Thermophilic Aerobic Treatment of High Strength Organic Production Wastes and Waste Activated Sludge from a Pharmaceutical Manufacturer: Bench-Scale Test Results and Full-Scale Design Issues

A pharmaceutical intermediate manufacturer currently generates dilute process wastes, high organic strength liquid process wastes and waste biological sludge some of which are treated onsite while the remainder are hauled off-site for additional treatment and disposal. The high organic strength waste streams are generated from batch processes and contain a variety of solvents such as methanol, acetone, methylene chloride, MIBK, and toluene. The COD range of the high strength waste is 40,000 mg/L – 500,000 mg/L. There is also a high inorganic salt content associated with the high strength wastes that includes chloride, sulfate, and sodium ions at concentrations of 2,000 – 170,000 mg/L measured as non-volatile dissolved solids (NVDS). The high strength waste is currently sent to onsite storage tanks prior to being trucked off-site to a nearby treatment and disposal facility. With production expected to increase in the coming years and the new pharmaceutical effluent guidelines taking effect in 2001, capital improvements would be needed to treat the additional loading to the existing WTP. Plant and corporate personnel wanted to evaluate thermophilic treatment of the high strength wastes (maximum 5,000 lb/day COD) and excess biological sludge (maximum 375 lb/day COD) for its potential to lower the COD loading to the existing WTP, minimize off-site disposal, lower WTP plant operating costs, and keep the WTP in compliance with the new pharmaceutical effluent guidelines. This paper discusses the approach utilized to evaluate the performance of the thermophilic treatment process on the target wastes along with presentation of the results and the implications of the results on the full-scale design of the system.