微污染原水强化混凝处理技术研究

Micro-polluted Raw Water Treated by Coagulation-sedimentation Process

为提高南方某水厂常规工艺对微污染原水的净化效率,以聚合氯化铝(PAC)为混凝剂,分别采用预氧化(KMnO4、H2O2和O3)、粉末活性炭、助凝剂(PAM)和回流污泥等技术强化微污染原水的混凝过程.结果表明:预氧化强化混凝把原水中有机物氧化分解为分子量较小、疏亲水性较高的有机物,进而提高有机物混凝去除效果,KMnO4、H2O2和O3的适合投加量分别为1.5～2、4～6和4～6 mg/L;粉末活性炭强化混凝是利用粉末活性炭吸附分子量在0.6～3 kD的有机物,从而提高CODMn和色度去除率,粉末活性炭的适合投加量为20～30 mg/L;助凝剂强化混凝是助凝剂PAM能有效提高絮体颗粒尺寸,使得颗粒沉降速度加快,并使CODMn去除率得到提高,PAM投加量为0.2 mg/L;污泥强化混凝沉淀是以回流污泥提供凝聚核心,充分发挥其吸附、卷扫的作用,提高CODMn去除率,污泥适当投加量为15 mg/L.

In order to improve the purification efficiency of micro-polluted raw water in drinking water plant,polyaluminium Chloride（PAC） was used as coagulants,and the enhanced coagulation were studied using pre-oxidation,activated carbon,coagulant aid and sludge for raw water.The results were as follows：（1） organic matter was broken down into smaller molecular weight,sparse higher hydrophilic organisms by pre-oxidation enhanced coagulation,and the dosages of KMnO4,H2O2 and O3 were 1.5~2,4~6 and 4~6 mg/L,respectively;（2） organic matter with molecular weight in 0.6~3 kD was assorted to improve the removal of CODMn and color by powdered activated carbon enhanced coagulation,and the dosages of powdered activated carbon was 20~30 mg/L;（3） PAM can effectively improve the floc particle size,particle settling velocity to accelerate the CODMn removal efficiency,and the dosages of PAM was 0.2 mg/L;（4） return sludge can provide a condensed core and give full play to the increased role of the adsorption and the volume swept,and the dosages of sludge was 15 mg/L.