TREATMENT OF TOTAL PHOSPHORUS IN WASTEWATER CONTAINS ORGANOPHOSPHORUS PESTICIDE BY MEMBRANE BIOREACTOR (MBR)

Abstract

A membrane bioreactor using microporous (0.3 µm) polyethylene hollow fiber membrane (Mishubishi) was studied to treat total phosphorus of wastewater from a Glyphosate herbicide manufacturer pretreated by an electro-fenton system. Experimental results show that the efficiency of phosphorus treatment depended on aeration/non-aeration mode, sludge retention time and hydraulic retention time. Phosphorus treatment efficiency increased with increasing aeration time and reducing non-aeration time in a cycle, increasing in sludge retention time and hydraulic retention time. However, the sludge retention time should not exceed 30 days. Phosphorus treatment efficiency was about 64.4% when aeration/non-aeration time was 70 minutes/50 minutes with sludge retention time of 28 days and hydraulic retention time of 9 hours. At that time, the phosphorus concentration in the outlet water was about 3.24 mg/l, meeting the discharge standards according to QCVN 40:2011/BTNMT column A. The results of this study opened up the possibility of applying membrane bioreactor to post-treat the phosphorus in wastewater contaminated with pesticides.