ANAEROBIC TREATABILITY OF A PHENOLIC COAL CONVERSION WASTE-WATER AFTER DIISOPROPYL ETHER EXTRACTION

The combined treatment requirements for a high strength phenolic wastewater were examined in semicontinuous methogenic cultures. Selective pH adjustment of H-coal wastewater followed by diisopropyl ether extraction was used to control the phenolic concentration fed to the serum bottle cultures. This pretreatment did not completely remove the unidentified inhibitory compound(s) from the wastewater. Thus the addition of activated carbon to the cultures and a reduced feed rate were required to stabilize their activity. However, by the end of the 250-day test period, the cultures were maintained with a 12.5-day hydraulic retention time and were fed approx. 9 parts pH 9-extracted H-coal wastewater and 1 part inorganic nutrient solution. The influent phenol concentration was near 900 mg/l, whereas the effluent concentration was < 2 mg/l. Residual dissolved diisopropyl ether did not inhibit the anaerobic process nor was it biodegraded to methane.