Feasibility study for evaluating the client application of membrane bioreactor (MBR) technology for decentralised municipal wastewater treatment in Vietnam

Scarcity of water is becoming an increasingly serious problem in many Asian countries. The situation is aggravated further by the pollution of fresh water resources due to the discharge of untreated wastewater from industrial enterprises and municipal wastewater. These problems have become worse since ground water reservoirs are also exhausted. The concurrent wastewater treatment and water re-use secures the sufficient availability of fresh water. A EU-founded project (Asia-Pro-Eco-programme, contract number: VN005/104759) was created to conduct a feasibility study for introduction of membrane-supported bioreactor technology (MBR) under tropic conditions. The study will reveal: (1) whether and in which way membrane bioreactors can be applied under tropic conditions to treat municipal wastewater; (2) the possibility of the adaptation of MBR technology to the technical, climatic and socio-economic circumstances of Asia; (3) in general the introduction of modern wastewater treatment plants will improve the environmental situation in Asia. A pilot plant was constructed and built in Vietnam with Vietnamese workers. MBR technology was chosen because it allows to build up decentralised wastewater treatment plants in areas where no municipal sewage system exists. It provides improved health conditions due to a almost bacteria-free effluent and the possibility of re-using the treated water.

Fig. 5. Removal of COD after run-in of the MBR training plant. It was shown that it is possible to construct an MBR with simple methods under local conditions of a developing country. The applied treatment plant and membrane system showed sufficient results. The new developed membrane showed good results concerning the material stability in warm water. The overall conclusion is that decentralised or semi-central plants can be started in these countries to recover water at the source of pollution. Membrane-supported bioreactor (MBR) technology is one eminently important process for decentralised wastewater treatment plants. It is possible to degrade the organic substances with biological wastewater treatment and to purify water of suspended solids in one step. The treated water meets standards and is free of microorganisms, thus it can be re-used directly [8–10]. The main advantages of MBR technology are: C compact design C no excess sludge and C high quality of water.