Comparison of Efficiency between Poly‐aluminium Chloride and Aluminium Sulphate Coagulants during Full‐scale Experiments in a Drinking Water Treatment Plant
Comparison of Efficiency between Poly‐aluminium Chloride and Aluminium Sulphate Coagulants during Full‐scale Experiments in a Drinking Water Treatment Plant
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DOI：
10.1080/01496390801940903
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发表时间：
2008-04
影响因子：
2.8
通讯作者：
A. Zouboulis;G. Traskas;P. Samaras
中科院分区：
文献类型：
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作者：
A. Zouboulis;G. Traskas;P. Samaras
摘要在饮用水处理厂的全规模实验中，对两种常用混凝剂聚合氯化铝（PAC）和硫酸铝（明矾）的效率进行了比较研究。仔细监测悬浮固体（浊度）的去除和残留铝浓度，并将其用于评价每种混凝剂的有效性，以及确定最佳操作条件。研究了两种替代处理工艺：（a）常规混凝-絮凝-沉淀工艺，然后通过砂滤床进行重力过滤，以及（B）直接过滤工艺，即，混凝-絮凝和砂滤，但没有中间沉淀步骤。PAC 1被证明是比明矾更有效的凝结剂，因为较低剂量的PAC 1（在这种情况下为约1.35mg Al/L）导致产生具有低浊度和残留铝含量的经处理的水。此外，发现通过双砂-无烟煤滤床的直接过滤过程与常规过滤过程一样充分，即，在这种情况下，0.70 mg Al/L的PAC 1导致低浊度水（约0.1 NTU）和残留铝含量（低于150 µg/L）。此外，过滤器的运行时间延长至24小时以上。
Abstract The efficiency of poly‐aluminium chloride (PACl) and of aluminium sulphate (alum), two commonly applied coagulant agents, was studied comparatively in this work, during full‐scale experiments in a drinking water treatment plant. The removal of suspended solids (turbidity) and the residual aluminium concentrations were carefully monitored and they were used for the evaluation of effectiveness for each coagulant, as well as for the determination of optimal operative conditions. Two alternative treatment processes were examined: (a) the conventional coagulation‐flocculation‐sedimentation process, followed by gravity filtration through sand filter beds, and (b) the direct filtration process, i.e., coagulation‐flocculation and sand filtration, but without the intermediate sedimentation step. PACl proved to be a more efficient coagulant than alum, as lower dosages of PACl, about 1.35 mg Al/L in this case, resulted to the production of treated water with low turbidity and residual aluminium content. In addition, the direct filtration process through dual sand‐anthracite filter beds was found to be equally sufficient, as the conventional one, i.e., when applying the sedimentation step; in this case, 0.70 mg Al/L of PACl resulted in low turbidity water (around 0.1 NTU) and residual aluminium content (lower than 150 µg/L). In addition, the operation time of filters was extended to more than 24 hours.