低温低浊河网水的有机高分子助凝处理研究

用不同特征黏度的聚二甲基二烯丙基氯化铵(PDM)与聚合氯化铝(PAC)、两种市售无机复合聚铝分别复合,用以改进无机混凝剂对低温低浊微污染河网水的混凝脱浊效果。考察了无机混凝剂的种类及其与PDM的复合配比对低温低浊微污染河网水脱浊效果的影响。结果表明,对温度为7～10℃,浊度为4.5～8NTU的低温低浊河网水,在与实际生产相近的混凝搅拌强度下,要达到2NTU左右的出水余浊标准,PAC、复合聚铝1、复合聚铝2分别需4.0、3.5、2.8mg/L的投加量。而用特征黏度分别为0.52、1.47、2.46 dL/g的PDM配制的、无机复合聚铝与PDM复合质量比为20:1、10:1、5:1的复合混凝剂PAC/PDM、复合聚铝1/PDM、复合聚铝2/PDM,比单独使用同种无机混凝剂,分别约能减少10%～25%、8.6%～28.6%、7.1%～28.6%的无机药剂投加量,无机复合聚铝与PDM复合比例越低、PDM特征黏度越高,复合混凝剂脱浊效果越好。因此,PDM对低温低浊河网水具有明显的强化混凝脱浊效果。

Effect of organic polymeric coagulation aid on low temperature and low turbidity river-net water treatment

For the purpose of improving the effect of inorganic coagulant on turbidity removal from low tem-perature and low turbidity micro-polluted river-net water,polydimethyl diallyl ammonium chloride(PDM) with different intrinsic viscosity were composited with polyaluminum chloride(PAC) and two kinds of inorganic composite PAC on sale respectively.The impact of inorganic coagulant sorts and their composite ratio with PDM on turbidity removal from low temperature and low turbidity,micro-polluted river-net water were investigated.The results showed that,for the low temperature and low turbidity river-net water with 4.5-8NTU initial turbidity and temperature 7-10 ℃,under the intensity similar with actual production,the necessary dosage of PAC,composite PAC 1 and composite PAC 2 were 4.0mg/L,3.5mg/L,2.8mg/L respectively when 2NTU residual turbidity was required for the effluent water.Compared with the single use of the inorganic coagulants,using PDM with intrinsic viscosity 0.52 dL/g,1.47 dL/g and 2.46 dL/g as coagulant aid,composite coagulants PAC/PDM,composite PAC 1/PDM,composite PAC 2/PDM with the ratios of inorganic composite PAC to PDM of 20:1,10:1 and 5:1 could decrease the original inorganic reagent dose by 10%-25%,8.6%-28.6%,7.1%-28.6% respectively,moreover,the lower the inorganic composite PAC-PDM composite ratio was as well as thehigher the intrinsic viscosity of PDM was,the better the turbidity removal performance of the composite coagulants would be.It could draw a conclusion that,PDM could improve the effect of turbidity removal remarkably in treatment of low temperature and low turbidity river-net water.