pH对聚合铝形态分布与混凝效果的影响

为了解聚合铝的混凝作用机理,以不同碱化度的聚合铝为混凝剂,考察了p H对聚合铝的形态分布、混凝效果及总溶解性残余铝的影响。结果表明,p H对聚合铝形态分布的影响十分明显,碱化度越低影响越显著;预制Alb和Alc在混凝过程中相对比较稳定,而低聚合度的Ala受p H影响显著;Ala在混凝过程中表现出阳离子的性质,电中和能力弱;与高Alb含量的聚合铝相比,高Alc含量的聚合铝出水浊度降低,但不能提高出水中的溶解性有机物去除率;总溶解性残余铝含量与混凝过程中Ala的含量有直接关联。

Influences of pH on polyaluminium chloride species distribution and coagulation effect

In order to clarify the coagulation mechanism of polymeric aluminum chloride(PAC),using polyaluminium chloride with different alkalinity as coagulants,the influences of pH on the species distribution of polyaluminium chloride,coagulation effect,and total soluble residual aluminium are investigated. The results show that pH has sig-nificant influence on species distribution of polyaluminium chloride. The lower the alkalinity is ,the more significant the influence is. The prefabricated Alb and Alc are relatively pretty stable in the coagulation process, and the Ala with low polymerization degree is affected by pH more significantly. Ala shows cationic property in the coagulation pro-cess,and its electro-neutrality is weak. Compared with polyaluminium chloride with high Alb content,the effluent turbidity of the polyaluminium chloride with high Alc is decreased,but the removing rate of soluble organic sub-stances from effluent cannot be increased. The total soluble residual aluminium content is directly related to the Al a content in the coagulation process.