S-1000
Regional Project
Animal
Manure and Waste Utilization, Treatment and Nuisance Avoidance for a Sustainable
Agriculture
2003 Station
Reports
2003 Annual Report, S-1000
North Carolina State University
Reporting Scientists: Philip W. Westerman1
Jiayang (Jay) Cheng1
John J. Classen1
Theo van Kempen2
Location: North Carolina State University 1Dept. of Biological and Agricultural Engineering 2Dept. of Animal Science
Raleigh, NC 27695-7625 Progress to Date (by objective):
Ekokan Upflow Biofiltration Treatment System
Several technology evaluations have been conducted or are being conducted
in North Carolina with swine manure under an agreement between Smithfield
Foods, Inc. and the North Carolina Attorney General. Ekokan Biofiltration
Treatment System was one of the projects selected for demonstration and evaluation
in North Carolina based in part on previous success with a pilot scale evaluation
at a North Carolina State University research farm. The full-scale system
was constructed in 2002 and acclimation of the system with diluted lagoon
liquid began August 14, 2002. The Ekokan ® LLC waste treatment system
consists of solids/liquid separation and biofiltration of the liquid with
upflow aerated biological filters. Five finishing barns (about 4,000
finishing pigs total) are connected to the waste treatment system, and the
barn pits are emptied automatically in sequence, supplying usually six flushes
per day. Flushed waste flows through a solids-liquid separator and then is
pumped to an equalization tank. Liquid flows from the equalization tank
by gravity and passes through first-stage and second-stage aerated biofilters
connected in series (two sets, or four biofilters in total), with each biofilter
having 130 m3 of plastic media in a 151 m3 (40,000 gal.) tank.
The biofilter tanks are covered, and the air and foam given off from the aerated
treatment are routed through PVC pipes to exit points over an anaerobic lagoon.
The time for liquid to flow through the two biofilters is less than 24 hours.
Two 45 kW (60 hp) blowers provide the air. Biofilters are backwashed
periodically to remove excess biosolids. Data showed 90% or more
TAN reduction during May-June, 2003. Nitrification improved with warmer
weather, but some nitrite remained in output in June. During May-June,
2003 most of the nitrification occurred in the first stage biofilters.
The operation of the treatment system was ended June 30, 2003 due to lack
of operating funds.
International Ecological Systems and Services (IESS) Biokinetic Air Systems
Waste Treatment System for Wastewater (Westerman)
The IESS, Inc. aeration pond treatment system was monitored from Nov. 2000
through December 2002. The system was installed on a commercial
hog farm for treating 190 m3/d (50,000 gal./d) of liquid from a swine anaerobic
lagoon. Objectives of the treatment system are to reduce amount of nitrogen
that has to be land applied, improve flush water quality and check for improvements
in environment inside the barns that may be reflected in ammonia levels,
and determine the changes in the anaerobic lagoon due to treating 50,000
gal./day. The aeration pond was divided into two sections by a hanging curtain.
Diffused air was supplied by a 30 Hp blower and slitted polyethylene pipe
laid across the pond bottom. Depth of liquid was maintained at about
3 m (9-10 ft.). Effluent from the aeration pond has low odor, usually
low total ammonia nitrogen, variable amount of nitrate/nitrite nitrogen,
and lower concentrations of phosphorus (40 % lower), and copper and zinc
(80 % lower) compared to the anaerobic lagoon. Treated effluent was
recycled to flush two finishing barns (720 pigs each) out of nine that empty
into the anaerobic lagoon. The nitrate that is formed in the aeration pond
is denitrified to nitrogen gas when the liquid flushes the barns and goes
to the anaerobic lagoon. Results for 24 mo. of operation have been reported
in a conference paper.
Phosphorus Removal by Struvite Crystallization (Westerman)
A struvite crystallizer has been developed as a possible
practical process for removing phosphorus from hog waste anaerobic lagoon
liquid. This process could become useful for farmers needing to remove
phosphorus from effluent that is applied to land because of likely regulation
of phosphorus nutrient management. Based on the success of a lab-scale crystallizer,
a field-scale continuous crystallizer was designed, built and tested with
lagoon liquid at flow rates of 351 L/h and 568 L/h. Removal of total
phosphorus, including both dissolved and suspended phosphorus, reached 80-90%
in the field system. This degree of removal implies that the system
may be useful at commercial livestock operations where phosphorus content
of the waste water needs to be significantly reduced. A patent application
has been submitted for the process. Obj. 2, Task 2 -- Aquaculture
Based Treatment
Nutrient Removal from Anaerobically Treated Swine Wastewater by Growing
Duckweed (Cheng)
Organics destruction and nutrient uptake in an integrated
pilot system of anaerobic digestion and duckweed nutrient removal for swine
wastewater treatment were monitored under field conditions. Raw swine wastewater
of 100 gallons/day was first treated in a 1,000-gallon anaerobic digester
with floating ballast rings. Organic compounds in the wastewater were digested
to produce biogas. Many nutrients including nitrogen and phosphorus
remain in the effluent of the anaerobic digester. Duckweed (Lemna gibba 8678)
was grown in three 1,000-gallon tanks to recover nutrients from the anaerobic
effluent. The duckweed was periodically harvested and can be used as animal,
poultry, and fish feed. This research provides an initial understanding of
the attached-growth anaerobic digester and the characteristics exhibited by
Lemna gibba in the treatment of swine wastewater under conditions similar
to those found in North Carolina. Both the anaerobic digester and the
duckweed tanks were run as completely mixed systems. The performance of the
system was monitored by measuring chemical oxygen demand (COD), total Kjeldahl
nitrogen (TKN), ammonia nitrogen, total phosphorus (TP), ortho-phosphate-phosphorus,
and pH in the influent and effluent of each treatment unit. The treatment
achieved by the anaerobic digester was sufficient and it became evident from
our operation that the loading rate to the duckweed was the limiting factor
of the system. The overall removal of COD through the entire system
was from an average of 3713 +/- 6322 mg/l in the influent to 372 +/- 81 mg/l in the effluent.
The N concentration declined from 350 +/- 70 mg/l to 94.5 +/- 34 mg/l. The P concentration was reduced from 144 +/- 38 mg/l to 35 +/- 13 mg/l. These levels
would be lower if there was less of a loading rate and the system was allowed
to stabilize. Obj. 2, Task 3 – Stabilizing
or Recovery of Solids
BEST Solids-Liquid Separation Systems and Solids Combustion (Westerman)
The solids/liquid separation portion of the BEST system
consists of two solids separation systems placed in series for flushed swine
manure. One system has a screw-press separator (FAN) followed by tangential
flow gravity-settling tanks (TFS system), and the other system has a screen
and hydraulic press separator (Filtramat) followed by TFS system. The
objective of this project is to separate and collect swine manure solids with
dry solids content of more than 30 %. The FAN/TFS system and the Filtramat/TFS
system were operational by May 1, 2003. Approximately 36,000 kg (79,000
lb.) of wet solids (about 68 % moisture) were collected in large bags during
May through July 2003, and trucked to EPI in Idaho for combustion testing.
Combustion testing began on August 1, 2003. Initial combustion tests indicated
that a 3:1mixture of turkey litter and separated swine solids combusted adequately
producing a good ash product. The resulting ash was sent to a
test facility in Alabama to incorporate into fertilizer blends.
Belt System (van Kempen)
A belt-based housing system was evaluated for approximately
100 grow-finish pigs. Evaluation is completed and results will be reported
at ASAE meetings Oct. 2003. The belt system works well for collecting
dry fecal stream (50% DM) and results in a substantial reduction in ammonia
emission (6.5% of feed nitrogen). Objective 3, Task 1 --
Airborne emissions
Sources of Emissions in Swine House (van Kempen)
A project is in progress to identify the sources of airborne
emissions from swine houses. Trials to date show that animal and/or
floor surface is source of phenolics/VFA. Alkanes are from pit. Ammonia
is from floor and pit (50/50), and methane is from animal only. Together with
the DIAS (Danish institute of animal science), the source of odor will be
more closely examined (slats vs. animal).
b. Usefulness of findings:
The demonstration and evaluation of alternative swine manure treatment systems
will provide information on treatment effectiveness, reliability, and operational
requirements. Other teams of researchers will also provide economics
and measurements of odor, pathogens and ammonia emission for the farm-scale
projects. This information will allow more complete evaluation of alternative
systems to improve manure management and byproduct utilization, and reduce
environmental effects to air and water. Research on the sources of airborne
emissions from swine houses will allow for targeted approaches to reduce
these emissions.
c. Planned work for 2003-2004:
Demonstration and evaluation will continue on alternative manure management
systems under the agreements between Smithfield Foods, Inc./Premium Standard
Farms and the N. C. Attorney General. Treatment systems. Systems
include an SBR system, two belt systems, an aerated upflow biofilter system
(Ekokan, Inc.), and energy and ash from combusting separated swine solids
and turkey litter (BEST, LLC). For all these systems, technical and
economic analyses will be conducted.
For nutrient utilization, work will continue to develop and evaluate a continuous-flow
duckweed system for nutrient removal from swine wastewater after anaerobic
digestion. The goal of future research with this system is to determine
the proper feeding rate necessary to create a stable situation that can treat
a steady flow of influent. Future research will also be performed to
compare the performance of three different types of duckweed to provide for
the best possible system design.
d. Publications Issued:
Refereed Articles
Arogo, J., P. W. Westerman and A. Heber. 2003. A review
of ammonia emissions from confined swine feeding operations. Transactions
of the ASAE 46(3):805-817.
Arogo, J., P. W. Westerman and Z. S. Liang. Comparing ammonium ion
dissociation constant in swine anaerobic lagoon liquid and deionized water.
Transactions of the ASAE (in press).
Chaiprapat, S., J. Cheng, J. J. Classen, J. J. Ducoste and S. K. Liehr.
2003. Modeling nitrogen transport in duckweed pond for secondary treatment
of swine wastewater. Journal of Environmental Engineering 129(8):731-739.
Conference Papers and Proceedings
Arogo, J., P. W. Westerman, A. J. Heber, W. P. Robarge and J. J. Classen.
2003. Ammonia emissions from animal feeding operations. In: Proceedings
of AWRA 2003 Spring Specialty Conference Agricultural Hydrology and Water
Quality. May 12-14, 2003, Kansas City, MO. AWRA, Middleburg, VA.
Bowers, K. E. and P. W. Westerman. 2003. Phosphorus removal
in a novel fluidized bed crystallizer. ASAE Annual International Meeting,
July 27-30, 2003, Las Vegas, NV. ASAE Paper No. 03-4123. ASAE, St. Joseph,
MI.
Cheng, J., S. Liehr and C. Lyerly. 2003. Swine wastewater treatment
in an integrated system of anaerobic digestion and duckweed nutrient removal.
ASAE Annual International Meeting, July 27-30, 2003, Las Vegas, NV.
ASAE, St. Joseph, MI.
Sweeten, J., L. Jacobson, A. Heber, D. Schmidt, J. Lorimor, P. Westerman,
J. R. Miner, R. Zhang, C. M. Williams and B. W. Auverman. 2003.
Odor mitigation for concentrated animal feeding operations: White paper
and recommendations. In: Proceedings of AWRA 2003 Spring Specialty Conference
Agricultural Hydrology and Water Quality. May 12-14, 2003, Kansas City,
MO. AWRA, Middleburg, VA.
Westerman, P. W., J. Arogo, A. Kantardjieff and P. Kantardjieff. 2003.
Evaluation of Ekokan biofiltration treatment system on a swine farm.
ASAE Annual International Meeting, July 27-30, 2003, Las Vegas, NV.
ASAE Paper No. 03-4125. ASAE, St. Joseph, MI.
Westerman, P. W. and J. Arogo. 2003. Performance of the IESS
biokinetic air waste treatment system on a swine farm. In: Proceedings
of the 9th International Symposium on Animal, Agricultural and Food Processing
Waste, October 12-15, 2003. Research Triangle Park, NC. ASAE,
St. Joseph, MI.
Westerman, P. W., J. Arogo, G. Boyd and K. Elmer. 2003 Evaluation
of the “BEST” system – solids/liquid separation and solids combustion.
In: Proceedings of the NCSU Animal Waste Management Conference, October 16-17,
2003, Research Triangle Park, NC. N. C. State University, Raleigh, NC.