UBC Theses and Dissertations
The aerobic biological treatibility of a high strength mixed petrochemical industrial sludge Whalen, Thomas F.
Investigations were performed on the aerobic biological degradation potential of a high-strength, industrial sludge from the Chatterton Petrochemical site in Delta, BC. The sludge was located at the bottom of one of the wastewater treatment equalization lagoons. The lagoon was used to store process water and on site drainage from the Phenol processing plant operations. The plant had been in operation from 1961 to 1991. The sludge contained high concentrations of: Phenol, Diphenyl, Diphenyl Ether, Diphenyl Methane and Xylene and had a Total COD of over 250 000 mg/L. It also contained over 1000 mg/L of copper and cobalt. Treatment was initially attempted using a Modified Batch Process (MBP). Nine batches were run, to determine the best initial sludge loading level in the treatment system and to assess the degree of treatability of the waste mixture. In each set of experiments, a control was run to determine the degree of volatilization of the organic compounds from the waste. Twenty litre batches, having been diluted up to ten times, were run for more than forty days. In later batches, due to microorganism growth problems, both ammonia and phosphorus were added to the system; phosphorus was needed both for the growth of microorganisms and the precipitation of dissolved copper. The performance of the systems was monitored using Total COD, Total BOD and the concentration of selected target organics present in the mixture. The most notable batch data resulted from a reactor loaded with an initial Total COD of approximately 30 000 mg/L. All the organic compounds of the sludge were removed from the mixture to below the detection limit of the Gas Chromatograph and the Total B0D was reduced to a negligible concentration. The success of the run was attributed, in part, to the high concentration of phosphorus present in the system. The concentration was 100 mg/L higher than the nutrient requirements of the culture and the elevated nutrient loading apparently resulted in the precipitation of much of the dissolved copper present in the reactor. The control showed that when the system was run under ideal conditions, the loss due to volatilization could be limited to less than 5%, based on Total COD. The system was then modified to operate as a True Batch Process (TBP). Treatment was attempted by keeping 75% of the previous run's final product in the reactor, while inputting a new load of sludge and dilution water to make up the volume difference. Results from the run indicated that treatment kinetics of the new system were three time faster than the best batch run based on Total BOD degradation. All of the organic compounds had been removed to below the detection limit of the Gas Chromatograph in the end product sludge. However, questions remained about the accumulation of copper in a true batch treatment system. Pretreatment of the sludge to remove copper may be necessary to achieve the high Total BOD removal rates seen in the true batch system.
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