微污染源水的混凝处理及絮体粒径研究

微污染源水的处理已经成为一个重要课题并在全世界范围内引起广泛关注，其中的浊度、腐殖质等影响到了饮用水水质。混凝是一种安全、实用、高效的水处理技术，而混凝剂是混凝技术的核心，选择一种合适的混凝剂至关重要。以硫酸铝（AS）、聚合氯化铝（PAC）、氯化铁、聚合氯化铁（PFC）等4种混凝剂处理微污染源水，再分别与助凝剂PAM、活化硅酸（ASI）复配使用，PAM与ASI具有较好的吸附架桥能力，大大提高了絮凝效率。通过检测浊度、UV₂₅₄、絮体粒径3个指标，得出这4种混凝剂单独使用时的最佳投加量分别为22、18、16、8 mg/L；与PAM复配使用时PAM的最佳投加量分别为0.1、0.1、0.05、0.2 mg/L；与ASI复配使用时ASI的最佳投加量分别为0.5、1.5、1.0、1.0 mg/L。另外，自然水体中有机物的降解会产生腐殖酸，从而污染水质。分别使用聚丙烯酰胺（PAM）、PAC以及两者复配，通过检测混凝后的UV₂₅₄以及絮体粒径指标，得出PAM、PAC单独使用时的最佳投加量分别为8、100 mg/L，PAM与PAC复配时PAM的最佳投加量为0.8 mg/L，证明复配可在低投加量下有效增强混凝效果。

Coagulation treatment of micro-polluted water and study of floc size

Treatment of micro-polluted water is considered to be a vital issue and has attracted more and more attentions around the world. The turbidity and humus affect the quality of drinking water. As a widely used type of water treatment technology, coagulation is known for safety, practical and high-efficiency, and has been considered as a prospective technology for micro-polluted water. Coagulants are the core of coagulation technology and choosing a suitable coagulant to achieve high coagulation efficiency in the treatment process is crucial. Different kinds of coagulants, coagulants containing aluminum such as aluminum sulfate (AS) and polyaluminum chloride (PAC), coagulants containing ferric such as ferric chloride and polyferric chloride (PFC) were applied, and then followed by compound of coagulant aid polyacrylamide (PAM) and activated silicic acid (ASI) respectively. These coagulant aid possess good adsorption bridging ability and can improve the flocculation efficiency greatly to a certain extent. And in this work, turbidity, UV₂₅₄ and floc size were investigated to indicate the coagulation efficiency. The optimum coagulation conditions are determined as follows: AS dosage of 22 mg/L, PAC dosage of 18 mg/L, FeCl₃ dosage of 16 mg/L, and PFC dosage of 8 mg/L when used alone. PAM dosage of 0.1, 0.1, 0.05, 0.2 mg/L respectively when compounded with PAM. ASI dosage of 0.5, 1.5, 1.0, 1.0 mg/L respectively when compounded with ASI. In general, large amounts of humic acid are produced by the degradation of organic matter for aquatic organisms, and as a result, the water quality are seriously endangered. Thus, the removal of humic acid from wastewater has become imperative. In the passage, two common coagulants, PAC and PAM were applied in the treatment of humic acid wastewater, and PAC compounded with PAM was explored too. Same as before, the coagulation effect was determined by the measure of turbidity and floc size. The result shows that the optimal coagulation efficiency is achieved with PAM dosage of 8 mg/L, PAC dosage of 100 mg/L respectively when used alone. PAM dosage of 0.8 mg/L when compounded with PAC. The result shows that the compound can effectively enhance the coagulation effect at low dosage.