The Study On Treating Of Low Concentrations Of Cd²⁺ Wastewater By MBR With Additives（PAC）

Heavy metals is one of the main problem about water pollution, heavy metals governance has been the major topic of research in the field of water environment. The membrane bioreactor in the water pollution control has a broad development trends and application prospects. This paper will research cadmium (Cd2+) when based on membrane bioreactor and used powdered activated carbon as an additive, we through the comparison of membrane bioreactor and additives coupled membrane bioreactorTo understand the coupling mechanism of the additive for provide effective technical guidance for the removal of heavy metals and the application of MBR development.In this paper, the reality of the manual configuration of waste water containing cadmium, parallel experiments of MBR and PAC-MBR effect of cadmium and analysis of the coupling effect of the PAC.The experimental results show that the MBR removal of cadmium in wastewater, with the increase of the initial concentration of cadmium in water, the membrane bioreactor decreased cadmium removal. PAC coupling has greatly improved the reactor removal efficiency of cadmium in a certain dosage range, with the increase of PAC dosage, cadmium removal efficiency enhancement. Within the experimental range, the HRT is 4 h, the MBR on the initial concentration of 2.5mg/L cadmium removal efficiency of 98%, the effluent concentration of 0.049 mg/L. Under the same conditions, the optimal dosage of PAC coupling of 1.0 g/L PAC-MBR of cadmium removal efficiency of 99.7% water cadmium concentration of 0.007 mg/L. PAC coupling to improve the removal efficiency of cadmium increased the reactor COD removal efficiency, delay membrane fouling.PAC coupling to improve the environment for the growth of microorganisms, forming a sludge floc activated carbon skeleton, an increase of the particle size of sludge particles in the reactor, reactor removal efficiency of pollutants.