Hydrophilic Modification Of PVDF Membrane And Its Application In Wool Scouring Wastewater Treatment

With the development of industrialization, impact of industrial wastewater on the environmental is getting worse. Oil wastewater is a common industrial wastewater, which is mainly derived from petrochemicals, steel, textiles, machinery processing. Wool scouring wastewater is a typical oily wastewater present in the textile industry, mainly containing lanolin, sediment, sheep manure, weeds, and detergents. If we discharge this wastewater into the environment directly, it will bring out high COD value of the water and will endanger on human health and the growth of plants and animals.Membrane process is a novel wastewater treatment technology, which has many advantages, such as small footprint, low energy consumption, easy operation, no secondary pollution, etc. Most traditional polymer membranes are easily fouled by oil droplets because of the low hydrophilicity. Thus, hydrophilic modification of polymer membrane is necessary.Sulfobetaine PVDF membrane and ion-responsive PVDF membrane were firstly prepared in the experiment. To evaluate the performance of as-prepared two PVDF membranes for wool scouring wastewater treatment, the effects of the lanolin concentration, surfactant(sodium dodecyl sulfate) concentration, pH and temperature on the separation process were investigated taking lanolin emulsion as simulated wool scouring wastewater. Then, the real scouring wastewater was pretreated by acid precipitation to remove sediment, sheep manure and other impurity in water followed by membrane filtration. The COD value of untreated wool scouring wastewater was 18120mg/L. After acid precipitation and sulfobetaine PVDF membrane filtration, the COD value of filtrate declined to 2002 mg/L. The removal rate of CODCr was 89% and the flux was 917 L.m-2.h-1.bar-1. After acid precipitation and iron-responsive PVDF membrane filtration, the COD value of filtrate declined to 1613 mg/L. The removal rate of CODCr was 91.1% and the flux was 120 L.m-2.h-1.bar-1. These two hydrophilic modification PVDF membrane greatly reduced the COD value of wool scouring wastewater with higher flux.