A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Science in Environmental Engineering and Management

Thesis (M.Sc.) - Asian Institute of Technology, 2011

Water pollution, salt intrusion and over exploitation of water resources are main causes of water shortage in HCMC. Untreated industrial wastewater is a main cause of polluted water resources that leads to many negative effects on agricultural activities in peri-urban areas of HCMC. This result is lack of quantity and quality of water used for agriculture and low crop yield. It also has adverse effects on farmer health such as itches and scabies, etc. The amount of industrial wastewater discharged in 2010 is 241,000 m³/d which is expected to increase to 376,000 m³/d in 2020. Thus, there is high potential for reuse of this treated effluent for agricultural activities in HCMC. Pilot scale study of airlift-membrane bioreactor (A-MBR) and UF membrane use as tertiary treatment after conventional activated sludge process (CAS) was carried out at central wastewater treatment plant (CWWTP) of Le Minh Xuan industrial park for 6 months. This study focuses on the treated water quality of A-MBR and UF process to compare with effluent quality of CAS and standard for industrial wastewater discharge and reuse to estimate potential applying membrane technology in treated industrial wastewater reuse for agricultural activities in peri-urban areas of HCMC. Effluent COD of A-MBR, UF and CAS process was 54, 68 and 87 mg/L, respectively. Effluent BOD5 of A-MBR, UF and CAS process was 13, 15 and 18 mg/L, respectively. Effluent SS of A-MBR and UF was not detected whereas effluent SS of CAS process was 50 mg/L. Effluent Ni and Cd was not detected with three process. However, Effluent Zn of A-MBR, UF and CAS process was 0.25, 0.27 and 0.28 mg/L, respectively. Effluent Cr of A-MBR, UF and CAS process was 0.15, 0.60 and 0.96 mg/L, respectively. Effluent total coliform of A-MBR, UF and CAS process was 1.3x10^2, 2.2x10^1 and 1.7x10^4 MPN/100 mL, respectively. Effluent E.coli of A-MBR, UF was nearly not detected whereas effluent E.coli of CAS process was 1.4x10^3 MPN/100 mL. Effluent quality of A-MBR, UF is higher than CAS process. Treated water quality of A-MBR and UF process meet standard for industrial wastewater reuse for agriculture.