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ClearCove Systems Enhanced Primary Treatment Demonstration at the Ithaca Area Wastewater Treatment
Facility
Agreement No. 38782
Reporting Period: 5/21/2104 – 10/3/2014
All report materials can be found at www.clearcovesystems.com/pon2722, password: pac1
Report Summary:
-
Energy Reduction: Section II reports the removal rates of various parameters achieved by the
Enhanced Primary Treatment (EPT) pilot which will be used to calculate the energy and cost savings at
full scale.
o For more information regarding how the EPT pilot was optimized for both operational mode
and chemical dosing refer to Appendix A.
o Expanded removal data from the ClearCove EPT pilot can be found in Appendix B.
 Mass Balance: Preliminary Results
-
Energy Production: Section III details the energy production piloting operation and results of:
o Phase 1 and Phase 2 of the mini-digester pilot
 Expanded data for the mini-digester pilot can be found in Attachments 2A and 2B.
o Biochemical Methane Potential Testing
 Individual Biochemical Methane Potential (BMP) reports can be found in Appendix C.
-
Sludge Processing: Section IV explains how the sludge processing impacts of both the EPT and
Recommended Viewing:
A tutorial animation of how the technology works including key features impacting energy reduction and
production can be found at: http://clearcovesystems.com/the-idea/settling-system-design/
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Introduction
Using data collected from the ClearCove Enhanced Primary Treatment (EPT) pilot unit (EPT pilot), ClearCove Sludge
Classifying Press (SCP), and custom constructed mini-digesters (O’Brien and Gere) located at the Ithaca Area Wastewater
Treatment Facility (IAWWTF), the goal of the study is to predict potential impacts to plant-wide operations should the
solution be implemented at full-scale at the IAWWTF. It is anticipated that when operating at full-scale, the technology
solution will provide the IAWWTF with the following benefits:





Aeration energy savings as a result of enhanced BOD removal;
Increased biogas generation as a result of enhanced primary sludge capture;
Relative capacity increase of the digesters as a result of increased sludge biodegradability and improved
inorganics removal;
Improved sludge processing as a result of higher percent solids and improved ratio of primary to secondary
sludge; and
Plant chemical usage/costs compared to current chemical usage/costs.
I. Background
Figure 1: EPT Pilot Unit
The technology is a physical / chemical process that: equalizes the flow; stops the water; removes 100% of the grit; 100%
of the fibers; settles the high value organics through chemical dosing and gravity; filters the effluent through a 50 micron
screen; removes the sludge to a classifying press; routes the material to a sludge holding tank or to disposal. (Please see
video and animation file)
The pilot EPT unit consists fully automated 20,000 gallon per day (GPD) fully operational, multiple section reactor tank as
shown in Figure 1. The unit has been installed in close proximity to the head works of the IAWWTF. Raw sewage is pumped
to the pilot from the influent feed channel of the IAWWTF downstream of a 1.5” Climber Screen and the return of plant
process side streams from the thickeners, Anaerobic Digesters, belt press, and tank drains, and upstream of any chemical
addition. Twenty four (24) hour composite samples of the pilot influent, pilot effluent, pilot sludge, and IAWWTF primary
clarifier effluent are collected on Monday, Tuesday, Wednesday, and Thursday at 8 am and analyzed by CES
Environmental, a third party laboratory for:






Biochemical Oxygen Demand, 5-day (BOD5)
Soluble Biochemical Oxygen Demand, 5-day (SBOD5)
Chemical Oxygen Demand (COD)
Total Suspended Solids (TSS)
Volatile Suspended Solids (VSS)
Total Phosphorous (TP)
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
Total Kjeldahl Nitrogen (TKN)
The purpose of this accumulated data is to calculate the aeration energy savings, sludge impact, methane gas production,
and chemical usage calculations for the potential full-scale build-out of the IAWWTF.
Biogas production (as a proxy for energy production) is being evaluated using two distinct methods. The first method uses
pilot-scale mini digesters (four (4), 350 gallons each). The second is through biochemical methane potential testing using
Bioprocess Control’s Automatic Methane Potential Test System (AMPTS) II.
The CCS EPT Pilot sludge is processed through the Sludge Classifying Press (SCP). The SCP technology removes inorganics,
difficult to digest organics, and trash from the sludge, which would unnecessarily take up digester capacity. Additionally,
encased and large organics, which would otherwise be sent to the landfill, are forced through a small diameter opening
to promote digestibility of the materials. Sludge samples are tested for COD, TS, and VS before and after the SCP to help
quantify the sludge processing, solids disposal, and energy generation benefits of the technology.
II. Enhancing BOD Removal for Aeration Energy Reduction
Raw sewage is pumped to the pilot from the influent feed channel of the IAWWTF at 80 gallons per minute (GPM). A
chemical injection point is located just prior to where the wastewater enters the pilot’s influent feed system (shown in
Figure 2). Numerous dosing and operating variations were tested to identify the optimal dosing and operating
methodology for BOD removal (COD was used as a surrogate for BOD due to shorter analysis period using an on-site COD
reactor). Jar testing was also performed to help determine the optimal chemical selection and dosing (see Appendix A).
Through jar testing and beta runs, it was determined that maximum removal rates were achieved by dosing the influent
with a Ferric Chloride coagulant at 80 milligrams per liter (mg/l), in addition to 0.25 mg/l of an anionic polymer. The
methodology and results from this process are summarized in Appendix A with more detail available upon request.
There are approximately 15 to 16 seconds hydraulic retention time between the chemical injection point and the pilot
unit. No formal mixing occurs in the system, but the liquid does flow through three (3) elbows before reaching the pilot
unit. Attempts are currently underway to improve mixing conditions. It is hypothesized that for a full-scale system, the
placement of a formal mixing mechanism and longer hydraulic retention times should result in lower required dosing rates
or higher organic and solids removal rates.
Figure 2: Chemical Feed System
Chemical Injection Point
Influent Piping
The dosed wastewater enters the pilot unit through the influent feed system (IFS) located at either end of the tank. The
grit and heavier solids settle in the IFS. After filling the IFS, the de-gritted wastewater spills over the weirs at either end
of the pilot unit and into the main chamber of the unit as shown in Figure 3.
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Figure 3: Influent Feed System and Weir
Wastewater first enters the
system through the Influent
Feed Systems located at both
ends of the tank
Grit and dense solids settle out
in the Influent Feed System
Water flows down the face of
the weir and into the main
chamber of the tank
After the main chamber has filled, there is a 35 minute settling period during which the organics settle into the central
hopper of the pilot unit. While the tank is full, floatables are removed by scum troughs located at either end of the tank.
Following the settling period, the sludge that has accumulated both in the hopper and the IFS with an approximate volume
of 60-gallons or approximately 250-300 gallons per day (GPD) is removed from the pilot unit via actuated valves and piped
to a holding tank for subsequent processing in the SCP.
Figure 4: Decanter Screen Box
The screen box is lowered into
the low BOD, low solids
supernatant after the settling
period.
Wastewater flows through the
screen and into the box then
down a central effluent hose.
50 micron stainless steel screen
on all 4 sides of the screen box.
Air scour bubbles deflect any
floating material from coming in
contact with screen.
The sludge wasting process is being optimized based on the COD concentration of the hopper sludge compared to the
volume of sludge removed from the pilot unit. The goal is to provide a stable COD load / concentration and residual
coagulant / polymer content in the EPT. Once the sludge has been removed, a 50 micron screen box (stainless steel), as
shown in Figure 4, is lowered into the low BOD, low solids water. The water flows in to the box through the screen, then
down a central effluent hose connect to the base of the screen box. In a full-scale application, the effluent would then
continue on to the activated sludge process. Since the bulk of organics have been removed, as shown in Table 1, it would
require significantly less energy to treat than wastewater coming from a conventional primary clarifier. A number of the
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pilot unit’s parameters can be adjusted via its Supervisory Control and Data Acquisition (SCADA) interface including but
not limited to settle time, chemical dosing, pump rate, screened decanter position, screen loading rate, sludge and grit
withdrawal time and frequency, and mode of operation (Batch, Continuous, Storm). Composite samplers are directed by
the pilot’s SCADA system to collect influent and effluent samples. Because the pilot operates in a batch configuration, the
influent samples are only collected when the tank is filling; and the effluent samples are only collected when the tank is
discharging.
Results
Provided in Table 1, are calculated values showing the maximum removal rates achieved in the pilot after completing the
chemical dosage optimization work, other dosing rates and results are provided in Appendix A for later economic analysis
as related to gas generation and energy reduction. For the detailed results which generated the averages below please
refer to Appendix B.
Table 1: Pilot Unit Results
80 mg/L Ferric : 0.25 mg/L Polymer (15 Composite Samples; collected 7/29/14 – 9/12/14)
BOD Rem
SBOD Rem
Min
58%
14%
Max
79%
Avg
67%
TSS Rem
VSS Rem
COD Rem
Phos Removal TKN Removal
77%
75%
39%
66%
13%
48%
91%
91%
82%
83%
50%
28%
84%
84%
62%
76%
26%
Refer to Attachment 1 for Certified Lab reports
In Process Adjustments: WWTP’s are not predictable, at times
The IAWWTF has a new trucked waste receiving facility that accepts organic industrial waste, food waste, septage, and
other organic waste material. On occasion, smaller septic trucks are directed to dump directly into the influent feed
channel of the influent building. At times when the pilot unit is filling simultaneously to the septic hauler emptying into
the influent channel which caused the pilot unit will draw this higher concentration material into the unit’s feed tank.
Fortunately, the IAWWTF keeps a time log that indicates septic hauler deposits, which can be referenced if a sample result
returns an abnormally high BOD concentration. The removal rates, as supported by the data, during these anomalies did
not degrade and in fact seemed to improve as BOD concentrations ran higher.
The IAWWTF is a functioning WWTP with many liquid streams returning to the Influent Building upstream of the pilot’s
influent pump. These liquids may enter the pilot unit during a fill cycle thus causing some anomalies in sample data.
The influent pump to the pilot can pass a 2” solid and occasionally would plug with solids. On several occasions this
occurred when the pilot was not staffed resulting in the need to scrap those composite samples.
The sludge withdrawal actuated valve requires 10-seconds to open and 10-seconds to close with a 3-second wait period
programmed into the SCADA. This resulted in rat holing (pulled in water versus solids) causing low solids percentage and
60+ gallons of liquid exiting the EPT sludge hopper during each of the 18-daily cycles. This volume exceeded the 775Gallon capacity of the sludge holding tank. In order to provide a mass balance and to be in alignment with the project
300-gallons of sludge to be removed each day, sludge withdrawal was changed to every 4-cycles. This did not improve
the % solids of the sludge as the flow rate (GPM) was not lowered.
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III. Enhancing Primary Sludge Capture for Increased Biogas Generation
Mini Digesters
Four (4) mini digesters are installed in the digester room of the IAWWTF. Samples are collected on Monday, Wednesday
and Friday from the feed tanks and digester overflows and analyzed by a third party laboratory for total solids, volatile
solids, COD, ammonia and orthophosphate. Samples are collected twice daily from the digester drain and tested for pH
on-site in the IAWWTF laboratory by a ClearCove operator. Biogas samples are taken once daily from the digester gas
sample lines and tested on-site for methane content using a handle-held Fyrite CO2 analyzer. Biogas flow is also measured
through the use of a flow meter outside of the digester room. The accumulated data will be used in the energy production
calculations for the potential full-scale build-out of the IAWWTF. All biogas and mini-digester data was generated by
O’Brien & Gere Engineers.
Mini Digesters – Phase 1
In March 2014, four (4) 500 gallon mini digesters (Figure 6) were installed. Each mini digester has a dedicated 100 gallon
feed tank (Figure 6) to provide each digester a specified sludge. Hot water is used to heat the mini-digesters. Temperature
and pH are manually monitored and adjusted as needed. Each digester is fed at a different rate, as shown in the schedule
below. The first digester serves as a control, and mirrors the current feeding conditions at the IAWWTF.

Digester 1 (MD-1): IAWWTF Thickened Sludge (combination of IAWWTF Primary and Secondary Sludge collected
from full scale sludge thickening tank) loaded at the same rate as that of the IAWWTF’s full-scale primary digester;
0.05 pounds of VSS per cubic foot per day (lb /cf /day).

Digester 2 (MD-2): IAWWTF Primary Sludge (from IAWWTF Primary Clarifier) loaded at a rate similar to IAWWTF
primary digester.

Digester 3 (MD-3): ClearCove Enhanced Primary Sludge (collected from small thickening tank that follows pilot)
loaded at a rate similar to IAWWTF primary digester.

Digester 4 (MD-4): ClearCove Enhanced Primary Sludge – Double Feed Rate (collected from small thickening tank
that follows pilot) loaded at two times the rate of the IAWWTF primary digester. (The double feed rate is based
on laboratory testing that suggested that sludge from the ClearCove EPT pilot unit is more readily biodegradable
than sludge produced conventionally. During Phase 1, an attempt was made to achieve the double feed rate;
however, due to challenges encountered during the phase (see below) this did not occur.)
Figure 5: Mini Digester Process Diagram
Influent
ClearCove EPT
IAWWTF
Sludge
Thickening
Tank
IAWWTF
Primary
Clarifier
ClearCove
EPT Sludge
ClearCove
SCP
1
ClearCove EPT Sludge
300 Gallon
Thickening Tank
Mini-Digesters
2
3
4
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Figure 6: Phase 1 500 Gallon Mini Digesters
Figure 7: Phase 1 100 Gallon Feed Tanks
Phase 1 Process Adjustments
A number of challenges were encountered with the 500 gallon mini-digesters: fouling of feed pumps, inadequate mixing,
freezing of gas lines, plugging of overflows (which resulted in a digester overflowing), sludge getting into gas lines, leaks
in the gas lines, and an over temperature event.
Due to the small volumes of feed material that were to be handled by these units, small diameter hoses and small volume
pumps were originally installed, which led to plugging of lines and inadequate mixing in the mini-digesters. Upon opening
the cover of one mini-digester to investigate, “dead zones” were observed. It was suspected that the poor mixing was a
result of an inadequate recycle flow and the flat bottom shape of the digester tanks, which together resulted in separation
of the solids separation within the digesters. As such, samples collected from the overflows and drains of the digesters
were found to have higher percent solids than expected.
Sludge thickening evolved over the course of the pilot project. Initially, thickening was done by manually filling five (5)gallon pails of effluent from the pilot, allowing it to settle for 45-minutes, then manually decanting it and allowing it to
consolidate. At this point in the project, the Sludge Classifying Press (SCP) was not yet installed. The thickening process
was altered when the SCP was introduced into the pilot such that captured sludge was pumped to the SCP and into a 300gallon coned-bottom tank. The settling was limited to 45-minutes because of sampling time required for Pre & Post SCP
sludge, startup and shutdown of the SCP, delivery of the sludge to the mini-digesters and to BMP, testing of COD, TS, and
VS% before the IAWWTF laboratory closed. The short settling period and the limited depth (<56”) resulted in a solids
content of the sludge from 1 to 2%. In pilot scale we found thickening capabilities to be less than that of a full scale system
where primary sludge is typically thickened to 3-5%.
The short settling time also resulted in a non-defined solids liquid separation layer. Samples of the sludge were taken
using a sludge judge and a scoop for the decant. Both of these were tested leaving the balance of the contents of the
tank being somewhere between these test results.
Flow meters were installed on the sludge and grit lines into the 900-Gallon storage tank. The low volume and flow rate
of the grit pipe caused the flow readings to be unrecorded. Inconsistencies of the sludge flow meter created concerns so
that visual readings from graduations on the side of the tank were used instead of the flow meter readings.
Phase 1 Design Improvements for Phase 2


The digester tanks needed to be replaced; flat bottom tanks could not be mixed effectively.
Critical Control Parameters
i. Proper Mixing
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1. Need to have a homogenous mixing pattern
2. Tank volume turnover rate for full-scale 30-60 minutes
ii. Temperature Control
1. Range needs to be 950F to 980F
2. Better to be cooler than too hot
iii. pH control
1. pH issues can be managed by reducing loading rate or adding chemicals\
iv. Feed Rate
Phase 1 Results
Despite the Phase 1 challenges, valid data was collected during the phase (Table 2). During this period, data shows that
mini-digester #3 (MD-3; EPT pilot sludge) produced 1.8 times more biogas per pound of VS applied than mini-digester #2
(MD-2; IAWWTF primary sludge).
Table 2: Phase 1 Biogas Results: Per O’Brien & Gere
Methane
Number of VS Loading Biogas Flow Content
Dates
Data Points (lb/kcf/d)
(sL/d)
(%)
IAWWTF
2005-2009 unknown
50
106,000 scfd
66.0
MD-2 (IPS)
4/11-6/17
68
50
423
65 **
MD-3 (SCP)
4/11-6/17
68
44
676
65 **
** methane content estimated due to CO2 meter out of calibration
Phase 1
Methane
Yield
(scf CH4/
lb VS fed)
5.2
4.0
7.4
Mini Digesters – Phase 2: Rebuild
In June 2014, due to the mixing and clogging challenges encountered, the four (4) 500 gallon min-digesters were removed
and four (4) 350 gallon mini-digesters (Figure 8) were installed. The new digesters were designed to operate with 100
gallons of working volume. The new mini-digesters have a cone-shaped bottom and a greater number of internal nozzles
than the original digesters, to ensure complete mixing is achieved within the tank. In addition to the new tanks, larger
double diaphragm pumps, and larger diameter hose lines were installed to prevent clogging. Again, each digester has a
dedicated feed tank (Figure 9), feed pump, and heating/mixing pump with heat exchanger; and temperature and pH were
manually monitored and adjusted as needed.
The new mini-digesters were placed in service in late June. The new MD-1 (IAWWTF Thickened Sludge) was seeded with
solids from the IAWWTF full-scale primary digester. The other three new mini-digesters were seeded with acclimated
sludge that had been saved from the Phase 1 mini-digesters and stored. The new MD-2 was seeded with material from
the old MD-2 and the new MD-3 and MD-4 units were seeded with material from the old MD-3. The digesters acclimated
to increasing loads throughout the month of July. Biogas flow readings were used to monitor the degree of acclimation
of each mini-digester.
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Figure 8: Phase 2 Mini Digester
Figure 9: Phase 2 Sludge Feed Tank
Digesters MD-1, MD-2 and MD-3 are fed as in Phase 1 at 0.05 lbs VS/cf/day. Digester MD-4 is fed at double that rate, 0.1
lbs VS/cf/day. The feed sludge is constantly pumped in a recirculation loop running from the feed tank to the mini digester
and back to the feed tank. A solenoid valve connected to a timer periodically redirects the feed from the recirculation loop
into the digester. The feed timer is set based on the results of daily total solids tests, so that the desired pounds of solids
are delivered to each mini-digester. Feed volumes are measured and samples are collected to determine the actual
loading rates on a daily basis.
Phase 2 Process Adjustments
An issue encountered during Phase 2 has been the leaking and rupturing of hoses in the heating and mixing lines of the
digester due to vibration/pulsing causing rubbing against various surfaces. This resulted in three of the four digesters
losing around half to all of their contents in one instance per digester. Keeping the pH in digesters MD-2, MD-3 and MD-4
at in the optimal range of pH 7 – 7.2 has required the addition of sodium bicarbonate so steady operating conditions can
be achieved in a quicker timeframe. The pH of the digesters is monitored twice daily to ensure quick reaction to any drop
in pH value. Regardless of adjustments we were able to recover from all issues and operate the digesters at steady state
for data collection.
Phase 2 Results
We were able to recover from Phase 1 and collect the necessary data points on the Phase 2 mini- digesters. Total Solids
(TS) and Volatile Solids (VS) testing are performed multiple times per week on feed sludge and the mini digester overflow.
This data are used to calculate the feed rate to the digesters and evaluate if volatile solids destruction is occurring in the
digesters. Provided in Table 3 are the calculated values for the average TS and VS of the feed sludge.
Table 3: Average % Total Solids & Volatile Solids
Dates
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
ClearCove Enhanced Primary Sludge
ClearCove Enhanced Primary Sludge 2X
Note:
7/15-9/12
7/21-8/15
8/18-9/30
9/3-9/30
# of
Samples
27
13
20
10
Feed Sludge
% TS
% VS
2.0
2.0
1.9
1.8
63.1
71.1
69.4
70.3
Digester
Overflow
% TS % VS
58.0
1.4
66.8
1.3
59.0
1.1
59.2
1.3
The IAWWTF Thickened Sludge was tested for scale and loading comparison with IAWWTF Primary Digester and
Primary Sludge was tested for direct comparison with CCS Enhanced Primary Sludge. IAWWTF Thickened Sludge is
P a g e | 10
taken directly from the sample port at their full-scale thickening tanks. The IAWWTF Primary Sludge and ClearCove
Enhanced Primary sludge were pre-thickened prior to being fed to the digesters, the data above represents the
percent solid post-thickening. Based on bench top testing the sludge is expected to thicken to 5-7% using a gravity
deck.
Table 4 displays the Phase 2 mini-digester performance data in comparison with data collected from the
IAWWTF on their full scale primary digester performance (labeled IAWWTF on table).
Table 4: Phase 2 Mini-Digester Results: Per O’Brien & Gere
Phase 2
IAWWTF
MD-1 (ITS)
MD-2A (IPS)
MD-3 (SCP)
MD-2B (SCP-2x)
Dates
2013-2014
7/14-9/14
7/21-8/15
8/18-10/1
9/3-10/1
Detention
VS
VS
Biogas Methane Methane Yield Methane Yield
# Data Time # Reactor Loading Destroyed
Flow
Content
(scf CH4/
(scf CH4/
Points
(d)
Volumes (lb/kcf/d)
(%)
(sL/d)
(%)
lb VS fed) lb VS removed)
548
23
N/A
72
52% 156,000 scfd 68.0
7.8
15.1
63
13.5
4.7
59
38%
169
70.6
5.4
14.3
26
12.8
2.0
70
38%
178
60.1
4.1
10.7
45
17.5
2.6
46
50%
204
71.5
8.3
16.7
30
9.7
3.1
81
41%
360
67.6
7.9
19.4
Note: ITS – Ithaca Thickened Sludge, IPS – Ithaca Primary Sludge, SCP – ClearCove Post-SCP Sludge
Biochemical Methane Potential Testing
Biochemical methane potential (BMP) testing is performed simultaneously with operation of the mini digesters, using
sludge from the same collection vessels. Bioprocess Control’s Bioprocess Control’s Automatic Methane Potential Test
System (Figure 10) is used for BMP testing. BMP testing is performed as a recommended alternative by the NYSERDA PAC
to mini digesters in the event of performance failures. The BMP testing will be also used as a correlation tool with the
mini-digesters. Gas generation is recorded and viewable in real time on a dedicated computer connected to the BMP
equipment using a software platform provided by Bioprocess Control.
Figure 10: Bioprocess Controls AMPTS II Equipment
Gas Volume
Measuring Device
CO2 Fixing Unit
Reactors
Sample Incubator
The BMP system allows for fifteen (15) 640 ml reactors to be run at the same time. For each batch, the following five (5)
sludge types are run in triplicate to ensure accuracy and repeatability of the results:
P a g e | 11





IAWWTF Thickened Sludge
IAWWTF Primary Sludge
ClearCove Post-SCP Sludge
ClearCove Post-SCP Sludge 2X (Double VS Loading Rate)
Inoculum Only (Serves as the experimental control)
BMP Results Summary
To date, six BMP tests have been conducted. The calculated average of the test results are shown in Table 5. With each
subsequent test the results are more consistent and seem to track to the mini digesters where reliable data are present.
On average, it appears that the ClearCove EPT sludge generated approximately 1.8 times more methane than the IAWWTF
Thickened Sludge, and 1.3 times more methane than the IAWWTF Primary Sludge. In terms of total methane production,
the ClearCove EPT double loading rate generated just over double that of the normal loading rate ClearCove EPT sludge.
The six BMP tests performed during this reporting period were as follows:
-
6/24 – 7/1 (Exhibit 1)
7/1 – 7/8 (Exhibit 2)
7/8 – 7/24 (Exhibit 3)
7/25 – 8/11 (Exhibit 4)
8/15 – 9/2 (Exhibit 5)
9/3 – 9/15 (Exhibit 6)
For further details on each of the individual BMP tests see Appendix C and refer to the Exhibit numbers above.
Table 5: Average BMP Results
Substrate
Average VS
Load
(g)
Average Total
Methane (Nml)
Average Applied
Yield (scf methane/
lb VS applied)
IAWWTF Thickened
IAWWTF Primary
ClearCove EPT
ClearCove EPT 2X
1.58
1.70
1.71
3.71
298
481
633
1,351
3.0
4.4
5.7
5.7
Compared to
Ithaca
Thickened
Sludge
146%
188%
189%
The IAWWTF’s Environmental Lab ran a BMP test of their own comparing the EPT sludge and the IAWWTF Thickened
sludge as an additional control experiment, the results of which are shown in Table 6. Expanded data and calculations
can be found in Attachment 3.
Table 6: IAWWTF BMP Results
Substrate
Average VS
Load
(g)
Corrected
Average Total
Biogas (mL)*
Applied Yield (mL
biogas/
g VS applied)
Compared to
Ithaca Thickened
Sludge
IAWWTF Thickened
ClearCove EPT
0.155
0.255
22
97
140
381
270%
*Corrected Average Total Biogas values have been adjusted to remove inoculum gas generation from the total
gas produced.
P a g e | 12
IV. Improved Sludge Processing as a Result of Higher Percent Solids and Improved Ratio of
Primary to Secondary Sludge
In order to quantify any sludge processing effects, a mass balance is being established around the EPT pilot in Ithaca. As
depicted in the process schematic in Figure 12, sludge from the main hopper and IFS of the pilot is sent to a 900 gallon
holding tank prior to being processed through the Sludge Classifying Press. A flow meter has been placed on these lines
between the pilot and the 900 gallon tank in order to quantify the sludge exiting the EPT unit. The sludge is mixed within
the 900 gallon tank to keep it homogeneous, and then pumped from the tank to the SCP. The SCP also has a flow meter
on its influent line. From the SCP, a coagulant is added to the “cleaned” sludge, which is then sent to a 300 gallon
thickening tank. The total volume sent to the 300 gallon tank is measured, as are the distinct volumes of sludge and
decant after a one (1) hour settling period. Split samples are collected Monday, Wednesday Friday and analyzed for
COD, TS, and VS on-site by a ClearCove operator and sent to a third part lab for analysis. Samples are collected from the
following points:



900 gallon Pre-SCP holding tank sludge
300 gallon Post-SCP holding tank sludge
300 gallon Post-SCP holding tank decant water
The on-site testing allows for a faster turnaround time and allows for predictive information to be gathers and acted upon
which waiting for the third party lab result.
These organic sources, in addition to the organic sources collected during the influent and effluent composite sampling
events (from the pilot), should account for all of the organics sources coming in to and out of the system.
Figure 12: ClearCove Pilot Mass Balance Data Point Process Diagram
P a g e | 13
Appendix A
Chemical Selection and Dosage Optimization
Chemical selection and dosage optimization were performed on the ClearCove EPT pilot to determine which
chemicals and dosage rates (mg/l) would achieve the best organic removal. Three coagulants were tested: Ferric
Chloride, PCH 180, and Slack Plus; all in combination with two (2) anionic polymer dosing rates (0.5 mg/l and 1.0
mg/l). Based on jar testing performed on-site, Ferric Chloride was determined to provide the best results based
on flocculation observation and measurements of COD and turbidity as shown in Table 1. Ferric Chloride is also
what the IAWWTF uses in its full scale operation.
Table 1
Chemical Selection Jar Test Results
PCH180
Turbidity (NFAU)
50
COD mg/L
238
Slack Plus
64
244
FeCl3
50
230
Blank
107
297
Once the Ferric Chloride was chosen, the optimal dosage of coagulant and polymer was determined by pilot
scale operation. The coagulant and polymer were tested at six (6) different dosage combinations, after which
the COD and turbidity of the influent and effluent was tested to determine which dosage combination provided
the best results.
Two different operational modes were tested for each of the six (6) different dosage combinations. These two
modes were referred to as Set Point #1 and Set Point #2. The main difference between the two set points was
their sludge removal method.
Set Point #1
Set Point #1 performs a sludge scour every batch, meaning that after each completed batch of the pilot it would
empty out the entire tank. After the tank was completely scoured of sludge a new cycle would begin with an
empty tank. The reasoning for this mode of operation is that it would prevent the organic and solids
concentration from getting too high and thus effecting the organic removal rate of the screened decanter. The
EPT is a solids and organic concentrator as roughly 25 to 35% of the influent organics and solids remain in the
EPT tank until removed via the sludge hopper or IFS. As shown in Table 2 below, 60 mg/l Ferric Chloride with 1.0
mg/l anionic polymer delivered the bester results for this set point.
Table 2: Set Point #1 Results
Coag (mg/l)
40
50
60
40
50
60
Polymer (mg/l)
0.5
0.5
0.5
1.0
1.0
1.0
Average % Removal
51.80
56.17
61.05
40.89
56.76
66.07
Max % Removal
55.40
64.65
66.67
40.89
64.52
73.92
Min % Removal
48.53
44.10
53.81
40.89
48.48
61.75
Set Point #2
Set Point #2 was different in that it would never completely empty the tank, but instead there would be a timed
draw off of sludge after the settle cycle of each batch resulting in approximately 25 gallons of sludge being
P a g e | 14
drained. The reasoning for this mode of operations was to maintain the residual chemical in the tank to improve
flocculation and contact time each cycle. It was determined that a 50 mg/l dosage of Ferric Chloride with a 1.0
mg/l dosage of anionic polymer provided the best COD removal as shown in Table 3.
Table 3: Set Point #2 Results
Coag (mg/l)
40
50
60
40
50
60
Conclusion
Polymer (mg/l)
0.5
0.5
0.5
1.0
1.0
1.0
Average % Removal
64.45
58.43
69.07
60.46
72.18
50.05
Max % Removal
66.53
60.58
71.34
63.36
77.32
62.94
Min % Removal
61.37
55.52
66.80
57.25
66.22
40.98
Based on the results of the jar testing, set point testing, and dosage optimization tests the 50 mg/l Ferric Chloride
with 1.0 mg/l polymer dose was chosen using the Set Point #2 mode of operation. These will be the operational
parameters for the rest of the project going forward to ensure the highest level of organic removal is achieved
from the pilot.
P a g e | 15
Appendix B
Optimized Case Study Data: Dosing of 80 MGL Ferric / .25 MGL Poly
BOD
SAMPLE #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
80 MGL Ferric / .25 MGL Poly
Date*
7/29/2014
7/30/2014
8/1/2014
8/5/2014
8/6/2014
8/7/2014
9/2/2014
9/3/2014
9/4/2014
9/5/2014
9/8/2014
9/9/2014
9/10/2014
9/11/2014
9/12/2014
Min
Max
Avg
Sampler
AW
AW
AW
AW
AW
AW
CW
SM
AW
AW
SM
CW
CW
CW
CW
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Inf BOD
276
161
159
126
105
150
148
191
174
162
179
184
196
136
211
105
276
176
Prim Eff BOD Prim BOD Rem
237.00
14%
77.35
85.00
39%
19%
172.00
171.00
161.00
213.00
223.00
213.00
230.00
195.00
77
237
180
10%
2%
1%
-19%
-21%
-9%
-69%
8%
-69%
39%
-2%
CCS Eff BOD
67
63
48
49
32
31
62.0
73
70
43
51
74
62
38
66
31
74
55
CCS BOD Rem
76%
61%
70%
61%
70%
79%
58%
62%
60%
73%
72%
60%
68%
72%
69%
58%
79%
67%
P a g e | 16
SBOD
SAMPLE #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
80 MGL Ferric / .25 MGL Poly
Date*
7/29/2014
7/30/2014
8/1/2014
8/5/2014
8/6/2014
8/7/2014
9/2/2014
9/3/2014
9/4/2014
9/5/2014
9/8/2014
9/9/2014
9/10/2014
9/11/2014
9/12/2014
Min
Max
Avg
Sampler
AW
AW
AW
AW
AW
AW
CW
SM
AW
AW
SM
CW
CW
CW
CW
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Inf SBOD
24
45
37
29
23
19
17
34
40
51
26
47
27
62
42
17
62
34
Prim Eff SBOD
31
26
48
35
47
32
44
31
63
47
26
63
40
CCS Eff SBOD CCS SBOD Rem
14
42%
33
27%
36
3%
25
14%
12
48%
15
21%
15
12%
31
9%
30
25%
38
25%
16
38%
36
23%
13
52%
53
15%
31
26%
12
14%
53
48%
27
28%
P a g e | 17
TSS
SAMPLE #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
80 MGL Ferric / .25 MGL Poly
Date*
7/29/2014
7/30/2014
8/1/2014
8/5/2014
8/6/2014
8/7/2014
9/2/2014
9/3/2014
9/4/2014
9/5/2014
9/8/2014
9/9/2014
9/10/2014
9/11/2014
9/12/2014
Min
Max
Avg
Sampler
AW
AW
AW
AW
AW
AW
CW
SM
AW
AW
SM
CW
CW
CW
CW
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Inf TSS
360
176
236
234
147
280
214
293
213
260
240
187
260
196
256
147
360
241
Prim Eff TSS
136
Prim TSS Rem
62%
110
120
53%
18%
124
150
148
453
327
391
590
230
110
590
253
58%
30%
43%
-89%
-75%
-50%
-201%
10%
-201%
62%
-5%
CCS Eff TSS
45
40
22
30
33
26
46
43
40
38
42
25
41
33
39
22
46
36
CCS TSS Rem
88%
77%
91%
87%
78%
91%
79%
85%
81%
85%
83%
87%
84%
83%
85%
77%
91%
84%
P a g e | 18
VSS
SAMPLE #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
80 MGL Ferric / .25 MGL Poly
Date*
7/29/2014
7/30/2014
8/1/2014
8/5/2014
8/6/2014
8/7/2014
9/2/2014
9/3/2014
9/4/2014
9/5/2014
9/8/2014
9/9/2014
9/10/2014
9/11/2014
9/12/2014
Min
Max
Avg
Sampler
AW
AW
AW
AW
AW
AW
CW
SM
AW
AW
SM
CW
CW
CW
CW
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Inf VSS
393
148
218
164
130
240
162
193
147
227
200
136
207
153
200
130
393
181
Prim Eff VSS
176
Prim VSS Rem
55%
96
26%
84
105
124
380
273
264
490
150
84
490
214
56%
29%
45%
-90%
-101%
-28%
-220%
25%
-220%
56%
-16%
CCS Eff VSS
43
35
20
18
33
22
36
32
25
29
27
18
30
21
27
18
43
28
CCS VSS Rem
89%
76%
91%
89%
75%
91%
78%
83%
83%
87%
87%
87%
86%
86%
87%
75%
91%
84%
P a g e | 19
COD
SAMPLE #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
80 MGL Ferric / .25 MGL Poly
Date*
7/29/2014
7/30/2014
8/1/2014
8/5/2014
8/6/2014
8/7/2014
9/2/2014
9/3/2014
9/4/2014
9/5/2014
9/8/2014
9/9/2014
9/10/2014
9/11/2014
9/12/2014
Min
Max
Avg
Sampler
AW
AW
AW
AW
AW
AW
CW
SM
AW
AW
SM
CW
CW
CW
CW
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Inf COD
760
440
180
240
220
260
341
390
341
391
428
333
350
391
350
180
760
359
Prim Eff COD Prim COD Rem
330
57%
220
0%
341
333
391
333
391
350
376
300
220
391
337
13%
2%
0%
22%
-17%
0%
4%
14%
-17%
57%
7%
CCS Eff COD
138
270
63
110
100
85
112
154
112
133
120
134
184
134
154
63
270
134
CCS COD Rem
82%
39%
65%
54%
55%
67%
67%
61%
67%
66%
72%
60%
47%
66%
56%
39%
82%
62%
P a g e | 20
Phosphorous
SAMPLE #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
80 MGL Ferric / .25 MGL Poly
Date*
7/29/2014
7/30/2014
8/1/2014
8/5/2014
8/6/2014
8/7/2014
9/2/2014
9/3/2014
9/4/2014
9/5/2014
9/8/2014
9/9/2014
9/10/2014
9/11/2014
9/12/2014
Min
Max
Avg
Sampler
AW
AW
AW
AW
AW
AW
CW
SM
AW
AW
SM
CW
CW
CW
CW
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Inf Phos
6.49
3.75
3.09
2.27
2.44
3.60
3.94
3.22
2.97
3.48
3.86
3.94
4.00
3.37
3.75
2.27
6.49
3.41
Prim Eff Phos Prim Phos Rem
2.86
56%
1.70
30%
2.73
2.46
3.18
3.15
3.72
3.94
3.97
3.34
1.70
3.97
3.11
15%
17%
9%
18%
6%
2%
-18%
11%
-18%
56%
10%
CCS Eff Phos
1.22
0.78
0.69
0.75
0.49
0.62
1.33
0.95
0.89
0.98
0.95
1.15
1.19
2.18
0.96
0.49
2.18
1.01
Phos Removal
81%
79%
78%
67%
80%
83%
66%
83%
70%
72%
75%
71%
70%
35%
74%
66%
83%
76%
P a g e | 21
TKN
SAMPLE #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
80 MGL Ferric / .25 MGL Poly
Date*
7/29/2014
7/30/2014
8/1/2014
8/5/2014
8/6/2014
8/7/2014
9/2/2014
9/3/2014
9/4/2014
9/5/2014
9/8/2014
9/9/2014
9/10/2014
9/11/2014
9/12/2014
Min
Max
Avg
Sampler
AW
AW
AW
AW
AW
AW
CW
SM
AW
AW
SM
CW
CW
CW
CW
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Inf TKN
35.90
23.60
22.90
17.50
15.80
27.20
35.60
28.20
25.20
27.60
29.10
32.00
34.40
39.00
34.10
15.8
39.0
27.4
Prim Eff TKN
18.60
Prim TKN Rem
48%
20.30
-28%
35.30
32.50
35.90
35.30
38.80
43.90
41.30
39.90
18.6
43.9
34.2
-25%
-29%
-30%
-21%
-21%
-28%
-6%
-17%
-30%
48%
-20%
CCS Eff TKN
17.90
18.40
17.80
13.10
11.00
14.40
23.70
21.50
21.80
22.00
21.80
25.20
27.60
34.10
28.00
11.0
34.1
21.2
TKN Removal
50%
22%
22%
25%
30%
47%
33%
24%
13%
20%
25%
21%
20%
13%
18%
13%
50%
26%
P a g e | 22
Alternative Dosing Experiment (For reference only; not used for any other experiments): Dosing of 50 MGL Ferric / 1 MGL
Poly
SAMPLE #
1
2
3
4
5
6
7
8
9
SAMPLE #
1
2
3
4
5
6
7
8
9
50 MGL Ferric /1 MGL Poly
Date*
8/12/2014
8/15/2014
8/18/2014
8/19/2014
8/20/2014
8/21/2014
8/26/2014
8/27/2014
8/29/2014
Min
Max
Avg
50 MGL Ferric /1 MGL Poly
Date*
8/12/2014
8/15/2014
8/18/2014
8/19/2014
8/20/2014
8/21/2014
8/26/2014
8/27/2014
8/29/2014
Min
Max
Avg
Sampler
AW
AW
SM
AW
SM
AW
BH
SM
SM
Sampler
AW
AW
SM
AW
SM
AW
BH
SM
SM
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Inf BOD
141
117
106
201
210
138
166
165
189
106
210
159
Inf TSS
244
140
152
192
264
204
200
176
198
140
264
197
Prim Eff BOD Prim BOD Rem
81
43%
81
31%
98
8%
100
50%
129
39%
107
22%
113
32%
123
25%
150
21%
81
8%
150
50%
109
30%
Prim Eff TSS
74
80
76
236
116
178
142
84
100
74
236
121
Prim TSS Rem
70%
43%
50%
-23%
56%
13%
29%
52%
49%
-23%
70%
38%
CCS Eff BOD
52
51
33
60
96
47
76
78
94
33
96
65
CCS Eff TSS
26
37
36
38
57
34
53
56
53
26
57
43
CCS BOD Rem
63%
56%
69%
70%
54%
66%
54%
53%
50%
50%
70%
60%
CCS TSS Rem
89%
74%
76%
80%
78%
83%
74%
68%
73%
68%
89%
77%
Inf VSS
140
120
116
172
228
168
172
170
170
116
228
162
Inf SBOD
35
28
12
27
45
19
60
51
49
12
60
36
Prim Eff SBOD
15
25
12
15
34
13
15
39
56
12
56
25
Prim Eff VSS
66
71
56
212
11
148
132
80
73
11
212
94
Prim VSS Rem
53%
41%
52%
-23%
95%
12%
23%
53%
57%
-23%
95%
40%
CCS Eff SBOD CCS SBOD Rem
16
54%
18
36%
8
32%
21
22%
38
16%
15
21%
55
8%
35
31%
48
2%
8
2%
55
54%
28
25%
CCS Eff VSS
26
33
27
29
47
25
43
48
42
25
48
36
CCS VSS Rem
81%
73%
77%
83%
79%
85%
75%
72%
75%
72%
85%
78%
P a g e | 23
SAMPLE #
1
2
3
4
5
6
7
8
9
50 MGL Ferric /1 MGL Poly
Date*
8/12/2014
8/15/2014
8/18/2014
8/19/2014
8/20/2014
8/21/2014
8/26/2014
8/27/2014
8/29/2014
Min
Max
Avg
SAMPLE #
1
2
3
4
5
6
7
8
9
Sampler
AW
AW
SM
AW
SM
AW
BH
SM
SM
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
50 MGL Ferric /1 MGL Poly
Date*
8/12/2014
8/15/2014
8/18/2014
8/19/2014
8/20/2014
8/21/2014
8/26/2014
8/27/2014
8/29/2014
Min
Max
Avg
Inf COD
280
260
156
272
352
216
310
340
439
156
439
292
Sampler
AW
AW
SM
AW
SM
AW
BH
SM
SM
Prim Eff COD Prim COD Rem
180
36%
160
38%
116
26%
156
43%
196
44%
180
17%
240
23%
220
35%
341
22%
116
17%
341
44%
199
32%
Type
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
Comp
CCS Eff COD
110
100
78
118
156
100
190
140
150
78
190
127
Inf TKN
22.20
20.30
20.80
28.80
29.30
20.10
26.40
30.80
38.00
20.10
38.00
26.30
CCS COD Rem
61%
62%
50%
57%
56%
54%
39%
59%
66%
39%
66%
56%
Prim Eff TKN
25.00
22.70
23.10
31.00
29.30
21.70
31.40
36.40
39.90
21.70
39.90
28.94
Inf Phos
2.91
2.65
2.85
3.75
4.96
2.99
3.48
3.78
3.79
2.65
4.96
3.46
Prim Eff Phos Prim Phos Rem
2.23
23%
1.94
27%
1.67
41%
2.51
33%
2.82
43%
0.15
95%
2.74
21%
2.60
31%
2.74
28%
0.15
21%
2.82
95%
2.16
38%
Prim TKN Rem
-13%
-12%
-11%
-8%
0%
-8%
-19%
-18%
-5%
-19%
0%
-10%
CCS Eff TKN
14.20
15.60
15.60
18.60
19.60
14.90
23.50
25.30
31.40
14.20
31.40
19.86
CCS Eff Phos
0.98
1.01
0.79
1.04
1.28
0.78
1.23
1.38
1.66
0.78
1.66
1.13
Phos Removal
66%
62%
72%
72%
74%
74%
65%
63%
56%
56%
74%
67%
TKN Removal
36%
23%
25%
35%
33%
26%
11%
18%
17%
11%
36%
25%
P a g e | 24
Appendix C
BMP Reports
Exhibit 1: 6/24/2014 – 7/1/2014
Summary
This test was started on 6/24 and concluded on 7/1. All reactors were seeded with sludge from the
IAWWTF Primary Digester however no separate inoculum bottle was run for this BMP test. The bottles
were loaded at an inoculum/substrate ratio of 1.5.
As shown in the table below reactors fed the same sludges as the mini-digesters with extra bottles of
Pre-SCP sludge and Post-SCP Thickened sludge being tested as well. The Pre-SCP sludge was tested to
determine if greater biogas production is achieved after the sludge has been processed by ClearCove’s
SCP technology. The Post-SCP Thickened sludge was tested to determine if greater biogas production is
achieved by thickening the Post-SCP sludge to approximately 7.1% solids from 1.0% solids.
In this test, the Pre-SCP sludge produced approximately the same methane yield per pound of VS
applied as the Post-SCP sludge. The Post-SCP Thickened sludge produced approximately 30% more
methane than the normal Post-SCP sludge.
Substrate
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Pre-SCP Sludge
Post-SCP Sludge
Post-SCP Thickened
Inoculum Source
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
Inoculum/Substrate Ration: 1.5
Bottle Breakdown:
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Pre-SCP Sludge
Post-SCP Sludge
Post-SCP Thickened Sludge
Total:
3 Bottles
3 Bottles
3 Bottles
3 Bottles
3 Bottles
15 Bottles
Substrate Volatile Solids Concentrations
Substrate
VS%*
IAWWTF Thickened Sludge
1.9
IAWWTF Primary Sludge
2.2
Pre-SCP Sludge
2.1
Post-SCP Sludge
0.8
Post-SCP Thickened
5.5
*% VS is of the wet weight
Inoculum
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
VS%*
.90
.90
.90
.90
.90
P a g e | 25
Results
Sludge
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Pre-SCP Sludge
Post-SCP Sludge
Post-SCP Thickened
VS Load (g)
1.5
1.55
1.54
1.17
1.73
Total Methane
(nml)
297
376
424
320
613
Applied Yield (scf
methane/ lb VS
applied)
3.2
3.9
4.4
4.4
5.7
*As inoculum negative bottle was not run, inoculum methane gas generation was estimated to be 145
Nml
Methane Production
900
IAWWTF Thickened 1
800
IAWWTF Thickened 2
IAWWTF Thickened 3
700
IAWWTF Primary 1
Volume (Nml)
600
IAWWTF Primary 2
IAWWTF Primary 3
500
CCS Pre-SCP 1
400
CSS Pre-SCP 2
CCS Pre-SCP 3
300
CCS Post-SCP 1
CCS Post-SCP 2
200
CCS Post-SCP 3
100
CCS Post-SCP Thickened 1
CCS Post-SCP Thickened 2
0
0
25
50
75
Hours
100
125
150
CCS Post-SCP Thickened 3
P a g e | 26
Exhibit 2: 7/1/2014 – 7/8/2014
Summary
This test was started on 7/1 and concluded on 7/8. All reactors were seeded with sludge from the
IAWWTF Primary Digester however no separate inoculum bottle was run for this BMP test. The bottles
were loaded at an inoculum/substrate ratio of 1.5.
As shown in the table below the digesters were fed the same sludges as the mini-digesters, with the
exception of Pre-SCP sludge which is not fed to the mini-digesters. This test was also the first test to
include reactors which were loaded Post-SCP sludge at double the volatile solids loading rate, this sludge
is referred to as Post-SCP Sludge 2X. These bottles were run to collect supplementary data to the fourth
mini digester which is fed Post-SCP at double the conventional loading rate.
In this test, the Pre-SCP sludge provided approximately half the methane yield per pound of VS applied
as the Post-SCP sludge. The Post-SCP 2X sludge produced approximately double the methane volume of
the Post-SCP conventional load sludge and provided a slightly higher yield per pound VS loaded.
Substrate
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Pre-SCP Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Source
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
Inoculum/Substrate Ration: 1.5
Bottle Breakdown:
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Pre-SCP Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Total:
3 Bottles
3 Bottles
3 Bottles
3 Bottles
3 Bottles
15 Bottles
Substrate Volatile Solids Concentrations
Substrate
VS%*
IAWWTF Thickened Sludge
1.63
IAWWTF Primary Sludge
1.98
Pre-SCP Sludge
1.30
Post-SCP Sludge
3.36
Post-SCP Sludge 2X
3.36
*% VS is of the wet weight
Inoculum
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
VS%*
.86
.86
.86
.86
.86
P a g e | 27
Results
Sludge
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Pre-SCP Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
VS Load (g)
1.36
1.41
1.29
1.52
3.06
Total Methane
(nml)
212
382
291
582
1,219
Applied Yield (scf
methane/ lb VS
applied)
2.5
4.3
3.6
6.1
6.4
*As inoculum negative bottle was not run, inoculum methane gas generation was estimated to be 145
Nml
Methane Production
1600
IAWWTF Thickened 1
1400
IAWWTF Thickened 2
IAWWTF Thickened 3
1200
Volume (Nml)
IAWWTF Primary 1
IAWWTF Primary 2
1000
IAWWTF Primary 3
CCS Pre-SCP 1
800
CSS Pre-SCP 2
600
CCS Pre-SCP 3
CCS Post-SCP 1
400
CCS Post-SCP 2
CCS Post-SCP 3
200
CCS Post-SCP 2X 1
CCS Post-SCP 2X 2
0
0
25
50
75
Hours
100
125
150
CCS Post-SCP 2X 3
P a g e | 28
Exhibit 3: 7/8/2014 – 7/24/2014
Summary
This test was started on 7/8 and concluded on 7/24. All reactors were seeded with sludge from the
IAWWTF Primary Digester, this is the first test which was run with a separate Inoculum Only “blank”
bottle. The bottles were loaded at an inoculum/substrate ratio of 1.5.
As shown in the table below the digesters were fed the same sludges as the mini-digesters with the
exception of the additional Inoculum Only bottle. This test was the second test to include reactors which
were loaded Post-SCP sludge at double the volatile solids loading rate, this sludge is referred to as PostSCP Sludge 2X.
In this test, the Post-SCP 2X sludge produced over double the total methane volume of the Post-SCP
conventional load sludge and provided a slightly higher yield per pound VS loaded. The inoculum only
reactors produced very little methane volume and yield.
Substrate
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Only
Inoculum Source
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
Inoculum/Substrate Ration: 1.5
Bottle Breakdown:
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Only
Total:
3 Bottles
3 Bottles
3 Bottles
3 Bottles
3 Bottles
15 Bottles
Substrate Volatile Solids Concentrations
Substrate
VS%*
IAWWTF Thickened Sludge
2.03
IAWWTF Primary Sludge
1.60
Post-SCP Sludge
2.19
Post-SCP Sludge 2X
2.19
Inoculum Only
0.92
*% VS is of the wet weight
Inoculum
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
VS%*
0.92
0.92
0.92
0.92
0.92
P a g e | 29
Results
Sludge
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Only
Total Methane
(nml)
352
481
611
1,340
85
VS Load (g)
1.88
1.77
1.92
3.84
3.68
Applied Yield (scf
methane/ lb VS
applied)
3.0
4.4
5.1
5.6
0.4
Methane Production
1600
It Thickened 1 Volume [Nml]
It Thickened 2 Volume [Nml]
1400
It Thickened 3 Volume [Nml]
Primary 1 Volume [Nml]
1200
Volume (Nml)
Primary 2 Volume [Nml]
1000
Primary 3 Volume [Nml]
Inoculum Only 1 Volume [Nml]
800
Inoculum Only 2 Volume [Nml]
Inoculum Only 3 Volume [Nml]
600
Post SCP 1 Volume [Nml]
Post SCP 2 Volume [Nml]
400
Post SCP 3 Volume [Nml]
Post SCP 2X 1 Volume [Nml]
200
Post SCP 2X 2 Volume [Nml]
0
Post SCP 2X 3 Volume [Nml]
0
50
100
150
200
Hours
250
300
350
400
P a g e | 30
Exhibit 4: 7/25/2014 – 8/11/2014
Summary
This test was started on 7/25 and concluded on 8/11. All reactors were seeded with sludge from the
IAWWTF Primary Digester. The bottles were loaded at an inoculum/substrate ratio of 1.5.
As shown in the table below the digesters were fed the same sludges as the mini-digesters with the
exception of the additional Inoculum Only bottle. This test was the third test to include reactors which
were loaded Post-SCP sludge at double the volatile solids loading rate, this sludge is referred to as PostSCP Sludge 2X.
In this test, the Post-SCP 2X sludge produced approximately double the total methane volume of the
Post-SCP conventional load sludge and provided a slightly higher yield per pound VS loaded. The
inoculum only reactors produced very little methane volume and yield.
Substrate
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Only
Inoculum Source
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
Inoculum/Substrate Ration: 1.5
Bottle Breakdown:
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Only
Total:
3 Bottles
3 Bottles
3 Bottles
3 Bottles
3 Bottles
15 Bottles
Substrate Volatile Solids Concentrations
Substrate
VS%*
IAWWTF Thickened Sludge
1.40
IAWWTF Primary Sludge
1.36
Post-SCP Sludge
1.57
Post-SCP Sludge 2X
1.57
Inoculum Only
0.93
*% VS is of the wet weight
Inoculum
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
VS%*
0.93
0.93
0.93
0.93
0.93
P a g e | 31
Results
Sludge
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Only
Total Methane
(nml)
350
477
630
1,287
205
VS Load (g)
1.72
1.70
1.78
3.56
3.72
Applied Yield (scf
methane/ lb VS
applied)
3.3
4.5
5.7
5.8
0.9
Methane Production
1600
It Thickened 1 Volume [Nml]
1400
It Thickened 2 Volume [Nml]
It Thickened 3 Volume [Nml]
Volume (Nml)
1200
Primary 1 Volume [Nml]
Primary 2 Volume [Nml]
1000
Primary 3 Volume [Nml]
Inoculum Only 1 Volume [Nml]
800
Inoculum Only 2 Volume [Nml]
600
Inoculum Only 3 Volume [Nml]
Post SCP 1 Volume [Nml]
400
Post SCP 2 Volume [Nml]
Post SCP 3 Volume [Nml]
200
Post SCP 2X 1 Volume [Nml]
Post SCP 2X 2 Volume [Nml]
0
0
50
100
150
200
250
Hours
300
350
400
450
Post SCP 2X 3 Volume [Nml]
P a g e | 32
Exhibit 5: 8/15/2014 – 9/2/2014
Summary
This test was started on 8/15 and concluded on 9/2. All reactors were seeded with sludge from the
IAWWTF Primary Digester. For this experiment the bottles were loaded at an inoculum/substrate ratio
of .5 to observe if they produced more gas over a longer period of time. This inoculum/substrate ratio
means that there was twice the volatile solids load of substrate in comparison to the volatile solids load
of the inoculum.
In this test, each sludge produced more methane as expected from the higher VS loading rate and the
reactors ran for a longer period of time before methane production stopped. When methane generation
was normalized for VS load, Post-SCP, Post-SCP 2X, and IAWWTF Primary Sludge achieved slightly higher
than the average yield of previous tests. The IAWWTF Thickened sludge however had an abnormally
high yield in comparison to any previous test previously run leading one to believe there may have been
an operator error during the setup of the BMP test.
Substrate
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Only
Inoculum Source
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
Inoculum/Substrate Ration: 1.5
Bottle Breakdown:
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Only
Total:
3 Bottles
3 Bottles
3 Bottles
3 Bottles
3 Bottles
15 Bottles
Substrate Volatile Solids Concentrations
Substrate
VS%*
IAWWTF Thickened Sludge
2.26
IAWWTF Primary Sludge
1.03
Post-SCP Sludge
1.60
Post-SCP Sludge 2X
1.60
Inoculum Only
0.63
*% VS is of the wet weight
Inoculum
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
IAWWTF Primary Digester
VS%*
0.63
0.63
0.63
0.63
0.63
P a g e | 33
Results
Sludge
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP Sludge 2X
Inoculum Only
VS Load (g)
3.24
2.27
2.82
5.63
2.52
Total Methane
(nml)
2,652
851
1,208
2,233
283
Applied Yield (scf
methane/ lb VS
applied)
13.1
6.0
6.9
6.4
1.8
P a g e | 34
Exhibit 6: 9/3/2014 – 9/15/2014
Summary
The test was started at 5:00 PM on 9/3 and concluded on 9/15. The BMP test performed from 9/3-9/15
is the first test performed using paired inoculums from the mini-digesters. The reason for doing so is to
test if there is a greater biogas yield when the reactors are seeded with an inoculum that is acclimated
to their specific substrate. The reactors for Post-SCP and Post-SCP 2X were both seeded with material
from Mini-digester 3 as the inoculum because the material from the Post-SCP 2X digester was not yet
mature enough to use as an inoculum. The inoculum/substrate ratio was set back to 1.5 for this test. \
Substrate
IAWWTF Thickened Sludge
IAWWTF Primary Sludge
Post-SCP Sludge
Post-SCP 2X Sludge
Inoculum/Substrate Ration: 1.5
Bottle Breakdown:
IAWWTF Thickened Sludge
Thickened Sludge Inoculum (MD-1)
IAWWTF Primary Sludge
Primary Sludge Inoculum (MD-2)
Post-SCP Sludge
Post-SCP Sludge Inoculum (MD-3)
Post-SCP 2X Sludge
Total:
Inoculum Source
Mini-Digester 1
Mini-Digester 2
Mini-Digester 3
Mini-Digester 3
3 Bottles
2 Bottles
2 Bottles
2 Bottles
2 Bottles
2 Bottles
2 Bottles
15 Bottles
Substrate Volatile Solids Concentrations
Substrate
VS%
IAWWTF Thickened Sludge
1.48
IAWWTF Primary Sludge
1.58
Post-SCP Sludge
1.37
Post-SCP 2X Sludge
1.37
Inoculum
Thickened Sludge Inoculum (MD-1)
Primary Sludge Inoculum (MD-2)
Post-SCP Sludge Inoculum (MD-3)
Post-SCP Sludge Inoculum (MD-3)
VS%
0.71
0.75
0.60
0.60
Results
Sludge
IAWWTF Thickened Sludge
Thickened Inoculum
IAWWTF Primary Sludge
Primary Inoculum
Post-SCP Sludge
Post-SCP Inoculum
Post-SCP 2X Sludge
Post-SCP Inoculum
VS Load (g)
1.43
2.84
1.52
3.00
1.24
2.40
2.48
2.40
Total Methane
(Nml)
281
47
317
293
449
176
675
176
Applied Yield (scf
methane/lb VS applied)
3.1
0.27
3.3
1.6
5.8
1.2
4.4
1.2
P a g e | 35