Keystone Sanitary Landfill, Inc. is a privately owned, 720 acre municipal solid waste landfill located in Dunmore, Pennsylvania, USA that processes 5,000 tons of sanitary wastewater each day. The landfill operates under the revised Commonwealth of Pennsylvania regulations, which conform to the US Environmental Protection Agency’s Sub Title D requirements and is in full compliance with 25 PA Code, Chapter 273.
Headworks adds that Keystone needed an economical retrofit that would increase the capacity of the wastewater treatment process to 108,000 GPD while reducing BOD5 and ammonia for effluent discharge. The ActiveCell® biological treatment process from Headworks BIO™ Inc. was selected for the application to retrofit and upgrade four existing biological reactors that were previously used as a static fixed film media process equipped with a down draft mixer.
Moving Bed Biofilm Reactor (MBBR) technology employs robust, reliable biological technology. The process biodegrades wastewater using thousands of suspended media that operates in a continuously mixed environment. Each piece of media provides an active surface area sustaining heterotrophic and autotrophic bacteria within protected cells. This dynamic population of bacteria achieves high rate biodegradation productivity within the system, while also offering process resiliency and automated operation. MBBR technology enables industrial facilities, marine vessels, communities, and commercial businesses to reliably meet or exceed stringent environmental regulations.
When the static media was removed from the existing biological reactors, it was packed with biosolids and was anaerobic and septic. The down draft mixers were replaced with coarse bubble air diffusers and regenerative blowers. Last, the basins were loaded with ActiveCell450 biofilm carriers.
The complete mix aerobic ActiveCell process operates without build-up of excess biomass since the carriers are in constant motion where dead biomass is continuously sloughed from the active surface area. This eliminated an anaerobic digester process and as a result, provided the landfill with increased treatment capacity, enhanced performance, and optimized reliability of the wastewater treatment facility.
The landfill leachate is directed to a pre-treatment process followed by an ammonia stripper to provide a 62% reduction in ammonia mass loading on the biological treatment system. After an economiser heat exchanger, the stripper effluent is then directed to four ActiveCell bioreactors plumbed in series to provide optimal biokinetics for COD reduction and nitrification of ammonia. The bioreactor effluent is directed to a clarifier for final discharge to the sewer drain.
Headworks’ MBBR treatment process eliminated the problematic anaerobic digester process while increasing flow capacity from 35,000 GPD to 100,800 GP, a 209% increase, all within the same overall footprint.