Biological Fluidized-Bed Treatment of Wastewater from Byproduct Coking Operations: Full-Scale Case History

• Published in: Water environment research 1999-01, Vol.71 (1), p.5-9
• Main Authors: Sutton, Paul M., Hurvid, Jim, Hoeksema, Martin
• Format: Article
• Language: English
• Subjects: Ammonia; Applied sciences; Biological and medical sciences; BIOLOGICAL TREATMENT; Biological treatment of waters; Biomass; Biotechnology; Chemical oxygen demand; Coal and derived products; COKING OPERATIONS; Energy; Environment and pollution; Exact sciences and technology; FLUIDIZED‐BED REACTORS; Fuels; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Industrial effluents; Industrial wastewaters; Miscellaneous: general maintenance, miscellaneous installations, waste waters, etc; PHENOLICS REDUCTION; Pollution; Reactor design; Research Papers; Sand; Start up firms; THIOCYANATE REDUCTION; Wastewater; Wastewater treatment; Wastewaters; Water treatment and pollution
• ISSN: 1061-4303; 1554-7531
• DOI: 10.2175/106143099X121698

The Algoma Steel byproduct coke plant consists of three coke-oven batteries capable of producing approximately 3 000 t/d of coke. The source of the primary process wastewater from the coke plant is the excess flushing liquor or weak ammonia liquor produced during initial cooling of coke-oven gases. This raw liquor stream is directed to an ammonia still where ammonia is recovered through steam stripping. Wastewater is then directed to a biological treatment plant designed for phenolics removal. The biological treatment scheme used at Algoma is a fluidized-bed reactor (FBR) system. Design of the system anticipated a median phenolic load of 1 117 kg/d (2 463 lb/d), consisting of a phenolics concentration of 1 012 mg/L in the wastewater and a flow of 46.1${\rm m}^{3}/{\rm h}$(203 gpm). Nine days after start-up, the FBRs were receiving more than 40${\rm m}^{3}/{\rm h}$of wastewater containing 1 000 mg/L of phenolics and an approximately equal amount of clean mill water, added as dilution water for temperature control. Effluent from the system contained less than 5 mg/L phenolics. During a 6-week performance assessment of the system, which began approximately 2 weeks after process start-up, FBRs achieved more than 99% phenolics reduction based on diluted wastewater feed concentration. Approximately 5 weeks after process start-up, thiocyanate in the effluent was reduced to less than 5 mg/L, representing approximately 95% removal based on diluted wastewater feed concentration. At this time the biomass concentration, measured as volatile solids, in the FBRs was greater than 15 g/L.