The Choice And Research Of Application Effect In The Printing And Dyeing Wastewater Treatment Reconstructed Engineering Project Of JiangSu Lianfa Dyeing And Finishing Factory

JiangSu Lianfa dyeing and finishing factory is a branch of JiangSu Lianfa Ltd.. The factory has had a set of wastewater treating process and the ability is 2300t/d. The original process is a combined process of hydrolysis and acidification-biological oxidation- dissolved air flotation (DAF). After using 6 years, some problems were found; the main problem was that the out effluent quality could not meet the national discharge standard. According to raise production capacity and promote wastewater effluent quality, JiangSu Lianfa dyeing and finishing factory modified its original wastewater treating process. The treating ability of the reconstructed project is 3000t/d and out effluent quality must be better than the national discharge standard. After inviting public bidding, many plans are put forward and four feasible projects are selected from these projects. In order to keep the effluent meeting discharge standard, decreasing the gross investment and easy to use and maintain, we analyze some feasible project by Analytic Hierarchy Process (AHP). AHP was developed in the 1970's by Dr. Thomas Saaty and it is a powerful and flexible decision making process to help people set priorities and make the best decision when both qualitative and quantitative aspects of a decision need to be considered. By reducing complex decisions to a series of one-on-one comparisons, then synthesizing the results. In the end, we choose the 2nd project. A combined process of hydrolysis and acidification-two phase biological oxidation-DAF was applied for dyeing and finishing wastewater treatment in this project. We enlarge the capacity of balancing tank and add a phase biological oxidation process. In the same time, we change the air flotation tank and extend HRT. The water quality measuring results is: SS 67mg/L, B0D5 12.9mg/L, COD 70 mg/L and chroma 18. The results indicated that they meet the first level of concerned national discharge standard, respectively, with SS, BOD5, COD and chroma removal efficiencies of 63.6%, 93.4%, 92.3% and 92.9%.