The Xiangxiang Leather Industrial Park Wastewater Treatment Plant Design And Practice

Tannery wastewater has the characteristics of large water volume, complicated composition and high pollutant concentration, so it is difficult to deal with. It has been the most important problem to design a set of wastewater treatment technology with low operation cost and fine treatment efficiency. In this thesis, a set of integrated tanning wastewater system was designed according to the practical requirement of wastewater treatment of Xiangxiang's tanning enterprises, and it was also put into practice.According to the wastewater quality analysis at the leather industrial area in Xiangxiang city of Hunan province and fully comparison of existing wastewater treatment technology, physicochemical-biological oxidation technology was selected to treat wastewater of Xiangxiang tanneries. The discharge wastewater quality was required to meet the demand of Integrated Wastewater Discharge Standard (GB8978-1996) according to the wastewater quality and requirement of local government.The detailed technical proposal, processing design, estimation of project investment and economical analysis had been carried out, and the wastewater treatment plant.The experimental results of biological oxidation at lab showed that the removal ratio of COD_Cr was 90%. The practical operating records indicated that this wastewater treatment processing had high removal efficiency of COD, BOD₅ and sulfides (S^2- and SS). The effluent quality could achieve or exceed the demand of GB8978-1996 even though the integrated tanning wastewater quality (COD, BOD₅, S^2- and SS) fluctuated extensively.In a word, the treatment processing was reasonable and effective for the integrated tanning wastewater, and could be popularized or spreaded as a model project.