PHYSICAL-CHEMICAL PROCESSES
TECHNOLOGY TRANSFER DESIGN SEMINAR
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL ENVIRONMENTAL RESEARCH CENTER
CINCINNATI, OHIO

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        PHYSICAL-CHEMICAL PROCESSES
             Prepared for the
     U. S. Environmental Protection Agency
      Technology Transfer Design Seminar
    National Environmental Research Center
Advanced Waste Treatment Research Laboratory
      Office of Research & Development
              Cincinnati, Ohio
                August 1973

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                      PHYSICAL-CHEMICAL PROCESSES*

                    I. J. Kugelman and J. M. Cohen
INTRODUCTION
The most recent advance in the art of sewage treatment is the application of
physical-chemical technology to raw sewage treatment.  In reality, physical-
chemical treatment of sewage is not a completely new technology.  Chemical
treatment of sewage was widely practiced in England and the United States In
the latter portion of the 19th Century.  However, this technique gradually
fell into disuse with the advent of activated sludge, because activated
sludge systems achieved higher degrees of treatment (1).  In the 1930*s a
number of systems employing physical and chemical treatment in combination
were evaluated.  These produced treatment superior to primary sedimentation
followed by activated sludge (conventional treatment) but at a cost 1.5 to
2 times as great (2).  This additional Increment of cost discouraged adoption
of physical-chemical treatment at that time.

During the last decade advances in physical-chemical treatment technology
resulting from Environmental Protection Agency-supported .research have signi-
ficantly reduced the cost of physical-chemical treatment.  In addition, it is
apparent that higher levels of treatment will be required in the future to
maintain water quality.  As a result of these alterations in conditions,
physical-chemical treatment Is now an alternative to conventional treatment,
especially for situations where significant phosphorus removal Is required.


GOALS OF SEWAGE TREATMENT

The fundamental goal of sewage treatment is sufficient reduction In the level
of pollutants in the wastewater to allow discharge to the environment.  The
pollutants in sewage are grouped Into classes of similar compounds which have
the sane environmental impact rather than being individually dealt with.  At
present the five major pollutant groups of interest are:  suspended solids,
organic matter as measured by BOD, TOC or GOD, phosphorus compounds, nitrogen
compounds and pathogenic microorganisms.  It is Impossible to specify one set
of effluent standards which is  applicable to all or most situations.  However,
it is generally agreed that a good quality effluent will have the character-
istics given in Table 1.  In addition, complete disinfection will be required.
As yet no general agreement on a nitrogen level is in evidence.  It must be
repeated the goals listed above are not design standards, but are guides in
describing a good quality effluent.

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                                    -  2  -

THE CLARIFICATION-ADSORPTION  PROCESS

The physical-chemical  treatment  system  which at  present is most advanced in
development, and which seems  the best is the clarification-adsorption system
schematically  illustrated  in  Figure 1.  In this  system chemical clarification
and filtration are  utilized to achieve  almost complete suspended and colloidal
solids removal.  With  a high  enough dose of the  proper chemicals essentially
complete phosphorus removal can  also  be obtained.  The function of the
activated carbon step  is the  removal  of soluble  organics.  As in any conven-
tional system  preliminary  screening,  grit removal and final disinfection
are provided.  The  filtration step is shown as optional but conservative
design dictates its use.  The positioning of this step prior to or after carbon
adsorption  is  dictated by  the type of waste-carbon contacting system provided.
The three steps of  chemical clarification, filtration and carbon adsorption
will  be discussed in some  detail below.

This  system does not provide  ammonia  or nitrate-nitrogen removal.  'Physical-
chemical methods  for soluble  nitrogen removal are covered in another lecture
of this symposium.   Any of these nitrogen removal methods can be integrated
into  the clarification-adsorption system.


CHMCAL CLARIFICATION

Chemical clarification provides  the bulk of the  pollutant removal achieved
by this type of treatment  system.  In this unit  operation an appropriate
chemical is dosed  to the wastewater and the mixture  is flocculated and
settled.  All  of  these steps  can be conducted in independent units, or
combined into  a single unit which is  usually referred to as solids-contact
siarifier.

Chemicals which have been  successfully  used to clarify raw sewage include
organic  polymers  (3),  iron salts (A), aluminum salts (5), and lime  (6)(7).
The  inorganic  coagulants have the advantage of providing for phosphorus
reoovalo  At present there is no  rational method for predicting the dose
of chemical required.   For planning purposes, jar tests are suggested.
Fortunately field control  of the coagulant dose  is  possible.  For all
coagulants  except  lime the suggested  method is monitoring of the clarlfier
affluent  turbidity.  Monitoring of phosphorus also  appears promising,  as
good clarification is  always  obtained when sufficient chemical  is added  to
provide  good phosphorus removal.  With  lime as the  coagulant excellent
control  is  obtained by pH measurement.  The  pH required to achieve  good
clarification and phosphorus  removal  is dependent on the chemical charac-
teristics of the  sewage.  In areas where  the alkalinity and hardness are
low  the  high lime process  in which the  pH is  raised to approximately 11.5
is  requiredo  Generally, two-stage precipitation with intermediate  recarbon-
ation is  utilized.   In hard water, high alkalinity areas a  low  lime single-
       precipitation at pH 9.5 to 10 is  sufficient.

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                                   - 3 -

Table 2 illustrates the treatment obtained with chemical clarification in
pilot plants at a variety of locations.  In addition to the expected high
levels of suspended solids and phosphorus removal significant organic
removal was obtained.  Based on these data and others it can be expected
that chemical clarification of raw sewage will consistently yield organic
removal in the 65-75 percent range.  With this degree of organic removal
from chemical coagulation the carbon need provide  only a small increment
of additional removal to match the performance of a good secondary treat-
ment system.

Sludge disposal plays a dominant role in the economics of any chemical
clarification system.  Only limited data on the characteristics of sludges
resulting from the chemical treatment -of raw sewage are available.  These
data indicate that with iron or aluminum salts as coagulants:

    1.  The resulting sludge volume sometimes exceeds and sometimes is
        less than primary sludge from the same sewage.

    2.  The chemical sludge is more difficult to dewater in a vacuum filter
        than the corresponding primary sludge.

However, with lime as the coagulation chemical dewatering is extremely rapid
just by gravity thickening.  Eimco (8) reported lime-raw sewage sludge solids
concentrations of 15% to 25% after gravity thickening.

In addition to yielding a sludge amenable to rapid and easy dewatering lime
is the only coagulation chemical which can be economically recovered.
Recalcining the lime sludge in a furnace has been successfully conducted in
a tertiary plant at South Lake Tahoe and has been state-of-the-art in water
softening plants for a considerable period of time (9).  In addition to
regenerating the lime, the organic solids are incinerated thereby accomplish-
ing ultimate disposal of the sludge.  For these reasons it is anticipated
that lime will be the coagulant of choice for most situations.

Design criteria for the coagulation equipment is similar to that used In
water treatment plants.  A flash mix of one minute, flocculatipn for 15 to
30 minutes and sedimentation at upflow rates of 0.5 and 1.0 gpm/ft*.
CARBON ADSORPTION

The role of the carbon adsorption step is the removal of soluble organics
from the wastewater.  -Although the chemical clarification step does the bulk
of the pollution control job, the carbon adsorption step Is required to
produce a good quality effluent.  The total organic removal achieved by the
combination of clarification and carbon adsorption at several physical-
chemical pilot plants is illustrated in Table 3.  It can be seen that not
only is the removal achieved quite high (95%+) but equally important the
residual organics after treatment are quite low.  These effluents are
superior to the usual quality of secondary effluent (TOG «*s 20 ag/l,
COD «s 40 to 50 mg/1).

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                                   - 4 -

The results reported in Table 3 were obtained with carbon contacting systems
employing granular carbon.  In such systems the waste is passed either upward
or downward through columns containing the carbon.  Downflow columns function
as packed beds and accomplish filtration of the wastewater.  Flow rates of
2 gpm/ft2 to 8 gpm/ft2 have been employed.  In this flow range essentially
equivalent adsorption efficiency is obtained provided the same contact time
is employed.  At flow rates below 2 gpm/ft2 adsorption efficiency is reduced,
while at flow rates above 8 gpm/ft2 excessive pressure drop takes place.
Contact times employed are in the range of 30 minutes to 60 minutes on an
empty bed basis.  In general increases in contact time up to about 30 minutes
yield proportionate Increases in organic removal.  Beyond 30 minutes the rate
of increase falls off with increases in contact time and at about 60 minutes
contact becomes negligible.  Carbon beds to be operated at the lower end of
the flow rate range are generally designed for gravity flow.  Those systems
designed for the higher flow rates employ pressure vessels.  A pressure
vessel is more expensive to contruet than a gravity flow vessel but it requires
less land area, and provides greater ability to handle fluctuations In flow
rate.

Provision must be made to periodically backwash downflow carbon beds because
even if they are preceded by a filter they gradually collect suspended solids.
In addition, biological growth takes place on the carbon granules and tend* to
clog the bed.  It is advisable to Include a surface wash and air scour to be
assured of removal of the gelatinous biological growth.

Backwash of the carbon beds satisfactorily relieves clogging but does not
completely remove the biological growth.  Consequently, significant biolog-
ical activity is manifest in the carbon beds at most times.  This leads to
the development of anaerobic conditions in the carbon bed and generation of
sulfides.  Aeration of the column feed has been utilized to prevent anaerobic
conditions, but this produced so much biological growth that excessive back-
wash was required.

In an attempt to overcome these difficulties upflow carbon columns have been
operated in a slightly expanded mode  (about 10% expansion).  This allows for
significant accumulation of biological activity on the carbon granule with
little increase in head loss.  Consequently, aerobic conditions can be main-
tained and sulfide generation prevented.

If the expanded bed system is utilized backwash facilities must still be
provided as it has been found necessary to occasionally remove excess growth.
With this system the flow rate range which can be used is more restricted
than with packed be.d^ystems.  With the commercial sites of carbon available
(8x30 mesh or 16x40 mesh) flow rates above 4 to 5 gpm/ft2 are required to
achieve the proper degree of expansion.   In addition, care must be exercised
to avoid hydraulic surges which could wash carbon out of the system.  The
filtration section of the physical-chemical treatment plant must  follow
carbon contact when the expanded bed system is used.

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                                   - 5 -

The latest carbon contacting scheme to be applied to waste treatnent
utilizes powdered carbon (particle size below 200 mesh).  This procedure
provides for a mixture of a carbon slurry and the wastewater in a Reactor-
Clarifier.  Polymer addition is generally required to achieve a good gravity
separation of the carbon from the wastewater following contact.  The
potential advantages of this system are the use of a cheaper carbon (IOC par
pound vs. 30$ per pound for granular carbon) and a simpler type of contacting
system.

A critical aspect of the design of any carbon contacting system is the
expected capacity of the carbon for the organics.  In the chemical processing
industries this is evaluated by running adsorption isotherm tests.  In the
waste treatment field isotherms are of limited utility because the biological
activity which develops on the carbon tends to greatly enhance its apparent
capacity for organic removal.

The role of the design engineer is to utilize a system which makes greatest
utility of the capacity of the carbon regardless of what the capacity is.
In order to provide a good effluent and utilize most of the available capacity,
countercurrent contact is required.  This is achieved by having the waste flow
through a number of contactors or stages in series in one direction, while the
carbon moves in the opposite direction.  In the powdered carbon contacting
system this is exactly the procedure used.  With granular carbon this procedure
cannot be used as undesirable attrition losses will take place.  Rather when
an undesirable effluent is obtained the lead contactor is removed from service
and a spare contactor with fresh carbon placed at the end of the line.  Each
contactor is then moved up one position in the line.  This is accomplished
by piping and valving a series of columns to shift the inflow and outflow
points of the series accordingly rather than physically moving the columns.
As the number of stages increases, the piping and valving arrangement becomes
more complex and costly.  In design* a compromise between the advantage of
adding another stage to more closely approach the highest use of the carbon
capacity, and the cost of each additional stage must be achieved.

Ah alternate arrangement wb'ch is used in some plants provides parallel flow
through a number of identical contactors.  Each is at a different stag* of
exhaustion and produces a slightly different effluent quality.  These
individual effluents are blended to produce the final product.

Table 4 reviews the various factors which must be considered in designing
any carbon removal system.

In Table 5 carbon capacities obtained in field operation at various pilot
plants are given.  In view of the fact that the waste, effluent criteria,
number of contact stages etc., varied from plant to plant It is not sur-
prising that some spread In the results is observed.  These capacities are
expressed as pounds of organics removed (either as COD or TOC) per pound of
carbon.  For general planning purposes a capacity of 0.5 pounds of COD par
pound of carbon is reasonable.  This is approximately equivalent to a
requirement of 500 pounds of activated carbon per million gallons of sewage
treated.

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                                    -  6  -

A carbon requirement at  this  level  would be  prohibitively expensive if
regeneration and reuse of  the exhausted carbon were not possible.  At
present a technically and  economically  feasible method is available for
the regeneration of granular  activated  carbon.  This method requires
heating of the carbon in a multi-hearth furnace in the presence of steam
to SB 1750°F.  This treatment  burns  away the  adsorbed and trapped organics.
During a regeneration cycle some  of the carbon is physically lost by burning
and attrition, and some  of each particle*s capacity is lost by alteration of
surface properties.  The overall  loss expressed as percent by weight of
virgin carbon required to  restore the total  original capacity of the batch
ranges from 5 to 10 percent (10).  Thus, for planning purposes carbon make*
up requirements at a plant should range from 25 to 50 Ibs per million
gallons of sewage treated.

At present experiments on  a fluidized bed  regeneration system for powdered
carbon are moving into the large-seftle  pilot stage.  Successful completion
of these tests will be a big  step forward  in making a powdered carbon system
a technical and economic reality.  The  key factor will be maintaining the
carbon loss at a low enough level during the regeneration.


DESCRIPTION & PERFORMANCE  OF SOME PHYSICAL.CHEMICAL PILOT PLANTS

In the previous sections of this  paper  summaries of performance from a variety
of physical-chemical treatment plants were presented.  In this section a
somewhat more detailed  look will  be taken  at a selection of these plants.

Ewlng-Lawrence  (4)

For the  last several years FMC Corporation has been conducting studies of
physical-chemical  treatment at the  Ewing-Lawrence Treatment Plant near
Princeton,  N.J.   Figure 2  illustrates the  clarification section of the plant.
These units were  somewhat  overdesigned  to  insure a good  feed to the adsorption
section  of the  plant,  as the major  purpose of the  research was to evaluate
carbon  performance.   Figure 3 is a  schematic of  the overall plant.  Packed
bed versus  expanded bed carbon contact  in  parallel was studied at this plant.
Figure 4 indicates  that the performance of the  packed  bed contactor was
slightly superior to that  of the expanded  bed contactors.   However, the
investigators  indicated that the advantage was not  sufficient to offset  the
need  to  backwash  more  frequently and the potential  difficulties  from  anaerobic
conditions  in  the carbon beds.   Figure 5 illustrates  the  BOD  removal  obtained
over  a 3-1/2 month period.  It can  be seen that  despite  considerable  variation
in  influent strength a consistently good effluent  was  produced.  This  figure
also  reiterates  that the bulk of the treatment  is  accomplished  in the chemical
clarification  step.

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                                   - 7 -

Blue Plains (7)

At the Blue Plains treatment plant in Washington, D.C., a  pilot  physical-
chemical treatment system is being operated as part of a joint effort of
EPA and the District of Columbia.  Figure 6 is a schematic of the treatment
system.  Two-stage high lime clarification is provided with a small dose of
ferric chloride in the second stage for flocculation of calcium  carbonate.
This stage of the plant has a capacity of 100,000 gal/day.  The  filtration,
ion exchange and downflow two-stage carbon beds have a capacity  of 50,000
gal/day.  This plant is highly automated and thus runs with a miniumum of
manual control.  For example, the lime dose is automatically set by monitoring
the pH and alkalinity in the clarifiers, and backwash of the filters, ion
exchange columns, and carbon columns is automatically initiated  by pressure
drop and/or a time cycle.

Figure 7 illustrates the treatment performance obtained at this  plant for a
variety of pollution control parameters. Nitrogen removal  was obtained by the
use of an ion exchange process with a zeolite which has a  high affinity for
ammonium ion.  Again, these data indicate that the bulk of the work is done
by the clarification step with the filter and carbon columns serving as
polishing devices.  Table 6 gives the average effluent characteristics for
this installation.  This effluent is far better in quality than  normal
secondary effluent.


Salt Lake City. Utah (8)

Under contract between EPA and Eimco Corporation an evaluation is being
conducted of a physical-chemical treatment system employing powdered carbon
contact after chemical clarification.  Figure 8 illustrates the  pilot plant.
Two counter-current stages of carbon contact in Reactor-Clarifier are provided
following chemical clarification.  Some results with lime  as the coagulant
are given in Table 7.  These results are not quite as good as in the plants
using granular carbon discussed previously.  The effluent, however, must
still be classified as of good quality.  One potential advantage of this
contacting system is the ability to pace the carbon dose to the  organic
demand.  Evaluation of powdered carbon regeneration will take place at this
installation.  The spent carbon will be dewatered on a vacuum filter prior
to being fed to the fluid bed furnace.


Rocky River, Ohio (3)

Several studies have been made utilizing polymer addition  to existing primary
plants followed by small-scale pilot carbon adsorption.  One such study was
done at the 10 MED primary facility at Rocky River, Ohio.  An anionic polysttr
was added to the existing primary clarifier at a dosage of 0.3 «g/l, and a

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                                   - 8 -

side stream of clarified effluent was applied to small carbon columns for a
period of about one month.  The summary of the data is shown in Table 8.  It
can be seen that, even with less than optimum clarification, effluent
comparable to good secondary effluent was produced with 33 minutes carbon
contact time.  On the basis of this preliminary work the City of Rocky River
applied for and was awarded a Research and Development Grant from EPA to
help support a full-scale investigation of the clarification-adsorption
process for secondary treatment.

One of the principal motivations for the city to use physical-chemical treat*
ment is shown in Figure 9.  The installation of conventional activated sludge
facilities would necessitate the condemnation of a considerable area of
expensive property, whereas a carbon adsorption system could easily fit Into
the existing site.  Testing has been undertaken to determine what coagulant
or combination of chemicals will be used in the clarification system.  If
phosphorus removal is required an inorganic coagulant will necessarily be
the choice.
ADVANTAGES OF  PHYSICAL-CHEMICAL TREATMENT VS. CONVENTIONAL TREATMENT

Several times  in  this discussion  advantages of physical-chemical treatment
have been referred  to.   Perhaps the most important is the stability of
operation provided  by a treatment system based on physical and chemical
technology.  Biological systems are notoriously sensitive to changes in
environmental  conditions.   If a toxic material gains even temporary entrance
to the plant or a hydraulic peak  occurs not only will the efficacy of the
biological plant  drop off  but recovery may take several days to several
weeks.  In a physical-chemical plant the filtration system backs up the
clarifier and  the carbon system backs up the  first two thus upsets should
be unlikely.   In  addition, it can be expected that an immediate recovery of
the plant will take place  once the source of  upset is eliminated.  This
Inherent stability  of performance is also reflected in greater design and
operational flexibility.  Whole sections of a physical-chemical plant can
be cut in or out  of the process stream as required, and a temporary overload
can be absorbed with little effect.  A list of many of the major advantages
of a physical-chemical  system is. given in Table 9.  Most have been discussed
at some point  in  this paper.

COST ESTIMATES
Smith  (11)  has  taken the available information from pilot  plants  and preliminary
designs  of  several  proposed large-scale plants and has  made cost  estimates for various

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                                   - 9 -

size plants referenced to October 1970.  Amortization was 6 percent for
24 years.  These are presented in Table 10.  Note that ranges are given
for each plant size.  These ranges represent the spread of data available.
As a comparison Smith1s estimate for primary and secondary treatment with
sludge incineration is 16.5 cents per 1000 gallons at the 10 MGD level.
With the addition of single stage lime for phosphorus removal the cost
would rise to 23.5 cents per 1000 gallons which is essentially the same
as physical-chemical treatment.
FUTURE DEVELOPMENTS

As a result of the advantages of physical-chemical treatment discussed
above and the favorable economic comparison, a number of full-scale
treatment plants are being planned or designed.  These are listed in
Table 11.  Only the first two, Rocky River and Painesville, Ohio, will
receive Federal research funds.  All the others are being planned with
no expectation of Federal funds other than the normal construction grant.

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                               REFERENCES
 1.   Gulp.  G., "Chemical Treatment of Raw Sewage - 1"
     Water & Wastes Engineering. .4, 61 (July 1967).

 2.   Gulp, G., "Chemical Treatment of Raw Sewage - 2"
     Water & Wastes Engineering. 4., 54 (Oct. 1967).

 3.   Rizzo, J. L., Schade, R. P.,
     "Secondary Treatment with Granular Activated Carbon/'
     Water & Sewage Works. 116, 307 (Aug. 1967).

 4.   Weber, W. J., Hopkins, C. B., and Bloom, R.
     "Physio-Chemical Treatment of Wastewater,"
     JWPCF, 42, 83 (Jan. 1970).

 5.   Hannah, S. A., "Chemical Precipitation of Phosphorus,"
     Paper presented at the Advanced Waste Treatment & Reuse
     Symposium, Dallas, Texas, January 12-14, 1971,
     EPA sponsored.

 6.   Vllliers, R. V., Berg, E. L., Brunner, C. A., and Masse, A.  N.
     paper presented at ACS meeting, Toronto, Canada,  May 1970.

 7.   Bishop, D. P., O'Farrell, T. P., and Steinberg, J. B.,
     "Physical-Chemical Treatment of Municipal Wastewater*"
     paper presented at the 43rd Annual Conference WPCP,
     Boston, Mass., October 1970.

 8.   Monthly Progress Reports  - Contract No. 14-12-585
     between Eimco Corporation, Salt, Lake City, Utah & EPA.

 9.   Smith, C. E., "Recovery of Coagulant, Nitrogen Removal  and
     Carbon Regeneration in Wastewater Reclamation,"  Pinal  Report,
     FWPCA Grant, WPD-85 (June 1967).

10.   Appraisal of Granular Carbon Contacting," TWRC Report 11,
     USDI-FWPCA, May 1969.

11.   Smith, Robert, Internal Report, R. A. Taft Water Research
     Center - EPA, February 1971.

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DESIRED
        TABLE 1
     EFFLUENT
  BOD
  COD
  SS
  P
            QUALITY
10 MG/L
60 MG/L
10 MG/L
 1 MG/L

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                            COAGULANT
 RAW
SEWAGE
PRELIMINARY
 TREATMENT
                                         CLARIFICATION
                                  SLUDGE TO RECOVERY
                                  SYSTEM OR DISPOSAL
                      CHLORINE
 +
DISINFECTION
                         r
                           FILTRATION
                           (OPTIONAL)
  CARBON
ADSORPTION
                                                    i	1
                                                      FILTRATION
                                                      (OPTIONAL)
                                                        MAKE-UP CARBON
                                            CARBON
                                         REGENERATION
     FIG.1  FLOW DIAGRAM OF A PHYSICAL-CHEMICAL TREATMENT SYSTEM

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         TABLE 2 ACHIEVEMENTS OF CHEMICAL CLARIFICATION
      PLANT         CHEMICAL       ORGANIC        SS REMOVAL      P REMOVAL
                                 REMOVAL %         %             %
 EWING-LAWRENCE   170 mg/l FeCI3       80             95             90
NEW ROCHELLE  (ZM)  LIME pH 11.5        80             98             98
  WESTGATE.VA.    125 mg/l FeCI3       70
 SALT LAKE CITY   80-IOOmg/l FeCI3     75                            80
   BLUE PLAINS     LIME pH 11.5        80             90             95

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      TABLE 3 TOTAL TREATMENT  P~G PLANTS

      PLANT          ORGANIC           EFFLUENT
      	        REMOVAL %       CONCENTRATION
  BLUE PLAINS           95-98             TOC=6
   LEBANON              95               TOC=II
EWING-LAWRENCE         95-98             TOC=3-5
 NEW ROCHELLE           95               COD=8

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     TABLE 4 CONSIDERATIONS
  IN CARBON  TREATMENT  DESIGN

 1. TYPE OF CARBON-GRANULAR OR POWDERED
2. CONTACT TIME
3. FLOW RATE
4. CONFIGURATION-SERIES OR PARALLEL
5. NUMBER OF STAGES
6. FLOW DIRECTION - PACKED OR EXPANDED
7. HYDRAULIC FORCE - PUMPED OR GRAVITY
8. ORGANIC CAPACITY

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                       TABLE 5
  CARBON  CAPACITY IN P-C TREATMENT PLANTS
     PLANT                   CARBON CAPACITY
                           LBS TOC     LBS COD
                            LB A.C.      LB A.C.
  BLUE PLAINS                0.15         0.41

EWING-LAWRENCE             0.3

NEW ROCHELLE(ZM)             -          0.6

   LEBANON                  0.22         0.5

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                UPFLOW CLARIF
PRIMARY
EFFLUENT
WASTE SLUDGED  BACKWASH,
            WATER AHfl AIR
           FIG. 2
                                        BACKWASH
                                        DRAIN
       FLOCCULATORS
  FLOW DIAGRAM OF CLARIFICATION SYSTEM

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                FIG. 3
      EXPERIMENTAL SET-UP
      FOR  24 FT. CARBON BEDS
  PRIMARY EFFLUENT
                    CHEMICAL
                   CLARIFICATION
     FILTER
EXPANDED BED
   ADSORBERS
PACKED  BED
  ADSORBERS

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O

UJ
a:
o
00
oc.
   40
   30
o

o 20
o
QL
O
O
    10
	  PACKED  BED ADSORBERS

•• • •  EXPANDED  BED ADSORBERS
                                               6 FT

                                         BED  DEPTH -
      0       10      20      30      40      50      60

                 TOTAL  ORGANIC  CARBON APPLIED^ Ito


  FIGURE 4  -Cumulative sorptlon of total organic carbon for packed-

bed and expanded-bed adsorbers as a function of TOC applied.   (Lb X

0.454 = kg; ftX0.3 = m.)

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   60
   50
   40
to*
   30
  20
   10
       PRIMARY EFFLUENT
            CLARIFIED PRIMARY EFFLUENT
           o   PACKED BED  a

        o  D°o7    EXPANDED BED
     n  n     n-^ o 0*3— o o
      on    D  ^_ n n o
         p     to   Don    n

en                    DD     o

          MAY    '  JUNE    I  JULY  '   AUG

    FIG. 5 REMOVAL OF BOD  BY CHEMICAL

      CLARIFICATION  AND  ACTIVATED CARBON

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                       FIG. 6
      INDEPENDENT PHYSICAL CHEMICAL TREATMENT
                 LIME PRECIPATION
RAW WATER
 RECYCLE
[CLE 1
771J
       (FT)
CaO     RECYCLE FeCI3
"•-







C02



i

t

b




LT
LT

U
TJ

LT
LT

TJ
TJ





.-

^
s«,
U

^
                            f
                            i
                     C02
CARBON    ION  EXCHANGE
                                    t
                              FILTERS

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IOC)
              FIG. 7 REMOVAL EFFICIENCIES
              PHYSICAL CHEMICAL TREATMENT
                  BLUE PLAINS PILOT PLANT
 80
   TOC
BOD
COD
SS
TOTAL N
                                            LIME CLARIFICATION

                                            FILTRATION

                                            ION EXCHANGE &
                                          CARBON ADSORPTION

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                     TABLE 6
EFFLUENT QUALITY-P-C PILOT PLANT AT BLUE PLAINS
                TOC    6mg/l
                BOD    5mg/l
                COD    13mg/l
                 SS     5mg/l
              TOTAL P    0.15mg/l
              TOTAL N    4.6mg/l

-------
                                               FIGURE  8
HY!
Bcw Sowisgo
                 •cv»B«s
H<
ll<
                               I. itaw C«(OM).
                               n. AIM AI.OOJ.
                               •. r«n«c CMerM* tfCI, f
                                                                                                    ENVIROTECH
                                        9ACUskcw»
                                                 CAR8OM RZCCKEK/tTKKI

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                                TABLE 7
                 POWDERED CARBON  PILOT PLANT
                       OPERATING CONDITIONS
                          FLOW RATE 50 GAL/MIN
                    CHEMICAL 425  mg/l LIME TO pH 10.8
                     CARBON 150 mg/l + 0.4 mg/l polymer
                                RESULTS
                  COD
   RAW SEWAGE    222
CLARIFIED EFFLUENT  65
   FINAL EFFLUENT   35
BOD
144
47
13
SS
200
28
7
P
7.3
1.4
0.4
                         ALL RESULTS GIVEN IN mg/l

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                TABLE 8
            ROCKY  RIVER
      WASTE  TREATMENT PLANT
  CLARIFICATION-CARBON  PROCESS
SUSPENDED
SOLIDS , mg/l
|OD, mg/l
          RAW
107
118
      POLYMER
     CLARIFICATION
 65
 57
        CARBON
        CONTACT
         TIME,
        MINUTES
       14  23.4 32.6
          PERCENT
          REMOVED
13
15
93.3
21
11  8
93.3
COD,'mg/l
235
177
67   50 44
       81.3

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                 TABLE 9
           ADVANTAGES OF
    PHYSICAL-CHEMICAL TREATMENT
                 VS.
CONVENTIONAL PRIMARY + SECONDARY
   1. LESS AREA REQUIREMENT^ TO Y4
   2. LOWER SENSITIVITY TO DIURNAL VARIATION
   3. NOT AFFECTED BY TOXIC SUBSTANCES
   4. POTENTIAL FOR SIGNIFICANT HEAVY METAL REMOVAL
   5. SUPERIOR REMOVAL OF P COMPOUNDS
   6. GREATER FLEXIBILITY IN DESIGN AND OPERATION
   7.  SUPERIOR ORGANIC REMOVAL

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           IT"
    THICKENERS
i
L
    .-to -nuiT -X. ;*- ~~^-J ^^»*)> i.fnA

    LDIGGSTORSi
    V' J 11 •^••••••"J i iH'-'KMaiiaim v« ' *V' ««»
   FILTERS BLDG.
                     L A R I F I E R
                     FIGURE 9

  X'PROPIRTY      AREA COMPARISON
   XXUNE      FOR CLARIFICATION-CARBON
                         vs.
        X    ACTIVATED SLUDGE PLANTS
RAPING   \     AT ROCKY  RIVER
 STATION
"^PROPOSED PROPERTYi
^ACQUISITION FOR!
^B ACTIVATED
J
E;
o
c
c
i
ARBON
OLUMN
BLDG.
00
PO
00
oo
1M&
4^
^SLUDGE PLANtt
>===,
t=
t=
F=
fc=
f=
k *=
£*#.•<>*.» IJ F=
L . . . . . ->/ fe
FUTURE ^ e
ICPANSION ^
F CARBON -
PLANT =
2.6 ACRES^
i
i
i
— : 	 =1
	 ^ 	 4
1

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                       TABLE 10




  PRELIMINARY COST ESTIMATE PHYSICAL-CHEMICAL TREATMENT



      Total Amortization + O&M,  cents per 1000 gallons
Plant Size, MGD
*
Chemical Clarification
Carbon Adsorption
Filtration
TOTAL
5

9.5-13.5
11.5-18.0
2.9-4.5
23.9-36.0
10

7.3-9.6
9.1-13.5
2.1-3.3
18.5-26.4
100

4.0-5.3
4.5-7.8
1.0-1.4
9.5-14.5
*
  Two-stage lime recalcination of sludge.

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                          TABLE 1 ]
            PHYSICAL-CHEMICAL PLANTS
      SITE
Cortland, N.Y.
Cleveland, Ohio
Fitchburg, Mass.
Garland, Texas
Le Roy, N.Y.
Niagara, N.Y.
Owosso, Mich.
Rocky River, Ohio
Vallejo, Calif.
Rosemount, Minn.
Freehold, N.J.
 STATUS
Design
Design
Construction
Design
Design
Design
Design
Construction
Design
Construction
Operation
CAPACITY: mgd    EFF. REQ.
     10
     50
     15
    30(90)
      1
     48
      6
     10
     13
     0.6
    0.05
TOD<35
BOD<15
BOD<10
BOD<10
BOD<10
COD<112
BOD<7
BOD<15
BOD<45
BOD<10
BOD<10

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                             TABLE lla
        TERTIARY PHYSICAL-CHEMICAL PLANTS
    SITE
 Arlington, Va.
 Colorado Spgs, Colo.
 Dallas, Texas
 Fairfax Co., Va.
 Los Angeles, Calif.
Montgomery Co.,  Md.
 Occoquan, Va.
Orange  Co.,  Calif.
 Piscataway,  Md.
St. Charles, Mo.
So. Lake, Tahoe, Calif.
 Windhoek, So. Africa
 STATUS
 Design
Operating
 Design
 Design
 Design
 Design
 Design
Construction
Operating
Construction
Operating
 Operating
CAPACITY:mgd
     30
      3
     100
     36
     5(50)
     60
      18
      15
      5
     5.5
     7.5
     1.3
     EFF. REQ.
     BOD  3
     BOD  2
     BOD  10
     BOD  3
     COD  12
BOD 1 COD 10
BOD 1 COD 10
     COD  30
      BOD  5
 none required
     BOD  10
     COD  10

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ADDITIONAL INFORMATION
Not referred to In text
   March 1972
                PMSICAl-CHEMICAl
                    TREATMENT:
                  A H£W COHttPT IH
               WASTtWATt* TREATMENT

-------
           PURPOSES Of
      CHMICAl CLARIFICATION
LSUSPIHW & COLLOIDAL SOLIDS REMOVAL
2.PMOSPHORVS REMOVAL
3.PARTICULATE ORGAHICS REMOVAL

-------
CHEMICALS USED
      fOR
 CtARIflCATIOH

   1.IROH SALTS
   2MUMIHVM SALTS
   3.LI Ml

-------
         ALUM
         CLARIFICATION
         OF
         RAW SEWAGE

  DOSE    13 MG/L AS Al 0.25 POLYMER
OVERFLOW        0.6GPM/FT2
  RATE

          INF.(MG/L)  EFF.(MG/L)  %REM

   SS        110         30       73
 TOTAL P     5.8         1.2       79
  COD       158         45       72

      SLUDGE: 3.5% OF PLANT FLOW 1300 LB/MG

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 Fed? CLARIFICATION
             OF RAW SEWAGE
 DOSE   41 mg/1 as Fe + 1.0 mg/l POLYMER
OVERFLOW   o.75 gpm/ft2
 KAIt
  SS
TOTAL P
  COD
        INF.lmt/H
EFF.|mi/l
   13
    0.9
   38
%REM
 82
 85
 69
           SLUDGE: 0.9% OF PLANT FLOW 1300 Ib/nf

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              IIME CLARIFICATION
              Of RAW SEWAGE
              •§••••
DOSE 460 MG/L Ca(OH)2
pH 10.9
OVERFLOW RATE 0.5 -1.0 GPM/FT2

          »NF.(MG/L) EFF.(MG/L)  %REM
   SS        84         16      81
 TOTAL P     5.9         1.5      75
  COD       130         73      44
      SLUDGE: 0.5% PLANT
      FLOW 6500 LB/MG

-------
            RAW SWAGt ClARIFICATIOH
                 AT SALT LAKl CM
CHEMICAL
SLUDCE PRODUCTION
SLOWDOWN SOLIDS
THICKENED SOLIDS
fILTER WELD
150 ng/L ALUM

1200 Ib/MG

3 gm/L
   gm/L
0.8 tbjhrjft*
  AT 5 Ibid ay I ft2
 fSOLIDS LOADIN$)
 TO 80% MOISTURE
  WITH 20% (wt)
LIME CONDITIONING

-------
             RAW SEWA6£ CLARIFICATION
                  AT SALT LAKt CITV
CHEMICAL
SLVDCE PRODUCTION
SLOWDOWN SOLIDS
THICKENED SOLIDS
FILTER yiELD
no tng/L feCI3
  gn/L
30 gn/L

7.2
 AT 15
fSOLIDS LOADIHG)
TO 80% MOISTURE
  WITH 20% (wt)
LIME CONDITIONS

-------
            RAW SEWAGC CLARIFICATIOH
                  AT SALT LAKE CITY
CNEMICAL                460 mg/L MDRATED LIME (pN 10.9)
SLUDGE PRODUCTION       7000 Ib/MC

SLOWDOWN SOLIDS        120 gmJL

THICKtNtD SOLIDS        200 gnJL             « lb/4*yjft2
                                         fSOLIDS LOADING)
fILTft y/UD             10  Ibjhrjft2         TO 60% MOISTURE
                                         NO CONDITIONING

-------
IMPORTANT SLUDGE CHARACTERISTICS
  UYPtCAL VOLUME PRODUCED     _
     LIME              0.5-1.5%   °F
     ALUM & IRON       0.8-8.0%
k TOTAL
  FLOW
  2.TrP/CAL SOLIDS CONTENT
     LIME               3-10%
     ALUM & IRON       0.5-5%

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           P-C SLUDGE DEWATERING DATA
                   SALT LAKi C/W
SLUDGE TYPE         VACUUM fltTER ARM        CAKE MOISTURE
                                             %
IRON                      62                  SO

ALUMINUM                 S4                  SO

LIME f LOW pH)              29                  60

-------
         METHODS OF SLUDGE DISPOSAL
  1.THICKEN I NO
   FILTRATION
LAND SPREADING
   OR BURIAL
                2.THICKENING
                  FILTRATION
                INCINERATION
                             3.fFOR LIME SLUDGES)
                                  THICKENING
                                CLASSIFICATION
                                RECAtCINATION
                                  LIME REUSE

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          SLUDGE DISPOSAL P-C PLANTS
PLANT                    PROCEDURE
OWOSSO          GRAVITY THICKEN, FILTER PRESS, INCINERATE
NIAGARA  FALLS    GRAVITY THICKEN, VACUUM FILTER, LANDFILL
GARLAND         GRAVITY THICKEN, FILTER PRESS, INCINERATE
CLEVELAND       CENTRIFUGE, RECALCINE

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PURPOSES OF ACTIVATED CARBON TREATMENT
      1 .ADSORPTION    | 2.8IOIOGICAI OXIDATION
           OF        \          Of
   DISSOLVED ORCANICS  !  ADSORBED ORGANIC*

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           PLANT DESCRIPTION
              COLORADO SPRINGS
FEED
FLOW

PROCESSES
TRICKLING FILTER EFFLUENT
2 MGD (DESIGN)
3 MGD (MAXIMUM)
LIME CLARIFICATION
DUAL-MEDIA FILTRATION
GRANULAR ACTIVATED
CARBON ADSORPTION

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            DESIGN  PARAMETERS
               COLORADO SPRINGS
                   (AT 2 MGD)
CLARIFICATION
FILTRATION
ADSORPTION
RISE RATE
RETENTION TIME
DEPTH
FLOW RATE
CONFIGURATION

LOADING
CONTACT TIME
0.77 GPM/SQ. FT.
115 MINUTES
8 FT.
12.3 GPM/SQ. FT.
2-STAGE DOWNFLOW
PRESSURE
4.4 GPM/SQ. FT.
34 MINUTES (TOTAL)

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PLANT PERFORMANCE (A)
     COLORADO SPRINGS
      MARCH-JULY 1971

BOD
COD
IOC
TSS
LIME
INFLUENT
129
BIS
83
62
DOSE 370 mg/l
CLAR
58
148
46
IS
(pH II. 1)
FILT
57
139
43
IS

CARBON
24
39
13
3

TOTAL %R
81
88
84
95


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          PLANT PERFORMANCE (B)
               COLORADO SPRINGS
                MARCH-JULY 1971

TOTAL P
TOTAL N
COLOR
INFLUENT
10.8
42.5
173
CLAR.
0.7
29.5
46
FILT.
0.7
— •
39
CARBON
0.9
28.0
18
TOTAL %R
92
34
90
LIME DOSE 370 mg/l (pH II.I)

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FEATURES OF P-C-T
   ^^^^M^hte^fcM^Mta^«M^ftM^ftM^feM^BM^ta^kte^^ta^^tt^BM^BM^Bfe^MJ
   W*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^**
   /.MINIMUM LAND AREA
   2.LOW SENSITIVITY TO FLOW VARIATION
   3.UN AFFECTED By TOXIC MATERIALS
   4.HIGH FlEXMUTy, E.G. RAPID STARTUP
   5.HIOH ORGANIC REMOVAL
   6.HIGH PHOSPHORUS REMOVAL
   7. CAPABILITY FOR HEAVY METAL REMOVAL

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                 TREATMENT COSTS  FOR
             PHYSICAL TREATMENT (10 MGD)


                                    TOTAL COST*       PERCENT
STEP                                 CENTS PER        OF TOTAL
                                     1000 6ALS.       PLANT COST
PRELIMINARY TREATMENT
UME COAGULATION t RECALCINATION
FILTRATION
ACTIVATED CARBON ADSORPTION
DISINFECTION
0.8
10.1
3.6
12.9
0.9
2
36
13
46
3
TOTAL PLANT COST                        28.3              100
  *NOTE: TOTAL COST INCLUDES CAPITAL COSTS, OPERATING
        AND MAINTENANCE COSTS, t AMORTIZATION

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PHYSICAL-CHEMICAL
  TREATMENT COST
 CENTS PER IOOO GALLONS
 PLANT SIZE M.G.D.
  AMORTIZATION
    OPERATION
  MAINTENANCE .
       10
100
24-36  18-26  10-15

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              PILOT  STUDY.   GARLAND.   TEXAS


       130 mg/1 LINE,  4 mg/1 Fe,  30  Mln.  CARBON CONTACT

                    IN.           OUT           %  R

       COD         550            20           97


       BOD         300            10           97


       S.S.        250             1           99.5
            GARLAND. TEXAS  DESIGN


   Flow, 30 MGD     Chemical      150 mg/1 Ume,  10 ng/1 FeCl3


CLARIFIER                750 gal/d/ft2

FILTER                   8 gal/m/ft2,  Multi-Media,
                         Air & Water Backwash

CARBON                   Gravity, Upflow, 30 mln Contact
                         Single  Stage

CARBON CAPACITY          0.5 Ib  COD/lb A.C.,
                         1800 Ib A.C./M.G.

-------
          NIAGARA  FALLS   -   PILOT  DATA
               L1me to pH    11.5
             30 M1n.  Carbon   Contact
            IN.        OUT        %  R
 BOD        65         15          77
 COD       150         30          80
 SS         300         35          88.5
 PO-         8         2.0        75
            NIAGARA  FALLS  DESIGN
      FLOW  -  45 MGD        UME to pH 11.5

CLARIFIER           700 gal/d/ft2
                    HORIZONTAL FLOW, SINGLE STAGE
FILTERS             NONE
CARBON              GRAVITY DOWNFLOW, SINGLE STAGE,
                    40 M1n CONTACT. AIR & WATER BACKWASH
CARBON CAPACITY     750 Ibs/MG

-------
               OWOSSO  PILOT  DATA


         L1me to pH 8.8-9.4 (150-175 mg/1)

          Carbon Contact 28' (35 Minutes)

COO
BOD
S.S.
PO,
M
360
145
170
10
OUT
25
7
20
1.3
% R
93
95
88
87
               OWOSSO   DESIGN


        FLOW = 6 MGD    CHEMICAL-LIME 125 mg/1


CLARIFIER           600 gal/d/ft2

FILTER              10-20 gal/m1n/ft2,
                    EXTERIOR WASH

CARBON              EXPANDED BED, 2-STAGE,
                    PARALLEL, 35 M1n CONTACT

CARBON CAPACITY     0.65 Ib COD/lb A.C..
                    600 Ib A.C./M.G.

-------
                   P-C  SLUDGE  DEWATERING  DATA
                           SALT  LAKE  CITY
          SLUDGE TYPE

          IRON
          ALUMINUM
          LIME (Low pH)
VACUUM FILTER AREA
      Ft2/M60
        62
        84
        29
CAKE MOISTURE
	*	.
      60
                   WESTERLY VACUUM FILTER PERFORMANCE
                     LIME SLUDGE
                     LOADING
                     CAKE SOLIDS
                     SOLIDS CAPTURE
        pH  10.5
        3-19 . lb/hr/ft2
        19% - 36%
        90% - 98%
                        SLUDGE CHARACTERISTICS
PRIMARY & WASTE
ACTIVATED SLUDGE
LIME, low pH
LIME, High pH
ALUMINUM
IRON
CHEMICAL TREATMENT
SLUDGE SOLIDS
1.0
11.1
4.4
1.2
2.25
RAW SEWAGE
WT. SOLIDS
Ib/MG of
TREATED SEWAGE
2,200
5,630
9,567
1,323
2,775
                                                            VOLUME SLUDGE
                                                              gal/MG of
                                                            TREATED SEWAGE
                                 22.000
                                  8,924
                                 28,254
                                 23,000
                                 21,922
   AVERAGE OF DATA FROM BLUE PLAINS, LEBANON, TAFT CENTER, SALT LAKE CITY

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        CALCULATION OF SLUDGE QUANTITIES
                ALUM OR IRON SALTS
       A « MOLE METAL ADDED PER LITER
       B » MOLE P PER LITER IN WASTEWATER
       C «=• SUSPENDED SOLIDS, mg/1
       D « MOLE WEIGHT METAL PHOSPHATE
       E = MOLE WEIGHT METAL HYDROXIDE
X « WEIGHT METAL PHOSPHATE = B X 8.34 X D
Y « WEIGHT METAL HYDROXIDE = (A-B) X 8.34 X E
Z « WEIGHT SEWAGE SOLIDS = * REMOVAL X^C X 8.34
       TOTAL SLUDGE WEIGHT = X+ Y + Z
        CALCULATION OF SLUDGE QUANTITIES
                      LIME

     A « MOLES PER LITER OF PHOSPHORUS
     B = CALCIUM HARDNESS, mg/1 as CaC03
     C - ALKALINITY, mg/1 as CaC03
     D ** SUSPENDED SOLIDS, mg/1
         Low pH Lime Process (pH 9.5-10)
     X •* HYDROXYL APATITE - 509 X A X 8.34
                             96
     Y <> CALCIUM CARBONATE = (2C-50) 8.34 if B> C
                           « (B + C-50) 8.34  If C>B
     Z « WEIGHT SEWAGE SOLIDS = % Removal X D X 8.34
                                        100
         TOTAL SLUDGE WEIGHT  «= X + Y + Z

-------