Application Assessment of Ultra-Low-Pressure NF Membrane in Advanced Treatment by Conventional-NF Process
The research object was the sand filter outflow of a water treatment plant in Taihu Basin,and two novel ultra-low-pressure nanofiltration(ULP-NFs)(CDY1 and CDY2)membranes were utilized to advanced treatment of drinking water.The key parameters of the two ULP-NFs were focus on the pressure,properties recovery of chemical cleaning,removal ratio of CODMn,calcium,total harness,et al.The results indicated that the removal ratio of CODMn,TOC,sulfate,ammonia nitrogen,turbidity of CDY1 and CDY2 were equivalent with the conventional nanofiltration membrane(main nanofiltration membrane products from domestic and abroad).Besides,the CDY1 and CDY2 could effectively control the water quality risks such as stibium,geosmin and 2-methylisoborneol.Whereas,the removal ratio of total hardness,calcium by CDY1 and CDY2 were significantly decreased.However,due to the variance between ultra-low pressure nanofiltration membranes,CDY2 showed slightly lower removal ratio of turbidity,CODMn,TOC,total hardness and calcium than those of CDY1,but larger removal ratio of sulfate and stibium.Besides,chemical cleaning effect analysis results showed that CDY2 was easily polluted by humic acid related humus,while CDY1 was susceptible to microbial metabolites + humic acid related humus + fulvic acid and humic acid pollution.
ultra-low-pressure(ULP)NF membranedrinking wateradvanced treatmentwater quality index