Three pilot-scale activated sludge units were operated in parallel with common pretreatment utilizing wastewater streams from a Class D refinery. Effluents from the following systems were tested: 1. Conventional Treatment: A conventionally operated activated sludge unit + final filtration. 2. GAC Treatment: A conventionally operated activated sludge unit + final filtration + granular activated carbon contactors. 3. Commercial PAC Treatment: An activated sludge unit to which a blend of commercially available powdered activated carbons was added + final filtration. 4. Experimental PAC Treatment: An activated sludge unit to which an experimental high-surface-area@ powdered activated carbon was added + final filtration. Half-strength and full-strength effluents from the pilot units were compared over three separate 30-day test periods using conventional effluent parameters and continuous-flow fish bioassays with sheepshead killifish@ Cyprinodon variegatus. Short-term (96-hour) and long-term (30-day) bioassays were conducted to distinguish between transient system upsets and longer-term cumulative effects. Fish tissue was examined microscopically for histopathological changes and was analyzed for accumulation of polynuclear aromatic hydrocarbons and metals (single sampling).
API PUBL 958-1981 history
1981API PUBL 958-1981 Pilot Studies on the Toxicity of Effluents from Conventional and Carbon Enhanced Treatment of Refinery Wastewater-Phase III