The report gives results of a survey of current uses of biological treatment methods for U.S. iron and steel industry wastewater. It includes identification and characterization, on a pollutant component basis, of waste streams receiving treatment; capabilities of biological treatment; advantages and disadvantages of various biological systems; nitrification and denitrification; current utilization of biological treatment by the industry; and possible alternatives to current biological methods. The coke plant, particularly its waste ammonia liquor, is the major wastewater source for biological treatment. The liquor contains phenol, ammonia, cyanide, thiocyanate, carbonate, sulfide, oil, suspended solids, and dissolved solids. Biological treatment of wastewater can remove 99% of its phenolic constituents. Adjusting operational parameters, including increasing retention time, increases removal of ammonia, cyanide, and thiocyanate. Ammonia reduction exceeding 90% is achievable in nitrification and denitrification units; however, biological systems are susceptible to upsets due to fluctuations in temperature or waste loading. Current use of biological treatment is limited, with interest centered on phenol removal. Pilot studies have shown some physical/chemical methods to be competitive with biological treatment.

"IIT Research Institute." "Industrial Environmental Research Laboratory." "January 1979." Includes bibliographical references (pages 21-22). "Contract no. 68-02-2617, Task no. 2-5, Program element no. 1BB610."