Characteristics of bio-diatomite dynamic membrane process for municipal wastewater treatment

The characteristics of bio-diatomite dynamic membrane (BDDM) process in municipal wastewater treatment were investigated with a laboratory-scale continuous-flow device. Experimental results indicate that the BDDM reactor was highly effective in removal of COD, NH4-N and TN, and exhibited the advantages of good retention capacity for suspended solids (SS), short precoating time, high filtration flux, and easy backwash. In the precoating stage, a retention time of 25 min could reduce the effluent SS to non-detectable level. The filtration resistance of BDDM was composed of thickness-increase resistance and compaction resistance. At a low flux, microbial adhesion occurred on the interface between the BDDM and the stainless steel support mesh, which negatively impacted the system operation and backwash. However, microbial adhesion could be effectively minimized by increasing the filtration flux.