PROCESS FACT SHEETS
DCWASA will consider only proven technologies for further evaluation. Proven is defined as operating at
least at one facility (>20-30 MGD) with municipal sludge for at least one full year. However, if the
technology has a strong potential to meet the proven criteria it may be considered for processing a portion
of the solids, if cost effectiveness can be established.
ACID GAS PHASE DIGESTION
I.
Description
The Acid Gas Process consists of a highly
loaded “acid phase” digester followed by a
more lightly loaded “methane phase”
digester.
The first phase provides hydrolysis and
acidification during the 1 – 2 day detention
time; while the second stage maximizes gas
production and usually has a detention time
of about 10 days.
This process can result in Class A biosolids
only if one phase is operated in
thermophilic mode.
II.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America.
Note:
Acid Gas Phase Digestion typically uses conventional anaerobic digesters. The methanogenic
bacteria used are difficult to grow and sensitive to overloads. Two-phase digestion is resilient to
changes in feed volume and composition because the acidogenic bacteria are hardy and do well
under extreme loading conditions. It is also claimed that the technology minimizes or eliminates
foaming problems.
Acid Gas Digestion is undergoing Phase II screening as a digestion alternative for biosolids
management at Blue Plains.
Acid Gas Phase Digestion
-1-
AUTOTHERMAL THERMOPHILIC ANAEROBIC DIGESTION - TEMPERATURE PHASED ANAEROBIC
DIGESTION (ATAD-TPAD)
I. Description
ATAD-TPAD is a dual digestion system
consisting of aerobic and anaerobic
digestion.
mesophilic temperatures. The process also
produces methane gas which can be used
for process heating.
The first step is a short residence time
Autothermal Thermophilic Aerobic
Digestion (ATAD). ATAD achieves Class
A pasteurization in small aerobic digesters
operating at thermophilic temperatures,
with 1-2 day detention time. Autothermal
heating, pre-conditioning, and Class A
pasteurization occur in this step.
The second step is Temperature Phased
Anaerobic Digestion (TPAD), where
thorough volatile solids destruction and
stabilization occur.
The pasteurized, pre-conditioned biosolids
are digested in a series of three anaerobic
phases descending in temperature from
thermophilic to high mesophilic to low
II.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America.
Note:
ATAD-TPAD is currently operating in Barrie, Ontario (Canada), Henderson, NC (USA), and
Tacoma, WA (USA). Its advantages include minimum heating requirements with most of the heat
required in the TPAD stage is obtained from the auto thermal stage.
Some challenges presented by ATAD-TPAD include installation and maintenance of the Oxygen
generation system. While air can be used in the ATAD stage, it has a markedly lower efficiency than
oxygen.
ATAD-TPAD is undergoing Phase II screening as a digestion alternative for biosolids
management at Blue Plains.
ATAD-TPAD
-2-
BELT FILTER PRESS DEWATERING
I.
Description
The belt filter press process consists of a
multiple, woven belt, gravity and
compression unit. Belt Filter Press sizes are
measured by belt width in meters with
standard units ranging from .5 to 3.5 meters.
Hydraulic loading can vary from 25 to 100
gpm per meter of belt width and dry solids
loading from 500 to 1000 lbs/hr per meter
of belt width. Solids capture is typically 8598% and resulting total solids (TS) of the
cake have concentrations of 18-32%.
Conditioned biosolids are applied to belts
that filter solids and drain released water
from the mixture. Gravity and pressing
forces are applied to the biosolids as the
belts transfer the mass through the press.
The process, which has a dry solids output
of 18-32% may be solids limited for feed
streams that are greater than 4-6% TS.
II.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America.
Note:
Belt Filter Presses are mostly used for post-digestion dewatering. They typically consume less
energy and generate less odorous cake than centrifuges, which may be required for options that
produce Class A biosolids product that is not heat dried..
Belt Filter Press dewatering is undergoing Phase II screening as a dewatering alternative for
biosolids management at Blue Plains.
Belt Filter Press
-3-
CAMBI
I.
Description
The process subjects thickened primary and
secondary sludge to high pressures and
temperatures. The treatment process, as
depicted in the next figure, can be
summarized as follows (adapted from
Stowa fact sheets).
The sludge is pre-dewatered to around 15%
to 20% dry solids (DS) content. The sludge
is then pre-heated in the 1st reactor (Pulping
Tank 1), as it is continuously fed to the
reactor.
It is batch fed into the 2nd reactor (Pulping
Tank 2), to which steam is added at 12 bar
in order to achieve temperatures of 150 to
160°C and pressures of about 8 to 9 bar.
Before discharging from the 2nd reactor the
pressure is decreased to approximately 2
bar; the released steam is recirculated to the
1st reactor for pre-heating of the incoming
sludge.
The sludge cools down in the 3rd reactor to
about 100°C. The hydrolyzed sludge is
cooled down further to 35°C by tube-intube heat exchangers for the production of
hot water, diluted and subsequently fed to
II.
the digester. Typical retention times in the
digester range from 10 to 12 days, however,
in Dublin plant the SRT is 15 days.
How the Cambi fit in the overall treatment scheme
12-14%
The Cambi Components
•
•
•
Achieve up to 62% VSR
Reduce digester volume by ~ 50%
Dewatered cake about ~33-40%,
centrifugation
Technology Classification: Innovative
Cambi
-4-
III. Installations: Treatment plants that operate Cambi facilities include:-
Location
Brisbane
Bydoszcz
Niigata
Hias
Sarsborg
Lillehammer (NOR) (1996)
Chertsey (GB) (1999)
Næstved (DEN) (2000)
Frederica (DEN)
Aberdeen (Scotland)
Dublin-Ringsend (Ireland)
Solids Production, dtpy
15,000
8,000
1,200
3,600
4,000
4,600
8,000
1,600
8,000
16,500
36,000
Notes from Dublin plant visit:
1. Cambi is a sophisticated process to operate, and requires well trained operators. The Dublin Cambi
process seems to be currently operated mainly by Black & Veatch engineers
2. The technology may raise safety and cost concerns from high pressure operation.
3. Further investigation is required in order to address the increased ammonia concentration in the
digester.
4. Cambi components need to be enclosed in order to treat odor emissions from the tanks.
5. The recycled centrate should be evaluated for its nutrient, hydrocarbon, and soluble solids quality.
While the facility is supposed to produce >30% solids, the dark appearance of the centrate indicated
low solids recovery.
6. Fecal Coliform reactivation regrowth should be investigated if the biosolids produced are to be
dewatered via centrifugation.
CAMBI process is undergoing Phase II screening as a pre-treatment alternative for biosolids
management at Blue Plains.
Cambi
-5-
CENTRIFUGE DEWATERING
I.
Description
Centrifugal thickening and dewatering is a
high speed process that uses the force from
rapid rotation of a cylindrical bowl to
separate wastewater solids from liquid
(U.S. EPA, 1987).
High speed rotating equipment develop large
gravitational forces separating liquids from
solids.
Centrifuge thickeners have been placed
before digesters in order to reduce tank
volume needed for digestion. Centrifuges
are also used post digestion to dewater
sludge before hauling, as at Blue Plains.
Centrifuges operate as continuous feed
units which remove solids by a scroll
conveyor and discharge liquid over the
weir. The bowl is conical-shaped which
helps lift solids out of the liquid allowing
them to dry on an inclined surface before
being discharged (Kemp, 1997).
II.
Typical centrifuge capacities range from 200-300
gpm to 850 gpm. The output total solid content
on anaerobically digested sludge is typically 2834%. Solids capture is typically 88-95% with
polymer applications of 16 lb/ton-dry solids.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America.
Note:
Centrifuge units are undergoing Phase II screening as thickening and dewatering alternatives for
biosolids management at Blue Plains.
Centrifuge
-6-
COMPOSTING
I.
Description
Composting is a system that uses microbial
activity to degrade raw organic materials,
such as yard trimmings and sludge solids,
so that the end-product is relatively stable,
reduced in quantity (in comparison to the
initial amount), and free from offensive
odors. It is typically employed post
dewatering in order to obtain the finished
compost material for land application.
Class A biosolids can be generated based
upon times and temperatures in the process.
Initially, high microbial activity and heat
production cause temperatures within the
compostable material to rise rapidly into
the thermophilic range (50oC and higher).
This temperature range is maintained by
periodic turning or the use of controlled air
flow.
After the rapidly degradable components
are consumed, temperatures gradually fall
II.
during the "curing" stage maintaining a
temperature of 131oF for 3 to 15 days.
Moisture, bulking material, and aeration
control are required and multiple handling of
the material is typical. Space is usually an
issue.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America.
Note:
Due to odor management issues, the composting facility that was previously operated onsite at Blue
Plains was taken offline.
Composting is not undergoing Phase II screening as a mainstream alternative for biosolids
management at Blue Plains. However, composting, as a peak shaving option, will be considered.
Composting
-7-
THERMAL DRYING
I.
Description
Thermal drying is employed after digestion
and dewatering to reduce the moisture
content of sludge. It uses heat to reduce the
volume and mass of dewatered solids by
evaporating water from biosolids, creating
a Class A product. It typically increases the
solids content from between 18-30% to
between 90-96%. The high temperatures
applied can also help meet US EPA Part
503 requirements for pathogen destruction
and vector attraction reduction. Resulting
Class A biosolids can have the consistency
of fine granules, flakes, small pellets or
larger fragments depending on the type of
thermal drying system used, characteristics
of biosolids processed and the use intended
for the product.
with wet biosolids. The high temperatures
transferred to the solids evaporate the water.
Examples of direct dryers are rotary drum,
flash and belt dryers.
With indirect heat dryers, solid metal walls
separate wet biosolids from the heattransferring medium such as steam, hot
water or oil. Biosolids temperatures are
raised by contact with hot metal surfaces
and the water subsequently evaporated.
Indirect dryers include vertical tray, paddle,
disc, and indirect-type fluidized bed dryers.
Thermal drying systems are typically
referred to in two primary categories; direct
and indirect heat dryers.
In direct dryers hot air or gas produced by
oil or gas-fired furnaces flows through the
drying vessel and comes into direct contact
II.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America.
Note:
Thermal drying ensures high-value, marketable products and provides a diversification option for
sustainable biosolids management.
Thermal drying is undergoing Phase II screening as an alternative for biosolids management at
Blue Plains.
Enzyme Hydrolysis
-8-
ENZYMIC HYDROLYSIS
I.
Description
Enzymic Hydrolysis (EH) is a form of twophase digestion that uses enzymes
produced by bacteria to hydrolyze organic
matter. During the hydrolysis step large
complex molecules such as carbohydrates,
proteins, and fats are converted to soluble
simpler molecules which may be
assimilated by bacteria.
Enzyme Hydrolysis uses thickened sludge
as a feed material typically and is followed
by mesophilic anaerobic digestion. In this
biological process extracellular enzymes
serve as catalysts to destroy cell
components prior to digestion. This
enhances gas productionr, reduces HRT in
the digester, and typically provides for
better dewatering.
In the methanogenesis step, obligate
anaerobes convert the hydrolyzed
molecules to methane gas.
A typical enhanced EH design involves 2day retention at 42oC resulting in 99.9%
E.Coli reduction. In order to obtain a Class
A product, an enhanced EH design
consisting of 3 tanks operated at 55oC
optimizes VS destruction.
II.
Technology Classification: Innovative
III. Installations: Treatment plants that operate enhanced Enzyme Hydrolysis facilities include:-
Location
Blackburn, UK
Solids Production, dtpy
13,500
Note:
Enzymic Hydrolysis is undergoing Phase II screening as a pre-treatment alternative for biosolids
management at Blue Plains. This being considered as a subset of acid gas digestion.
Enzyme Hydrolysis
-9-
GASIFICATION
I.
Description
The technology reduces the volume of
dried biosolids producing gas that can be
used to generate electricity.
The gasification process converts sludge or
biosolids into a combustible gas, referred to
as synthesis gas, or “syngas,” which can be
recovered. While incineration fully
converts the input waste into energy and
ash, gasification heats the material under
controlled conditions, deliberately limiting
the conversion so that combustion does not
take place directly.
Syngas can be used as a fuel to generate
electricity and heat. The fuel value of
Syngas is not typically as high as that of
digester gas, perhaps 60% of digester gas
energy values.
The gasification process takes place in two
steps: pyrolysis and partial combustion.
During pyrolysis, biosolids are degraded in
the absence of oxygen at 1400-1650oF
resulting in the formation of gas and a
black, carbon-rich substance called “char.”
Gasification Image
The Balingen Plant, Germany
In the second reaction, the char is gasified
by partial combustion in the presence of
oxygen or air to produce the syngas. The
gas will require purification prior to
beneficial reuse.
Due to the concentrating effect of the
constituents in the original biosolids, the
remaining char is usually applied in a
landfill.
Kopf Umwelt- und Energietechnik GmbH
gasification technology
Gasification
- 10 -
II.
Technology Classification: Embryonic
III. Installations: Treatment plants that operate Gasification facilities include:-
Location
Philadelphia Water Department, PA
Balingen Sewage Works, Germany
Solids Production, dtpy
3, 650
1,460
Notes:
The pilot-plant installation in Balingen shows the following performance:

Cold gas efficiency between 65 and 70 % depending on the degree of drying which means that
about two thirds of the energy contained in the sewage sludge was becoming combustible gas.

The gas engine produces about 70 kW of electrical energy, of which about 15 kW are required for
gasification. The rest is available for the sewage works to cover its energy demand.

The thermal output of the co-generation (about 140 kW) is used to heat the digester towers. The
surplus of gas which cannot be used in the co-generation is disposed of in a post combustion
chamber.

The mineral granule amounts to 85 kg/h, it is used in an asphalt mixing plant.
The key component of the KOPF (Kopf Umwelt- und Energietechnik GmbH) gasification process is
the gasification reactor, where combustible gas is produced from dried sewage sludge. This occurs in a
stationary fluidised bed by sub-stoichiometric combustion at temperatures up to 900°C. In the raw gas
quench, the gas is cooled down and subsequently reprocessed by filtering and drying. In a block type
heat-power system, the gas is used to produce electricity and heat. After a retention time of 30 minutes,
the sewage sludge is reduced to an inert granule.
As an embryonic process, Gasification does not demonstrate proven capability to operate at Blue
Plains’ scale (>20 MGD).
Gasification is not undergoing Phase II screening as an alternative for biosolids management at
Blue Plains.
Gasification
- 11 -
INCINERATION
Description
I.
Incineration is the burning of dewatered
sludge at temperatures ranging from 12001700o F. A minimum of 25% feed solids is
usually provided to reduce supplemental
fuel.
There are two types of incinerators in
general use: the multi-hearth and fluidized
bed. The latter type is typically installed
today in retrofit applications.
In addition to supplemental fuel, additional
combustion air is normally required; air
pollution control measures are now a
significant cost component.
Biosolids volume reduction is in the range
of 75-85% with options available for reuse
of the ash.
II.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America. However, no new large installations
have been built in recent years.
Note:
While incineration provides energy recovery and low quantity ash production advantages, the
regulatory approval process for timely permit review and approval makes this process non-viable for
implementation at Blue Plains.
Incineration is not undergoing Phase II screening as an alternative for biosolids management at
Blue Plains.
Incineration
- 12 -
LIME STABILIZATION
I.
Description
During lime stabilization involves addition of
lime to biosolids in order to raise the pH to
levels unfavorable for pathogen growth. The
heat produced by the reaction of the lime with
the water in the biosolids raises the pH and
temperature of the biosolids sufficiently to
comply with U.S. EPA’s 40 CFR Part 503
regulations for pathogen destruction for both
Class A and Class B biosolids.
Generally, lime stabilization meets the Class B
requirements when the pH of the sludge-lime
mixture is at 12 or above after 2 hours of
contact and subsequently maintained above pH
11.5 for another 22 hours without further lime
addition.
Class A requirements can be achieved when the
pH of the mixture is maintained at or above 12
for at least 72 hours, with a temperature of
52oC maintained for at least 12 hours during
this time. Class A biosolids requirements can
also be satisfied by combining the Class B
requirements with elevated temperatures (70oC
for 30 minutes) or other EPA-approved
time/temperature processes. Producing a Class
A product generally requires a significantly
larger lime addition than is required for Class B
biosolids. The process is approved by EPA as
satisfying one of the five Processes to
Significantly Reduce Pathogens (PSRP) listed
in the Part 503 regulations.
significantly enhance pathogen destruction.
Other materials such as hydrated lime can also
be used. In general, lime stabilization is a nonproprietary process, although several patented
processes are available.
Lime stabilization has been demonstrated to
reduce total Coliform, fecal Coliform, and fecal
streptococci by more than 99.9 percent.
Exceptional Quality (EQ) biosolids can be
produced if Class A pathogen reduction, vector
attraction reduction, and metal concentration
requirements are met. The process converts
sewage sludge into a stable product, improves
the density and physical handling
characteristics of the biosolids and offers a
cost-effective, flexible, and environmentally
protective alternative that promotes beneficial
reuse. The lime stabilized biosolids provide a
rich source of essential fertilizer to farmland,
improve acidic soils, and are excellent for land
reclamation and as soil substitute for landfill
cover or as soil conditioner.
Quicklime (calcium oxide) is commonly used
because it has a high heat of hydrolysis and can
II.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America.
Note:
Lime Stabilization is Blue Plains’ current sludge treatment process. Upgraded, it can be used to
process peak loads in excess of the max 30-day design load of up to 200 dtpd.
Lime stabilization is undergoing Phase II screening for biosolids management at Blue Plains, as
a peak shaving option. Class A lime stabilization is not being considered as a mainstream option
as the high pH product may limit its suitability for land application.
Lime Stabilization
- 13 -
MESOPHILIC ANAEROBIC DIGESTION
I.
Description
Mesophilic Anaerobic digestion is a
stabilization process that reduces the
quantity of sludge, its pathogens, and odor
in the absence of oxygen. The organic
portion of sludge is biologically degraded
to produce methane gas. The methane is
generally burnt on site for heating or to
produce electricity on a small scale.
This type of digestion can be used in
combination with other technologies to
produce either a Class A or Class B
biosolids.
Anaerobic digesters will require an energy
input to retain the material at elevated
temperatures (between 20 and 40°C - the
mesophilic range) in order to speed
digestion. Some of the energy available
from the methane generated (typically 2040% of the total energy produced) can be
recycled for this purpose. Residence times
depend on the amount of sludge to be
processed and vary between 15 – 30 days.
II.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America.
Note:
Mesophilic Anaerobic Digestion can be combined with pre- or post- treatment processes in order to
generate reduced quantities of biosolids.
Mesophilic Anaerobic Digestion is undergoing Phase II screening for biosolids management at
Blue Plains.
Mesophilic Anaerobic Digestion
- 14 -
PASTEURIZATION
I.
Description
Pasteurization is a two-stage process that is
pre-treatment process that utilizes sludge
heat exchangers and small biopasteurization tanks, followed by anaerobic
digestion.
In the first stage of the process, a
BioPasteurTM system heats the sludge to
70oC for a minimum of one hour in order to
provide for pathogen destruction and meet
EPA’s Class A pathogen reduction
requirements.
can be treated to a level that will allow for
various uses.
Pasteurization not only reduces the quantity
of sludge and its pathogens, but also
reduces odor as well. This type of digestion
can be used ahead of a number of other
technologies and depending on the
operation and accompanying process can
generate either a Class A or Class B
biosolids.
In the second stage, anaerobic digestion
systems provide the volatile solids
reduction at either thermophilic or
mesophilic operating temperatures.
Three batch pasteurization reactors are
operated in a staggered configuration to
ensure continuous discharge of sludge into
anaerobic digesters. Gas is produced and
II.
Technology Classification: Innovative
III. Installations: Treatment plants that operate Pasteurization facilities include:Location
Alexandria Sanitation Authority, VA WWTF
City of Carmel, IN WWTP
Charlottetown WWTP, Prince Edward Island, Canada
Plant size (MGD)
50 MGD
12 MGD
6 MGD
Note:
Pasteurization is not undergoing Phase II screening as an alternative for biosolids management
at Blue Plains.
Pasteurization
- 15 -
TEMPERATURE PHASED ANAEROBIC DIGESTION (TPAD)
Description
I.
Thermophilic digestion is often coupled
with mesophilic digestion in a temperaturephased anaerobic digestion (TPAD) system.
Studies have reported that TPAD systems
may produce more biogas, increase volatile
solids destruction, and inactivate
pathogenic microorganisms more
completely than comparable conventional
mesophilic digestion systems.
In thermophilic digestion the reaction rate
and pathogen disinfection are increased by
raising the temperature to 122-135 ºF (50
to 57ºC) to support thermophilic bacteria.
TPAD can have several variations:
 Thermophilic digesters in series followed
by mesophilic
 Mesophilic Thermophilic 
Mesophilic
 Thermophilic  Mesophilic (TPAD)
Since thermophilic digestion is typically
not a batch process, it is not recognized as a
Class A process. The process can be run in
batch mode to meet time-temperature
relationship established by EPA.
II.
Technology Classification: Established
III. Installations: Multiple facilities exist across North America.
Note:
TPAD is undergoing Phase II screening as a digestion alternative for biosolids management at
Blue Plains.
TPAD
- 16 -
VITRIFICATION/ GLASSPACK® PROCESS
I.
Description
The technology converts sludge into glass
aggregates, which is inert material that can
be used in construction material such as
bricks, asphalt paving, shingles, etc.
The sludge goes through a closed loop of
drying and melting processes. The process
eliminates the need to co-fire fuel to
achieve Vitrification.
glass flows out of Zone 2 into the quench
tank, where it is cooled to form the glass
aggregate product.
In Zone 3, gas cooling occurs. The
exhaust gas blends with re-circulated gas
(375oF), thereby reducing the temperature
of the gas mixture to 1,400oF.
Melter Zones
Only natural gas is used heat the melter to
the required temperature before the sludge
is introduced. The heat recovered from the
vitrification loop provides the required
heat to dry the sludge.
According to Minergy, the melter is
comprised of a three-zone operation with
separate, but interconnected chambers.
In Zone 1, melting and combustion occurs.
Synthetic combustion air (mixture of 90%
pure oxygen and recovered exhaust gas) is
introduced tangentially to the combustion
chamber and is mixed with the incoming
granulate at a temperature between 2,400oF
and 3,000oF. The organic fraction of the
granulate is combusted (fuel source), while
the inorganic fraction of the solids melt to
form a pool of molten glass.
In Zone 2, the separation of the molten
glass and exhaust gas occurs. The molten
II.
Technology Classification: Innovative
III.
Installations:
Location
Demonstration unit in Winneconne, WI
North Shore Sanitary District, IL
Solids Production, dtpy
4,380
11,680
Note:
As an embryonic process, Vitrification does not demonstrate proven capability to operate at Blue
Plains’ scale (>20 MGD).
Vitrification is not undergoing Phase II screening as an alternative for biosolids management at
Blue Plains.
Vitrification
-17-
SLURRYCARBTM
I. Description
The SlurryCarb process is based on the
pyrolysis concept and involves exposing
the biosolids to elevated temperature
(450-600oF ) and pressure (800-1,800
psig)for a defined period of time,
followed by cooling, depressurization,
dewatering and, if desired, drying and
pelletization of the product solids.
Current practice is to operate at 450oF
and 1,200-1,500 psig, which is lower
pressure and temperature than typical
pyrolysis.
The effect of elevated temperature and
pressure on biosolids is to partially
solubilize the solids through breakdown
of the cell walls, breaking molecular
bonds and, in this case, releasing CO2
gas via the carbonization process. The
remaining solids (char) can be readily
dewatered using a high-speed centrifuge,
allegedly to about 50-55% solids
chemical conditioning. For ease of
transportation and increased fuel value,
the product can be further dried and, if
needed, pelletized, and used as a
substitute for coal in power generation
plants.
II.
Mitsubishi Plant
The Rialto Facility (under construction)
Technology Classification: Embryonic
III. Installations: Treatment plant under construction with SlurryCarb facilities:Location
Rialto Regional Biosolids Processing Facility- operational
end of 2008; Rialto, California
Solids Production, wtpd
683 wtpd
Notes:
There are no SlurryCarb facilities that process municipal sludge. The Rialto facility is
under construction and is expected to be in operation at the end of 2008. Although HDR
provided due diligence to guarantee performance of the process, reliability and actual
performance remains to be seen.
SlurryCarbTM is not undergoing Phase II screening as an alternative for biosolids
management at Blue Plains.
SlurryCarbTM
-18-