Evaluating possibility to treat paper processing waste water by biological process

Abstract

Paper manufacturing industry occupies an important position in the economy of our country. Along with the development of the industry, the other services, the demand for paper products is increasing. However, besides these few benefits achieved tremendous economic - social, this industry also generated many pressing environmental issues need to be solved, especially waste water generated in the paper making process and such wastewater is very difficult to handle. Currently there are about 90 paper factories are operating in the country. Paper production capacity in South of Vietnam is about 90,000 tons/year, of which HCM accounts for over 12,000 tons/year (Institute of Environmental Technology, 2009). Wastewater generated from paper industry contains very high organic matters with COD concentration in the range of 22,000 to 46,500 mg/l; BOD/COD ratio accounts for 40-60%. The wastewater treatment system in every factory is good enough for treating wastewater, but the cost for treat each m3 of wastewater is quite high and complicate to operate. Beside of that, the outcome wastewater is also need to increase the quality for better environment. In this research, I successfully to treat wastewater from DongNai Paper Company from high value of organic matters with COD concentration in the range of 400 to 800 mg/L to low concentration in the range of 16 to 24 mg/L by using different pre-treatment step and reactor SBR model. Key word: Pulp and paper wastewater, coagulation-flocculation, activated sludge treatment.