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A clean
water technology recovers nitrogen, as ammonia, from various dilute waste
streams and converts it into ammonium sulfate, a marketable commercial
grade fertilizer. The ammonia recovery process (ARP), unveiled by
ThermoEnergy Corp. (1300 Tower Bldg., 323 Center St., Little Rock, AX
72201; Tel: 501/376-6477, Fax: 501/375.5249), has been selected as one of
1999's 100 best technologies by R&D Magazine. ARP has the potential to
reduce large quantities of nitrogen discharged daily into local bodies of
water by municipalities, concentrated animal farming operations, and
industry.
The low-cost,
environmentally sound cleaning process was successfully proven in a
large-scale field demonstration project at New York City's Oakwood Beach
Wastewater Treatment Plant (Staten Island, NY 10310). Foster Wheeler
Environmental Corp. (Perryville Corporate Park, Clinton, NJ 08809-4000;
Tel: 908/ 730-4000) oversaw the pilot plant, which ran for 12 weeks. The
New York City Dept. of Environmental Protection (59-17 Junction Blvd.,
10th Floor, Corona, NY 11368; Tel: 718/337-4357) and EvTEC, the
Environmental Technology Evaluation Center (1015 15th St. NW, Suite 600,
Washington, D.C. 20005; Tel: 202/842-0555, Fax 202/ 789-2943), provided
independent, third party testing to verify performance claim
.
The technology consistently
removed greater than 90% of the ammonia before the effluent was
discharged, a rate equivalent to a 40% reduction in the total nitrogen
load to the wastewater treatment plant. Based on laboratoryscale ammonia
recovery processes developed by Battelle and Pacific Northwest National
Laboratory (902 Battelle Blvd., P.O. Box 999, Richland, WA 99352; Tel:
509/375-2121, Fax: 509/372-4791), ARP is a reversible chemisorption
process that controls the spread of ammonia and resulting nitrates to
waterways and drinking water.
Using an adsorption resin and regeneration solution, the
technology extracts ammonia from sewage treatment liquid (centrate) or
livestock waste. ARP is tied into the centrate line from the digester
effluent before it is returned to the head of the treatment plant. An
intermediate scrubber unit brings the volatilized ammonia back into
solution and converts the nitrogen-rich backwash into commercial grade,
ammonium sulfate crystals-a dry, odorless soil nutrient. The system can be
used at sewage treatment plants and feedlots to avoid environmental fines
and potential shutdowns. The process effectively removes low
concentrations of ammonia at lower cost per gallon than the conventional
ammonia removal methods, air stripping, water stripping, and biological
nitrogen removal. The process recovers more ammonia, requires less space
and adds no chemicals to the discharge effluent.
ARP is just one part of a trio
of ThermoEnergy wastewater treatment technologies for the reduction of
wastewater sludges and excessive levels of nitrogen in effluent. The
sludge-to-oil reactor system converts wastewater sludge into useful,
burnable fuel oil, the hydrothermal NitRem (nitrogen removal) process
transforms organic and inorganic nitrogen into nitrogen gas, carbon
dioxide, and water.
ARP was
developed to treat the soluble, nitrogen-rich effluent left by the
sludge-to-oil reactor before it is returned to the head of wastewater
treatment plants, but can be used as a stand alone process. Because all
three technologies are non-biological treatments, they are less sensitive
to fluctuations in wastewater influent parameters.
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