Biological treatment History of engineering & technology Purification Sewage Technology: general issues antibacterial property antifouling property artificial neural network biofouling carbonate ions control method dip-coating dyes fertilizers flat sheet flux forward osmosis (FO) fouling prediction halide ions hollow fibre humic acid influencing factors mathematical model membrane membrane bioreactor membrane distillation membrane fouling nanocomposite nitrate ions photodegradation