A novel technology of preparation of felt-metal supported modified polyvinyl alcohol（PVA） ultrafiltration（UF） membrane was invented, which could avoid the blockage of the holes of support layer and the leakage of ...A novel technology of preparation of felt-metal supported modified polyvinyl alcohol（PVA） ultrafiltration（UF） membrane was invented, which could avoid the blockage of the holes of support layer and the leakage of the casting solution through the holes of support layer. Felt-metal supported ferric sulfate modified PVA composite UF membranes were prepared by the innovative technology. The results show that the composite membranes are used to treat 1 000 mg/L oil/water emulsion at trans-membrane pressure from 0.25 to 0.45 MPa, the permeate flux is from 36 to 52 L/（m2·h）, and the retention of chemical oxygen demand（COD） is over 92%. The composite membrane resistance increases with the increase of trans-naembrane pressure.展开更多
Metal-polyvinyl alcohol(PVA) composite ultrafiltration membranes were prepared by coating a certain concentration of PVA solution on metallic fiber sintered membranes. The effects of preparation conditions, such as th...Metal-polyvinyl alcohol(PVA) composite ultrafiltration membranes were prepared by coating a certain concentration of PVA solution on metallic fiber sintered membranes. The effects of preparation conditions, such as the coating solution concentration, sequence and times of coating, and heat-treatment on the properties of the composite membranes were studied. The results show that the hole diameter of the composite membrane decreases with the increase of the concentration of PVA, the hole diameter of composite membrane is different when the sequence of coating is different. When the higher concentration of PVA solution is used to coat the metallic membrane for the first time and the other smaller one for the second time, the hole diameter of the composite membrane is relatively small, compared with that of the composite membrane made by the smaller concentration of PVA solution for the first time and the other higher one for the second time. The holes of the composite membrane contract and the stability of the membrane is improved by heat treatment. When metal-PVA composite hydrophilic membranes are used to treat the oil/water emulsion with the concentration of 1 000 mg·L -1 , the retention is from 80% to 90%, and the permeate flux is from 15 L·m -2 ·h -1 to 40 L·m -2 ·h -1 at pressure of 0.2 to 0.3 MPa.展开更多
水厂排泥水处理过程中会产生较大量的污泥脱水液。为避免南水北调引江水资源的浪费,同时积极推进水厂的“零排放”建设目标,面向以引江水为水源的超滤处理工艺,评价了将污泥脱水液回流至原水池进行稀释回用的可行性。考察了不同污泥脱水...水厂排泥水处理过程中会产生较大量的污泥脱水液。为避免南水北调引江水资源的浪费,同时积极推进水厂的“零排放”建设目标,面向以引江水为水源的超滤处理工艺,评价了将污泥脱水液回流至原水池进行稀释回用的可行性。考察了不同污泥脱水液/引江原水混合比例下超滤系统的运行特性,发现当污泥脱水液适当稀释后,其对超滤净水效果和膜污染的影响急剧降低,当稀释比例达到1∶800时,出水水质与跨膜压增长曲线已接近引江原水直接超滤的情况。试验中引江原水的跨膜压增长速率为19.7 k Pa/d,而污泥脱水液原液则达到25.8 k Pa/d。当两者以1∶800比例稀释后,跨膜压增长速率下降为21.3 k Pa/d,接近于引江原水。膜表面微观表征结果显示随着稀释比例的提高,滤饼层厚度、溶解性有机物、特征官能团红外峰强、污染元素相对质量分数均显著降低,逐渐下降到与原水直接超滤相近的水平。引江原水组的超滤膜滤饼层厚度为1.77μm,而污泥脱水液原液组的滤饼层厚度为4.00μm,污染程度较重。两者按1∶800比例稀释后的滤饼层厚度降低至1.82μm,污染程度显著降低。研究结果可为南水北调受水城市超滤水厂的“零排放”建设提供参考。但值得注意的是,污泥脱水液的合理处置与利用问题目前仍处于起步和探索阶段,未来仍需从水质生物安全性和化学安全性的角度加以系统评估。同时可考虑氧化、吸附、微滤分离等预处理手段,以提高污泥脱水液回用过程的安全性。展开更多
文摘A novel technology of preparation of felt-metal supported modified polyvinyl alcohol（PVA） ultrafiltration（UF） membrane was invented, which could avoid the blockage of the holes of support layer and the leakage of the casting solution through the holes of support layer. Felt-metal supported ferric sulfate modified PVA composite UF membranes were prepared by the innovative technology. The results show that the composite membranes are used to treat 1 000 mg/L oil/water emulsion at trans-membrane pressure from 0.25 to 0.45 MPa, the permeate flux is from 36 to 52 L/（m2·h）, and the retention of chemical oxygen demand（COD） is over 92%. The composite membrane resistance increases with the increase of trans-naembrane pressure.
文摘Metal-polyvinyl alcohol(PVA) composite ultrafiltration membranes were prepared by coating a certain concentration of PVA solution on metallic fiber sintered membranes. The effects of preparation conditions, such as the coating solution concentration, sequence and times of coating, and heat-treatment on the properties of the composite membranes were studied. The results show that the hole diameter of the composite membrane decreases with the increase of the concentration of PVA, the hole diameter of composite membrane is different when the sequence of coating is different. When the higher concentration of PVA solution is used to coat the metallic membrane for the first time and the other smaller one for the second time, the hole diameter of the composite membrane is relatively small, compared with that of the composite membrane made by the smaller concentration of PVA solution for the first time and the other higher one for the second time. The holes of the composite membrane contract and the stability of the membrane is improved by heat treatment. When metal-PVA composite hydrophilic membranes are used to treat the oil/water emulsion with the concentration of 1 000 mg·L -1 , the retention is from 80% to 90%, and the permeate flux is from 15 L·m -2 ·h -1 to 40 L·m -2 ·h -1 at pressure of 0.2 to 0.3 MPa.
文摘水厂排泥水处理过程中会产生较大量的污泥脱水液。为避免南水北调引江水资源的浪费,同时积极推进水厂的“零排放”建设目标,面向以引江水为水源的超滤处理工艺,评价了将污泥脱水液回流至原水池进行稀释回用的可行性。考察了不同污泥脱水液/引江原水混合比例下超滤系统的运行特性,发现当污泥脱水液适当稀释后,其对超滤净水效果和膜污染的影响急剧降低,当稀释比例达到1∶800时,出水水质与跨膜压增长曲线已接近引江原水直接超滤的情况。试验中引江原水的跨膜压增长速率为19.7 k Pa/d,而污泥脱水液原液则达到25.8 k Pa/d。当两者以1∶800比例稀释后,跨膜压增长速率下降为21.3 k Pa/d,接近于引江原水。膜表面微观表征结果显示随着稀释比例的提高,滤饼层厚度、溶解性有机物、特征官能团红外峰强、污染元素相对质量分数均显著降低,逐渐下降到与原水直接超滤相近的水平。引江原水组的超滤膜滤饼层厚度为1.77μm,而污泥脱水液原液组的滤饼层厚度为4.00μm,污染程度较重。两者按1∶800比例稀释后的滤饼层厚度降低至1.82μm,污染程度显著降低。研究结果可为南水北调受水城市超滤水厂的“零排放”建设提供参考。但值得注意的是,污泥脱水液的合理处置与利用问题目前仍处于起步和探索阶段,未来仍需从水质生物安全性和化学安全性的角度加以系统评估。同时可考虑氧化、吸附、微滤分离等预处理手段,以提高污泥脱水液回用过程的安全性。
