Application Of Ultrafiltration Technology To Surface Water Treatment

Water pollution and water shortages have aroused growing concern, a variety of water quality standards have also been improved, the previous water treatment technology has not lived up to the high standards and demands of people for water quality and quantity. Because of the high efficiency and energy-saving, membrane water treatment technology has been used more and more widely in the areas of surface water, industrial wastewater and domestic sewage treatment.The ultrafiltration technology as the core of the third generation of water purification process has being recognized for the safety and reliability of the treated water. In order to study the application of the ultrafiltration technique to the surface water treatment, some improvements to the traditional drinking water treatment technology were made. Norit X-Flow's hollow fiber ultrafiltration membrane device was introduced, and a pilot-scale plant was established, as a result, the sedimentation-ultrafiltration and sand filtration-ultrafiltraion processes were formed. Luan River was the raw water during the experiments.During the experiment of Luan River water treatment with the sand filtration-ultrafiltration process, main water quality indexes of the raw water and treated water were monitored, such as pH, turbidity, CODMn, UV254, microbial indicators, chlorination by-products and precursors. The results showed that the quality of the water from membrane fulfilled the requirement of the Standards for drinking water quality (GB 5749-2006), which was also more stable than traditional treatment progress. For the sake of determining the parameters that made ultrafiltration membrane system operate more stably during different water quality stages, a number of operating conditions were designed and the membrane fouling conditions were investigated, the final results showed that pre-chlorination plus CEB (Chemical Enhanced Backwash) could effectively control the membrane fouling.In addition, the sedimentation-ultrafiltration and sand filtration-ultrafiltration processes were compared from two aspects. On the one hand, the treatment efficiency of the Luan River was compared, including turbidity, organic matters and microbial indicators; on the other hand, the economics of both processes were also roughly evaluated. The conclusion was that the sand filtration-ultrafiltration process was better in each aspect than sedimentation-ultrafiltration process in the application of surface water treatment. It was an economic and effective drinking water treatment method.