ABSTRACT
This chapter focuses on the reuse of gasification wastewaters. Treatment options examined include solvent extraction, steam stripping, activated sludge treatment for organics removal, and nitrification/ denitrification. Research at University of North Dakota Energy Research Center (UNDERC) has examined the effect of stripped gas liquor (SGL) and biologically treated SGL on the operation of pilot scale cooling towers. The principal goals of this research are to develop treatability and environmental data on effluents from coal gasification. In order to separate the effects of organic removal from those of nitrogen removal, the SGL was pretreated at UNDERC using a complete-mix activated sludge system described in detail by Gallagher et al. Antifoam was needed rarely since the organic content of the feed wastewater to the nitrification and denitrification reactors was very low. The sole purpose of the denitrification work was to demonstrate process feasibility with this wastewater.
