.S.  Kisenbauer,  and V.G.  Fox. An  Innovative Bi-
    ological Nutrient Removal  System.  In:  Proceedings  of  the
    Conference on Environmental  Engineering, ASCE, Atlanta,
    Georgia, 1981.

35. Krichten, D.J., and S.N. Hong. Biological  Nutrient  Control
    Plant Demonstration. In:   Proceedings  of WATER FORUM  «81,
    ASCE, San Francisco, California, 1981.

36. Krichten, D.J., Air Products  and Chemicals,  Inc.  Informa-
    tion provided to  Roy F, Weston,  Inc.,  August 2, 1982.

37. Stensel, H.D.,  "   Sakakibara, D.R. Refling, and C.R. Bur-
    dick. Performance of First U.S. Full-Scale Bardenpho Facili-
    ty. Presented at  the EPA International Seminar on Control  of
    Nutrients in Municipal Wastewater  Effluents, San Diego,  Cal-
    ifornia, 1980.

38. Burdick, C.R., D.R. Refling,  and H.D.  Stensel. Advanced  Bio-
    logical Treatment to Achieve  Nutrient  Removal. Water Pollu-
    tion Control Federation J.,  54(7):1Q78-1086, 1982.

39. Burdick, C.R., and G. Dallaire. Florida Sewage Plant First
    to Remove Nutrients with Bacteria  Alone - No Need for Costly
    Chemicals. Civil  Engineering  J.f ASCE, 48<1Q): 51-56,  1978.

40. Barnard, J.L. Biological Nutrient  Removal Without the Addi-
    tion of Chemicals. Water Research  J.,  9:485-490, 1975.

41. Buchan,  L. Possible Biological Mechanism of i-hosphorus Re-
    moval. Presented  at Post Conference Seminar on Phosphate
    Removal in Biological Treatment Processes, International
    Association on Water Pollution Research, Pretoria,  South
    Africa,  1982.

42. Barnard, J.L., and D.W. Osborn.  Advanced Solutions  to Pollu-
    tion Problems in  South Africa. Presented at the Water Pollu-
    tion Control Federation Conference, Miami, Florida, 1975.

-------
  43-
  44-
                                                Aspects °£
                               nt
 fecence Seminar on  Wraanhati  2!    P"
 Processes, international AssociatI™ n
 «arch, Pretoria, South Africa' 198?.
                                                         on wat
                                                   phosphate Re-
                                                   t  the  Post Con-
                                             "°lo9lcal  Treatment
                                             """ Pollution "<=-
 Johannesburg  Present^ !t th»
 Phosphate Reiioval I
 national ftSuJi   on
 South Africa, 1982.
                                       -*- Nlcholls-
                                         ? «f"°val Plants in
                                         Conference Seminar on
                                             , ProcesseB' I"ter-
                                             Research, Pretoria,
 Research  Laboratory
 use,  Tahoe city,
                                                   Engineering
30:776, 1966.
                                           in Biology,   Btrue-
                                     Bacteriology  Reviews,
54th Annual
Michigan, 1981.
                                 onto   «n    Presented « the
                                control Conference, Detroit,
50 •
    ed Enhanced Phosphoemva

-------
53. Nicholls, H.A., and D.W. Osborn. Bacterial Stress:  Prereq-
    uisite for Biological Removal of Phosphorus. Water Pollution
    Control Federation J.» 51(35:557-569, 1979.

54, Lawson, E.N., and N.E. Tonhazy. Changes in Morphology and
    Phosphate-Uptake Patterns of Ac inetobactor calcoaceticus
    strains. Water SA, 6:105, 1980.

55, Deinema, M.H., et al. The Accumulation of Polyphosphate in
    Acinetobactor Spp_. Microbiology Letters, Federation of Mi-
    crobiological Societies, 273-279, 1980,

56. Senior, P.J., et al. The Role of Oxygen Limitation in the
    Formation of Poly B Hydroxybutyrate during Batch and Contin-
    uous Culture of Azotobacter beijerincku. Biochemistry J.,
    128: 1193, 1972.

57. Hong, S.N., et al. A Biological Wastewater Treatment for Nu-
    trient Removal. Presented at the 54th Annual water Pollution
    Control Federation, Detroit, Michigan, 1981,

58. Rensank, J.H., H.J.G.S. Donker, and H.P. deVries. Biological
    P-Removal in Domestic Wastewater by the Activated Sludge
    Process. Presented at the 5th European Sewage and Refuse
    Symposium, Munchen, Procs. 487-502, 1981,

59, Gaudy, A., and E. Gaudy, Microbiology for Environmental Sci-
    entists and Engineers. McGraw-Hill Book Co., 1980.

60. Marais, G.V.R., R.E. Loewenthal, and I. Siebritz. Review:
    Observations Supporting Phosphate Removal by Biological Ex-
    cess uptake. Selected Papers on Activated Sludge Process Re-
    search at the University of Capetown, South Africa, 1981.

61. Funs, G.W., and M, Chen, Microbial Basis of Phosphate Remov-
    al in the Activated Sludge Process for the Treatment of
    Wastewater. Microb. Ecol. 2:119-138, 1975.

62. Brodish, K.E.O., and S.J. Joyner. The Role of Microorganisms
    Other Than Acinetobactor in Biological Phosphorus Removal in
    Activated Sludge Processes.  Presented at Post Conference
    Seminar on Phosphate Removal in Biological Treatment Proc-
    esses, International Association on Water Pollution Re-
    search, Pretoria, South Africa, 1982.

63. Osborn, D.W., and H.A. Nicholls,  Optimization of the Acti-
    vated Sludge Process for the Biological Removal of Phosphor-
    us. Presented at the International Conference on Advanced
    Treatment and Reclamation of Wastewater, Johannesburg, South
    Africa, 1977.
                               64

-------
64. Stensel H.D. Biological Nitrogen Removal System Design,
    American Institute of Chemical Engineers, Water, Vol. 70,
    Number 209, 1980.

65. Knowles, G., et al. Determination of Kinetic Constants for
    Nitrifying Bacteria in Mixed Culture with the Aid of an
    Electronic Computer, Gen. Microbiology J., 38:263, 1965.

66. U.S. EPA. Innovative and Alternative Technology Assessment
    Manual. MCD-53, EPA-430/9-78-009, 1980.

67. U.S. EPA. £reawide Assessment Procedures Manual. Vol. Ill,
    EPA-600/9-76-014, 1976.

68. U.S. EPA. The 1980 Needs Survey, Conveyance, Treatment, and
    Control of Municipal Wastewater, Combined Sewer Overflows,
    and Stormwater Runoff, Summaries of Technical Data.  EPA-43Q/
    9-81-008, FED 23, 1981.
                                65

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                           APPENDIX A

             COST AND ENERGY ANALYSIS — ASSUMPTIONS
    In order to compare the various alternatives,  a basis for
the cost comparison was required. The major sources of costs
(capital, and operations and maintenance)  and energy requirement
data were the Innovative and Alternative (ISA)  Technology As-
sessment Manual (66), with additional input from the Areawide
Assessment Procedures Manual, Appendix H (67).  Costs for the A/0
and Bardenpho processes were developed based on preliminary con-
cept design and WESTON's in-house cost estimates.

    In order to accommodate the specific design conditions, num-
erous assumptions were required to adjust  and extrapolate cost
data that will reflect the specific design case. The assumptions
utilized for technology evaluation are as  follows:

    •   Construction costs were updated to October 1982 ut-
        ilizing the Engineering Mews Record (ENR)  Construc-
        tion Cost Index of 3875.

    •   Operation and maintenance costs were updated to Oc-
        tober 1982 utilizing EPA's Escalation Index of
        3.55 and electrical energy cost of $O.Q5/kwh.

    •   Construction costs were upgraded to capital costs
        by inclusion of noncomponent costs. The noncompo-
        nent costs and the percentage of construction costs
        used are as follows:

                 Item                     Percent

            Piping                          10
            Electrical                       8
            Instrumentation                  5
            Site Preparation                 5

    •   Engineering services and contingency costs were
        each assumed to be 15 percent of the capital cost.
        The sum of the construction costs, noncomponent
        costs, engineering services, and contingency yield-
        ed the total installed capital cost.
                                66

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 For present worth analysis, all equipment was as-
 sumed to have a 20-year service life (zero salvage
 or replacement cost over cost-effectiveness time
 period), and present worth was equal to the sum of
 capital cost plus present worth of annual O&M
 costs. A discount rate of 7-5/8 percent, which was
 effective as of October 1982, was assumed. Present
 worth factor = 10.0983.

 For each of the alternative cases shown in Table 4,
 costs were developed for the following  three plant
 sizes:

         1,892 m3/d    ( 0.5 ragd)
        18,925 m3/d    ( 5.0 mgd)
       189,250 ra3/d    (50.0 mgd}

 Influent wastewater characteristics were assumed as
 follows:

      BOD5   =210 mg/L
      TSS    = 230 mg/L
      VSS    = 172 mg/L
      TP      =10 mg/L
      TKN    =  35 mg/L
      NH3N   =  20 mg/L

 Preliminary treatment  (including  bar  screens  and
 grit  chambers)  and primary  clarifiers were  assumed
 to  precede  the  biological  treatment.  The primary
 clarifiers  were  assumed  to  provide  60 percent  TSS,
 35  percent  BOD,  10 percent  TP,  and  14 percent  TKN
 removal.

 The baseline  technology  for  BOD,  TSS, and phosphor-
 us  removal  was assumed  to be conventional activated
 sludge with alum addition.  This baseline technology
 was compared  with  the  PhoStrip  and  A/O processes.
 To  produce  effluent TP of 1  mg/L, additional efflu-
 ent filters were  assumed to  be  required  for the
 A/O process in Case 1-.

 The baseline  technology for  BOD,  TSS, phosphorus,
 and ammonia nitrogen removal was  assumed to be high
 rate activated sludge followed by nitrification ac-
 tivated sludge with separate clarifiers  in each of
 the two stages. This baseline technology was com-
pared with the A/0 process.

-------
*   The baseline technology for BOB, TSS, phosphorus,
    and total nitrogen removal was assumed to be high
    rate activated sludge, followed by nitrification
    activated sludge, and by denitrification activated
    sludge with separate clarifiers in each of the
    three stages. This baseline technology was compared
    with the Bardenpho process. In both cases, effluent
    filtration would be required to achieve a TN resid-
    ual of 3 rag/Lr but since the cost would be the same
    for bothi filtration was not included in the com-
    parison.

•   The design conditions for the PhoStrip process were
    assumed to be the same as those indicated in Pact
    Sheet 2.1.17 of the I&A Manual (66).

•   The A/0 process design detention times were assumed
    to be as follows:

                               Detention time, hours
                                 TP        TP & NHj-N
        Stage                  removal      removal

    Anaerobic (3-stage)          1.0          1.0
    Anoxic {3-stage)             	          1.0
    Oxic (aerobic, 4-stage)      3.0          ^._0

      Total                      4.0          6.0

    MLSS = 2,000 mg/L

    Internal flow recycle from oxic to anoxic stage
    - 200 percent (for A/0 with nitrification)

•   To minimize the return of phosphorus contained in
    the sidestreams of the A/O Process, an additional
    lime dosage of 7.9 kg/1,000 m3 (gg Ibs/million
    gallons) was assumed for aerobieally-digested
    sludge, ?.nd 30 kg/1,000 m3 (250 Ibs/million
    gallons) was assumed for anaerobically-digested
    sludge.
                            68

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The Bardenpho process design detention times were
assumed to be as follows;

    Stage                     Detention time, hours

Anaerobic                              1.5
First anoxic                           4.0
Aeration  (nitrification)               6.5
Second anoxic                          3.0
Reaeration                             1 _. 0

  Total                               16.0

MLSS = 3,500 mg/L

Internal flow recycle from the aeration to first
anoxic stage - 400 percent

The excess biological sludge from the Bardenpho
process was assumed to require no further digestion
since the solids residence time (SRT) in the system
was estimated at 27 days under design conditions.

The anaerobic and anoxic tanks in the A/Q or
Bardenpho processes are to be covered.

Surface mechanical aerators were assumed to be used
in the aerobic stages. Maximum aerator capacity of
1.5 times the daily average requirement was pro-
vided. Mixing power of 10 kw/1,000 m^ (50 hp/mil-
lion gallons) tank capacity was assumed in all an-
aerobic and anoxic stages.

For the Bardenpho process and A/O with nitrifica-
tion and partial denitrification, the amount o£ ox-
ygen required is estimated to be reduced by 2.8
times the amount of nitrate nitrogen (HH3-N)  de-
nitrified.

The primary sludge was assumed to have a solids
concentration of 4 percent from the clarifier un-
derflow. The waste activated sludge was assumed to
have a solids concentration of 0.8 percent (except
1.5 percent in the case of A/0) from the clarifier
underflow. The waste activated sludge was to be
further thickened to a minimum of 4 percent by dis-
solved air flotation (DAF) prior to combining with
the primary sludge for digestion, except at 1,892
in3/d (0.5 mgd).
                        69

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 §SSiJ?nSefS!£Ss;ii:;
                     beds »as asaumed for

 taring via vacuun'iT"" Plant' and dewa-
unitary landfill  pproprKL   Disposed of ia

sludge qeneration rates for var?SSUmPti°nS as to
sumed to allow for Sinn   ya^ous cases were as-
in the I&A Manual.    raolfied from data presented
               70

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                            APPENDIX B

               COST COMPARISON AND ENERGY ANALYSIS


    Tables B-i through B-12 deal with cost comparison of  the
various facility sizes; Tables B-13 through B-24 present  an en-
ergy analysis for the same facilities.
                                •71

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       TABLE B-l.  COST COMPARISON -- 1,892 ro3/d  (0.5 ragd) FACILITY1

                                   CASE 1
                 PHOSPHORUS REMOVAL  (EFFLUENT TP  = 1 mg/L)
                              ENR INDEX = 3875
   Process unit
Alternative
   1-A
 one-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
   1-B
 PhoStrip
Alternative
    1-C
    A/O
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Den itrificat ion/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAP)
Digestion (Aerobic)
Dewatering (Drying Bed)
Sludge Hauling/Landf illing
Sub-Total
Noncomponent Costs2
Engineering and Construction
Supervision
Contingency
TOTAL CAPITAL CGtiTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$ 188,000
47,000
122,000
447,000
	
31rOOO
	
	
63,000
	
96,000
78,000
	
125,000
78,000
204,000
$1,479,000
414,000

284,000
284,000
$2,461,000
$ 202,000
$4,501,000
$ 188,000
47,000
122,000
447,000
595,000
	
	
	
63,000
	
96,000
78,000
	
125,000
66,000
200,000
$2,027,000
568,000

389,000
389,000
$3,373,000
$ 253,000
$5,928,000
$ 188,000
47,000
122,000
501,000
-__
5,000
_ _ _
— <• —
63,000
297,003
96,000
78,000
___
130,000
66,000
204,000
$1,797,000
503,000

345,000
345,000
$2,990,000
$ 210,000
$5,111,000
     Appendix A for details of assumptions used in the cost analysis.
^Noncomponent costs include piping, electrical, instrumentation, and site
 preparation.
3present worth computed assuming 20-year life at 7-5/8 percent interest
 rate (PWF = 10.0983).
                                     72

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       TABLE  B-2.   COST COMPARISON — 18,925 m3/d (5.0 mgd)  FACILITY1

                                   CASE 1
                 PHOSPHORUS REMOVAL  (EFFLUENT TP = 1 mg/L)
                              ENR INDEX = 3875
   Process unit
Alternative
   1-A
 one-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
   1-B
 PhoStrip
Alternative
    1-C
    A/O
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Deni tr if icat ion/ Clarification
Ch lor i nation
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Vacuum Filter)
Sludge Hauling/Landf illing
Sub-Total
^loncomponent Costs^
Engineering and Construction
Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$ 705,000
196,000
438,000
2,035,000
— _
78,000
_ —
— -
191,000
	
310,000
250,000
204,000
470,000
658,000
251,000
$ 5,786,000
1,620,000

1,111,000
1,111,000
$ 9,628,000
$ 805,000
$17,757,000
$ 705,000
196,000
438,000
2,035,000
1,096,000
— — _
— — . — .
— — _
191,000
___
310,000
250,000
188,000
470,000
595,000
246,000
$ 6,720,000
1,882,000

1,290,000
1,290,000
$11,182,000
$ 690,000
$18,150,000
$ 705,000
196,000
438,000
2,129,000
12,000

_ .*. _
_ _ _
191,000
1,300,000
310,000
250,000
196,000
500,000
595,000
247,000
$ 7,069,000
1,979,000

1,357,000
1,357,000
$11,763,000
$ 775,000
$19,589,000
LSee Appendix A for details of assumptions used in the cost analysis.
-Noncomponent costs include piping, electrical, instrumentation,  and site
 preparation.
^Present  worth computed assuming 20-year life at 7-5/8 percent interest
 rate (PWF = 10.0983).

-------
     TABLE  B-3.   COST COMPARISON -- 189,250 lR3/d (50.0 mgd) FACILITY1

                                   CASE 1
                 PHOSPHORUS REMOVAL  (EFFLUENT TP =  I mg/L)
                              ENR INDEX = 3875
                                  Alternative
                                     1-A
                                   one-stage
                                   activated
                                    sludge
                                   with alum
                                   addition
                                   (baseline)
Process unit
Alternative
   1-B
 PhoStrip
Alternative
    1-C
    A/o
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Deni tr if icat ion/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Vacuum Filter)
Sludge Hauling/Landf illing
Sub-Total
Noncomponent Costs2
Engineering and Construction
Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$ 3,

2,
12,






1,
1,

2,
2,

$ 29,
&,

5,
5,
$ 49,
$ 5,
$101,
600
783
270
995
-
579
_
_
798
-
190
000
391
740
818
467
631
297

689
689
306
200
817
i
i
t
i
-
i
-
-
f
-
r
i
i
t
r
f
r
r

f
i
r
r
r
000
000
000
000
-
000
_
_
000
-
000
000
000
000
000
000
000
000

000
000
000
000
000
$ 3,

2,
12,
2,





1,
1,

2,
2,

$31,
8,

6,
6,
$52,
$ 3,
$89,
600
783
270
995
740
_
-
_
798
-
190
000
344
740
583
457
500
820

048
048
416
666
436
i
r
i
r
r
-
-
-
r
-
I
r
t
r
f
r
/
i

r
r
f
f
i
000
ooo
000
000
000
-
-
-
000
-
000
000
000
000
000
000
000
000

000
000
000
000
000
$ 3,

2,
11,





5,
1,
1,

2,
2,

$33,
9f

6,
6,
$56,
$ 4,
$98,
600,
783,
270,
797,

230,
—
—
798,
950,
190,
000,
360,
818,
583,
467,
846,
477,

498,
498,
319,
212,
853,
000
000
000
000
-
000
-
-
000
000
000
000
000
000
000
000
000
000

000
000
000
000
000
%ee Appendix A for details of assumptions used  in the cost analysis.
^Noncomponent costs include piping, electrical,  instrumentation, and  site
 preparation.
^present worth computed assuming 20-year life at 7-5/8 percent  interest
 rate (PWF = 10.0983) .
                                     74

-------
       TABLE B-4.  COST COMPARISON — 1,892 m3/d  (0.5 mgd) FACILITY1

                                   CASE  2
                 PHOSPHORUS REMOVAL (EFFLUENT TP = 2 mg/L)
                              ENR INDEX  =3875
                                  Alternative
                                     2-A
                                   one-stage
                                   activated
                                    sludge
                                   with alum
                                   addition
                                  (baseline)
Process unit
Alternative
   2-B
 PhoStrip
Alternative
    2-C
    A/0
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Deni tr if icat ion/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aercb'u)
Dewatering (Drying Bed)
Sludge Hauling/Landf illing
Sub-Total
Noncomponent Costs^
Engineering and Construction
Supe1 vision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$ 188,000
47,000
122,000
447,000
	
25,000
	
	
63,000
	
96,000
78,000
	
125,000
78,000
204,000
$1,473,000
412,000

283,000
283,000
$2,451,000
$ 197,000
$4,440,000
$ 188,000
47,000
122,000
447,000
595,000
___

	
63,000
	
96,000
78,000
	
125,000
66,000
200,000
$2,027,000
568,000

389,000
389,000
$3,373,000
$ 253,000
$5,r^,ooo
$ 188,000
47,000
122,000
501,000
	
5,000
___
	
63,000
-_-
96,000
78,000
	
130,000
66,000
204,000
$1,500,000
420,000

288,000
288,000
$2,496,000
$ 183,000
$4,344,000
-'-See Appendix A for details of assumptions used in the cost analysis.
^Noncomponent costs include piping, electrical, instrumentation, and site
 preparation.
^present worth computed assuming 20-year life at 7-5/8 percent interest
 rate (PWF = 10.0983).
                                     •7K

-------
       TABLE B-5.   COST COMPARISON -- 18,925 m3/d (5.0 mgd)  FACILITY1

                                   CASE 2
                 PHOSPHORUS  RIMOVAL  (EFFLUENT TP = 2 rag/L)
                              ENR INDEX = 3875
                                  Alternative
                                     2-A
                                   one-stage
                                   activated
                                    sludge
Process unit
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Denitrif icat ion/Clarification
Ch lor i nation
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Vacuum Filter)
Sludge Haul ing/Landfill ing
Sub-Total
Noncomponent Costs^
Engineering and Construction
Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORT H^ COSTS3
with alum
addition
(baseline)
$ 705,000
196,000
438,000
2,035,000
	
62,000
	
___
191,000
_ _ _
310,000
250,000
204,000
470,000
658,000
251,000
$ 5,770,000
1,616,000

1,108,000
1,108,000
$ 9,602,000
$ 774,000
$17,418,000
Alternative
2-B
PhoStrip
$ 705,000
196,000
438,000
2,035,000
1,096,000
— _ _
	
__ _
191,000
_ _ ™
310,000
250,000
188,000
470,000
595,000
246,000
$ 6,720,000
1,882,000

1,290,000
1,290,000
$11,182,000
$ 690,000
$18,150,000
Alternative
2-C
A/0
$ 705,000
196,000
438,000
2,129,000

12,000

_ _ _
191,000
mt ^ ^
310,000
250,000
196,000
500,000
595,000
247,000
$ 5,769,000
1,615,000

1,108,000
1,108,000
$ 9,600,000
$ 641,000
$16,073,000
!See Appendix A for details of assumptions used in the cost analysis.
2Noncomponent costs include piping, electrical, instrumentation, and site
 preparation.
3Present worth computed assuming 20-year life at 7-5/8 percent interest
 rate (PWF = 10.0983).
                                     76

-------
      TABLE B-6.   COST COMPARISON — 189,250 m3/d (50.0 mgd) FACILITY1

                                   CASE 2
                 PHOSPHORUS  REMOVAL (EFFLUENT  TP  =  2 mg/L)
                              ENR INDEX = 3875
   Process unit
Alternative
   2-A
 one-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
   2-B
 PhoStrip
 Alternative
     2-C
     A/O
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Denitrification/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening  (DAF)
Digestion (Aerobic)
Dewatering  (Vacuum Filter)
Sludge Hauling/Landfilling
Sub-Total
Noncomponent Costs^
Engineering and Construction
 Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$ 3,600,000  $ 3,600,000
    783,000
  2,270,000
 12,995,000

    463,000
    798,000
   783,000
 2,270,000
12,995,000
 2,740,000
   798,000
$ 3,600,000
    783,000
  2,270,000
 11,797,000

    230,000
    798,000
1,190,000
1,000,000
391,000
2,740,000
2,818,000
467,000
$29,515,000
8,264,000
5,667,000
5,667,000
1,190,000
1,000,000
344,000
2,740,000
2,583,000
457,000
$31,500,000
8,820,000
6,048,000
6,048,000
1,190,000
1,000,000
360,000
2,818,000
2,583,000
467,000
$27,896,000
7,811,000
5,356,000
5,356,000
$49,113,000  $52,416,000
$ 4,890,000  $ 3,666,000
$98,494,000  $89,436,000
             $46,419,000
             $ 3,540,000
             $82,167,000
-'•See Appendix ft for details of assumptions used in the cost analysis.
2Noncomponent costs include piping, electrical, instrumentation, and site
 preparation.
•^Present worth computed assuming 20-year life at 7-5/8 percent interest
 eate (PIP = 10.0983).

-------
       TABLE B~7.
COST COMPARISON — 1,892 m3/d  (0.5 mgd)
         FACILITY1
                              CASE  3
              PHOSPHORUS  REMOVAL AND NITRIFICATION
              (EFFLUENT TP =  2 mg/L, NH3~N  =  1  mg/L)
                        ENR  INDEX  = 3875
   Process unit
               Alternative
                  3-A
                two-stage
                activated
                 sludge
                with alum
                addition
               (baseline)
                                                  Alternative
                                                      3-C
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip
Chemical Addition
Ni tr i f ication/Clarif ication
Denitrif icat ion/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
De water ing (Drying Bed)
Sludge Haul ing/ Land fill ing
Sub-Total
Noncomponent Costs^
Engineering and Construction
Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$ 188,000
47,000
122,000
411,000
	
25,000
360,000
_-_
63,000
	
96,000
78,000
	
125,000
78,000
204,000
$1,797,000
503,000

345,000
345,000
$2,990,000
$ 227,000
$5,282,000
$ 188,000
47,000
122,000
676,000
	
5,000
	
___
63,000
	
96,000
78,000
	
130,000
66,000
204,000
$1,675,000
469,000

322,000
322,000
$2,788,000
$ 195,000
$4,757,000
^See Appendix A for details of assumptions used in the cost
 analysis.
^Noncoinponeiit costs include piping, electrical, instrumenta-
 tion, and site preparation.
"'"esent worth computed assuming 20-year life at 7-5/8 percent
   cerest rate (PWP = 10.0983).
^A/O also provides partial denitrification (effluent TN = 10
 mg/L, NO3-N = 8 mg/L) .

-------
                            FACILITY1
                                             iu-/u
                              CASE 3
               PHOSPHORUS REMOVAL AND NITRIFICATION
              (EFFLUENT TP = 2 mg/L, NH3-N = 1 mg/L)
                         ENR INDEX = 3875
   Process unit
Alternative
   3-A
 two-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
    3-C
    A/04
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip
Chemical Addition
Nitrification/Clarification
Denitrification/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening  (DAP)
Digestion (Aerobic)
Dewatering  (Vacuum Filter)
Sludge Hauling/Landfilling
Sub-Total
Noncomponent Costs^
Engineering and Construction
 Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$   705,000
    196,000
    438,000
  1,614,000

     62,000
  1,487,000

    191,000

    310,000
    250,000
    204,000
    470,000
    658,000
    251,000
$ 6,836,000
  1,914,000

  1,313,000
  1,313,000
$11,376,000
$   854,000
$20,000,000
    705,000
    196,000
    438,000
  2,728,000

     12,000
    191,000

    310,000
    250,000
    196,000
    500,000
    595,000
    247,000
$ 6,368,000
  1,783,000

  1,223,000
  1,223,000
$10,596,000
$   702,000
$17,685,000
!See Appendix A for details of assumptions used in the cost
 analysis.
^Noncomponent costs include piping, electrical, instrumenta-
 tion, and site preparation,
^Present worth computed assuming 20-year life at 7-5/8 percent
 interest rate (PWF = 10.0983).
^A/0 also provides partial denitrification (effluent TN = 10
 mg/L, NO3~N = 8 mg/L).

-------
      TABLE B-9.   COST COMPARISON — 189,250 m3/d  (50.0 mgd)
                             FACILITY1

                              CASE 3
               PHOSPHORUS REMOVAL AND NITRIFICATION
              (EFFLUENT TP = 2 Hig/L, NH3-N = 1 mg/L)
                         ENR INDEX = 3875
   Process unit
Alternative
   3-A
 two-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
    3-C
    A/04
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip
Chemical Addition
Nitrification/Clarification
Denitrif ication/Clarif ication
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAP)
Digestion (Aerobic)
Dewatering (Vacuum Filter)
Sludge Hauling/Landf illing
Sub-Total
Noncomponent Costs^
Engineering and Construction
Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$ 3,600,000
783.000
2,270,000
8,510,000
— -
463,000
8,768,000
	
798,000
	
1,190,000
1,000,000
391,000
2,740,000
2,818,000
467,000
$ 33,798,000
9,463,000

6,489,000
6,489,000
$ 56,239,000
$ 5,369,000
$110,457,000
$ 3,600,000
783,000
2,270,000
15,452,000

230,000

	
798,000
— — —
1,190,000
1,000,000
360,000
2,818,000
2,583,000
467,000
$31,551,000
8,834,000

6,058,000
6,058,000
$52,501,000
$ 3,952,000
$92,409,000
-"-See Appendix A for details of assumptions used in the cost
 analysis.
2Noncomponent costs include piping, electrical, instrumenta-
 tion, and site preparation.
3Present worth computed assuming 20-year life at 7-5/8 percent
 interest rate (PWF = 10.0983).
     also provides partial denitrif ication  (effluent TN = 10
 mg/L,  NO3-N = 8 mg/L) .

-------
      TABLE  B-10,   COST  COMPARISON — 1,892 m3/d (0.5 mgd)
                            FACILITY1

                              CASE 4
                PHOSPHORUS  RMGVAL,  NITRIFICATION,
     AND DENITRIFICATION (EFFLUENT TP = 2 mg/L, TN =  3 mg/L)
                         ENR INDEX = 3875
   Process unit
Alternative
   4-A
three-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
    4-D
 Bardenpho
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip
Chemical Addition
Nitrification/Clarification
Denitr if ication/Clarif ication
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Drying Bed)
Sludge Hauling/Landfilling
Sub-Total
Noncomponent Costs^
Engineering and Construction
Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL OSM COSTS
TOTAL PRESENT WORTH COSTS3
$ 188,000
47,000
122,000
411,000
___
25,000
360,000
266,000
63,000
	
96,000
78,000
	
125,000
78,000
204,000
62,063,000
578,000

396, OCO
396,000
$3,433,000
$ 274,000
$6,200,000
$ 188,000
47,000
122,000
835,000
	
	
	
	
63,000
___
96,000
78,000

94,000
67,000
181,000
$1,771,000
496,000

340,000
340,000
$2,947,000
$ 190,000
$4,866,000
•*-See Appendix A for details of assumptions used in the cost
 analysis.
%oncomponent costs include piping, electrical, instrumenta-
 tion, and site preparation.
-^Present worth computed assuming 20-year life at 7-5/8 percent
 interest rate (PWF = 10.0983).
                                81

-------
      TABLE B-ll.   COST COMPARISON -- 18,925 m3/d {5.0 mgd)
                            FACILITY1

                             CASE 4
     PHOSPHORUS REMOVAL, NITRIFICATION, AND  DENITRIFICATION
               (EFFLUENT TP = 2 jng/L, TN = 3 mg/L}
                        ENR  INDEX ~  3875
   Process unit
Alternative
   4-A
three-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
    4-D
 Bardenpho
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip
Chemical Addition
Nitrification/Clarification
De nitrification/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Vacuum Filter)
Sludge Hauling/Landf illing
Sub-Total
Noncomponent Costs-**
Engineering and Construction
Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$ 705,000
196,000
438,000
1,614,000
__..
62,000
1,487,000
924,000
191,000
	
310,000
250,000
204,000
470,000
658,000
251,000
$ 7,760,000
2,173,000

1,490,000
1,490,000
$12,913,000
$ 1,112,000
$24,142,000
$ 705,000
196,000
438,000
3,815,000
	
___
	
	
191,000
	
310,000
250,000
164,000
344,000
595,000
219,000
$ 7,227,000
2,024,000

1,388,000
1,388,000
$12,026,000
$ 701,000
$19,105,000
%ee Appendix A for details of assumptions used in the cost
 analysis.
%oncomponent costs include piping, electrical, instrumenta-
 tion, and site preparation.
3Present worth computed assuming 20-year life at 7-5/8 percent
 interest rate  (PWF = 10.0983).
                                82

-------
     TABLE B-12.  COST COMPARISON -- 189,250 m3/<3  (50.0 mgd)
                            FACILITY1

                              CASE 4
      PHOSPHORUS REMOVAL,  NITRIFICATION,  AND DENITRIFICATIQN
                (EFFLUENT TP = 2 mg/L, TN =  3 mg/L)
                         ENR INDEX = 3875
   Process unit
Alternative
   4-A
three-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
    4-D
 Barctenpho
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip
Chemical Addition
Nitrification/Clarification
Denttrification/Clarification
Chlotination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening  (DAF)
Digestion  (Aerobic)
Dewatering  (Vacuum Filter)
Sludge Hauling/Landfilling
Sub-Total
Noncomponent Costs^
Engineering and Construction
 Supervision
Contingency
TOTAL CAPITAL COSTS
ANNUAL O&M COSTS
TOTAL PRESENT WORTH COSTS3
$  3,600,000
     783,000
   2,270,000
   8,510,000

     463,000
   8,768,000
   5,010,000
     798,000

   1,190,000
   1,000,000
     391,000
   2,740,000
   2,818,000
     467,000
$ 38,808,000
  10,866,000

   7,451,000
   7,451,000
$ 64,576,000
$  7,469,000
$140,000,000
   3,600,000
     783,000
   2,270,000
  26,460,000
     798,000

   1,190,000
   1,000,000
     297,000
   1,957,000
   2,583,000
     373,000
$ 41,311,000
  11,567,000

   7,932,000
   7,932,000
$ 68,742,000
$  4,219,000
$111,347,000
Isee Appendix A for details of assumptions used in the cost
 analysis.
%oncomponent costs include piping, electrical, instrumenta-
 tion, and site preparation.
^present worth computed assuming 20-year life at 7-5/8 percent
 interest rate  (PWF = 10.0983).
                                83

-------
      TABLE B-13.   ENERGY ANALYSIS (ID3 kwh/y) — 1,892 m3/d
                        (0.5 mgd)  FACILITY1

                              CASE 1
            PHOSPHORUS REMOVAL  (EFFLUEtMT TP = 1  mg/L)
Alternative
   1-A
 one-stage
 activated
  sludge
with alum
 addition
(baseline)
   Process unit
Alternative
    1-B
  PhoStrip
Alternative
    1-C
    A/0
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Denitrif ication/Clarif ication
Chlorination
-Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Drying Bed)
Sludge Hauling/Landf illing2
Total, 10 3 kwh/y
Unit Energy Utilization,
kwh/1,000 m3
kwh/1,000 gals
9
12
8
135
---
8
	

4
	
	
	
_-_
90
	
43
309

447
1.69
9
12
8
135
55
	
	
-__
4
	
	
- —
	
90
	
40
353

511
1.93
9
12
8
1573
	
4
	
	
4
34
	
	
	
100
	
38
366

527
1.99
l-See Appendix A for details of assumptions used  in cost  anal-
 ysis.
^Energy equivalent of diesel oil  in kwh.
•^Including energy for internal flow recycle  (see Appendix  A) .
                                84

-------
     TABLE 8-14.  ENERGY ANALYSIS  (103 kwh/y) — 18,925 JB3/d
                        {5.0 mgd) FACILITYl

                              CASE  1
            PHOSPHORUS REMOVAL  (EFFLUENT TP = 1 mq/L)
   Process unit
Alternative
   1-A
 one-stage
 activated
  sludge
with alum
 addition
(baseline)
Alternative Alternative
    1-B         1-C
  Pho Strip      A/O
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Denitrification/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening  (DAF)
Digestion  (Aerobic)
Dewatering  (Vacuum Filter)
Sludge Hauling/Landfilling^
      90
      25
      45
   1,350

      40
      39
      90
      25
      45
   1,350
     1053
      39
                 120
                 900
                  75
                 397
   90
   25
   45
1,2603

   20
   39
  325
                 150
                 950
                  75
                 374
Total, 10 3 kwh/y
Unit Energy Utilization,
kwh/1,000 m3
kwh/1,000 gals
3,171

459
1.74
3,146

455
1.72
3,353

485
1.84
3-See Appendix A tor details of assumptions used in cost anal-
 ysis.
28nergy equivalent of diesel oil in kwh.
Including energy for internal flow recycle  (see Appendix A) .

-------
    TABLE B-15.  ENERGY ANALYSIS  (103  Rwh/y)  —  189,250 m3/d
                       (50.0 mgd)  FACILITY^

                              CASE 1
            PHOSPHORUS REMOVAL (EFFLUENT TP = 1 mg/L)
   Process unit
Alternative
   1-A
 one-stage
 activated
  sludge
with alum
 addition
(baseline)
Alternative Alternative
    1-B         1-C
  PhoStrip      A/0
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Deni tr if icat ion/ Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Vacuum Filter)
Sludge Hauling/Landf illing2
Total, 10 3 kwh/y
Unit Energy Utilization,
kwh/1,000 m3
kwh/1,000 gals
900
80
300
13,500
	
400
	
	
390
	
---
	
1,150
210
850
4,170
21,950

318
1.20
900
80
300
13,500
2103
	
	
	
390
	
	
	
750
210
650
3,970
20,960

303
1.15
900
80
300
12f 6003
-__
59
___
- —
390
3,100
	
-.--
1,000
240
650
4,170
23,489

340
1,29
     Appendix A for details of assumptions used in cost anal-
 ysis
^Energy equivalent of diesel oil in kwh.
3Including energy f cr internal flow recycle  (see Appendix A) .
                                86

-------
      TABLE B-16.  ENERGY ANALYSIS  (103  kwh/y)  —  1,892 m3/d
                        (0.5 mgd)  FACILITY!

                              CASE  2
             PHOSPHORUS RSMOVAL (EFFLUENT TP = 2 mg/L)
Process unit
                             Alternative
                                2-A
                              one-stage
                              activated
                               sludge
                             with alum
                              addition
                             (baseline)
Alternative Alternative
    2-B         2-C
  PhoStrip      A/O
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Denitrif ication/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Drying Bed)
Sludge Haul ing/Land fill ing 2
Total, 103 kWh/y
Unit Energy Utilization,
kwh/1,000 m3
kwh/1,000 gals
9
12
8
135
- —
8
— _
, 	
4
— —
— — _
_ —
__._
90
	
43
309

447
1.69
9
12
8
135
553

— — —
— — _
4
-,-» —
mm mm *•
„-, —
_— —
90
___
40
353

511
1.93
9
12
8
1573

4

*.*.,*
4

«M» •••
mm w _ .
».*...
100

38
332

481
1.82
 ysis
     Appendix A for details of assumptions used in cost anal-
2Energy equivalent of diesel oil in kwh.
3lncluding energy for internal flow recycle (see Appendix A) .
                                87

-------
     TABLE B-17.  ENERGY ANALYSIS (103 kwh/y) — 18r925 m3/d
                       (5,o mgd) FACILITY!
                              GASfi  2
            PHOSPHORUS REMOVAL (EFFLUENT TP = 2 mg/L)
   Process unit
Alternative
   2-A
 one-stage
 activated
  sludge
with alum
 addition
(baseline)
Alternative Alternative
    2-B         2-C
  PhoStrip      A/0
Low Lift Pumping                  90          90
Preliminary Treatment             25          25
Primary Treatment                 45          45
Aeration/Clarification         1,350       1,350
PhoStrip (with Lime Addition)  	           1053
Chemical Addition                 40       	
Nitrification/Clarification    	         	
Denitrification/Clarification  	         ---
Chlorination                      39          39
Effluent Filtration            	         	
Gravity Outfall                	         	
Miscellaneous Structures       	         	
Thickening (DAF>                 170
Digestion (Aerobic)              900
Dewatering (Vacuum Filter)        95
Sludge Hauling/Landfilling2      417

Total, 103 kwh/y               3,171       3,146
Unit Energy Utilization,
  kwh/1,000 m3                   459         455
  kwh/1,000 gals                   1.74        1.72
                              90
                              25
                              45
                              20
                              39
                             150
                             950
                              75
                             374
                           3,028
                             438
                               1.66
1-See Appendix A for details of assumptions used in cost anal-
 ysis.
^Energy equivalent of diesel oil in kwh.
^including energy for internal flow recycle (see Appendix A).
                                88

-------
     TABLE B-18.  ENERGY ANALYSIS  (103 kwh/y) — 189,250 m3/d
                        (50.0 mgd) FACILITY-1-

                              CASE 2
            PHOSPHORUS REMOVAL (EFFLUENT TP = 2 mg/L)
   Process unit
Alternative
   2-A
 one-stage
 activated
  sludge
with alum
 addition
(baseline)
Alternative Alternative
    2-B         2-C
  PhoStrip      A/O
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Denitrificat ion/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Vacuum Filter)
Sludge Hauling/Landfilling2
900
80
300
13,500
	
400
	
	
390
_ __
___
___
1,150
210
850
4,170
900
80
300
13,500
2103

_.._
— » —
390
_ _ _
_ _ .
— » —
750
210
650
3,970
900
80
300
12,6003

59

— — V.
390

	
» • w
1,000
240
650
4,170
Total, 103 kwh/y
Unit Energy Utilization,
  kwh/1,000 m3
  kwh/1,000 gals
   21,950
   20,960
      318
        1.20
      303
        1.15
20,389
   295
     1.12
 ysis
     Appendix A for details of assumptions used in cost anal-
2Energy equivalent of diesel oil in kwh.
3Including energy for internal flow recycle  (see Appendix A) .
                                89

-------
      TABLE B-19.   ENERGY ANALYSIS (1Q3 kwh/y} — 1,892 m3/d
                        (0.5 mgd)  FACILITY.1

                              CASE 3
               PHOSPHORUS REMOVAL AMD NITRIFICATION
              (EFFLUENT TP = 2 mg/L,  NH3-N = 1 mg/L)
                                 Alternative
                                     3-A
                                  two-stage
                                  activated
                                   sludge
                                  with alum       Alternative
                                  addition            3-C
   Process unit                  (baseline)           A/0


Low Lift Pumping                       9                9
Preliminary Treatment                 12               12
Primary Treatment                      8                8
Aeration/Clarification               118              2653
PhoStrip (with Lime Addition)        	              	
Chemical Addition                      8                4
Nitrification/Clarification          101              	
Denitrification/Clarification        	              	
Chlorination                           4                4
Effluent Filtration                  	              	
Gravity Outfall                      	              	
Miscellaneous Structures             	              	
Thickening (DAF)                      	              	
Digestion (Aerobic)                   90              100
Dewatering (Drying Bed}              	              	
Sludge Hauling/Landfilling2          _43               38

Total, 103 fcwh/y                     393              440
Unit Energy Utilization,
  kwh/1,000 m3                       569              637
  kwh/1,000 gals                       2.15             2.41
1-See Appendix A for details of assumptions used in cost anal-
 ysis.
^Energy equivalent of diesel oil in kwh.
3lncluding energy for internal flow recycle and credit for en-
 ergy reduction due to recycle of nitrate (see Appendix A).
                                90

-------
     TABLE B-20.  ENERGY ANALYSIS  (ID3 kwh/y) — 18,925 m3/d
                        (5.0 mgd) FACILITY*-

                              CASE  3
               PHOSPHORUS  REMOVAL AND NITRIFICATION
              (EFFLUENT TP = 2 mg/L, NH3-N = 1 mg/L)
                                 Alternative
                                    3-A
                                  two-stage
                                  activated
                                   sludge
                                  with alum       Alternative
                                  addition            3-C
   Process unit                  (baseline)           A/0


Low Lift Pumping                        90               90
Preliminary Treatment                   25               25
Primary Treatment                       45               45
Aeration/Clarification                 984            1,9903
PhoStrip (with Lime Addition)        	              —
Chemical Addition                       40               20
Nitrification/Clarification          1,010            	
Denitrification/Clarification        	
Chlorination                            39               39
Effluent Filtration                  —-
Gravity Outfall                      	
Miscellaneous Structures             	              	
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Vacuum Filter)
Sludge Hauling/Landfilling^

Total, 103 kwh/y                     3,815            3,758
Unit Energy Utilization,
  kwh/1,000 m3                         552              544
  kwh/1,000 gals                         2.09             2.06
J-See Appendix A for details of assumptions used in cost anal-
 ysis.
^Energy equivalent of diesel oil in kwh.
3Including energy for internal flow recycle and credit for en-
 ergy reduction due to recycle of nitrate  (see Appendix A).

-------
     TABLE B-21.  ENERGY ANALYSIS (103 kwh/y) — 189,250
                       (50,0 mgd) FACILITY-1-

                              CASE 3
               PHOSPHORUS REMOVAL AND NITRIFICATION
              (EFFLUENT TP = 2 mg/L, NH3-N - 1 mg/L)
                                 Alternative
                                     3-A
                                   two-stage
                                   activated
                                   sludge
                                   with alum        Alternative
                                   addition             3-C
   Process unit                   (baseline)            A/0


Low Lift Pumping                         900              900
Preliminary Treatment                    80                80
Primary Treatment                        300              300
Aeration/Clarification                9,352            18,6643
PhoStrip (with Lime Addition)         	               	
Chemical Addition                        100                59
Nitrification/Clarification           10,10^             	
Denitrification/Clarification         —>-               	
Chlorination                             390              390
Effluent Filtration                   — -               ---
Gravity Outfall                       ---
Miscellaneous Structures              	               ---
Thickening (DAP)                      1,150             1,000
Digestion  (Aerobic)                      210              240
Dewatering (Vacuum Filter)               850              650
Sludge Hauling/Landfilling2           4f170             4,170

Total, 103 kwh/y                      27,902            26,453
Unit Energy Utilization,
  kwh/1,000 m3                           404              382
  kwh/1,000 gals                          1.53             1.45


-'-See Appendix A for details of assumptions used in cost anal-
 ysis.
2Energy equivalent of diesel oil in kwh.
3Including energy for internal flow recycle and credit  for en-
 ergy reduction due to recycle of nitrate (see Appendix A).
                                92

-------
     TABLE B-22.   ENERGY ANALYSIS  (103 kwh/y)  — 1,892 ra3/d
                        (0.5 mgd) FAeiLITy.1

                              CASE  4
     PHOSPHORUS  REMOVAL,  NITRIFICATION,  AND DENITRIFICATION
               (EFFLUENT TP = 2 mg/L, TN = 3 mg/L>
   Process unit
Alternative
   4-A
three-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
    4-D
 Bardenpho
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clari fication
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Denitrification/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion  (Aerobic)
Dewatering (Drying Bed)
Sludge Hauling/Landfilling2

Total, 103 kwh/y
Unit Energy Utilization,
  kwh/1,000 m3
  kwh/1,000 gals
      9
     12
      B
    118

      8
    101
     24
      4
     90

     43

    417

    604
      2.28
      9
     12
      8
    2723
     55

     34

    383

    555
      2.10
     Appendix A for details of assumptions used in cost anal-
 ysis.
^Energy equivalent of diesel oil in kwh.
^Including energy for internal flow recycle and credit for en>
 ergy reduction due to recycle of nitrate  (see Appendix A).
                                93

-------
     TABLE B-23.  ENERGY ANALYSIS  (103  kwh/y}  -- 18,925 m3/d
                        (5.0 ragd) FACILITYl

                              CASE 4
      PHOSPHORUS RBlOvAL,  NITRIFICATION, AND DENITRIF1CATIOM
                (EFFLUENT TP =  2 flif/Lf Tfi =  3 mg/L)
   Process unit
Alternative
   4-A
three-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
    4-D
 Bardenpho
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Denitrification/Clarification
Chlorinatiori
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAF)
Digestion (Aerobic)
Dewatering (Vacuum Filter)
Sludge Hauling/Landfilling^

Total, 103 kwh/y
Unit Energy Utilization,
  kwh/1,000 m3
  kwh/1,000 gals
       90
       25
       45
      984

       40
    1,010
      220
       39
    4,035
      584
        2.21
       90
       25
       45
    2,5853
       39
    3,832
      555
        2.10
     Appendix A for details of assumptions used in cost anal-
 ysis
^Energy equivalent of diesel oil in kwh.
•^Including energy for internal flow recycle and credit for en-
 ergy reduction due to recycle of nitrate  (see Appendix A) .

-------
     TABLE B-24.   ENERGY ANALYSIS (103 kwh/y)  — 189,250 m3/d
                       (50.0 mgd)  PACILITYJ-

                              CASE 4
      PHOSPHORUS  REMOVAL,  NITRIFICATION,  AND DENITRIFICATION
               (EFFLUENT TP = 2 mg/L, TN = 3 mg/L)
   Process unit
Alternative
   4-A
three-stage
 activated
  sludge
 with alum
 addition
(baseline)
Alternative
    4-D
 Bardenpho
Low Lift Pumping
Preliminary Treatment
Primary Treatment
Aeration/Clarification
PhoStrip (with Lime Addition)
Chemical Addition
Nitrification/Clarification
Denitrification/Clarification
Chlorination
Effluent Filtration
Gravity Outfall
Miscellaneous Structures
Thickening (DAP)
Digestion  (Aerobic)
Dewatering (Vacuum Filter)
Sludge Hauling/Landfilling2

Total, 103 kwh/y
Unit Energy Utilization,
  kwh/1,000 m3
  kwh/1,000 gals
       900
        80
       300
     9,352

       400
    10,100
     2,100
       390
     1,150
       210
       850
     4,170

    30,002
       434
         1.64
       900
        80
       300
    25,8503
       390
       500
       115
       650
     3,340

    32,125

       465
         1,76
     Appendix A for details of assumptions used in cost anal-
 ysis.
^Energy equivalent of diesel oil in kwh.
3Including energy for internal flow recycle and credit for en-
 ergy reduction due to recycle of nitrate (see Appendix A).
                                95

-------
          APPENDIX C



RESPONSE OF PROPRIETARY FIRMS

-------
                                                  Air Products and Chemicals, fr>c.
                                                      Box 538- Allenscwrv PA 18105
                                                           (215)481-4911
                                                 11 April  1984
Mr. Edwin Barth
U.S. ENVIRONMENTAL  PROTECTION AGENCY
Municipal Environmental Research  Lab
Wastewater Research Division
26 W. St. Clair Street
Cincinnati, Ohio    45268

Dear Mr. Barth:

Thank you for the opportunity to  comment on the report,  "Emerging Technology
Assessment for Biological  Phosphorus Removal" prepared by Roy F. Weston,  Inc.

In general, we are  pleased with the report and feel  it accurately represents
the state of the art of the A/0 technology,   I would like to comment in more
detail in two areas.  The  first area concerns the discussion of the performance
of the process to which I  would like to add some thoughts.  In the second area,
cost comparisons, we feel  strongly that the analysis  given does not reflect
the magnitude of cost savings available to users of  A/0.


A.  A/0 Performance

    The concentration of phosphorus in the effluent  from a properly designed
    A/0 plant will  be mainly dependent upon the ratio of BOD to phosphorus of
    the wastewater  treated.  Our  experience has shown when this ratio exceeds
    10 to 1, an effluent soluble  phosphorus of 1 ing/1 or less can be expected.
    At ratios less  than 10 to 1 the A/0 process continues to function, but
    with increasing  effluent phosphorus levels as the ratio decreases.  One
    method of assuring performance to less than 1 mg/1 total P is the combina-
    tion of A/0 with chemical precipitation.  In this method, alum would be
    added either upstream  to adjust the BOD:P ratio  to the proper level or
    downstream to precipitate residual phosphorus.   By combining A/0 with
    chemicals where  BOO:P  may be  less than 10:1, permit compliance is guaranteed
    while cost savings compared with the straight chemical approach will always
    be obtained.

B.  Cost Comparisons

    A major portion of the report is an analysis of the costs of biological
    phosphorus removal compared with chemical  phosphorus removal.   The large
                                    97

-------
Mr. Edwin Barth
11 April 1984
Page Two
    number of figures and tables does not seem justified since simplified
    assumptions and inconsistent methods of estimating the component costs
    were used.  Specifically:

    1.  Some construction costs were reported to be estimated using the EPA
        I&A manual while other components are estimated using Weston in-house
        procedures.  Cost estimates should be on an equal basis or at least
        some comparison of Weston methods with I&A manual methods provided.
        A discussion of the major differences among the processes and the
        impact on the cost would be Vi ry helpful to a designer considering
        using the A/0 process.

    2.  The method of estimating the O&M costs is not given.   No cost breakdown
        is given to indicate where differences in operating cost arise.  The
        dosage and unit cost of chemicals are not given.

        Operating cost savings from lower chemical usage and less sludge pro-
        duction are a major incentive to prospective users of biological
        phosphorus removal plants.  If this reoort is to accurately assess
        the value of biological phosphorus removal, additional discussion and
        further detail is needed in this area.

    3.  No consideration is given to retrofit of existing activated sludge plants.
        Retrofit of A/0 can often lead to large operating cost savings over the
        life of the plant.

    4.  The relative cost advantage of biological phosphorus  removal is made to
        appear small by adding other non-phosphorus removal related components
        to arrive at a "total" cost figure.

    5.  The cost of tertiary filters appears high.  For example, the actual bid
        installed cost for an Enelco brand filter for the City of Largo (15
        MGD, bid November 1981) installed in an existing concrete shell was
        $850,000.  The figure given in the report for a 5 MGD case including
        concrete is $1,300,000.

    6.  It is assumed that the A/0 process will require effluent filtration to
        meet a 1 mg/1 total P standard.   A much less expensive method would be
        to supplement with chemicals.

        It should be recognized that chemical phosohorus removal processes will
        also produce a phosphorus rich sludge and may require effluent filters
        to meet 1 mg/1.  For example,  a typical activated sludge plant treating


                                   98

-------
Mr. Edwin Barth
11 April 1984
Page Three
        150 mg/1 BOD (after primaries) with an overall sludge yield of 0.8
        Ib. solids/lb.  BOD removed will produce 1000 pounds of waste sludge
        per million gallons.  If alum is added at a dosage of 15.0 mg/1
        (as A!*4"1") to precipitate 10 mg/1 phosphorus, an additional 437 pounds
        of sludge will  be made totaling 1437 pounds of waste sludge.  This will
        contain 75 pounds of phosphate resulting in a sludge phosphate content
        of 5.221,  Solids contained in the effluent will reflect increased
        phosphorus content.


Ed, thanks for your consideration in allowing me to comment on this report.  I
hope this will be of value to you.

                                    Sincerely,
                                    David J. Krichten
                                    Technical Specialist
                                    Environmental Products Department
DJK/cah
                                    99

-------
                         Process                         HAP III
                         Et>uiPW«>t                        *.>*l«  "- ts West Second Souih
                         Company                                   Posl Office Box 300

                                                                 Salt Lake City, Utah 84110-0300

                                                                 Telephone 801/526-2000
                                                                 Telex 388-331 or 388-320
                                    March 9, 1984
    Mr.  Ed  Barth
    Chief Biological Treatment Section
    Wastewater Research Division
    United  States Environmental Protection

    SSI, I'S           *-
   Subject:  Edging Technology  Assessnent Qf B.

   Dear Ed,


                                                   as
         Process  Equipmenl cojLS               2
             I^p^
                     s                               ^«t that the
             where denitrif cat on ic f  h°-1d be C0ns"ered only in
  removal.   We  strongly objec? to tli^ iuT"^^ 1n  add^ioHto phosphorus
  incorrect  and fails to S™«,£  5   Judgement and believe it is both

                               tt
   ™                          srVl      shH
  from  the presentations from Eimcn 7nrf nit.    !? uld be abljndantly clear
  eeptors, especially nitrate  fl^a?J.ot?ers that Control of all  electron ac
  fermentation perf^mancf a'nd ttSs emSlnfTT1?1*6 t0 prop^         "
  The introduction of nitrate to  the ferment ^tS°logical Phosphorus removal.
  if proper fermentation and pSsSSruf JS2S I re!Ct0r must be av°1ded
  Process does not evade this  issue inLmlh »  f! f° ^ccur'   The  Bardenpho
 KSmPl2ShSd Wlthin the Bardenpho  Howsheet   F?^1  ,n\t-r°9en cmt™l isP
 Bardenpho Process provides a positive  JpfLi    C°^elleves  that  th^
 assures that nitrate cannot deterioratP h I?nn-  c?nfZ9°rat1on Wh1c«
 No other configuration  provid" Si  «sSrJi? lcaj Ph?sPho™s removal.
 Proy1des nitrogen  removal, evln whin sochlf ^ The ^Ct that

                                "
assumption that a two or three  st™* cJ +   ' Seems to be based  on  the

a five stage system.   This  assumption Is erroneou^ ^ ?xpen!1ve  tna"
                                                    ''**e i L  Tai l es  to
                                   100

-------
Mr, Ed Barth                                                 March 9, 1984
Page 2
recognize that a rational process design will be based on providing the
necessary SRT to provide the required effluent quality in terms of BOD
and ammonia. As such the reactor volume should be nearly equalivant
regardless of the number of stages employed.  Eimco believes that it is
best to divide that reactor volume into five stages to provide nitrogen
control for reasons discussed above.  The difference, therefore, relates
to the number of inner partition walls and the specific function of the
subreactors created by location of those partition walls.  With that
in mind, it seems clear to us that a five stage reactor, which accounts
for the potential of nitrate formation during various seasons or operating
conditions at a full scale facility, and develops energy and akalinity
restoration benefits as a result of denitrification, is the preferred
configuration for applications requiring phosphorus removal.

Now it is true that many of the Bardenpho Process designs in the United
States have been based on long SRT operation.  The reason for this relates
to the fact that most of these situations involve applications requiring
total nitrogen control to levels of the order of 3 mg/£ TN.  With the
relatively longer SRTs required to assure achieving less than 1 mg/£
ammonia, and the anoxic volume required to achieve an effluent of
1-2 mg/£ nitrate, it becomes obvious that utilizing only a slightly
larger SRT could result in the production of a stab!ized sludge eliminating
the need for additional costly digestion and eliminating concerns of
phosphorus release during the digestion process.  We would stress, however
that this is a detailed design decision made by the engineer outside
the scope of whether a two, three or five stage system is employed.

Therefore, Eimco would like to see this judgement and statements concluding
where Bardenpho's "greatest market potential exists" removed from the
Summary Document.  For your reference, the most obvious examples of this
appear on page V, 14, & 53.

Secondly, there is a general implication and specific statements made
to the effect that the Bardenpho process capability to achieve effluent
phosphorus values of less than 2 mg/£ is not demonstrated.  The only two
operating Bardenpho plants in North America disproved this statement.
The Kelona, British Columbia facility, which was reported on at both
sessions of this workshop, has consistently produced an effluent of
less than 1 mg/£ phosphorus after its initial acclamation period while
the Palmetto, Florida Bardenpho facility presently averages 1.5 mg/£
effluent P without chemical addition.  This level of performance at
Palmetto can be directly attributed to the fact that the influent waste-
water BOD concentration is unusually weak for domestic wastewater and
less than 50% of the design value.  Labeling the Bardenpho process as
incapable or unproven in producing effluent phosphorus values better
than 2 mg/£ would seem to not be justified.  We are concerned that
this statement  in the Summary Document will be taken out of context by
others and interpreted in far too general a context.  To prevent this,

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Mr. Ed Barth                                              March 9, 1984
Page 3
we respectfully request that statements to this effect be removed from
Summary Document.  Such statements are found, for example, on pages
14 & 28.

Thirdly, the summary document presents numerous cost analyses of the
various biological phosphorus removal flow sheets.  In the first place,
the cost analyses again relegate Bardenpho only to those applications
requiring denitrification with no consideration given to the technical
and economic benefits of Bardenpho in other applications evaluated.  More
importantly, we have serious reservations about the validity of the cost
analyses performed.  For example, the Bardenpho Process was designed
arbitrarily and based on nominal detention times.  The dentention times
arbitrarily selected are, for the most part, higher than that normally
found in U.S. Bardenpho Process designs based on rational design approaches.
Therefore, we feel that the results of these cost analyses, particularly
where the Bardenpho Process is involved are neither accurate for the
general case nor even for the example selected for this analysis.  Actual
bid prices taken on several commercial plants during the past one - two
years testify to the inaccuracy of the cost analysis.

Our concern, of course, is that these analyses will be used and abused
as consulting engineers attempt to evaluate relative cost and performance
effectiveness of the Bardenpho Process.  Process selection decisions will
be made on the basis of these analyses and these decisions may,, in many
cases, be in error.  Doubting that process selection decisions will be
made based on these cost analyses is naive.  There are many const!ting
engineers in the United States today who utilize general cost information
such as that found in the EPA I&A Technology Manual and the infamous
CAPDET program.  This is done because it is not only the easiest thing
to do, but also readily accepted since the cost information is generally
associated with having been developed by various agencies of the Federal
Government such as the EPA and The Corps of Engineers.

Therefore, Eimco believes that presenting generalized cost information
such as that presented in the Summary Document is risky, inappropriate,
and in fact serves no real benefit.  On the other hand, there is an
unfortunate opportunity for misuse of that information.  Thus Eimco has
a strong preference to have this cost information removed from the Summary
Document,

In addition, there are several statements made in the Summary Document
which we believe are inaccurate.  Without trying to be too picky, we
would just highlight two of them here.  First, on page 56, a statement
is made that "some of the failures associated with the Bardenpho System
have been related to low COD:TKN ratios in the feed to the system".   This
statement is really not accurate.  In our opinion, the COO'.TKN ratio
was not a problem at all, but rather the inadequacy of the design to  account
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Mr. Ed Earth                                          March 9S 1984
Page 4
for the quantities of nitrate produced and reduced in the system.  As
such, there was excessive residual nitrate in the system which deteriorated
phosphorus removal capability.  As stated earlier in this letter, this
is precisely why Eimco feels so strongly that biological phosphorus
removal flowsheets must be capable of total nitrogen control.

The authors of the summary document briefly discussed operation and
maintenance considerations on page 20,  In that section* they state that
the Bardenpho Process is more complicated than PhoStrip or AO since the
former involves both phosphorus and nitrogen removal.  We simply can't
understand how the author can come to that conclusion with any understanding
of the various mechanisims operative in a biological phosphorus removal
flowsheet.  I'm sure you can understand our difficulty with this conclusion,
considering nur conviction that a five stage Bardenpho design is operation-
ally stable anJ forgiving since there are no swings in nitrification or
denitrification on a daily or seasonal basis.  Such may not be the case
for process designs based on the ragged-edge of nitrification SRT values
with inadequate capability to respond to various denitrification require-
ments.  The inherent stability of the Bardenpho Process is even more
obvious in situations where long SRTs are employed to achieve sludge
stablization.  Thus, we find the statement that Bardenpho is more difficult
to operate to be not only unjustified, but actually opposite to the real
situation.  We trust that the authors will have no problem in correcting
this conclusion in their report after considering the process related
aspects of each of the flowsheets more carefully.

Ed, I trust that the comments contained herein will find acceptance by
yourself and the authors of the Summary Document,  I also understand that
the Document is being reviewed by two extramural parties.  I am hopeful
that these parties will also bring some of the issues raised in this
letter to the attention of the authors for consideration.  I will look
forward to hearing from you on these issues and will be more than happy
to discuss them in more detail as necessary.

                                 Sincerely yours,

                                 Ejmco Process Equipment Company
DD/ms
David DiGregorio, Manager
Process Marketing & Development


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              Comments on "Emerging Technology Assessment
                   of Biological Phosphorus Removal"

                 G.V, Levin, Biospherics Incorporated
1.   Abstract - p.v., first paragraph, why not mention effect of I + A
     funding and construction grant program on present worth costs fco
     the community?  These programs have major impact on capital costs
     to the community, particularly in comparing the new processes,
     which are eligible for I + A, to the baseline process which it is
     not.

2.   Table 5, p. 37, same as 1. above.

3.   Pig. 5a, p. 43, same as 1. above.

4.   Table 6, p. 38, should compare apples to apples;  either PhoStrip at
     2 mg/1 TP effl. or alternatives at 1 mg/1 TP effl.  I think the
     latter is more appropriate since most effl. stds. are 1.0 mg/1 T.P.

5.   Table 6, p, 38, since $ crossover for PhoStrip occurs soon after
     5 mgd is passed  {see p. 53, first bullet) why not extrapolate point
     where crossover in present worth occurs and show it in Table?

6.   p. 3, 9th line from bottom, after "Figure 1," strike "or" and after
     "primary effluent" insert "or recycled stripper sludge."

7.   p. 3, bottom line, add "A variety of other PhoStrip modes has  been
     described by Biospherics, ranging from elimination of stripper tank
     through use of existing tankage for sludge stripping to a no chemicals
     version, buL none has been demonstrated full-scale."

8.   p. 3, 18th line from top, delete comma between "Biospherics" and "Inc."
     (ibid wherever else occurring}.

9.   p. 3, line 22, after "activated" add "air or oxygan."

10.  p. 4, Figure 1, Direct Sludge Recycle is given as "(0.2 to 0.3Q)".  I
     think it should be stated "(0.2 to 0.5Q)" since the process has fre-
     quently been operated at 50 percent direct return sludge.  This change
     would require corresponding change for "Phosphorus-Enriched Sludge" to
     "(0.2 to 0.5Q)."  Also, "Elutriation Prom Either:" should be "Elutri-
     ation Prom any of:" to be grairanatical.

11.  p. 11, 12th line from bottom, after "selection," I suggest insertion
     of "or inducement."  This is because there is still no definitive word
     on whether the population is selected or whether P-uptake and release
     results from enzyme inducement in the general biota.  The same addition
     would be made three lines below this where "selection" appears again.

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12.  p. 15, 13th line from bottom, if suggestion 10 above is accepted,
     change "0.3" to "0.5."

13.  Reference 4, change "Experimentia" to "Experienta."

14.  Reference 11, Change "Tarmy" to "Tarnay."

15,  Reference 13, change "Masse" to "Maase," and "J.J. Kish" to "A.J.
     Kish," and delete comma after Biospherics.

16.  Reference 31, remove comma after "Biospherics."
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