Study Of Coagulation-Cloth-Media Disk Filter For Wastewater Reclamation

Coagulation-Cloth-Media Disk Filter(CMDF)is a new and efficient technology for wastewater reclamation,which began to be used in the latest 10 years. The technology used a new-style of surface filtration—cloth filtration instead of the conventional deep-bed porous media filters.In the technology,flocculating and depositing occurred simultaneously in a single pool.On the basis of complete and systematical analysis and review of recent development of cloth filtration technology and theory in the world,a complete and intensive test on the technology and its application to the wastewater reclamation in China was performed.The main contents and results of these researches are as follows:(1)This study systematically inspected the Coagulation—Cloth-Media Disk Filter process for treatment of urban sewage secondary treatment effluent and the effect of general law by using secondary effluent of Dalian laohutan water treatment plant as the influent water.Through this research we can grasp the critical operating parameters and factors,and this research provided reliable information for using this process in wastewater reuse.(2)The performance of CMDF(without coagulation)was studied.The experimental results showed that CMDF can get a perfect effluent quality by direct filtration(Influent SS＜30mg/L,Effluent SS＜5mg/L and the average effluent SS is 3.1 mg/L).So when other water quality indicators can meet the target of wastewater reclamation indicators, the direct filtration removing SS can save coagulant costs and reduce the operating costs.(3)Coagulation—Cloth-Media Disk Filter(CMDF)technology as a pilot study, added two types of coagulant(Al₂(SO₄)₃ and FeCl₃)and chose suitable coagulant and best dosage.The pilot study showed that Al₂(SO₄)₃ is the appropriate coagulant,and the best dosage is 40mg/L.(4)The economic analysis of Coagulation—Cloth-Media Disk Filter process was studied.The results showed that the various economic indicators of Coagulation—Cloth-Media Disk Filter process are significantly lower than traditional technology.The results of the study showed that Coagulation—Cloth-Media Disk Filter process is suitable for China's national conditions in the water reuse technology.In comparison to conventional filtration systerms,this process has a more compact design,smaller footprint,a lower washing water and less expensive.This study provided certain theoretical and practical basis for the promotion and application of Coagulation—Cloth-Media Disk Filter process in our country.