ZenoGemÔ Process
ZENON ENVIRONMENTAL INC.
(ZenoGemÔ Process)
TECHNOLOGY DESCRIPTION:
ZENON Environmental Inc.'s ZenoGemÔ Process integrates biological treatment with membrane-based ultrafiltration (see figure below). This innovative system treats high strength wastes at long sludge retention time but short hydraulic residence time. As a result, the bioreactor's size is significantly reduced. Membrane filtration reduces the turbidity of the treated waste to less than 1 nephelometric turbidity unit.
In the ZenoGemÔ Process, wastewater contami-nated with organic compounds first enters the bioreactor, where contaminants are biologically degraded. Next, the process pump circulates the biomass through the ultrafiltration membrane system, or ultrafilter. The ultrafilter separates treated water from biological solids and soluble materials with higher molecular weights, including emulsified oil. The solids and soluble materials are then recycled to the bioreactor. The ZenoGemÔ Process captures higher molecular weight materials that would otherwise pass through conventional clarifiers and filters.
The ZenoGemÔ Process pilot-scale system is mounted on a 48-foot trailer and consists of the following six components:
· Polyethylene equalization/holding tank: reduces the normal flow concentration fluctuations in the system
· Polyethylene bioreactor tank: contains the bacterial culture that degrades organic contaminants.
· Process and feed pumps: ensure proper flow and pressure for optimum system performance
· Ultrafiltration module: contains rugged, clog-free, tubular membranes that remove solids from treated water
· Clean-in-place tank: includes all the necessary valves, instrumentation, and controls to clean the membrane filters
· Control panel and computer: monitor system performance
The treatment capacity of the pilot-scale trailer-mounted system is about 500 to 1,000 gallons of wastewater per day; however, a full-scale system can treat much larger quantities of wastewater. The trailer is also equipped with a laboratory that enables field personnel to conduct tests to evaluate system performance. The system is computer-controlled and equipped with alarms to notify the operator of mechanical and operational problems.
WASTE APPLICABILITY:
The ZenoGemÔ Process is designed to remove biodegradable materials, including most organic contaminants, from wastewater to produce a high quality effluent. The process consistently nitrifies organics and can denitrify organics with the addition of an anoxic bioreactor. The process is limited to aqueous media and may be used to treat high strength leachates, contami-nated groundwater, and soil washing effluent.
STATUS:
The ZenoGemÔ Process was accepted into the SITE Demonstration Program in summer 1992. The ZenoGemÔ Process was demonstrated at the Nascolite Superfund site in Millville, New Jersey from September through November 1994. Groundwater at this 17.5-acre site is contaminated with methyl methacrylate (MMA) and other volatile organic compounds from manufacturing polymethyl methacrylate plastic sheets, commonly known as Plexiglas. The
Demonstration Bulletin (EPA/540/MR-95/503) is available from EPA.
DEMONSTRATION RESULTS:
During the 3-month demonstration, permeate sampling results showed that the system achieved average removal efficiencies of greater than 99.9 percent for MMA and 97.9 percent for chemical oxygen demand (COD). MMA concentrations measured in the off-gas emission stream and activated carbon filters indicated insignificant volatilization. The ultrafiltration system effectively dewatered the process sludge, which yielded a smaller waste volume for off-site disposal. Sludge dewatering resulted in an approximate volume reduction of 60 percent and a solids increase from 1.6 to 3.6 percent. The process effluent was clear and odorless, and accepted for discharge by the local publicly owned treatment works. During the demonstra-tion, the system was left unattended at night and on weekends, demonstrating that computer con-trol is practical for extended operating periods.
FOR FURTHER INFORMATION:
EPA PROJECT MANAGER:
Daniel Sullivan
U.S. EPA
National Risk Management Research
Laboratory
2890 Woodbridge Avenue
Edison, NJ 08837-3679
908-321-6677
Fax: 908-906-6990
TECHNOLOGY DEVELOPER CONTACT:
F.A. (Tony) Tonelli or Philip Canning
ZENON Environmental Inc.
845 Harrington Court
Burlington, Ontario, Canada
L7N 3P3
905-639-6320
Fax: 905-639-1812