Methanotrophs for Biological Pollution Control: Feasibility of Developing anAttached Microbial Film Reactor and Kinetics of TCE Removal. Final Report, July 15, 1987-March 31, 1989. Phase 1 and Phase 2

摘要

The group of aerobic bacteria that use methane gas as an energy source growrapidly and have simple nutrient requirements. They have been shown to be capable of biodegrading a wide range of toxics. The two-phase effort defined the potential for combining a high rate attached film reactor, the expanded bed (MAFEB), with applications for trichloroethylene (TCE) and nutrient removals from wastewater. The MAFEB reactor resulted in a highly stable biological reactor capable of operating at hydraulic retention times of several minutes. The methanotrophic films were thin and dense, especially for an aerobic system. Microbial film densities exceeded 100 gVS per liter of attached film and the concentration of microorganisms exceeded 25 gmVS per liter of expanded bed reactor. TCE degradation kinetics were examined in numerous batch trials. The degradation rates approach the higher literature values of 20 mg/gVS-d, with resulting maximum removal rates of 800 mg TCE/L-d. A relatively high value of KS of 3 mgTCE/L was estimated. The use of the MAFEB system was tested for potential use as a tertiary treatment system. Denitrification was not found to occur at measurable levels with methane as an energy source. Nutrient assimilation via cell yield showed promise as a method to remove dissolved nitrogen and phosphorus from wastewater.