Schoeller Technical Papers, Inc. (Schoeller), which manufactures photographic and other specialty papers, is located in Pulaski, New York. The wastewater treatment system consists of a primary clarifier and two settling lagoons. Secondary treatment using a biotower was proposed to meet the new New York State Pollutant Discharge Elimination System (SPDES) discharge limits for BOD and TSS. The effluent from each basin is discharged directly to the Salmon River, at an approximate average flow of 1.6 million gallons/day (mgd).
A biotower pilot study was performed to evaluate the suitability of a biotower treatment process for treating the total effluent from Schoeller's facility. The pilot study was used to select the media for the full-scale biotower and to confirm the design loading for the full-scale biotower, which proceeded in parallel with the pilot study due to the schedule constraints. Two pilot systems were operated to compare a conventional cross-flow and vertical media. Test data were collected to evaluate the performance of each pilot treatment system at a range of loading conditions and to develop the design loading information for the full-scale plant.
The pilot units were operated for a period of 10 months. BOD concentrations to the pilot units averaged 58 mg/l with a peak of 210 mg/l. Approximately 80% of the BOD was soluble. BOD loadings averaged 21 lb BOD/day/1,000 cubic feet with a peak of 77 lb BOD/day/1,000 cubic feet. Both pilot units achieved excellent BOD removals exceeding 75%, with average effluent soluble BOD concentration less than 10 mg/l and average effluent TSS concentrations of 12 mg/l. The two media achieved comparable performance throughout most of the pilot study.