[Study on the technology of treating low temperature and low turbidity water by membrane bioreactor]

For the purpose of solving the problem of low temperature and low turbidity water treatment, a pilot study was made on the treatment of Songhuajiang River raw water with low temperature and low turbidity by using membrane bioreactor (MBR) process, and the removal effects of organic pollutants and turbidity and membrane filtration period were also investigated. The results showed that the effluent turbidity was lower than 1 NTU and its removal efficiency was over 90%. The removal efficiency of permanganate index and UV254 were about 40% - 50% and 30% - 45%, respectively. The operation time of the MBR was as long as 60 - 70 hours. Adding powder activated carbon (PAC) has increased the organic pollutant removal efficiency but it has no significant influence on the membrane permeability. Therefore, the MBR was capable of effectively treating waters typically used for drinking water supplies, particularly when the low temperature and low turbidity water are treated. The effluent water quality of MBR was better than that of conventional process. PAC-MBR combined process can be used to enhance organic pollutants removal efficiency when raw water was polluted severely.