| Pulp and paper industry is one of the most significant resources of water pollution.At present,the amount of the wastewater discharged and CODCrranked first.The study on efficient methods to treat pulp & paper wastewater has become a prevailing and difficult issue in the environmental field.In this dissertation,since the effluent from secondary biological treatment process in a pulp & paper mill can not reach the strict wastewater discharge standard,an available advanced treatment proposal,anaerobic treatment + aerobic treatment + coagulation and precipitation advanced treatment,was raised based on the in-depth study and analysis of existing wastewater treatment system along with the relevant research and application at home and abroad The proposed treatment build upon the existing wastewater treatment system in which new anaerobic treatment device was built in front of aerobic treatment system while following it is a deeply coagulation and precipitation treatment device. Comparison results of the treatment showed as following:CODCrof effluent from biological treatment system decrease from about 370mg/L to no more than 300mg/L after annexing anaerobic treatment process.CODCrof effluent from coagulation and precipitation deeply process decreased to less than 150mg/L and the average removal of CODCrincreased from 82.2%to 93.7%;BOD in effluent decreased to no more than 40mg/L and the average removal of BOD5 increased from 88.6%to 94.2%;SS decreased to less than 70mg/L and the average removal of SS increased from 90.3%to 95.2%.The new treatment processing is stable in operation removal of pollutants.The water quality reachs the discharge standard in Shandong province(DB37/336-2003).The results showed that the new treatment proposal was viable both in theory and in practice.The treatment system was characterized by its reliability for meeting strict wastewater discharge standard,low capital investment and operation cost.And also it will lay foundation for wastewater resource.
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