ABSTRACT
University of North Dakota Energy Research Center (UNDERC) is conducting studies on the treatment of coal-derived wastewaters as part of the coal conversion research program. The objective of the research was to determine the treatability of UNDERC's and Great Plains' coal gasification wastewaters using a bench scale four-stage rotating biological contactor. The total organic loading approach is capable of predicting substrate removals and treatment efficiencies over a wide range of loading conditions regardless of the kinetics displayed by the system. Negative kinetic constants for Chemical oxygen demand and total organic carbon were caused by the relatively steep slope of the fitted line for the loading rates tested. If higher loading rates had been used, the plots would have become flatter and possibly curved upwards as they neared the vertical axis indicating that removal rates had reached a maximum and might decrease due to toxicity and/or oxygen transfer limitation.
