陶瓷微滤膜处理大理石加工废水的研究

采用孔径为0 .8 μm 的陶瓷膜处理大理石生产过程中产生的废水, 研究了操作压差和膜面流速等对膜性能的影响。结果表明, 合适的操作条件是操作压差0.07 M Pa , 膜面流速1 .0 m/ s, 滤出液中固体颗粒的截留率在99 .2 %～ 99 .8 %, 膜微滤过程对废水的pH 值和COD 值的影响不大。运行中膜通量稳定平均值为400 L/(m2 · h), 料液的固体质量浓度大于55 g/ L 时, 膜通量明显下降。对污染膜用清水清洗20 min 和体积分数为1 %的H NO3 溶液清洗30 min , 膜通量可以得到完全恢复。渗透液返回生产工序循环使用, 截留液进入沉降池。

Treatment of Marble Processing Wastewaters by Ceramic Micro-Filtration Membrane

Treatment of marble processing wastewaters by ceramic micro-filtration membrane with pore size of 0.8 μm was performed.The effects of the transmembrane pressure and crossflow velocity on the MF performance were investigated.The experimental results show that the feasible transmembrane pressure is 0.07 MPa and crossflow velocity 1.0 m/s.The solid rejections of the permeate samples were from 99.2% to 99.8%.The MF process has no remarkable effect on the wastewater pH and COD,the membrane flux remained constant throughout the experiment,the average value is 400 L/(m2·h).The flux was remarkable decline when the solid concentration of feed liquid is over 55 g/L.The membrane flux can be recovered completely after cleaned by the water with 20 minutes and nitric acid solution(volume fraction 1%)with 30 minutes.The MF process allowed the treated water to be recycled into the process,whereas the concentrated stream(rich in particulate matter) turned into sedimentation pool.