Magnetic Ion Exchange Resin-coagulation-UF Combined Process Of Wastewater Treatment

This thesis was based on the technology needs of using Beijing’s regenerated water in rivers and lakes landscape, to analyze the differences among secondary effluent sewage treatment plants and urban rivers, lakes present surface water, IV Grade water. With magnetic ion exchange resin-coagulating sedimentation-ozone oxidation/ultrafiltration membrane wastewater treatment combined process as the research object, carried out the MIEX dosage, coagulating sedimentation, ozone dosage, ultrafiltration membranes individual technologies and its synergistic effect on pollutant removal efficiency, to establishment the combined processing system of magnetic ion exchange resin-coagulating sedimentation-ozone oxidation/ultrafiltration membrane wastewater treatment. By optimization study the composition and operation mode of the complex process system, enable the effluent water quality reach the standards of surface water environmental quality IV Grade.The optimum reaction conditions of the combined process was as follows:MIEX mixing speed500r/min, reaction time30min, precipitation time20min, PAC slow mixing speed120r/min, reaction time20min, rapid mixing speed for300r/min, reaction time4min, sedimentation time30min.MIEX-PAC-film combinations perform the best removal effect for TP, TN, COD and DOC, and the removal rate were57.14%,69.80%,46.95%and45.77%, for NO3--N and turbidity the removal rate also at a higher state, and the removal rate are53.26%and99.13%respectively. In view of the raw water quality characteristics, the subject focuses on considering the COD and TP removal efficiency. Meanwhile in the process of using O3will produce some disinfection byproducts, which is not conducive to reach the water quality standards. Finally this subject determines to select the resin-PAC-film combinations to complete the combined process. The most economical test proposal was as follows MIEX10ml/L, coagulant PAC160mg/L and a set of combined process module:magnetic ion exchange resin-coagulating sedimentation-ultrafiltration membrane.We have made Long-term operation and monitoring for the combined process, it shows that on the condition of influent water pollutant concentrations:COD35mg/L～70mg/L, BOD56mg/L-15mg/L, TN2mg/L-11mg/L, TP0.3～1.0mg/L, chlorophyll a80μg/L-130μg/L, turbidity4-23mg/L, when raw water was treated by the combined process technology systems, the effluent water pollutant concentrations:COD10mg/L-30mg/L, BOD53mg/L-6mg/L, TN lmg/L～5mg/L, TP0.05～0.3mg/L, chlorophyll a5μg/L～10μg/L, turbidity0.1-0.6mg/L. The removal rate of major pollutants in water was as follows:COD over50%, BOD5over30%, TN over35%, TP over70%, chlorophyll a over70%, the turbidity over90%, and effluent quality reaches the national surface water environmental quality standard GB3838-2002IV class limits.