高濃度活性炭-膜ろ過法による浄水処理

浄水水質向上効果と膜ファウリングの抑制

抄録

Laboratory-scale experiments on a microfilter (MF) combined with high-concentration powdered activated carbon (PAC) was carried out using synthetic secondary effluent as a raw water. The MF membrane has a nominal pore size of 0.1μm and a surface area of 0.05m², and it was submerged into a 5-L reactor containing either 0g/L (control), 10g/L, or 40g/L of PAC. As a result of continuous filtration experiments, improvement of filtrate water quality and control ofmembrane fouling was demonstrated by the addition of PAC. However, when the organic substrates in the synthetic raw water were separated into three groups, i.e., 1) peptone and beef extract, 2) humic acid, tannic acid and sodium lauryl sulfate, and 3) arabic gum powder and lignin, it was found that the raw water containing arabic gum powder accelerated the membrane fouling process by creating a cake layer of PAC on the MF membrane. The primary cause of membrane fouling in the PAC-MF process was cake+gel layer formation (>98% of the total resistance), and the membrane pore blocking was very small (<2%), which was further reduced by PAC.