The changes of bamboo pulping waste water residuals in biological treatment process: The changes of bamboo pulping waste water residuals

The residuals of the bamboo pulping wastewater were analysed systematically. The COD (chemical oxygen demand) decreased significantly by adding appropriate coagulant (1.5 kg/m(3) 10% Al-2 (SO4)(3) as coagulant and 2 mg/L anionic PAM as coagulant aid) to the effluent in secondary sedimentation tank. The study found that hydrolytic bacteria in primary sedimentation tank and balancing tank may increase the ratio of BOD/COD and promote the release of ammonia nitrogen (NH3-N), which was benefit to further degradation of organic pollutants by aerobic biological treatment. Through optimizing biochemical process and adjusting contents of nitrogen, phosphorus, and mineral elements, the effects of wastewater treatment has been greatly enhanced and the quality of discharged water could met the new national standard GB3544-2008.