EPA-600/2-76-146
October 1976
                   Environmental Protection Technology Series
WASTEWATER  SAMPLING, TRANSFER AND
                      CONDITIONING SYSTEM

                        Municipal Environmental Research Laboratory
                             Office of Research and Development
                            U.S. Environmental Protection Agency
                                    Cincinnati, Ohio 45268

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                RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency,  have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping  was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:

     1.    Environmental Health Effects Research
     2.    Environmental Protection Technology
     3.    Ecological Research
     4.    Environmental Monitoring
     5.    Socioeconornic Environmental Studies
This report  has been  assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate  instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides  the new  or improved technology  required for the control  and
treatment of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                            EPA-600/2-76-146
                                            October 1976
       WASTEWATER SAMPLING, TRANSFER

          AND CONDITIONING SYSTEM
                    by

              Louis S, DiCola

             Raytheon Company
          Portsmouth, R.I.  02871
          Contract No. 68-03-0250
              Project Officer

              Robert H. Wise
       Wastewater Research Division
Municipal Environmental Research Laboratory
          Cincinnati, Ohio  45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
    OFFICE OF RESEARCH AND DEVELOPMENT
    U.S. ENVIRONMENTAL PROTECTION AGENCY
           CINCINNATI, OHIO  45268

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                                 DISCLAIMER

     This report has been reviewed by the Municipal Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views and
policies of the U.S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or recommendation
for use.
                                      ii

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                                FOREWORD


     The Environmental Protection Agency was created because of

increasing public and government concern about the dangers of pollu-

tion to the health and welfare of the American people.  Noxious air,

foul water, and spoiled land are tragic testimony to the deterioration

of our natural enviroment.  The complexity of that environment and

the interplay between its components require a concentrated and

integrated attack on  the  problem.

     Research and development is that necessary first step in problem

solution and it involves defining the problem, measuring its impact,

and searching for solutions.  The Municipal Environmental Research

Laboratory develops new and improved technology and systems for the

prevention, treatment, and management of wastewater and solid and

hazardous waste pollutant discharges from municipal and community

sources, for the preservation and treatment of public drinking water

supplies, and to minimize the adverse economic, social, health, and

aesthetic effects of pollution.  This publication is one of the

products of that research; a most vital communications link between

the researcher and the user community.

     To help implement the above, this study describes development

of an automatic on-line sampling, transfer and conditioning system for

monitoring wastewater-treatment process streams.


                                    Francis T. Mayo, Director
                                    Municipal Environmental Research
                                    Laboratory

                                  iii

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                                  CONTENTS


                                                                 Page.

DISCLAIMER                                                        ii

FOREWORD                                                          iii

FIGURES                                                           vii

TABLES                                                            viii

ACKNOWLEDGEMENTS                                                  ix
I    INTRODUCTION

II   SUMMARY

III  CONCLUSIONS                                                     5

IV   RECOMMENDATIONS                                                 7

V    PRELIMINARY INVESTIGATION AND ACCEPTANCE TESTING                q
     OF COMPONENTS

     Sample Transfer Pump                                            ^
     Homogenizer
     Filter                                                          n
     Component-Testing Manifold                                      13
     Test Location                                                   13
     Acceptance Testing of Components                                13
     First Tests of Particle Size                                    -,0
     Further Tests of Particle Size                                  ^g
     Discussion of Particle-Size Testing                             22
     Pipe-Size Consideration                                         22
     Filter Tests                                                    23
     Some Observations                                               23
     Conclusions
                                                                     25
VI   FINAL SYSTEM DESIGN

     Establishing a Sampling Procedure                               25

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     Monitoring Both TOG and SOC                                26
     System Description                                         27
     Use of Dilution                                            27
     Adapting the Dilution Pump                                 36
     Overcoming Intermittent Flow                               37
     Timing of Samples                                          38
     Comparison with Standard Analytical Methods                39

VII  TEST RESULTS                                               41

     Reference Tests                                            41
     Sample Transfer and Conditioning System Test Data          41
     Performance of Automatic Analyzers                         41
     Comparison of Source and Interface Values                  46
     Test Results from Automatic Analyzers                      46

VIII REFERENCES                                                 48

APPENDIX A - Statistical Analysis                               49

APPENDIX B - Operation and Maintenance                          52

APPENDIX C - Design Specification Guidelines                    62

APPENDIX D - List of Equipment                                  67

GLOSSARY OF TERMS AND ABBREVIATIONS                             69
                                 vi

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                                LIST OF FIGURES





Number                                                             Page



  1    Hydr-0-Grind Pump	    10




  2    Raytheon In-Line Homogenizer	   12




  3    Preliminary Sampling Manifold Flow Diagram	14




  4    Site Description	15




  5    Millipore Filter Apparatus	17




  6    Sieve Assembly 	  19




  7    Raw Sewage, Particle-Size Reduction with Homogenizer.  ...   20




  8    Flow Diagram of the System	28



  9    Sampling System, Front View	29




 10    Sampling System, Rear View	30




 11    Control Panel, Front View	31




 12    Control Panel, Rear View	32




 13    Manifold Assembly, Front View	33




 14    Typical Hydr-0-Grind Pump Installation	34




 15    Typical Duplex Dilution Pump Installation	35




 16    Sampling Sequence	40




B,l    Dummy Plug Wiring to Skip SOC Mode	54




B.2    Timing Diagram		55




B.3    Typical Valve Pair	58




B.4    Ladder Wiring Diagram	59
                                  vii

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                                LIST OF TABLES


Number                                                            Page

  1     PRESERVATION OF THE INTEGRITY OF CHEMICAL
        COMPOSITION DURING THE COURSE OF TRANSPORT AND
        CONDITIONING OF RAW SEWAGE	21

  2     RESULTS OF FILTER TESTS	23

  3     SAMPLING MATRIX	25

  4     SAMPLE TRANSFER DATA	38

  5     SAMPLE TRANSFER AND CONDITIONING SYSTEM TEST DATA:	42

             SECONDARY EFFLUENT	42
             PRIMARY EFFLUENT	43
             RAW INFLUENT.	44
             MIXED LIQUOR	45
             RETURN ACTIVATED SLUDGE .  .  .	45

B. 1     TABLE OF OPERATION SEQUENCE	45
                                vlli

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                               ACKNOWLEDGMENTS
The support of Anthony Ventetuolo, Superintendent of the Water Pollution
Control Facility, Cranston, Rhode Island, is acknowledged with sincere thanks.
A. Joseph Mattera, Foreman, also provided valuable assistance.

Sincere thanks to Walter Schuk of the EPA for his guidance and assistance at
the outset of system testing.

The preliminary investigations, as well as all system designing, construction,
and testing, were performed with the invaluable assistance of H. Duane Evans.
                                     ix

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                                  SECTION I

                                INTRODUCTION

The purpose of this project was to develop automatic, on-line equipment for
sampling, transferring and conditioning wastewater-treatment process streams
for automated analyses for total and soluble organic carbon, ortho- and total
hydrolyzable phosphate, ammonia, nitrate, and nitrite.  Furthermore, these
sampling, transferring and conditioning steps were to be accomplished without
causing unacceptable chemical changes in the sample prior to any of the
analyses.  Ultimately, automated sample-handling equipment of this type will
be a necessary component of completely automated, wastewater-treatment
processes and plants.

The major factors requiring consideration were:  a) the necessity of limiting
the size of suspended solids particles in samples that could not be filtered
prior to analysis, b) fabrication of a suitable automatic manifolding and
switching network, c) assurance that all samples would be representative
of the process streams from which they were taken, and d) total system
reliability.  A brief discussion of each of these factors follows.

Limiting the Size of Suspended Solids Particles

The suspended solids and refractory matter present in wastewater prevent the
use of typical off-the-shelf colorimetric or organic carbon analyzers without
sample pretreatment.

The total organic carbon (TOC) analyzers presently used in most wastewater-
treatment laboratories accept samples of 50 inicroliters, or less.  These
relatively small volumes are required by the small injector assemblies and
combustion reactors incorporated in such laboratory analyzers.  In addition,
multiple injections of a well-homogenized sample are required for obtaining
reliable data.  Regardless of TOC-analyzer design, however, incoming samples
must meet suspended solids limitations not only on average particle size,
but also on particle-size range_; otherwise, not only would the analyzer tend
to clog, but the analyzer's data would contain intermittent and unpredictable
outliers or data "spikes" that could ruin much of the total output.

Colorimetric analyzers provide false data when high suspended solids concen-
trations are present in the sample streams.  Large particles tend to clog
the colorimeter's automatic delivery system, while small particles limit light
transmission.  Finely suspended material causes backscatter (Tyndall effect),
and this also creates artificially high absorbance values.  Thus, in either
case the true value is masked.

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Accurate data can be obtained only through proper conditioning (i.e.,
homogenization or filtration) of the sample before the sample enters
the analyzer.

Automatic Manifolding and Switching

The extended retention time of a typical wastewater-treatment process  dampens
the short-term changes in most measured variables.  This permits analytical
time sharing whereby a single analyzer can be used to monitor several  process
streams without significant loss of data; although occasionally, full-time
monitoring of a process variable may be necessary.

The optimum situation is to supply a continuous flow of several different
types of samples to a centrally located, valved manifold.  At this location,
the sampling sequence, sampling time and sample conditioning would be  controlled
by an automatic switching device, with a manual override for experimental work.

A centralized monitoring system offers the following benefits:

     1.  fewer analyzers to purchase,
     2.  fewer analyzers to maintain,
     3.  reduced chemical consumption,
     4.  easier surveillance,
     5.  easier isolation from the hostile environment of a wastewater-
         treatment plant.

Centralization, however, often requires long transfer distances which can
cause unreliable data.  Therefore, proper sizing of transfer lines to obtain
optimal  flow must be  taken into consideration.

Assuring Representative Samples

Of primary importance in any sampling and conditioning system is whether or
not the sample taken is representative of its source, and whether the sample
has undergone a chemical change as a result of the conditioning process.  This
factor is dealt with by proper sampling, sample transfer (i.e., transport),
and sample homogenization or filtration.

Reliability

Most automatic sample transfer and conditioning systems have been so poorly
designed and/or mechanically unreliable that the chemical integrity of the
transported sample has received little or no attention.  To be successful, an
automatic sampling system must utilize essentially troublefree hardware that
has been thoughtfully integrated into a highly reliable system capable of
continuous unattended operation.

With these facts in mind, Raytheon designed and constructed an automatic, on-
line, wastewater-sample transfer and conditioning system to make automated
process  stream analysis and process control possible, and thus fulfill a need
which is daily becoming more urgent.

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Test Location

The Water Pollution Control Facility for the City of Cranston, Rhode Island,
was chosen as the test facility for this program.  The facility utilizes an
activated sludge process and has a daily flow of 6.84 million gallons (26,500
cu m).  The plant's size and population it serves (75',000 persons) make it a
typical operation.  The proximity of the plant to Raytheon1s facility, as
well as the good working relationship between Raytheon and the City of
Cranston through the years, were additional factors that influenced the
decision to conduct the study at that particular location.

Although the Cranston facility has adequate laboratory and office space to
accommodate the project's requirements, piping the sample transfer lines to
the central laboratory would have been most awkward.  Also, such an arrange-
ment would have created a safety hazard for plant operators and maintenance
men since the piping would be crossing heavily traveled areas.  Instead, a
Raytheon owned, environmentally controlled (heated and air conditioned)
instrument trailer was set up at the Cranston facility to house the system to
be tested.

This program, which extended over a 15-month period, was carried out in two
phases.  Descriptions of both are reported herein:

     Phase I - Preliminary Investigation and Qualification of Components

     Phase II- Design, Implementation, Testing, and Evaluation of the
               Final Sampling System

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                                 SECTION II

                                   SUMMARY

This report describes the construction and field evaluation of an automatic
on-line hardware system for reliably sampling, transferring, and conditioning
various wastewater-treatment process streams such that the resulting transferred
and conditioned samples are suitable for interfacing with automatic on-line
colorimetric and total organic carbon analyzers.  Process streams to which
this hardware system was successfully applied included raw sewage, primary
effluent, secondary effluent, aeration tank mixed liquor, and return activated
sludge.  Primary sludge could not be sampled at the field-testing site because
the sludge had become too thick at its only feasible access point.  Analytical
parameters used to evaluate the hardware system included both total and soluble
organic carbon, orthophosphate, total hydrolyzable phosphate, and ammonia
nitrogen.  Nitrate and nitrite were not included; however, the hardware system's
performance with the soluble parameters studied indicate that nitrate and
nitrite should present no special difficulties.

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                              SECTION III

                              CONCLUSIONS
General

The sample transfer and conditioning program described in this  report has
demonstrated that various streams within a typical municipal wastewater-
treatment plant can be monitored remotely and reliably for TOC, SOC,  o-PO^
hydrolyzable P04, NH3~N, and N03/N02-N.
        Sampling, transferring and conditioning was accomplished
        reliably and continuously without affecting the representative
        nature of the sample except for particle size distribution.

        Comparison of wastewater sources and interface sample discharge
        concentrations, as measured by reference laboratory procedures,
        demonstrated very satisfactory agreement.

        The agreement in reference laboratory TOC values for source  and
        interface proves that sampling of streams containing particulate
        matter need not be a problem if the following simple rules are
        followed in designing the system:

        1.  Fluid velocities at, or greater than, 2 ft /sec should be
            maintained in the sample-transport lines.

        2 .  A sampling manifold that keeps all sample streams flowing
            continually must be provided.

        3.  For the automatic modes, a sampling sequence must be established
            for sampling the cleanest stream first, then sampling progressively
            dirtier streams.  At the end of each such sequence of samples,
            a complete flushing of the system with clean water must  be carried
            out.

        4.  All fittings, pipes and other wetted components in the sample-
            transport and manifold systems must be designed to eliminate
            restrictions and dead zones wherever possible.

        Sample dilution is a viable approach and, if implemented correctly,
        offers the following benefits:  a) multi-stream monitoring,  using a
        single transfer system for high solids and low solids sources,
        b) minimization of transfer-line contamination by diluting at the
        source, rather than at the interface, and  c) quick multi-stream
        switching with relatively short purge time (this is feasible because
        proper dilution minimized the transfer system's solids loading).

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The sample transport and conditioning system provides satisfactory
continuous sampling of a single process source; therefore, if
satisfactory automated analyzers were to be dedicated to only one
process source, continuous on-line remote analyses for that source would
be furnished.  For multiple-source operation as developed in this
study, the on-line colorimetric analyzers restricted the sampling
frequency to one process source per hour.  The time for transport
and conditioning of each sample, however, was only 17 minutes which
would have permitted analyses of approximatley three different
process sources per hour if sufficient colorimetric analyzers had
been added and suitably employed.

In any interfacing of a sampling manifold with an automatic analyzer,
transfer velocities and/or distances within the laboratory space are
just as important as are those used to deliver the samples to the
laboratory.  All automatic analyzers should be as close to the sampling
manifold as possible, especially if the sample to be analyzed contains
suspended material.

Where it is not possible to attain optimum analyzer location, analyzer
input velocities should be increased to insure that a representative
sample is actually being supplied to the analyzers within minimum
transport time.  This requirement means increase of sample delivery
rates to the analyzers, either by changing the sample pump (or pump
speed), reducing the diameter of the sample lines, or inserting an
additional sample pump to obtain, in each case, a resultant increase
in velocity.

The interface results for most of the automated on-line analyzers tested
did not satisfactorily agree with the interface results from reference
laboratory methods; the one satisfactory on-line analyzer was that
for orthophosphorus.  Further development of reliable automatic
on-line analyzers is necessary.

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                                  SECTION IV

                                RECOMMENDATIONS
With the initial phases of this program accomplished successfully, there are
several areas inviting further investigation:

        How would the costs of completely automated sampling compare with
        corresponding costs for existing manual sampling techniques?

        Would data reliability be improved by eliminating all human
        influences and human biases from the sample-collecting operation?

        If preceded by a reliable automated sampling system, could on-line
        analyzers operate continuously for extended periods without failure?

        Would the availability of real-time analytical data influence plant
        operation in such a way as to improve effluent quality significantly?
        Could it likewise be used to decrease plant operating cost
        significantly?

        Could the concept of "quality assurance" be realized by improving
        data reliability via appropriate combinations of automatic sampling
        and automatic analyses?

        What would be the magnitude of improved reliability resulting from
        the substitution of a three-way motor-driven valve for each pair of
        two-way valves?

        What effect would changes in arrangement of the analyzers (i.e.,
        relative to the ST & C system's homogenizer and filtration system)
        have on the consistency of the data, and what (if any) limitations are
        there in making such rearrangements?

Plant Expansions and New Plant Installation

In modifying and expanding existing plants,  and for plants to be built in
the future, installation of a permanent automatic sampling system would seem
to be the more viable approach.  It is quite likely that in the planning stages
of these facilities, much thought would be given to the centralization of

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sample streams for future monitoring purposes and, ultimately, for automatic
process control.  Tapping into lines would be no major problem because a new
plant could provide for readily accessible sampling ports; however, flow
regulation would require some design effort.  The flow rates within a large
plant are quite high  (thousands of gallons per minute), whereas the Raytheon
Sample Transfer and Conditioning System requires only 5-6 gallons per minute
(19.4 - 23.3 1/min).  Careful design of the entire sampling system would be
required to achieve a representative sample.  In addition, to make the
homogenizer function properly and to reduce the likelihood of plugging within
the sampling system, the sample would have to be pre-conditioned to reduce
occasional large particles to no more than 1/4-inch (6-mm) diameter.   An  in-
line grinder pump, rather than the drop-in type used for this project, would
be more suitable for such an application.

The concepts have now been proven; with judicious effort, the problem areas
stated above do not appear to present any insurmountable obstacles.

Raytheon recommends that further wastewater transfer and conditioning studies
be performed to answer these questions.

Portable Installations at Existing Plants

An effective sampling strategy must be adaptable to existing plants,  as well
as to those constructed or modified in the future.  A single sampling system,
adaptable to both, may be unnecessarily flexible and expensive.  The most
practical solution to this problem would be to design a mobile system for
investigating existing plants.  With the type of equipment developed during
this program, an investigator could go into a treatment plant with a trailer,
housing the sampling manifold and a battery of automatic analyzers, and
within a very short time, he should be able to assess the plant's efficiency
and initiate steps to rectify problem areas.  Being portable, such an
analyzer system would require no major on-site construction.  The mobile
facility might be owned by the EPA and leased to municipalities as required.
This is the most practical approach for existing plants since their piping
is not readily accessible.  Such an approach would allow rational investigation
of the possible cost benefits of a permanent sampling system; it could also
be coupled with existing automated plant controls without excessive capital
outlays.  In either case, such a portable system could help answer many of
the questions posed in the foregoing part of this Section.

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                                  SECTION V

             PRELIMINARY INVESTIGATION AND ACCEPTANCE TESTING OF
                                 COMPONENTS
The sample transfer and conditioning system was fabricated from a number of
components.  These components were a sample transfer pump, a homogenizer,
a filter, and a sampling manifold.  A discussion of the selection and design
criteria for each of the critical components is given below.

Sample Transfer Pump

There is great diversity in the physical makeup of wastewater-treatment
streams.  A pump must be able to handle clean streams, as well as streams
that contain high amounts of foreign material—plastics, paper, fibers, and
wood chips.  Such foreign material provides a formidable deterrent to
continuous pump operation.  Raytheon has utilized the Hydr-0-Grind pump
manufactured by the Hydromatic Pump Company in previously developed systems,
and has found it perfectly suited to sample raw influent, primary effluent,
and secondary effluent.

The Hydr-0-Grind is a submersible centrifugal pump, possessing a grinder unit
mounted on the input; see Figure 1.  The pump impeller is manufactured from
ductile iron and is cadmium plated.  The grinder's stationary and rotary
cutters are made of hardened, ground, stainless steel.  The pump and grinder
are mounted on a stainless steel shaft, supported by ball and sleeve bearings
that are oil lubricated.  No additional lubrication of the motor or seals is
required.

The Hydr-0-Grind's pump can be operated continuously at a regular flow
of 1 to 30 gpm (3.79 to 113.54 1/min) against a maximum head of 90 feet
(27.43 m).  The motor is 1-1/2 horsepower, 3-phase, and 209 to 230 volts.
The motor winding, rotor, and bearings are completely sealed in oil that
lubricates the bearings and transmits heat from the windings to the outer
shell.

The working elements of the grinder pump are a grinder ring and impeller
that macerate gross solids and a secondary cutter/impeller that further
macerates these solids to a reduced particle size of 1/4 inch (6 mm) for
pumping by the centrifugal pump.

The complete front end of the grinder pump (inlet, outer impeller, grinder
ring, inner impeller and centrifugal impeller) can be removed without
affecting the seals, motor or installation.

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CENTRIFUGAL
IMPELLER
                                  	 OUTER
                                     IMPELLER
                                                   DISCHARGE
                                                    INNER
                                                    IMPELLER
                                                 GRINDER
                                                 RING
                   INLET
                Figure  1. Hydr-O-Grind Pump
                             10

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Homogenizer

Waatewater streams contain all types of particulate matter (plastics, paper,
fibers  wood chips, etc.) as well as domestic sewage.  This material must be
continuously and reliably reduced to finely divided, uniform, particle sizes
in order to be assimilated by any TOG analyzer.

The Raytheon Homogenizer (patent pending), used on transported Hydr-0-Grind
effluent, was selected on the basis of its proven capability to fill the above
requirement.  This homogenizer (Figure 2)consists of the following parts:

      •  An electric motor — 1 hp, 115V, single phase, 3600 rpm

        Sealed bearings

      •  A micrometer adjustment wheel to regulate homogenizer-effluent
        particle size

        A housing manufactured of a material that is impervious to corrosion

        An abrasive stator and rotor

In operation, the sample is pumped at a prescribed flowrate of 3-6 gph
(11.36 - 22.71 1/hr) through the inlet of the homogenizer and is then processed
between the abrasive stones of the rotor and stator.  The design of the rotor-
stator abrasive stones permits the reduction of solids to small particles
without buildup of homogenized solids on the grinding surfaces; in effect, the
abrasive stones are self-cleaning.

Field experience with this type of homogenizer has demonstrated that it is
capable of reducing such difficult materials as plastics to a fine particle size
on a  continuous basis without any buildup on the grinding surfaces, a problem
typically associated with solids blenders.

Filter

As mentioned previously, filtering plays an important role in determining the
success or failure of colorimetric analyses.  This system's pretreatment
filtration unit incorporates an automatically controlled backwash sequence that
may be initiated by a manual push-button, or hy automatic internal sensing
elements.

The Raytheon Pretreatment Assembly (Model 2550) utilizes a two-stage filtration
process.  The first stage is a self-cleaning wash-flow filter which eliminates
the large particles.  The second-stage filter is a fixed-media bed which
reduces the filtrate from the first stage to particles of 12 micrometers, or
less.

Component-Testing Manifold

To expedite testing of the filter and other system components, a preliminary

                                       11

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INDICATOR   GAp
         ADJUSTER
                                                                0-RING
                                               rTT.--' „- '--_J STATOR ,-.v.-.
                                                                              4- COVER
                                                                                DO NOT DISTURB
                                                                              T THESE SCREWS
   FIGURE 2.    RAYTHEON  IN-LINE HOMOGENIZER

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 sampling manifold was constructed.   Figure 3 illustrates the flow diagram.
 The wash-flow filter,  the fixed-media bed,  and the filter's pump were piped
 to a test manifold consisting of a  series  of ball valves capable of directing
 various  samples  to the desired  locations.   Gauges were  installed at appropriate
 locations on the manifold to  provide pressure and temperature data which
 provided additional information to  establish effective  acceptance criteria
 for the  individual system components.  This preliminary manifold served as a
 valuable investigative tool in  the  acceptance testing of all system components.
 Its flexibility  enabled Raytheon personnel to test variations in particle-
 size reduction as a function  of sample flowrate merely  by changing orifice
 sizes.

 It  should be noted that the preliminary manifold  was essentially a test
 vehicle  and  that the  flow diagram shown in Figure 3 in  no way reflects the.
 final configuratidn of the sampling system described later in the "Final System
 Design"  Section.

 Test  Location

 Checkout  and testing  of the design  of the  sample  transfer and conditioning
 system were  conducted at  the  Water  Pollution Control Facility for Cranston,
 R.I.  A  mobile laboratory was located opposite the grease floatation unit as
 indicated in Figure 4.   The location was selected  so that unused  samples
 could be exhausted back into  the system without affecting the plant  operation.

 Acceptance Testing of Components

 To  demonstrate that a representative sample  could be taken,  transferred, and
 conditioned  without altering  the chemical  composition of the original sample,
 appropriate  analyses  were  performed  on paired samples.   Sets of  two  grab
 samples  (i.e., sample pairs)  were taken:   one sample from the stream source
 and another  sample following  sample  transport and conditioning.   Each of
 these sample pairs was then characterized  for particle-size  distribution and
 for TOG value, and the values for each pair  of samples were  "cross-compared".

 First Tests  of Particle  Size

 To determine particle-size reduction by homogenization, four tests were set
 up, using  the following generally-accepted techniques:   a) settleable solids
 measurements, b)  suspended solids measurement, c) microscopic examination, and
 d) sieving.

 Settleable solids measurements were made in an attempt to demonstrate that
 differences  in settling rate had  a direct relationship to particle-size
 reduction.  This  test  proved inconclusive.

 Suspended  solids measurements were also made in an attempt to show that solids
 content remained unchanged during sample transport and conditioning.  A Milli-
pore filter apparatus  (Figure 5) was used for this purpose.  This test also
 gave inconclusive results.
                                       13

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            FIXED MEDIA
            FILTER
SAMPLE COLLECTION FOR
FILTER PERFORMANCE
EVALUATION
                      20 CC/MIN
                      PERISTALTIC
               X	''PUMP
                                                          LEGEND

                                                          V =  2-WAY BALL VALVE
                                                          G =  PRESSURE GAUGE
                                                          T =  TEMPERATURE GAUGE
     TO
     DRAIN
                                                              TO
                                                              DRAIN
                                                     SAMPLE COLLECTION
                                                     FOR ESTABLISHING
                                                     HYQR-0-GRIND
                                                     PERFORMANCE
                                                                  TO
                                                                  DRAIN
                  TO
                  DRAIN
                                                            3-WAY BALL VALVE
                                               HOMOGENIZER
                                                                  ORIFICE
                           INPUT FROM
                           HYDR-0-GRIND
                                                              SAMPLE COLLECTION
                                                              FOR PARTICLE
                                                              SIZE REDUCTION
                                                              EVALUATION
FIGURE 3.
                           PKELIMINARY SAMPUHG MANJFOLD  FLOW DUGSAM

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                  X  \  I   /
      SLUDGE COtTIOL IOON

        ilD  HETEI IOOM-
SlUCGE OISESTIOH

    Tt»$
                                 FIGURE  4.   SITE  DESCRIPTION  (Sheet  1  of  2)

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 A Raw Sludge Pumps
 B  Sludge Density Meter
 C  Returned Activated Sludge Pumps
 D  Waste Activated Sludge Pumps
 E  High Level Air Blowers
 F  Low Level Air Blowers
 G  Motor Drives for Blowers
 H  Gas Engine Drive for Blower
J  Grease Well
 K  Concentrated or  Raw Sludge Pumps
L  Heated Sludge Recirculation Pumps
           M Sludge Heater
           N Sludge Well
           P Digested Sludge Pump
           Q Elutriated Sludge Pump
           R Filter Pumps
           S Conditioning Tanks and Vacuum Filters
           T Sludge Incinerator
           U Supernatant Liquor Pumps
           V Digestion Gas Booster Pump
           W Plant Heater
           X Waste Gas Burner
LIQUIDS SHOWN THUS:
SEWAGE SOLIDS SHOWN THUS:
GAS SHOWN THUS:          • •
       1   Raw Sewage Influent to Treatment Plant
       2   Raw Sewage Influent to Grit Removal Chamber
       3   Comminutor Effluent to Grease Removal Chamber
       4   Grease Removal Effluent to Primary Settling Tanks
       5   Primary Effluent to Aeration Tanks
       6   Aeration Effluent to Final Settling Tanks
       7   Final Effluent to Chlorine Contact Tank
       8   Chlorine Influent
       9   Treatment Plant Effluent to Pawtuxet River
      10   Raw Sludge or Scum from Primary Settling Tanks
      11    Sludge or Grease to Sludge Heater
      12    Heated Returned Sludge to Digest Tanks
      13    Activated Sludge from Final Settling Tanks
      14    Returned Activated Sludge to Aeration Tanks
      15    Waste Activated Sludge to Concentration Tank
      16    Concentrated Sludge to  Sludge Water
                            17   Waste Activated Sludge from Final Settling Tanks
                            18   Waste Activated Sludge to Primary Settling Tanks
                            19   High Level Air to Aeration Tanks
                            20   Low Level Air to Aeration Tanks
                            21    Grease to Sludge Heater
                            22    Digested Sludge  to Elutriation Tanks
                            23    Elutriated Sludge - Tank No. 1 to Tank No. 2
                            24    Elutriated Sludge to Vacuum Filters
                           25    Filtered Sludge to Truck or Incinerator for Disposal
                           26   Ash from Incinerator to Truck
                           27   Supernatant Liquor from Sludge Digestion Tanks
                           28   Sludge Digestion Gas to Plant Heaters and Incinerator
                           29   Elutriate to Primary Settling Tanks
                           30   Grit Removal
                           NOTE: Plant Water Piping, By-passes and Tank Drains
                                  are not shown.
Figure
                                                  site Description  (Sheet 2 of 2)

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\

              [FILTER! 1110 MICRONI210MICRONH 420 MICRON]
              PAPER I  ISCREEN   ISCREEN    ISCREEN
              FIGURE 5.  MILLIPORE FILTER APPARATUS
                                17

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Microscopic examination with a Bausch and Lomb microscope (//XL10BU-FW with
100-power magnification) was used to study particle—size distribution:
however, it did not yield quantitative data as to particle-size reduction.  The
microscopic data were quite subjective since they varied significantly from
individual to individual.  In addition, the field of view was quite limited.
and any single determination could be influenced by the occasional presence
of large particles.  In essence, the volume of sample examined (one drop)
was too small to yield good results.  Therefore, this method was abandoned
for particle-size determination, but was retained to confirm conclusions from
other methods.

Sieve analyses were carried out with a commercially available sieve assembly
(Figure 6).  These sieves were too heavy to be accurately weighed using
laboratory balances; therefore, results from initial tests proved unsuccessful.

Further Tests of Particle Size

With all the selected tests yielding inconclusive and unreliable results,
Raytheon had to devise its own method to determine particle size.

The utilized method consisted of filtering a sample through a series of
wire mesh filters.  The filtration was conducted such that the sample passed
through the filters in the direction of coarse to fine.  The filters were
dried and tared prior to use, and the dry weight was again determined after
filtration.  The weight of solids retained on each screen was used to
characterize the particle-size distribution in the sample.  Three sizes of
screen were used: 420 urn, 210 ym and 110 vim.  The filtration was carried out
in the modified Millipore filtration apparatus (Figure 5).  This method
proved very satisfactory and reliable.

Figure 7 demonstrates how typical data were utilized; it also demonstrates
particle-size reduction on a percentage basis.  As can be seen from inspection,
the particle-size distribution changed drastically when the homogenizer was
used.  A comparison of one point on the curve (e.g., 420 micrometers) indicates
that unprocessed raw sewage possessed approximately 87% of its solids with
particle sizes equal to, or less than, 420 micrometers.  With a single
homogenization this number increased to 99.2%.  Along with this determination,
suspended solids values were also obtained.  In each case, the values for total
suspended solids before and after homogenization agreed within 2%, proving
that no appreciable loss in solids occurred as a result of the conditioning
process.  This type of evaluation was performed on the six streams in
question: a) secondary effluent, b) primary effluent, c) raw influent,
d) mixed liquor, e) return activated sludge, and f) primary sludge.

Discussion of Particle-Size Testing

Good particle-size  reduction data were obtained for all six streams%  However,
for effective sampling of mixed liquor, return activated sludge, and*  primary
sludge, the  samples had  to be  diluted prior to introduction into the
homogenizer because these streams were very high in particulate matter  and
also very viscous,  making it inadvisable  to pump these streams with a
Hydr-0-Grind.  Dilution  pumps  were not available for  this phase of the  project;

                                      18

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FIGURE 6.  SIEVE ASSEMBLY

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                                            HOMOGENIZER
                                            EFFLUENT
                                        INPUT TO
                                        HYDR-0-GRIND '
                                        PUMP
                                    0 RAW SEWAGE, HYDR-0-GRIND INFLUENT
                                    [0 RAW SEWAGE, HOMOGENIZER EFFLUENT
      100
                     200             300            400

                           PARTICLE SIZE, MICROMETERS
500
FIGURE 7.  RAW SEWAGE,  PARTICLE-SIZE REDUCTION WITH HOMOGENIZER
                                     20

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 therefore,  dilution was  accomplished  by hand  to  prepare  the  input  sample  to
 the  homogenizer for particle-size  reduction tests  for  these  streams.  The
 results  from these  tests proved  the acceptability  of sample  dilution prior
 to homogenization.

 By using sample dilution at  the  source, high  solids loading  within transfer
 lines was avoided,  and the probability of  successful sample  transfer was
 increased.   The method used  will be covered in the "Final System Design"
 Section  of  this report.

 Demonstration of good particle-size reduction only proves that effective
 conditioning of a sample for TOG analysis  can be accomplished.  Questions arise,
 however,  whether or not  solids have been lost in the conditioning process, or
 will be  lost during transfer from  homogenizer to analyzer.   To demonstrate
 that no  solids were being lost,  TOC analyses  were  conducted, utilizing the
 Beckman  915  Total Organic Carbon Analyzer.  The  TOC of the sample stream  was
 measured  in  the vicinity of  the  Hydr-0-Grind  pump.  This TOC value was compared
 with the  TOC value  of the Hydr-0-Grind effluent  and also with the TOC value of
 the  Homogenizer effluent; such comparisons demonstrated no loss in TOC and
 proved that  transfer of  the  sample can be performed effectively.

 Table 1 demonstrates quite vividly that, in every  instance,  integrity of
 chemical  composition is  preserved  from the sample's point of origin through
 the  sample-conditioning  step.  This data, accumulated from monitoring raw
 sewage, is typical  of data obtained by sampling  the other five process streams.

                                   TABLE 1

                  PRESERVATION OF THE INTEGRITY  OF CHEMICAL
                      COMPOSITION DURING THE  COURSE OF
                  TRANSPORT AND  CONDITIONING  OF  RAW SEWAGE

 Date         Source             TOC, mg/1    Ortho-PO^, mg/1      N0_, mg/1


 1-14-74      Grinder  influent      310            6.52               8.3

 1-14-74      Grinder  effluent      305            7.67               8.3

 1-14-74     Homogenizer  effluent  280            6.30               8.3


 1-15-74     Grinder  influent      510            9.72               8.2

 1-15-74     Grinder effluent      495           10.19               8.14

1-15-74     Homogenizer effluent  500            9.72               7.32


1-17-74     Grinder influent      335            6.55               5.42

1-17-74     Grinder effluent      335            6.44               5.72

1-17-74     Homogenizer effluent  340            6.41               5.52

                                    21

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Pipe-Size Consideration

Sample flowrate and pipeline size are related because, taken together, they
determine sample velocity; hence, they must be considered together.  The
sample-line size must be large enough to give assurance that there will be
no plugging or clogging anywhere within the sample train.  However, the line
size must also be small enough to furnish high transport velocities so that
complete transfer of suspended solids is assured.  Obviously, upward velocities
of particulate matter in any vertical section of the sampling train must well
exceed the settling velocity of the maximum size particle to be sampled.

Settling of solids is an important consideration.  Sizing of transfer pipes
to obtain sample velocities that will preclude settling of solids was one of
the design goals addressed.  An EPA report by Shelley and Kirkpatrick  states
that the minimum line size for transfer of samples from a stream or combined
sewer should be 3/8 to 1/2-inch  (9.53 to 12.7 mm) inside diameter.  Also stated
was that minimum line velocities should be in the 2 to 3-ft/sec (.61 to 91-
m/sec) range.

With these basic guidelines defined, the transfer lines were selected.  In all
cases a minimum velocity of 2 ft/sec (.61 m/sec) was  strived for, but this
value could not always be obtained.  However, no transfer-line contamination
due to settling was noticed during the course of this study.

F_il_ter_Tests

To demonstrate an effective filtration apparatus, Raytheon  set up  a two-stage
filtration unit.  The first stage consisted  of a self-cleaning wash-flow  filter
which served  to eliminate  the larger particles;  the second  stage was  a  down-
flow filter which consisted of a fixed-media bed which  further reduced  the
sample's  particulate matter to a diameter  of 12 micrometers, or less.   Flow
was supplied  by  the grinder pump to  the  filter block  which  housed  a nominally
rated,  10-micrometer, nylon filter disk.   Sample across  the filter disc is
continuous  at a  rate  of  3  gal./min  (11.35  1/iain).  A  small  portion of this
 flow  is  drawn through the nylon,wash-flow,  disc   filter  using  a peristaltic
pump  adjusted to  20 ml/min.   This pump  in  turn  feeds  the fixed-media  gravity
 filter.   The final  filtrate  is  collected in an  overflow cup from which the
 sample  is drawn  by  the various  analyzers.

Table  2 demonstrates  results  from the  two-stage filter  test.   As  can be seen,
 suspended solids loading varied a great deal;  however,  the  filtering apparatus
was able to remove  (worst case)  94.3%  of all particulate material  in the
 stream with an average removal  of 97.5%.
                                       22

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                                    TABLE 2

                            RESULTS OF FILTER TEST

      Suspended Solids                              Particulate Material
      Loading,  mg/1                                 Removed,  %	

          440                                             97,1
          520                                             98.1

          570                                             97.7

          580                                             98.8

          610                                             94.3
          620                                             98.7
          650                                             96.9
          680                                             98.6

        1100                                             99.4
        1160                                             98.5


Some Observations

In addition  to providing the necessary flows, the preliminary manifold proved
to be an  invaluable design vehicle for establishing design "ground rules" such
as the following:

     1.   Ball valves  should be used only in a full-on or  full-off position.
          Intermediate positions cause dead spots in the flow passages, and
          this eventually causes line plugging.

     2.   Solenoid valves are prone to plugging and therefore are unreliable.

     3.   Settling in transfer lines is virtually eliminated if no sharp
          restrictions or stagnation points exist in the lines and if transfer
         velocities are maintained at no less than 2 ft/sec (.61 m/sec).  For
          instances where this is not feasible, it should be experimentally
         determined if lower transfer velocities are acceptable.

Preliminary Conclusions

From the results of the preliminary tests, certain conclusions could be drawn:

     1.  Use of Hydr-0-Grind pumps eliminates the need for homogenization
         prior to transferring samples over long distances.   This confers
         significant cost advantages, particularly for those applications
         requiring continuous sampling of numerous process streams.
                                      23

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2.  The Hydr-0-Grlnd pump reduces particle sizes sufficiently to enable
    quantitative sample transfer and efficient operation of only a
    single, centrally located, horaogenizer unit.

3.  The Raytheon homogenizer effectively reduces particle sizes for
    on-line TOC analyses without unacceptably altering the sample's
    chemical composition.

4.  The filtration unit removes an average of 97.5% of all particulate
    matter in a flowing stream, and produces a filtrate possessing a
    maximum particle size of 12 micrometers.

5.  The measured temperature rise through the homogenizer is less
    than one degree Celsius.

6.  The measured pressure drop through the homogenizer is 2 psi
    (13.79 kN/sq m).
                                  24

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                                   SECTION VI
                              FINAL SYSTEM DESIGN

 Establishing a Sampling Procedure

 Following the design specifications established in Phase I,  Raytheon set out
 to  design an effective sampling system that would be continuous,  reliable,
 and easily maintained without altering the  chemical composition of the original
 sample.   The first  step was  to establish a  sampling matrix capable of guiding
 the collection of data required to properly test the system.   Table 3 illus-
 trates  this matrix.

                                    TABLE 3

                                SAMPLING MATRIX

                                         *Sampling Points
Chemical Test
Total organic carbon
Soluble organic carbon
Orthophosphate
Hydrolyzable
phosphate
Ammonia nitrogen
Nitrate
Nitrite
Sec.
Effl.
CD
X
X
X
X
X
X
X
Prim.
Effl.
(2)
X
X
X
X
X
X
X
Ret.
Raw Mixed Act. Prim.
Infl. Liq. Sludge Sludge
(3) (4) (5) (6)
X XX X
X
X
X
X
X
x
     *Streams are listed in order of expected contaminate concentration
      and were s«im>led *-n thi-8 order, as mentioned earlier in the text.

From Table 3 it can be seen that streams 1, 2, and 3 (secondary effluent,
primary effluent, and raw influent, respectively) demanded the majority of
the sampling requirements.  Since the sampling-system design was greatly
influenced by these requirements, answers to the following questions were
required before system design could proceed:
                                      25

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     1.   How can one analyzer monitor  TOG  and  soluble  organic  carbon  (SOC)
         for the same stream?

     2,   What are the optimum modes of operation for the colorimetric
         analyzers and Pretreatment Unit after sampling of stream (3) has
         been completed;  i.e., while streams (.4), (5)  and (6)  are being
         sampled?

     3.   Can the system handle high solids loadings without adversely
         affecting either data reliability or  the system's self-cleaning
         capabilities?

     4.   Is any flushing of the sampling manifold and/or the transfer lines
         needed?  If so, then what are the flushing requirements?

Monitoring Both TOC and SOC

To solve the problem of monitoring both TOC and SOC for the same stream,
Raytheon modified its 'Model 2600" on-line TOC analyzer by adding a second
rough sample pump within the analyzer.  For the first cycle (i.e., secondary
effluent sample), the "Model 2600" monitored TOC by utilizing the rough
sample pump connected to the homogenizer output.  Upon command from  the
control panel, that pump was shut off.  The second pump  (connected to the
Pretreatment Unit output) was then turned on,  and a filtered portion of
secondary effluent  sample was supplied to the "Model  2600" for SOC analysis,
and to the various  colorimeters for determinations of phosphate, ammonia,
and nitrate/nitrite.  Following completion of this first  cycle, the  system
was switched to  the next sampling point (i.e., primary effluent) and the
first cycle was  repeated.  This sequence also was followed for the raw
influent sample.

On completion  of the  third sample  cycle (raw  influent),  no further colorimetric
or SOC analyses  were  required; only TOC monitoring was required for  streams
4, 5, and 6.   A decision had  to be made as  to what modes the Pretreatment
Unit and colorimeters would  be left in  during the interim because, if  the
units were  shut  down for the  three hours required for analyzing  streams
4, 5, and 6,  subsequent  startups would  require  operator  attention.   Therefore,
it was decided to continue operating  the units, but  to  use flush water  as
the  "sample"  stream.  This approach yielded a twofold benefit:

     1.  The analyzers  would not be operating without sample  input  (That
         type of operation is not  recommended).

     2.  The analyzers  would automatically  record  a zero point  during
         each complete run provided  the flush water were not  contaminated.

Following  the completion of  cycle 6,  an additional cycle was  employed,
whereby  the sampling manifold, the homogenizer, and its associated  plumbing
were all flushed with tap water.   The flush lasted for only one cycle interval;
 after  which, the system was  again ready to start sampling and conditioning
 Sample No.  1  (secondary effluent).  It should be noted that each cycle could
 be aborted at any time by switching to the manual mode.

                                      26

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 System Description

 The resultant flow diagram for the sample transfer and  conditioning
 system is shown in Figure 8,   The system, which was designed for  simple
 construction and operation,  has two modes of operation:   automatic  and
 manual.   Sample sequencing in the automatic mode is controlled  by a timer
 which can be adjusted for cycle times  of  1 to 60 minutes.   A second timer was
 incorporated to start a data acquisition  system for automatic data  logging.

 The sample-switching system  consists of pairs of motorized  ball valves  which
 operate  in tandem to select  a sample for  analysis upon  a  command  from the
 control  panel.   At any given time,  each sample is connected (via  the valve
 pairs)  to one of two manifolds:   sample manifold or drain manifold.

 Both manifolds  are fabricated utilizing standard PVC fittings chemically
 bonded  together so that all  joints  provide the minimum  amount of  obstruction
 to  the  flow.  The motorized  ball  valves are also PVC and  have union-type
 pipe connections.   This type  of valve  connection allows for easy  disassembly
 of  either the manifolds or the valves  should a problem arise.   The  assembled
 system,  plus  the more important sub-systems,  are shown  in Figures 9  through
 13.

 The sampling  assembly is supplied with samples from six remote  points,  utilizing
 Hydr-0-Grind  pumps for streams 1, 2, and  3  (Figure  14) and  duplex dilution
 pumps for streams 4,  5,  and  6  (Figure  15).   Each sample stream  is continuously
 fed to the sampling  assembly;  however, only one  stream can  be monitored at a
 time.  Therefore,  the other five  sample streams  are  directed  to the  drain
 manifold,  and back to the head of the  plant.   This bypass systemgkeeps  all
 the sample streams constantly  flowing, and  eliminates deadending  (Deadending
 a stream results  in  a stoppage of flow and  possible  deposition of particulate
 matter.   If a deadended stream were  selected  for monitoring,  good quantitative
 data could not be  obtained because of  the excessive  suspended solids loading
 that would occur when the flow started up again.  Such a sudden scouring
 of  the lines  could easily produce a  temporary, but heavy, overload of
 suspended  particles  that might also  impair  the long-term performance
 of  the homogenizer, Pretreatment -Unit  or automatic analyzers).  A second
 benefit  conferred by  a  bypass  system is a reduction  in the  time lag required
 for system purging by  the next sample  to be analyzed.  The bypass system
 thus has  greater useable analytical  time because of  greatly diminished purge
 times.

Use of Dilution

Another  important aspect of the sampling system is the manner in which mixed
liquor, return activated sludge, and primary sludge are conditioned and
transported.  Raytheon utilized the dilution concept in sampling these three
streams for the following reasons:

     1.  TOC values in  streams 4, 5, 6 were much higher than in streams
         1, 2, and 3; therefore, the need for a second TOC analyzer (or an
         analyzer capable of automatic range selection)  was eliminated.
                                    27

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FLUSH >
WATER S





V7A&

1 V8B
1
1
i
1
1
1
1
3—
h







0 V8A
                                                                                  PRETREATMENT
ro
oo
                                                         SAMPLE
                                                         MANIFOLD
  soc
V9A
  TOC
V9B
N03
+.
__L_

DATA
ACQUISITION
SYSTEM
                                                                             -V	i
                                                                                                                	I
                                                                                                                      •TRAILER
                                                                                            ELECTRICALLY OPERATED
                                                                                            BALL VALVES
                                                                                          0 - DRAIN
                                HYDR-0 GRIND
                                PUMPS
                                                  SAMPLE DILUTION
                                                        PUMPS
                                                 FIGURE  8.   FLOW DIAGRAM OF  THE  SYSTEM

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           HOMOGENIZER
FIGURE 9.  SAMPLING SYSTEM, FRONT VIEW
               29

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       • •••••••••»«••*••••••<•»•••  *

                             INPUT LINES TO
                            I SAMPLING SYSTEM
FIGURE 10.  SAMPLING SYSTEM, REAR VIEW
               30

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                WASTEWATER SAMPLE TRANSFER AND CONDITIONING SYSTEM
DATA ACQUISITION SYSTEM
         FIGURE 11.   CONTROL PANEL,  FRONT VIEW
                           31

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NJ
                                        FIGURE 12.   CONTROL PANEL, REAR VIEW

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  INCOMING
  FLUSH WATER
ACTUATORS FOR
ELECTRICALLY
OPERATED BALL
VALVES, IN TANDEM
                                                                                                      SUPPLY LINE TO
                                                                                                      PRETREATMENT ASSY
                                FLUSH WATER
                                SUPPLY LINES
      ELECTRICALLY OPERATED
      BALL VALVES
 TO PRETREATMENT
:AND ANALYZERS
                               TO SAMPLE
                               MANIFOLD
                                              SUPPLY LINE
                                             ITOHOMOGENIZER
                                  SAMPLE MANIFOLD
                                                                                                     EXHAUST
                                                                                                     MANIFOLD
                      INCOMING SAMPLES
                      FROM HYDR-0-GRINDS
FIGURE 13.   MANIFOLD ASSEMBLY,
              FRONT VIEW
                                                            INCOMING SAMPLES FROM
                                                            DILUTION PUMPS

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u>
            GRINDER
            PUMP
                         FIGURE 14.  TYPICAL HYDR-0-GRIND PUMP INSTALLATION

-------
                                                        FLOW RATE  \ I
                                                        CONTROLS
                         STATIC
                         MIXER
u>
                   DILUENT
                   (TAP WATER)
                                        MANIFOLD
                                 " CHECK VALVE
                                ASSEMBLY
1" CHECK VALVE
ASSEMBLY
                                   FIGURE  15.   TYPICAL DUPLEX DILUTION PUMP INSTALLATION

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     2.  Because suspended solids concentrations were so very high for
         streams 4, 5, and 6, if these streams had been transported in
         undiluted condition, the risk of sample-line contamination would
         have been significantly increased.  This would have affected the
         success of the program by reducing the likelihood of accurate
         measurement.

Dilution systems have been applied previously1 to analyzer inputs (i.e.  after
the samples had already reached the analyzer).  While this approach may have
been acceptable for sample analysis, sample-line contamination was always a
problem.

The decision was therefore made.to dilute at the source, rather than at the
analyzer interface, to minimize solids loading in the transport lines.  The
streams were diluted in such a way that they approximated the physical
characteristics of primary effluent.  A BIF, Series 1722, Duplex "Propsuperb"
metering pump was selected because of expected quick delivery and estimated
suitability for this application.  The pump is a positive-displacement
hydraulically-actuated diaphragm pump, with a manually adjustable stroke to
change the flowrate.  The pump has two sides which act independently  but
which are driven by a common drive.  This arrangement assures a constant
dilution ratio even though the drive speed varies.  A typical installation
of a dilution pump has already been illustrated by Figure 15; that illustration
shows the monitoring of mixed liquor at an aeration basin.  The sample dilution
ratio was 1:5.  The sample stream was drawn through the 3/4-in. (19-mm) check-
valve assembly on the left side of the pump, while the diluent (tap water)
was drawn through the 1-in. (25-mm) check-valve assembly on the right.  Both
streams were fed into a common manifold.

The resultant output was a pulsating non-homogeneous flow of both sample
and diluent.  An in-line static mixer (Kenics P/N 37-08-136) was installed at
the pump discharge to counteract this phenomenon.  This proprietary in-line
mixing assembly employs a series of fixed helical elements enclosed within a
tubular housing.  The Internal geometric design of the unit produces a unique
pattern of simultaneous flow division and radial mixing.

Subsequent to static mixing and transfer to the trailer, the sample was
homogenized just prior to TOC analysis.                        -r

Adapting the Dilution Pump

To install a pump of this type, certain preliminary tests must be performed
and certain conditions must be maintained.  Initially, for each specific
application, a performance curve (output vs. control setting) must be
experimentally obtained by each pump after it has been installed.  The
dilution ratio can then be set by adjusting the pump strokes according to
the empirically developed performance curves.

This particular type of positive displacement pump requires a non-varying
back-pressure to operate reproducibly.  When the back-pressure is low or
variable, erratic operation occurs.  A back-pressure valve is normally


                                     36

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 installed to provide unvarying back pressure.  However, this would also place
 an undesirable obstruction in the discharge line.  To simulate back-pressure
 but eliminate the unwanted obstruction, additional (i,e,, excessive) lengths
 of hose were used on the discharge side of the pump to create backpressure
 by increasing the head-loss across the sample line.  This simple modification
 solved the back-pressure problem.

 In addition to being back-pressure sensitive, the pump was found to be input-
 pressure sensitive.   The pump relies on proper check-valve sealing to get
 proper pumping action.   Therefore the pump will not operate acceptably if
 there is positive input pressure.  As a result, this type of pump has to draw
 its feed from a sample  reservoir which is essentially at ambient atmospheric
 pressure.   If the sample is being piped under pressure, as was the case with
 the return activated sludge and primary sludge, the pump cannot be connected
 directly to the pipe.   The sample must first drop into an overflow reservoir
 (i.e.,  cup) that is  constantly being fed with fresh sample, then the pump
 will draw the sample as required from the reservoir.

 Initial results demonstrated a fair amount of intermittent flow (i.e.,  flow
 discontinuities and  stoppages) caused by the presence of fibrous material in
 the stream.  The fibrous material affected the sealing capabilities of  the
 check valve and prevented proper pumping.   Cleaning of the check valves brought
 the pump back on-line.

 The problems encountered using these pumps are characteristic  of all pumps
 using check valves,

 Overcoming Intermittent Flow

 Intermittent flow can be minimized,  if not eliminated,  by using  low dilution
 ratios;  i.e.,  relatively high flows  through the "sample side" of  the pump.
 If  dilution ratios are  selected so  that sample flowrates  are high,  the
 subsequent flow velocities  through  the pump's  check valves  are also high;  such
 relatively high velocities  are advantageous because they  increase  the tendency
 of  fibrous material  to  pass cleanly  through check valves.

 A slightly different approach was tried to monitor  primary  sludge.   From tests
 conducted  in the Preliminary Phase,  the TOC values  were high and dilutions of
 100:1 were anticipated.  With dilution ratios  that  high,  it was a  certainty
 that  sample flowrate would  be very low.  As mentioned previously,  this  is not
 desirable.   Hence, the  same type of  pump was used,  but  it employed  a variable-
 speed B.C.  motor  rather  than a fixed-speed  A.C. motor.  This arrangement makes
 possible total  flow changes without  altering the dilution settings, and  this
 in  turn affords  the operator  greater latitude  for establishing optimum pump-
 operating  conditions.

 The particular piping configuration at  the  Cranston site generated a unique,
 primary sludge,  sampling problem:  the high solids level of primary sludge
(5-6% by weight) prevented continuous flow of sample to a reservoir.  Many
 different piping configurations were tried, but continuous flow could not be
attained.  Without major rework of the plant's piping and an accompanying
disruption of plant operation  to gain access to unthickened primary sludge,

                                     37

-------
this problem could not be rectified.  The basic sample-taking concept is valid,
however.  The primary sludge was only one of the six sample streams involved
in this project, and it had only one parameter of interest (TOG); therefore,
monitoring of this stream was a very small part of the total program, and
deletion of this sample stream detracted only modestly from the main purpose
of the project.  There is no reason to suspect that primary sludge, properly
supplied to a dilution assembly of the type described above, would cause any
significant problems during dilution, transfer, conditioning, and analysis.
The EPA concurred with our decision to delete primary sludge sampling,
particularly since control of this plant was out of our hands.

Timing of Samples

Timing is an important, but easily overlooked, consideration in the design
of a stream-switching system.  Of course, the frequency at which each point
is analyzed must be acceptable to process-control requirements.  In addition,
the dwell time on each sample must be of sufficient duration to purge the
sample manifold and passageways into the analyzers, and to allow sufficient
time for analyzer response.  There are three times which must be addressed:
a) transfer time, b) conditioning time, and c) analyzer response time.

Transfer times were obtained by measuring the flowrate of each pump and by
using the appropriate formula for the velocity in each line.  With the
transfer velocities and distances known, transfer times were easily calculated.
These data are shown in Table 4.

                                   TABLE 4

                            SAMPLE-TRANSFER DATA
Sample
Stream
'Secondary
effluent
Primary
effluent
Raw
influent
Mixed
liquor
Return
activated
sludge
Primary
sludge
Flow rate,
gal/min
(1/min)
4.87(18.4)
5.46(20.6)
5.82(22.0)
.46(1.74)
.44(1.67)
^ _ r|— -r-r
Flow Velocity,
ft/min
(m/min)
119.8(36.2)
114.7(44.1)
153.0(46.6)
79.5(24.2)
75.6(23.0)
— —
Transfer
Distance,
ft (m)
475(144.8)
55(16.8)
75(22.9)
210(64.0)
250(76.2)
•••^•^
Transfer
Time,
Min
3.95
.38
.49
2.64
3,30

                                     38

-------
 Because it was unnecessary to separate conditioning time from analyzer
 response time, these two times were measured in one combined test.   To
 measure the response time of the analyzers in conjunction with sample-
 conditioning time,  a flush cycle was initiated and a stable zero was reached
 on all monitoring equipment, thus providing a zero datum.   Primary  effluent
 was selected manually,  and the time was recorded.   Within ten minutes the
 TOG analyzer was reading 100% of final value, but  the colorimetric  analyzers
 required forty minutes  to reach 100% of the final  value.   Based on  this
 data,  the sample cycle  time was set at one hour.   Thus,  during a one-hour
 cycle,  the sample for TOC is taken from the continuous flow sample  stream
 30 minutes after preceding  portions taken for colorimetric analyses.

 Comparisons with Standard Analytical Methods

 To assess properly  the  success or failure  of  the sampling  system, manual
 grab samples were taken and analyzed by standard methods;  these values were
 also compared with  the  corresponding values obtained  from  the automatic
 analyzers in order  to determine analyzer performance.  To  assure a  valid
 evaluation of the sampling system,  two grap samples were taken:  one at the
 source of the process stream (before any automatic  sampling,  transferring,
 or conditioning)  to  establish  a reference  point, and  a second  at  either
 the homogenizer's exit  port (interface value  for TOC  analyzer)  or at the
 filter assembly's exit  port (interface value  for colorimetric  analyzers).
 Because of  the large  differences  in  analyzer  response  times  (ten minutes
 for the TOC  analyzer, and  forty minutes  for the colorimetric analyzers) it
was necessary to  take two  sets  of grab  samples at different  times.

As  previously  described, the control, system has two timers:  one for controlling
 the sampling  cycle and one  for  starting up auxiliary equipment  (i.e., the
data-acquisition  system).   To obtain representative grap samples for
comparison with automatic analyzers, the samples had to be obtained in
advance of the actual readout times; hence, readout time was established as
the last five minutes of each sampling cycle.  A grab sampling procedure was
established and is shown diagramatically in Figure  16.
                                     39

-------
Sequence of  events during a  sampling cycle:
         TIME INTO
        'CYCLE
DATA-READOUT
PERIOD
                                                        47

                                                       -f-
         SEQUENCE
         OF EVENTS
                                           -40 WIN**-
                                                                  45
                                                            10MIN*
                         FIGURE 16.  SAMPLING SEQUENCE
1.  Sample stream selected,

2.  Grab samples taken at sample source and from Pretreatment Unit effluent;
    these were referee samples for the colorimetric analyses and  for  SOC.

3.  Grab samples taken at sample source and homogenizer output; these were
    referee samples for the TOC analyses.

4.  Data-acquisition system was started up, and data were  recorded.

5.  As of this point in time, analyzer values and  the corresponding grab
    samples should agree.

6.  Cycle completed.  New stream selected.  Data-acquisition system turned
    off.

NOTE:  Sampling sequence is the same  for process streams 1, 2 and 3.
       However, for process streams 4, 5 and 6, only one set of grab  samples
       was taken at event  (3) since TOC was the only parameter of interest
       for these three streams.

       For a more detailed description of  the system's operationg and main-
       tenance procedures, refer to Appendix B.

* Time  lag between sample input to TOC analyzer and  the analyzer's
   corresponding readout of TOC.

** Time  lag between sample input to colorimetric analyzers and  their
   corresponding readouts  of  NH_,  o-PO,, etc.

-------
                                 SECTION VII

                                TESTS RESULTS
 Reference Tests
 With all the equipment installed,  operating,  and a sampling sequence
 established and proven, the next step was  to  establish the referee tests  to
 be performed on the grab samples.

 To measure TOC and SOC, a Beckman  "Model 915" Total Organic Carbon Analyzer
 was used.   The Beckman "Model 915" analyzes discrete,  50-microliter samples
 that must  be injected into the instrument  by  means of  a microsyringe.
 Samples  containing any significant amounts of suspended matter must be
 blended, acidified,  and sparged prior to injection into the instrument.   For
 this project,  referee TOC and SOC  samples  were manually acidified,  and a
 Waring blender was used to sparge  out the  C0« and simultaneously blend the
 sample's suspended solids.   For colorimetric  analyses,  methods specified  by
 "Standard  Methods  for the Examination of Water and Wastewater", 13th Edition,
 were used:

      1.  Phosphate - Method 223, "Ascorbic Acid  Method"

      2.  Ammonia - Method 132B,  "Direct  Nesslerization  Method"

      3.  Hydrolyzable Phosphate  -  Method 233F with a preliminary hydrolyzation
         step  whereby the sample was  acidified to a pH  of  1 and the  solution
         was boiled  for one hour.

 A  Bausch and Lomb  "Spectronic  70"  spectrophotometer was  used to perform the
 manual, colorimetric,  reference analyses for  orthophosphate, ammonia nitrogen
 and  hydrolyzable phosphate.

 Sample Transfer and  Conditioning System  Test  Data

 Table 5 shows  the  test  results for the sample  transfer and conditioning
 system when it was evaluated by Raytheon at the  Cranston Water Pollution
 Control Facility.  The  amount of data collected  is  sufficient for a preliminary
 evaluation of  the sampling  system.  Note, however,  that most of the erratic
 data in Table  5 were  produced by the various on-line analyzers being employed!

 Performance of Automatic Analyzers

TOC, SOC, orthophosphate and ammonia nitrogen were the only parameters
monitored "on-line".  The on-line hydrolyzable phosphate analyzer did not
                                     41

-------
TABLE  5.
S3
                                           SAMPLE TRANSFER AND CONDITIONING SYSTEM TEST DA1]
                                           SECONDARY  EFFLUENT  (Sheet 1 of 4)
'A:
Date
(1974)
11-5

11-8

11-11
11-12
11-13

11-14

11-15

11-18

11-20

11-22

11-25

11-26

11-27

TOC, mg/1
_, Inter- Ana-
Source
face lyzer
13.2 13.4
34.0 33.0 21.5
30.0 27.0 31.0

21.0 24.0 19.0
22.0 20.0 24.0
26. 0 25. 0 52. 0

23.0 21.0 45.0

- - -

30. 0 28. 0 29. 0

33.0 30.0 25.0

30.3 30.3 11.3

24. 0 26. 0 30. 0

22.0 26.0 20.5

25.0 22.5 21.0

SOC*. mg/1
0 Inter- Ana-
Source
face lyzer
14.8 11.8
31.0 33.0 21.0
20.0 52.0 30.0

18.0 17.0 13.0
16.0 15.0 21.0
19.0 19.0 43.0

20.0 18.0 43.0

- - -

17.0 17.0 20.0

25.0 34.0 22.9

22.6 24.3 15.0

14.0 17.0 26.0

24.0 18.0 21.0

17.0 17.0 20.5

o-PO , mg PO /I
Source
17.1
19.2
18.0
16.6
22.5
20.6
17.9
15.8
17.2
16.4
17.3
17.2
22.6
22.1
18.4
17.6
13.4
12.8
22.0
19.5
16.7
17.0
16.0
16.3
Inter-
face
16.8
18.7
16.0
16.4
22.1
19.8
18.0
16.8
16.4
16.1
16.6
17.0
17.4
21.6
17.4
17.5
10.8
11.2
20.3
12.2
16.3
16.5
15.0
15.9
Ana-
lyzer
16.5
18.4
-
17.1
23.5
21.2
17.1
16.0
14.4
17.0
17.0
16.9
20.9
22.8
17.7
18.0
10.6
11.8
19.4
20.2
17.8
17.5
17.8
18.2
NH , mg NH -N/l
Source
5.1
5.0
-
-
-
-
15.2
13.4
-
-
15.9
-
-
-
11.8
11.0
16.1
17.7
9.5
8.96
Inter- Ana-
face lyzer
3.3
3.9
-
-
-
-
15.4
13.6
23.7
25.2
15.6 16.4
16.4
-
-
12.7
10.8
15.6 18.3
16.6 18.6
11.4 17.8
6.8 9.0
12.1 12.1 18.3
11.3 11.2 16.5
15.5 14.8
14. 8 14. 1
Hyd. P04
Source
20.5
20.8
22.8
18.3
_
22.5
18.7
16.8
18.2
17.2
18.1
-
24.2
23.6
20.1
18.8
_
-
26.4
22.4
_
-
16.9
17.1
mgP04/l
Inter -
7.96
14.4
19.7
18.5
_
21.4
18.7
17.8
17.4
16.9
17.4
_
18.6
23.1
18.9
18.7
_
-
24.6
14.0

-
15.9
16.7
              *SOC particle size was less than 12 micrometers

-------
U!
                              TABLE 5.   SAMPLE  TRANSFER AND CONDITIONING SYSTEM TEST DATA
                                         PRIMARY EFFLUENT (Sheet  2 of 4)
Date
(1974)
11-5

11-8
11-11
11-12
11-13

11-14

11-15

11-18
11-20

11-22

11-25

11-26

11-27

TOC, mg/1
Source
86.0
145.0
307.0
125.0
92.0
138.0

94.0

-

113.0
121.0

119.0

133.0

104.0

102.0

Inter-
face
93.0
131.0
109.0
113.0
84.0
127.0

94.0

-

107.0
126.0

114.0

110.0

109. 0

96.0

Ana-
lyzer
-
131.0
115.0
81.0
133.0
197.0

115.0

-

87.5
105.0

19.0

105.0

80.0

80.0


Source
106.0
106.0
103.0
75.0
54.0
59.0

68.0

-

67.0
62.0

63.0

49.0

48.0

51.0

SOC*,
Inter-
face
64.0
101.0
104.0
55.0
53.0
60.0

66.0

-

95.0
83.0

89.0

64.0

73.0

58.0

mg/1
Ana-
lyzer
-
105.0
93.0
81.0
128.0
213.0

173.0

-

78.0
70,0

107.5

85.0

65.0

61.0

o-PO , mg
Source
14.9
15.0
15.6
17.8
13.8
16.0
16.4
13.2
13.5
-
-
15.4
14.2
15.3
16.2
19.3
20.1
18.1
14.0
15.4
14.3
14.6
Inter-
face
15.0
14.7
14.0
17.2
13.4
16.1
16.1
12.5
13.0
-
-
15.0
13.7
13.4
15.2
18.3
17.4
17.0
12.4
13.6
11.2
13.5
PO /I
4
Ana-
lyzer
15.5
15.1
14.6
17.4
16.2
15.8
15.9
14.1
15.2
-
-
16.1
14.3
15.3
15.6
16.3
17.3
17.8
14.2
15.4
15.8
16.8
NH3>
Source
33.0
32.2
-
-
-
29.2
24.6
_
-
30.0
27.2
-
25.2
25.7
25.8
23.9
28.4
27.5
25.4
29.9
26.8
26.8
mg NH -N/l
Inter-
face
33.6
32.0
-
_
-
28.4
25.6
_
-
29.2
2.74
-
25.2
24.3
23.8
24.0
26.7
27.7
25.6
27.0
26.4
26.5
Ana-
lyzer
_
58.5
-
_
-
_
33.8
46.9
42.4
36.8
-
-
„
-
33.3
29.3
27.3
27.7
54.3
58.8
_
-
Hyd. P04, mg PO A
Source
25.1
27.5
26.8
_
23.4
25.7
27.9
22.2
22.9
21.7
26.6
24.6
22.7
26.8
_
32.6
30.8
-
_
23.3
24.8

Inter-
20.2
21.7
24.1
_
23.2
20.8
23.6
21.0
22.9
16.8
21.4
24.3
22.1
23.6
_
28.2
28.9
-

18.3
22.9

               *SOC particle size less than 12 micrometers

-------
                TABLE 5.   SAMPLE TRANSFER AND CONDITIONING SYSTEM TEST DATA
                           RAW INFLUENT  (Sheet 3 of  4)
Date
(1974
11-5
11-8
11-11
11-12
11-13
11-14
11-15
11-18
11-20
11-22
11-25
11-26
11-27
TOC, mg/1
Source
130.0
172.0
235.0
202.0
206.0
155.0
178.0
-
229.0
220.0
153.0
136.0
177.0
139.0
Inter-
face
116.0
157.0
150.0
142.0
165.0
158.0
166.0
-
168.0
163.0
116.0
116.0
132.0
133.0
Ana-
lyzer
118.0
140.0
137-. 0
203.0
240.0
245.0
-
113.0
119.0
130.0
95.0
85.0
-
SOC*. mg/1
Inter- Ana-
Source ,
face lyzer
138.0 53.0
97.0 96.0 86.0
77.0 82.0 124.0
- - -
70.0 62.0 213.0
97.0 80.0 223.0
97.0 173.0 205.0
- - -
76.0 98.0 85.0
95.0 97.0 105.0
-
- - -
73. 0 84. 0 81. 0
223.0 75.0 81.0
o-P
Source
13.0
14.5
14.4
-
16.1
12.3
12.8
13.2
13.5
18.1
16.3
14.2
14.9
14.0
15.6
14.5
14.6
13.3
11.6
16.5
13.0
D4> mgPO4/l
Inter-
face
12.9
14.4
13.4
-
16.8
12.0
13.1
11.8
13.5
19.2
16.3
15.6
12.1
12.9
12.5
13.9
14.4
12.0
7.8
15.8
13.4
Ana-
lyzer
12.6
14.8
14.0
-
14.5
11.9
12.9
15.5
17.0
15.9
20.2
16.7
16.7
12.5
16.8
15.0
14.6
12.7
18.7
NH3,
Source
22.4
19.4
-
-
-
20.7
20.4
_
18.0
21.2
-
25.2
23.0
22.2
19.5
18.2
24.9
20,4
24.0
19.2
mgNH3-N/l
Inter-
face
22.8
20.4
-
-
-
21.6
20.3
_
22.2
18.1
-
18.8
21.9
21.5
21.2
18.0
24.5
21.7
25.9
21.1
Ana-
lyzer
48.3
29.8
-
-
-
25.3
21.6
30.8
26.2
16.0
-
-
22.5
20.4
18.2
47.8
43.5
-
Hyd. P04,
Source
25.4
20.2
28.8
-
28.9
27.5
23.6
25.1
24.3
26.6
23.0
31.2
29.9
27.3
-
35.1
32.8
-
23.1
24.7
mg P04/l
Inter-
face
21.7
18.4
26.9
-
29.8
26.9
20.8
22.4
24.3
28.2
23.0
34.3
24.3
25.2
-
38.2
32.4
_
34.7
25.5 !
*SOC particle size less than 12 micrometers

-------
                                   TABLE 5

              SAMPLE TRANSFER AND CONDITIONING SYSTEM TEST DATA
                               (Sheet 4 of 4)
MIXED LIQUOR

Date
(1974)
11-5
11-8
11-11
11-12
11-13
11-14
11-15
11-18
11-20
11-22
11-25
11-26
11-27
11-29

Source
75.0
142.0
132.0
102.0
120.0
118.0
-
114.0
119.0
188.0
151.0
109.0
-
120.0
118.0
127.0
_ * 	 e A.
TOC*, mg/1
Inter-
face
79.1
125.0
153.0
112.0
125.0
149.0
-
129.0
115.0
178.0
145.0
35.0
-
80.0
99.0
104.0

Ana-
lyzer
97.1
125.0
99.0
162.0
203.0
165.0
87.5
88.0
77.5
183.0
191.0
30.0
-
99.0
88.2
103.5
. 4-~U1 «
RETURN ACTIVATED SLUDGE

Date
(1974)
11-5
11-8
11-11
11-12
11-13
11-14
11-15
11-18
11-20
11-22
11-25
11-26
11-27
11-29
TOC,
Source
-
-
-
2530
1850
2080
-
2200
2890
1510
1510
2090
2050
2460
2510
2170
2300
mg/1
Inter-
face
-
-
-
1450
1670
2350
-
2650
3470
1970
1950
2060
2320
2810
2530
2970
2370

Ana-
lyzer
-
-
-
2080
2350
2540
1950
1400
2230
1950
1740
1350
1300
2520
2358
2619
2430
NOTE:  The "Source" samples for these two tables were composites of several,
       rapidly collected, grab samples taken directly from the mixed liquor
       basin, or, from the return activated sludge line.  Prior to analysis,
       each composite was diluted by a factor representing the known
       dilution factor (i.e., "dilution ratio") of the appropriate on-line
       dilution pump.
                                     45

-------
perform reliably and was not used.  The data shown for this parameter were
obtained by grab sample analyses.

The continuous ammonia analyzer, which has the capability to monitor
ammonia nitrogen, nitrate and nitrite with the substitution of different
manifolding arrangements and reagents, did not determine ammonia satisfactorily
for this project.  This ammonia analyzer was equipped by the manufacturer with
an outmoded, automatic-analyzer, wet-chemistry system (i.e., direct nessleri-
zation) which greatly promoted rapid fouling of the analyzer's optical
components; this, in turn, led to intolerable maintenance requirements and
excessive analyzer downtime.  A great amount of time was expended on attempting
to obtain acceptable on-line ammonia data; hence, little time or funds were
left to monitor nitrate or nitrite.  These latter parameters finally had to
be excluded from the field study.

Comparison of Source and Interface Values

Adequate agreement was achieved between source values and analyzer interface
values for almost all streams investigated; i.e., deviations generally fell
within the combined errors due to grap sampling and to the standard method
of analysis being used (see Appendix A).

The primary effluent stream (stream 2) yielded the most consistent data.  This
stream was high in suspended and colloidal solids; therefore, small losses
or gains of solids as the primary effluent was being transferred did not
significantly affect the results.

The secondary effluent, on the other hand, was a very clean stream for which
any loss or gain of solids would greatly affect the results.  This was
particularly true for total organic carbon analyses, and was probably the
reason why the standard deviation was greater for the secondary effluent
data than for the primary effluent data.

The raw influent values varied for another reason.  This stream, at the
front end of the plant, was subject to sudden and wide changes in contaminant
concentration and composition.  The variety and distribution of floating and
suspended material made the obtaining of representative samples extremely
difficult.  As expected, the raw influent stream measurements showed the
greatest variance.

Analysis of the data (again see Appendix A) demonstrated that streams
containing very high solids concentrations can be monitored effectively when
dilution pumps are properly applied.

Test Results^from Automatic Analyzers

Although various difficulties, as noted below, were encountered with some of
the automatic analyzers, the results obtained helped verify  (to a limited
extent) the performance acceptability of the sampling, transfer and condition-
ing system's components and the  integrated system's operating reliability.
Primarily, however, the performance of most of these automatic on-line
analyzers merely emphasized* that  commercially available and  truly reliable

                                     46

-------
 instrumentation of this type (applicable to wastewater-treatment process
 streams), is severely limited, both in variety and in number of suppliers.

 TOC-SOC;  Initial TOG problems made it necessary to install two TOG analyzers
 simultaneously  (Raytheon Company's TOG analyzer was ultimately selected for
 final testing of the sample transfer and conditioning system) .   Unfortunately,
 the use of two TOG analyzers in the limited space of the Experimental Trailer
 brought about an unfavorable positioning of several analyzers,  both TOG and
 colorimetric.  This "unfavorable positioning" involved the  placement of most
 of the analyzers further from their sample interfaces than  was  desirable for
 optimum results.  The TOG measurements,  especially,  were adversely affected
 by this situation.   It should be noted,  however,  that these TOG variations
 were not unidirectional; instead,  the data exhibited both high  and low biases.
 Unduly long transfer lines linking TOG interface  (i.e.,  homogenizer effluent)
 to the TOG analyzer allowed solids to settle out  slowly.  At first,  such
 solids settling would tend to produce slightly low values.   However,  when a
 sufficient amount  of solids had settled  out and the  transfer lines had  thus
 become narrowed and non-uniform in bore,  the resultant sporadic increases in
 sample velocity would suddenly scour the  lines and cause entrainment  of
 deposited solids by the sample stream.  This in turn would  produce occasional
 "high" TOG values.

Qrthophosphate;  The orthophosphate analyzer was  properly located, hence it
 operated  most consistently.   All three values,  (source,  interface, and
 automatic analyzer)  agreed very well.

Hydrolyzable  phosphate;   Measurements were  not  made with  an  automatic analyzer.

Ammonia nitrogen;  The  ammonia  measurements  suffered because of improper
placement of  the ammonia analyzer,  but even more because  of  random equipment
malfunction due  to the  obsolete wet-chemistry  system  furnished by  the
colorimetric  analyzer's  manufacturer.

Nitrate and Nitrite;  Measurements were not taken because the automatic
analyzer was  devoted almost solely  to ammonia-nitrogen samples.

Statistical Analysis

A statistical analysis of some  of this project's final test results was
conducted by  the EPA, and the statistical findings are the bases of the
claim for the acceptability of  the sample transfer and conditioning system's
on-line performance.  The statistical analysis is included as part of
Appendix A.
                                     47

-------
                                 SECTION VIII

                                 REFERENCES

1.  Sugar, J.W., and Brubaker, J.H., "Development of Sample Conditioning
    Systems for Automatic Environmental Instrumentation."  Presented at the
    19th Annual ISA Analysis Instrumentation Symposium, St. Louis, Missouri,
    April 24-26, 1973.

2.  Shelley, P.E., and Kirkpatrick, G.A., "An Assessment of Automatic Sewer
    Flow Samplers." EPA-R2-73-261, June 1973.

3.  Houser, E.A., Principles of Sample Handling and Sampling Systems Design
    for Process Analysis.  Instrument Society of America, Pittsburgh, Pa.,
    1972.

4.  American Public Health Association, Standard Methods for the Examination
    of Water and Wastewater, 13th ed., APHA, New York, 1971.
                                      48

-------
                    APPENDIX A - STATISTICAL ANALYSIS

          UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
o,,n,ror Testing for  Statistical Difference
SUBJECT: Between the  Sample Source  and the  Sample      °ATE:  Janu*ry 7,  1975
      Interface  Methods  of Data  Measurement
FROM*
      R. G. Eilers and Ella Hall
      Systems  &  Economic Analysis Section
      Robert  H.  Wise
      Pilot & Field Evaluation Section

           This  analysis  is intended to  determine  statistically
      if there exists  any evidence  of a  systematic difference
      between  the  sample  source  and the  sample interface  methods
      for measuring concentrations  of TOC, SOC, O/PO4, NH3, and  HP
      (hydrolyzable phosphorus)  in  wastewater.  A  statistical  test
      was applied  to 17 paired sets of measurement data,  and the
      results  appear in Table 1.

           The reference  for this procedure is  the book entitled
      "Statistical  Analysis  in Chemistry  and the Chemical Industry"
      by Carl  Bennett  and Norman Franklin, John Wiley and Sons (1966),
      pages 180-182.

           In  order to illustrate the statistical  theory involved
      here, a  detailed calculation  for the TOC-Secondary measure-
      ments will be given.   The  raw data  consisted of the following
      13 paired measurements  along  with their respective differences:

      Observation       Source       Interface      Difference, d

           1              13.2          13.4             -0.2
           2             34.0          33.0              1.0
           3             30.0          27.0              3.0
           4             21.0          24.0             -3.0
           5             22.0          20.0              2.0
           6             26.0          25.0              1.0
           7             23.0          21.0              2.0
           8             3O.O          28.0              2.0
           9             33.0          30.0              3.0
          10             30.3          30.3              0.0
          11             24.0          26.0             -2.0
          12             22.0          26.0             -4.0
          13             25.0          22.5              2.5

                                  49

-------
The mean of the differences, d = .5615, and the standard
deviation of the differences, s = 2.2948, are both calculated
and Student's t - Test is applied according to the equation:


              - .5615 (13)'5 _ .5615 (3.6056) _
              	2.29482.2948"


where n = 13 is the sample size with (n-1) = 12 degrees of
freedom.  Referring to the Students t - Distribution Table,
the values of t12 .05 = 2»179 (12 degrees of freedom, 5% level
of significance, two-tailed distribution) and t-j^  0-^ = 3.055
(12 degrees of freedom, 1% level of significance,'two-tailed
distribution) are selected.  Since  Itl  =  .8822 < 2.179 and
 (t| = .8822 < 3.055, it can be concluded  that there is no
evidence of a systematic difference between the two methods of
measurement at both the 5% and 1% levels  of significance.  What
this means, simply, is that if  |t| > 2.179 the possibility of
the two methods being statistically equivalent is only 5% or
less.  Similarly, if  |t| > 3.055, the possibility of the two
methods being statistically equivalent is only 1% or less.

     In practice a level of significance  of .05 or ,O1 is
customary, although other values can be used.  If, for example,
a 5% level of significance is chosen in designing a test of
hypothesis (the hypothesis in this case is that the two methods
are statistically equivalent), then there are about 5 chances in
100 that the hypothesis would be rejected when it should be ac-
cepted, i.e., 95% confidence exists that  the right decision has
been made.  In such a case it is said that the hypothesis has
been rejected at a .05 level of significance, which means a
.05 probability of being wrong.
                               50

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                   TABLE 1

RESULTS OF STATISTICAL COMPUTATIONS COMPARING
     SAMPLE SOURCE AND SAMPLE INTERFACE
   I t I   t(n-l),.Q5    t(n-l)..01
Conclusion
TOC-Secondary
SOC-Secondary
o/PO, -Secondary
NHL-Secondary
HP-Secondary
TOC-Primary
SOC-Primary
o/PO, -Primary
NH3-Primary
HP-Primary
TOC-Raw
SOC-Raw
o/PO -Raw
4
NH -Raw
HP-Raw
TOC-Mixed Liquor
TOC-Return Sludc
.882
1.014
3.117
1.399
2.295
1.181
.809
1.847
2.615
6.099
4.744
.737
2.031
.378
.031
1.065
e 1.147
2.179
2.179
2.069
2.145
2.110
2.179
2.179
2.093
2.131
2.120
2.179
2.262
2.093
2.145
2.120
2.160
2.179
3.055
3.055
2.807
2.977
2.898
3.055
3.055
2.861
2.947
2.921
3.055
3.250
2.861
2.977
2.921
3.012
3.055
.05 no difference
.01 no difference
.05 no difference
.01 no difference
.05 significant diff,
.01 significant diff,
.05 no difference
.01 no difference
.05 significant diff.
.01 no difference
.05 no difference
.01 no difference
.05 no difference
.01 no difference
.05 no difference
.01 no difference
.05 significant diff.
.01 no difference
.05 significant diff.
.01 significant diff.
.05 significant diff.
.01 significant diff.
.05 no difference
.01 no difference
.05 no difference
.01 no difference
.05 no difference
.01 no difference
.05 no difference
.01 no difference
.05 no difference
.01 no difference
.05 no difference
                                    .01 no difference
                     51

-------
                                 APPENDIX B

                         OPERATION AND MAINTENANCE

The Sampling Assembly consists of two main sub-assemblies:  the exhaust
manifold and the sample manifold.  These two manifolds are connected
together by means of two-way motor-driven ball valves.  These valves are
"True Union" ball valves which provide for assembly and disassembly
without additional pipe unions.  Each pair of ball valves is operated as a
unit to act as one three-way valve; when one is open, the other is closed.
They are numbered in the following manner (note that the "A" position of
any two-valve pair always results in a sample entering the sample manifold,
while the "B" position always diverts that sample to the exhaust manifold):

     VI(A)  permits secondary effluent to enter sampling manifold
     VI(B)  permits secondary effluent to enter exhaust manifold

     V2(A)  permits primary effluent to enter sampling manifold

     V2(B)  permits primary effluent to enter exhaust manifold

     V3(A)  permits raw influent to enter sampling manifold

     V3(B)  permits raw influent to enter exhaust manifold
     V4(A)  permits mixed liquor to enter sampling manifold
     V4(B)  permits mixed liquor to enter exhaust manifold
     V5(A)  permits return activated sludge to enter sampling manifold

     V5(B)  permits return activated sludge to enter exhaust manifold

     V6(A)  permits primary sludge to enter sampling manifold

     V6(B)  permits .primary sludge to enter exhaust manifold
     V8(A)  prevents sample from going to the Pretreatment Assembly
     V8(B)  allows flush water to be supplied to the Pretreatment Assy, while
            streams 4, 5, and 6 are being monitored.
     V7(A)  allows flush water to be supplied to the sample manifold and
            homogenizer plumbing following the sampling of stream 6.
                                      52

-------
The purpose of valve pairs VI through V6 is to introduce dynamic samples,
one at a time, to the sample manifold through "valve A".  In this way, all
sample-supply pumps run continuously to avoid settling of solids in the
transfer lines.

Valve 7 is used to introduce tap water to the homogenizer plumbing; this
simultaneously flushes the plumbing, homogenizer and TOC-analyzer input
lines.  In the manual mode, any one of these sample streams can be intro-
duced to the sample manifold by depressing the push button associated with
the desired sample stream.  When it is desired to select another stream,
the "All to Drain" button (located in lower right quadrant of the control
panel) is pushed, then this is followed by depressing the button associated
with the desired alternate stream.  However, if the stream desired is the
next stream in the programmed sequence only the button associated with that
sample should be pushed.  The circuitry permits forward sequencing, but
requires a reset ("All to Drain") to go backwards in the sequence.  Note:
when the sequence is performed manually, the buttons must be held until all
valve-drive motors have completed their cycles (approximately 2-4 seconds).

Valve-pair V8 cannot be manually actuated from the front panel.  It operates
so that sample streams 1, 2 or 3 (when selected) will be furnished to the
Pretreatment Unit through Valve 8A.  When sample streams 4, 5 or 6 are
selected, Valve 8A closes and tap water is introduced through Valve 8B to
the Pretreatment Unit and the colorimeters.

Valve-pair V9 is not found on the manifold, but is located in the TOG analyzer.
Its purpose is to furnish to the TOG analyzer one of two samples:  a homo-
genized sample to monitor TOG, or a filtered sample from the Pretreatment
Unit to monitor SOC.  In the installation at Cranston, ball valves were not
used for V9.  Two peristaltic pumps were installed with a common output
connection.  Pump "B" is energized to sample for TOG and it pumps the sample
from the homogenizer.  Pump "A" is energized to sample for SOC and it pumps
the sample from the pretreatment output.  The pump not energized acts as a
closed valve and prevents mixing of the two samples.

This was designed to be a function of the TOG analyzer because of the
impracticability of switching small streams with ball valves, and the relative
ease of doing it with a pump in the TOC analyzer.  The function, V9, cannot
be selected or controlled from the front panel.  Any time a new sample is
selected, V9 will operate in the "B" mode which furnishes homogenizer output.
Only when the system is in the automatic mode and has run through a timing
cycle on samples 1, 2 or 3 will the SOC mode be selected for the next cycle
on the same sample.  If SOC mode is not desired, then the TOC unit's first
input pump should be energized from its normal supply.  Placing the wired
"Dummy Plug" (Figure B.I) in J9 on the back of the Control Panel will allow
the system to skip the SOC cycle completely.
                                     53

-------
                       13579

                       2   4    6   8   10
                       T   T-^T   T

          Figure B. 1  Dummy Plug Wiring to Skip SOC Mode
                     (Numbers shown are the pin numbers of
                     the dummy plug actually used).
'In automatic operation the  system will progress through the sample
streams in increasing numerical order starting  with the one selected
by depressing a pushbutton.  After stream  #7  (flush water)  the system
will revert back to stream  //I.  The time duration of each sampling
cycle is controlled by the  setting of the  left  timer (facing the unit).
Figure B.2 shows the timing diagram for the system, and Table B.I shows
the operational sequence when a stream is  selected.
                                 54

-------
VALVE T0 T, 1
N°- ON ' '
I. SECONDARY
EFFLUENT
OFF-
ON-
2. PRIMARY
EFFLUENT
OFF-
ON-
3. RAW
INFLUENT
OFF-
ON-
4 MIXED
LIQUOR
OFF-
5. RETURN ON-
ACTIVATED
SLUDGE
OFF-
ON-
6. PRIMARY
SLUDGE
OFF —
ON-
7 FLUSH
WATER
OFF-
C A fclDI C"






2 T(3 T4 T5 T6 T7 T










8 T9 T0
lr





n









a PRETREATMENT
INPUT FLUSH J
WATER J
9, TOC HOMOG"
ANALYZER
INPUT pRETREAT_
ST/
CY(

kRT
:LE



^"^™
Tfl
(11
i
—
ITAL
JTIM
—"•^
SAMP
ERIN
;
—
LING
TER\



CYC
fALS)






LC

n_
n

i





.
_

END'OI
CYCLE
Figure B.2  Timing Diagram
                 55

-------
                                      TABLE B.I.  TABLE OF OPERATION SEQUENCE
Ul
Time
j reference
To
T
1
T2
T3
T4
T5
T6
T7
T8
T9
Stream
Secondary
effluent
Secondary
effluent
Primary
effluent
Primary
effluent
Raw
influent
Raw
influent
Mixed
liquor
Return
activated
sludge
Primary
sludge
Flush
water
Relays
energized
K1A, K8
K1A.K1B.K8,
K9
K2A, K8
K2A.K2B.K8,
K9
K3A, K8
K3A.K3B.K8
K9
K4A, K4B
K5A, K5B
K6A, K6B
K7
Relays
deenergized
Remainder
Remainder
Remainder
Remainder
Remainder
Remainder
K8, remainder
K8, remainder
K8, remainder
Remainder
Valves
opened
VIA, V8A,
all other "B"
valves
V1B.V8A.V9A,
all other "B"
valves
V2A, V8A,
all other "B"
valves
V2A.V8A.V9A,
all other "F1
valves
V3A, V8A,
all other "F'
valves
V3A, V8 A, V9A,
all other "F1
valves
V4A,V8B,V9B,
all other "F1
valves
V5A.V8B.V9B,
all other "F1
valves
V6A.V8B.V9B,
all other "B"
valves
V7,
all"F' valves
Valves
closed
V1B, V8B,
all other "A"
valves
V1B.V8B.V9B,
all other "A"
valves
V2B, V8B,
all other "A"
valves
V2B,V8B,V9B,
all other "A"
valves
V3A, V8B,
all other "A"
valves
V3B.V8B.V9B,
all other "A"
valves
V4B.V8A.V9A,
all other "A"
valves
V5B.V8A.V9A,
all other "A"
valves
V6B.V8A.V9A,
all other "A"
valves
All "A" valves
Action
accomplished
Sec. effl. to sample manifold,
TOC, o-PO , NH -N, hyd. PO,
..,43 4
monitored
Sec. effl. to sample manifold,
SOC, o-PO,, NH -N, hyd. PO.,
4 O 4
monitored
Prim. effl. to sample manifold,
TOC, o-P04, NH3-N, hyd. PO4>
monitored
Prim. effl. to sample manifold,
SOC, o-P04, NH3-N, hyd. PO4,
monitored
Raw infl. to sample manifold,
TOC, o-P04> NH3-N, hyd. PO4,
monitored
Raw infl. to sample manifold,
SOC, o-P04, NH3-N, hyd. PO4,
monitored
Flush water to P/T and ana-
lyzers, TOC monitored
Flush water to P/T and ana-
lyzers, TOC monitored
Flush water to P/T and ana-
lyzers, TOC monitored.
All streams to drain, flush
water to entire system

-------
 Theory of Operation

 Each valve pair is controlled by the two double-throw contacts of its
 associated relay;  i.e., valve-pair VI ("A" and "B")  is plugged into Jl where
 it will be controlled by K1A, etc. 115 volts AC is furnished through the
 de-energized relay contacts to close VIA and open VlB.  When the relay is
 energized, 115VAC  is furnished to open VIA and close VlB.   When the valves
 are operating normally, one valve of a pair will always be open and the
 other closed.

 When the unit is first turned on, all sequence relays are  deenergized.   The
 unit's operator can depress any one pushbutton,  SI thru S7,  to energize its
 associated relay.   (Note:   SI is associated with valve-pair  VI ("A" and "B"),
 Jl,  and Kl,  etc.)   This opens the associated Valve A (closing Valve B)  and
 permits that sample stream to flow to the  sample manifold.

 Jacks  Jl thru J9 are wired so that the "A" Valves are controlled through the
 even-numbered contacts (reference schematic shown in Figure  B.3 for a  typical
 valve  pair).   Each  valve is powered with a 115V  motor by means of  a cam-
 operated double-throw micro-switch.   The voltage which drives the  motor is
 returned to  the  panel through the activated micro-switch when the  valve is
 in  its  selected  position.   The  return voltage  lights  an  indicator  lamp  that
 shows  the  status of  the valve (green  light  indicates  valve open, and red
 light  indicates valve closed).   For valve-pairs  VI through V7,  the return
 voltages  fed  back from the  "A"  valve  are used  to  control the  relay logic
 for the  automatic sequential  operation.

 On  the ladder diagram (Figure B.4)  find K11A,  K11B,  K11C, K12,  and K14.
 Observe that K11A,  K11B and K11C operate together as  one relay of  eleven
 contacts.  When  Kll  is energized,  its normally open  (N.O.) contacts  connect
 the coil of  each relay (Kl  thru K7) to the green-light  circuit  of  the  "A"
 valve  that  precedes it (K7  to K6,  K6  to K5,  etc.).   Relay Kll is energized
 when the timer K12  completes  its  time cycle.   K12  (N.O.) contacts  close,
 energizing Kll.  Kll  contacts 9 to  5  close,  energizing K14.   K14 contacts
 1 to 4  open,  resetting timer  K12  and  deenergizing Kll  and K14.  K14 is  a
 delay-on-release relay; this  delay  is necessary  to allow K12  time  to reset.
 Each time Kll is operated,  it applies  115V  to  the coil of the next  relay
 (Kl through  K7)  in  the sequence.  Actuating any  relay  from Kl  through K7
 causes  its associated valves  to change condition:  "A" valves open  and  "B"
 valves  close.  As valve "A" starts  to open,  its microswitch S2 changes  con-
 dition,  removing the  holding  voltage  from  the  immediately  preceding relay
 in the  sequence.  Deenergizing  that relay causes its valves to assume the
 condition of  valve "A" closed - valve "B" open.

 The holding  circuits  of each  relay  (Kl thru K7) are wired from the red light
of the next valve in  the sequence through normally closed (N.C.) contacts of
K21A and K21B.  When  depressed, switch S10  ("All to Drain"), energizes K21,
opening  the holding circuits  of all sequence relays and deenergizing any
 energized relays.  Energizing K21 also resets the K12 timer.
                                     57

-------
     LI
                                                                            L2
liSVAC
 (HI)


11" 7f. /,, , ( 12
v v \ Ji i v o 	
KIA | 1
L ' '
1 1 Ol ' 3
I. J !

1 THROUGH 6 8 8. FOR VALVE PAIR 2 USE K2A 8 J2,
FOR VALVE PAIR 3 USE K3A 8 J3 8 ETC.
KIA SHOWN OEENERGIZED. VALVE A HAS RUN TO
A CLOSED POSITION.VALVE B HAS RUN TO AN
OPEN POSITION.


i 1 ! *
112 1 > 41 f. .( Iz
9 Til <; Jl 4 <. (j>
KIA ' 1
A <* ii - f A
8] 3


I12 84 tJT\( A7
T T OTK T
K7 { |
L _ 	 „!! 1 ' 	

i9
T
1
1 ^~~
1

L >Jll> O

,11
•*- 1 J I
f !

-------
               WHEN VALVE A IS CLOSED    WHEN VALVE A IS OPEN
               S2 CLOSES PIN 3 TO PIN 5   /SI CLOSES PIN 2 TO PIN 4
LI
                                                                                        L2
t /
12
K
II
\
t
||

K7 V7
IA x ._ . x 2
'A-
SI
4 v « -.\_
f2— — J4^)-
SI
|4,,,7V_
P J3-7/

IA-S2
/fe-i .K-QV—


IA
f '
1

KIB
• "1
1
-f
!|
1


7
3

H
10
^
5
5
H
II

K
9
5
\
5
K
12
,._
K2
— j
21
V
3
7
?4
1
h
10
1
5
1
9
t
9

t
II
<3
K2I
B
7
K
II
B
f 5
	 ^| 	 CJ5-3 « }• | x ,- _x ^ |
KA4 V4
ill |7 f...( 2
	 U| | 	 A-
H
SI
4 ^ •< T^

S2 K2I
^>JC3v I0|>

B


1
10
5

ll/
:i/s
(IE
n,
IK
:2,
:2i
n/
53
IK
:a
;3i
HE
34
III
"
55
III
C5

,
6
J
9
\
7
—
5 ,
9
5
9
8 .

6
k
9
i
5
5 ,

*
7 ,
9 	
— -I
6
i
9

,. isfl14
U
KIA
°ni4
u
KIB
K2A
K2B
K3A
K3B
I3r|l4
2 ~ 7
K4B
K5A
I3FI4
2 ~7
K5B
          SWITCHES OF "A" VALVES ARE SHOWN WITH SYSTEM IN "ALL TO DRAIN"
          MODE ;l.e..ALL "A" VALVES ARE CLOSED ("B" VALVES OPEN)

            Figure B.4    Ladder Wiring  Diagram (Sheet  I  of 2)
                                           59

-------
LI
                                                                             L2
S6
H
II
12
!5A V5A-SI KIIB
l7 x.. . f 2 |« \ .ITS "1 7
' VP-I *• " ' > J» '/
<7 V7-S2 K2IB K6A
>W /• 	 x 3l X5 v.--v lll> 3 5 9
S7
!
II
II

<6A V6A-SI KIIB
I7 f ir l f 2 I4 ^ JC Tl l2 8
<|A VA-S2 K2IB K7
xf3 x.. , x 3 xfc v .. -,v 12 |4 5J |9
P| 4 1 ? 1 II
K4B K5B K6B K7
yfe lU3 lU3 II xft
n -r i i r i
KIB
12 8
K2B
12 8
K3B
12 8
KI2N.O.
SIO
Sll
1 2
x^]
KI4 K2IA Sll x
|>4 9U1 3 1-4
Kl 
Af
L
(
K
13
13
KIIB
13
KIIC
K
13
13
K
LI C
\
CL2 /"
V.
KI2
2l
K
                                                                      Il4
                                                                    K7
                                                                    KB
                                                                    0s
                                                                    K9
                                                                      14
                                                                      14
                                                                       14
                                                                    K2IA
                                                                      14
                                                                      14
                                                                     M
                                                                        L2
                                                                         51 19
                                                                         KIIA
            Figure B.4   Ladder Wiring  Diagram  (Sheet  2  of 2)
                                       60

-------
 The selection of TOC/SOC by valve pairing is achieved by a modification of
 the basic logic of Kl, K2, K3, and K4.  K1A, K2A, and K3A control valve pairs
 VI, V2 and V3 respectively; K1B, K2B and K3B control V9 through K9.  If K9 is
 deehergized (i.e., if V9 is functioning in the TOG mode), and if K1A or K2A
 or K3A is suddenly energized, the actuation of Kll causes the associated K1B
 or K2B or K3B to energize concurrently.  Energizing K1B, K2B or K3B causes K9
 to energize (through N.O. contacts 12 to 8), thus actuating V9 to the SOC
 mode.   When K9 is energized by energizing a valve-pair (V1A-V1B, V2A-V2B, or
 V3A-V3B), the immediately preceding  actuation of Kll causes the "A" relay
 of the next valve pair to energize.   The sequence is as follows:  K1A,  K1A &
 K1B,  K2A, K2A & K2B, K3A, K3A & K3B, K4A & K4B, K5A & K5B,  K6A & K6B, K7,
 then  back to K1A, etc.  (K4A & K4B operate together as one  5-contact relay
 as do  K5A & K5B and K5A & K6B.)  If the dummy plug shown in Figure B.I is
 inserted into J9 (instead of a valve pair), the voltage from J9 (pin 7) is
 returned instantaneously to K1B or K2B or K3B contacts 11 to 7; this ener-
 gizes  the next "A" relay in sequence, causing that valve pair to actuate.
 The sequence then is Kl, K2, K3, K4, K5,  K6, K7, then back  to Kl, etc.

 K8 is  energized when K4, K5, K6, & K7 are deenergized.  Operating any
 relay  K4 through K7 opens a series-arranged contact pair which deenergizes
 K8.  When K8 is deenergized, it operates  valve-pair V8 to allow flush water
 to flow to the pretreatment unit.

 J10, Jll,  and J16 are trouble-shooting aids,  and are hard-wired so that any
 valve  pair (when plugged into)  will  do the following:

     J10 - opens valve A,  closes valve B

     Jll - opens valve B,  closes valve A

     J16 - closes both valves

 The voltages  from the divider network (IV.  to  7V.)  are made  available at
 J13-3  (Hi)  &  J13-1  ("0"V)  to give remote  indication of the program status.
 1  volt  indicates that the  TOC for sample  1  is  being monitored,  1.5V indi-
 cates  that  the  SOC  for sample 1  is being  monitored,  2V Indicates  sample 2
 TOC monitoring,  etc.

 The contacts of  timer K13  actuate K15  and K16  to operate auxiliary  equipment
 (i.e.,  a data acquisition  system and a  paper-tape-punch recorder).   For the
 period  of  time  that K13  (N.O. contact)  is closed  (before K12 completes  its
 time cycle), 115V AC  is  furnished to J14  to operate  the tape punch,  and the
 circuit  from J13  (pin 23)  to J13  (pin  27) allows the data acquisition system
 to print data.   K16 is a delay-on-energized relay.  When K15 and K16 are
energized, the circuit  from J13  (pin 10) to J13  (pin  16) closes  for  1 second
 (delay  of K16), and the circuit  from J13  (pin 13) to J13  (pin 19) opens  for
1 second; this operates the  "All Channel Buzz" of the tape punch, a solenoid
protection device peculiar to this particular punch mechanism.  K13 is  reset
along with K12 when K12 "times out" and operates Kll, K14.
                                     61

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                                 APPENDIX C

                       DESIGN SPECIFICATION GUIDELINES

T.    GENERAL

     A.   This specification applies to the design of an on-line hardware
          system which will automatically sample, transfer and condition
          all types of wastewater-treatment process streams for automatic
          analysis without the occurrence of unacceptable chemical change
          in the samples prior to their analysis.

     B.   Application

          1.  Municipal wastewater-treatment plants

     C.   The sampling system shall consist of a series of pumps and associ-
          ated piping at appropriate locations within a wastewater-treatment
          plant.  These pumps shall supply their various samples to a
          centrally located sampling assembly which has the capability to
          select any one of the streams and condition it sufficiently so
          that the processed sample is adaptable to automatic on-line TOG
          and colorimetric analyzers.  It shall have an interval flush cycle
          which can flush the total system after the completion of a total
          sampling cycle.  The sampling system shall be controlled by means
          of a control panel which can be operated either manually or auto-
          matically.

     D.   To minimize transfer-line contamination, dilution pumps shall be
          utilized when the streams being sampled have suspended solids
          loadings of 1000 mg/1 or greater.

 II.  TECHNIQUE

     Each sample shall be supplied continuously  to pairs of two-way valves
     which  operate in tandem so as to simulate a three-way valve.  The valve
     pairs  shall be connected by means of union-type plumbing fittings to a
     sampling assembly which shall consist of an exhaust manifold and a
     sampling manifold.  These valve pairings shall permit each sample to
     flow continuously, either to the sampling manifold or to the exhaust
     manifold.  Once the sample stream reaches the sample manifold, it shall
     be  valved  to a Pretreatment Assembly  (for removal of all particulate
     matter in  preparation for colorimetric analysis) or to a homogenizer
      (in preparation for TOC analysis).  The sampling of all process streams
     to  be  analyzed shall be a sequential operation.  When the sampling
                                      62

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     sequence has been completely traversed, the sampling assembly shall be
     automatically flushed with tap water prior to the initiation of another
     sampling sequence.

III. OBJECTIVES

     The system's objectives shall be:

     A.   To provide for multiple stream monitoring within a wastewater-
          treatment plant without altering any sample's initial chemical
          composition.

     B.   To provide control signals to allow process automation.

IV.  GENERAL PERFORMANCE CONSIDERATIONS

     A.   To handle the liquid streams within a wastewater-treatment  plant
          (raw influent,  primary effluent,  and secondary  effluent), cen-
          trifugal grinder pumps shall be used.   These pumps shall be
          capable of  reducing occasional large particles  of  suspended
          solids to a size of 1/4  inch (6.35  mm)  which is small enough
          to allow an in-line homogenizer to  function continuously.   How-
          ever,  when  the  stream contains a  large  amount of fibrous material
          (specifically raw influent),  a screen shall be  utilized to  prevent
          entrance of these fibers into the pump.

     B.    To handle streams  having higher solids loading  (mixed liquor,
          return activated  sludge and primary sludge), a  dilution pump
          arrangement shall be  used.  The sample shall be diluted at  the
          origin to minimize  solids loading within the transfer lines.  Dilu-
          tion shall be accomplished by utilizing a duplex pump driven by a
          common drive; this maintains  a  constant dilution ratio, even though
         rotor  speed may vary.  Each side of the pump shall have an adjustable
         stroke-setting to vary flowrates for desired dilution ratios.   The
         total  flow and the dilution ratios required will determine the size
         of the  check valves.  The pump shall be driven by a standard,
         constant speed, AC-drive motor or a suitable speed-controlled  motor.
         The latter configuration will allow for varying total flow once a
         dilution ratio is established.

    C.    The in-line homogenizer shall utilize an abrasive rotor-stator
         combination to reduce particle size.  The homogenizer must be  able
         to reduce all types of particulate matter (i.e., plastics, paper
         fibers, and  woodchips), as  well as sewage,  to a  finally divided size
         on a continuous  basis.  Rotor clearance shall be adjustable  by alter-
         ing the gap  between the rotor and  stator to  achieve a wide range of
         particle sizes.

    D.    The Pretreatment Unit shall  be a packaged  filtration system  which
         provides continuous flow of  representative samples  for up to six,
         on-line, water quality, monitoring instruments,  while removing
         virtually all  solid particles  above  10 micrometers  in size.


                                    63

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 V.   ELECTRICAL SPECIFICATIONS

     A.   Input Power

         The central location which contains the sampling assembly and
         conditioning equipment shall have provision for 100-ampere,  3-phase,
         230-volts, 60-HZ,  AC power.   The sampling system requires 50 amperes;
         the additional power is required for automatic analyzers.

     B.   Output Signals

         The control panel  shall have a voltage divider network serving as an
         indicator of which sample is being monitored in the following manner:

         Indicator
         Voltage            Sample Stream	    Parameter Monitored	

           1.0              Secondary effluent    Colorimetric analysis & TOC

           1.5              Secondary effluent    Colorimetric analysis & SOC

           2.0              Primary effluent      Colorimetric analysis & TOC
           2.5              Primary effluent      Colorimetric analysis & SOC

           3.0              Raw influent          Colorimetric analysis & TOC

           3.5              Raw influent          Colorimetric analysis & SOC
           4.0              Mixed Liquor                     TOC

           5.0              Return activated sludge          TOC
           6.0              Primary sludge                   TOC

           7.0              Flush water           Complete System Flush

VI.   MECHANICAL SPECIFICATIONS

     A.   The sample assembly, along with the control panel and homogenizer,
         shall not exceed 4 ft. (1.22m) width, 2-1/2 ft. (.76m) depth and
         6 ft. (1.83m) height.

     B.   Flush-water requirements shall not exceed 5 gal/min (18.92 1/min) at
         20 psi (137.9 kN/nr)  (Note:  this water is not used on a continuous
         basis but must always be available.)

     C.   The sampling manifold shall be firmly mounted to the floor.

     D.   Positioning of automatic analyzers is very important.  Automatic
         analyzers shall be located as close as possible to the source of the
         conditioned sample.  Where this is not practical, analyzer input
         velocities shall be investigated and the associated plumbing shall
         be adjusted to minimize line contamination.  (Minimum velocity shall
         be no less than 1 ft/sec. [.30m/sec.].)
                                     64

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 VII.  SAMPLE REQUIREMENTS

       A.  The dilution pumps must not be operated with positive input
           pressure.  Therefore, the high-solids streams shall have a
           reservoir-type feed so that the pumps may draw the required
           sample.  The reservoir must be continually replenished so that
           a representative (up-to-date) sample is always available.

VIII.  ADDITIONAL SERVICES REQUIRED

       A.  Additional services are dependent upon the requirements of the
           automatic analyzers selected; i.e., reagents, bottled gas, etc.

  IX.  CONTROL AND INDICATORS

       A.  The control panel shall be graphically representative of the
           flow diagram.   Red (no flow)  and green (flow) indicator lights
           shall be incorporated to display the sampling status.

       B.  The system shall have two modes:  automatic and  manual

           1.   The automatic mode shall  be controlled by a  timer located
               on the front panel.   Cycle time shall be manually selectable
               for times  up to 1 hour.

       C.  A second timer shall be  incorporated to  start up auxiliary
           equipment (e.g.,  data-acquisition system)  at any intermediate
           point within the cycle period.

   X.   ENVIRONMENTAL

       A.  Ambient Temperature:
              34°F (1  °C)  to 104°F  (40°C)

       B.  Humidity:
              0-95%, non-condensing

       C.  The grinder pumps shall be submersible pumps.  The dilution  pumps
           shall  withstand adverse weather  conditions.
           NOTE:   If the  temperature goes below freezing, adequate flow must
                  be maintained  to prevent  freezing within  tha lines.

       D.   The sampling system shall be contained within a  shelter which is
           environmentally controlled (heated and air-conditioned).

 XI.   SAFETY  PROVISIONS

       A.   In  the event of a leak in a sample line within the shelter,  all
           sample flow shall be directed to drain by pushing the "ail to drain"
           button on the control panel.
                                     65

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B.  Each pump shall have its own, independent, overload circuit
    located within the shelter.
                             66

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   APPENDIX D
LIST OF EQUIPMENT
                        Estimated Costs (1976 dollars)
Item

D
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)


Pump, Grinder
Control Box
Pump Dilution
with Control Box
Pump, Dilution with
Control Box
Mixer, Static
Homogenizer
Hose, 1"
Hose, 3/8"
Assembly, Control
Panel and Rack
Assembly, Grinder
Pump Cable
Assembly, Dilution
Pump Cable
Assembly, Connector
Panel
Pump, Peristaltic
As semb ly , Samp ling
and Exhaust
Cabinet, Reagent
Pretreatment Unit
Total Equipment Cost
Manufacturer

Hydr-0-Matic
Pump Co.
BIF
BIF/Seco
Kenics
Raytheon
B. F. Goodrich
B. F. Goodrich
Raytheon
Raytheon
Raytheon
Raytheon
Randolph
Raytheon
Raytheon
Raytheon

Part #

SPG-150A2
1722-92-9517
1722-92-9510
37-08-136
2650
BFG300
BFG300
Special
Special
Special
Special
Special
Special
2590
2550

Qty. Unit

3 875
2 690
1 — —
3 145
i ___
670 ft. .94/ft.
1,000 ft. .36/ft.
1 — — —
1,000 ft. 1.54/ft.
1,000 ft. .66/ft.
1 — — —
1 —
1
2 650
1 — —

Total

2,625
1,380
1,020
435
1,350
630
360
1,320
1,540
660
320
126
4,598
1,300
3.950
$21,614

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APPENDIX D - LIST OF EQUIPMENT (Cont'd)
Name






TOC Analyzer




Qrthophosphate Analyzer




Monitor IV




Data Acquisition System




TOC Analyzer




Microscope




Spectrophotometer
AUXILIARY EQUIPMENT






 Manufacturer            Part






 Raytheon                2600




 Raytheon




 Technicon




 Esterline Angus         D2020




 Beckman                 915




 Bausch & Lomb           XL1




 Bausch & Lomb
Qty





 1



 1



 1



 1



 1



 1



 1
                                68

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 Contamination

 Deadending

 Grab Samples

 Hyd. P04

 Interface
o-P04

P/T

SOC

Source


Sparging


Time-Lag

TOC
   GLOSSARY OF  TERMS AND ABBREVIATIONS


Settled particles in transfer lines.

Allowing a stream to stop flowing.

Samples taken  by hand.

Hydrolyzable phosphate expressed as phosphate.

That point at  which all sample transporting and
conditioning have been performed.

Ammonia expressed as nitrogen.

Orthophosphate expressed as phosphate.

Pretreatment Assembly (Filtration Unit).

Soluble organic carbon.

That point (usually a unit process) at which sampling
originates.

Process by which inorganic carbon is removed from a solu-
tion by agitation with a CO.-free gas.

Time during which valid data cannot be obtained.

Total organic carbon.
                                    69

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.
  EPA-600/2-76-146
                                                           3. RECIPIENT'S ACCESSION>NO.
4. TITLE AND SUBTITLE

  Wastewater Sampling, Transfer and Conditioning System
                                  S. REPORT DATE
                                   October 1976
                           (Issuing  date)
                                                           6. PERFORMING ORGANIZATION CODE
7, AUTHOR(S)

  Louis S.  DiCola
                                                           8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS

  Raytheon Company
  Submarine Signal Division
  P.O.  Box #360, Portsmouth, Rhode Island
                                  10. PROGRAM ELEMENT NO.  1BB043
                                    ROAP 21 - ASC; Task No.  20
                                  11. CONTRACT/GRANT NO.
                    02871
             Contract No.  68-03-0250
12. SPONSORING AGENCY NAME AND ADDRESS
   Municipal  Environmental Research Laboratory
   Office of  Research and Development
   U.S.  Environmental Protection Agency
   Cincinnati,  Ohio   ';5268	
                                  13. TYPE OF REPORT AND PERIOD COVERED
                                  Final:   .Tnng 1Q7^-Marrh
                                  14. SPONSORING AGENCY CODE

                                       EPA-ORD
15. SUPPLEMENTARY NOTES
16. ABSTRACT
        This  report describes the  construction and field evaluation of an automatic
  on-line hardware system for reliably sampling, transferring,  and conditioning
  various wastewater-treatment process streams such that the resulting transferred
  and conditioned samples are suitable for interfacing with automatic on-line
  colorimetric and total organic  carbon analyzers.  Process streams to which this
  hardware system was sucessfully applied included raw sewage,  primary effluent,
  secondary  effluent, aeration tank mixed liquor, and return activated sludge.
  Primary sludge could not be sampled at the field-testing site because the sludge
  had become too thick at its only feasible access point.  Analytical parameters
  used  to evaluate the hardware system included both total and  soluble organic
  carbon, orthophosphate, total hydrolyzable phosphate, and ammonia nitrogen.
  Nitrate and nitrite were not included; however, the hardware  system's performance
  with  the soluble parameters studied indicate that nitrate and nitrite should
  present no special difficulties.
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.lDENTIFIERS/OPEN ENDED TERMS
                                               c.  cos AT I Field/Group
  Sewage
  Waste water
  Sampling
  Continous  sampling
  Sequential sampling
  Chemical analysis
  Sequential analysis
Process control
Automatic control
Automatic sampler
In-line sampling system
Automatic analysis
Sample transport system
Sample transfer  system
In-line homogenizer
13B
18. DISTRIBUTION STATEMENT

  RELEASE TO  PUBLIC
                     19. SECURITY CLASS (ThisReport)
                      UNCLASSIFIED
                                                                         21. NO. OF PAGES
                               80
                     20. SECURITY CLASS (Thispage)
                      UNCLASSIFIED
                          22. PRICE
EPA Form 2220-1 (9-73)
                                            70
                                            1976 — 757-056/5407 Region 5-11

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