Technology Evaluation for Priority Pollutant Removal from Dyestuff Manufacture Wastewaters

摘要

Laboratory-scale studies were conducted to establish the technical feasibility of employing certain processes, including ozonation, GAC adsorption and biophysical (PACT) treatment, for the treatment of dyestuff manufacture wastewaters with special focus on the removal of organic priority pollutants. The GAC adsorption studies showed that GAC provided for excellent removals of both color and priority pollutants but cannot be expected to concomitantly provide for high levels of SOC removal due to comparatively high levels of non-adsorption organics that occasionally are present in dyestuff manufacture wastewaters. Excellent removals of organic priority pollutants were achieved by the PACT process. In addition, SOC and color removals were enhanced by the addition of PAC to an activated sludge system, generally in direct relation to the steady-state concentration of PAC in the reactor. Although ozonation provided for the removal of many organic priority pollutants to levels below detectability, some proved to be comparatively resistant to oxidation by ozone. As for GAC and the PACT process, ozonation provided excellent color removals. Only moderate organic carbon removals were achieved by ozonolysis, however. A priority pollutants survey showed the presence of a total of 23 organic priority pollutants in the raw wastewaters. With the exception of methylene chloride, removal levels of volatile organic priority pollutants generally exceeded 95 percent.