PRELIMINARY ASSESSMENT OF THE REMOVAL OF VOLATILE ORGANIC-COMPOUNDS IN A BIOLOGICAL SELECTOR PROCESS

The fate of selected volatile organic compounds (VOCs) in anoxic or an aerobic selectors was investigated at pilot scale. Tetrachloroethylene , 1,4-dichlorobenzene, and 1,3,5-trimethylbenzene were consistently re moved at efficiencies in excess of 30%. The removals observed in this study were highly compound specific. Compounds with similar chemical s tructures such as toluene and 1,3,5-trimethylbenzene displayed substan tially different behavior. The selector biomass concentration and hydr aulic retention time were found to have little apparent effect on the VOC removal efficiencies. However, the results were confounded by a ch ange in wastewater temperature that also influenced the loading of nit rate on the selector. The results of these experiments demonstrate the potential of selector technologies for reducing the mass loading of V OCs to aeration basins. The lower mass loadings should reduce the mass of aerobically recalcitrant VOCs that will be stripped to the atmosph ere.