Zimpro's Biophysical Treatment and Wet-Air-Regeneration-System Engineering Study for H-COAL Wastewater

摘要

As part of an overall environmental evaluation of the H-COAL liquefaction process, sour water treatability studies have been performed. These studies consisted of the following major components: H-COAL sour and stripped water characterization study; Zimpro's biophysical treatability and characterization study on H-COAL Wastwater; Zimpro's biophysical treatment system stress testing; Zimpro's biophysical treatment and wet air regeneration system engineering study; engineering analysis of reuse concepts for treated H-COAL wastewater; and evaluation of reverse osmosis treatment of treated H-COAL wastewater. These studies indicate that H-COAL Sour Water can be successfully treated for reuse or for discharge to public waters. Zimpro performed the first three studies on the biophysical treatment utilizing Powdered Activated Carbon Treatment (PACT). The PACT studies achieved the following results: Five-day biochemical oxygen demand (BOD sub 5 ) removal was > 98.8%; chemical oxygen demand (COD) removal was 85 to 87%; esentailly complete nitrification was achieved; phenolics removal was > 99%; priority pollutants were removed to levels below Environmental Protection Agency (EPA) defined detection limits; PACT operated well using wet air regenerated carbon; and carbon recovery was approx. 90% in the wet air regeneration step. The third step in the Zimpro studies was a larger scale pilot investigation to: Confirm information developed in bench-scale experiments on a larger scale; provide performance data necessary to evaluate the PACTs Wet Air Regeneration System; optimize PACT operating conditions; produce treatment wastewater for additional testing; and perform a stress test at elevated concentrations of cyanide and thiocyanate. The results of the third Zimpro study are presented here. (ERA citation 08:022951)