Abstract: Colloidal particles has long been a challenge in wastewater treatment due to its small size and high surface charge, which inhibits the aggregation and sedimentation. Usually, a combination of inorganic and organic flocculants are used for efficient separation of colloidal particles from wastewater, resulting in high cost of water treatment, large production of solid slag and lengthy technological process. Currently, inorganic-organic composite flocculants are often synthesized through physical blending method, but the flocculation performance is not so desirable owing to the uneven mixing of inorganic and organic components. In order to solve the above problems, the inorganic-organic hybrid material poly(silicate aluminum chloride-acrylamide) [P(SAC-AM)] was synthesized through situ-polymerization of organic monomers in inorganic solution, and the characterization result suggested that inorganic particles were well distributed in organic matrix. The effect of P(SAC-AM) was investigated for flocculation of colloidal particles in coal gasification wastewater, and the commercial polysilicate aluminum chloride (PSAC), polyacrylamide (PAM) and polydimethyldiallyl ammonium chloride (PDMDAAC) were tested for comparison. The results indicated that P(SAC-AM) performed better at a lower dosage than commercial flocculants which were used either alone or in combination, and it was mainly owe to high-efficient synergistic effect of charge neutralization and adsorption bridging. Larger and dense flocs were formed by P(SAC-AM), thus facilitating the sedimentation and separation of colloidal particles. In addition, small amounts of COD, Ca2+, Mg2+ and other pollutants were also removed by P(SAC-AM) from wastewater. This result provides a facile and efficient way for separation of colloidal particles from wastewater, and it would be beneficial to shortening the technological process and reducing the cost of wastewater treatment.

Key words: colloidal suspended solids, coal gasification wastewater, inorganic-organic hybrid material, flocculation

摘要： 胶体类悬浮物一直以来均是废水处理的难点，不仅消耗大量的絮凝剂，且常需多种药剂组合使用，造成水处理成本高、固体废渣产生量大、工艺流程冗长等一系列问题。为了克服物理共混法导致无机与有机材料复合不均匀的弊端，借助有机单体在无机组分中的原位聚合反应，成功研制出无机-有机杂化材料聚(硅酸氯化铝-丙烯酰胺)[P(SAC-AM)]。选择煤气化废水作为研究对象，并与常用市售絮凝剂聚合硅酸氯化铝，聚丙烯酰胺以及聚二甲基二烯丙基氯化铵进行对比，考察了P(SAC-AM)对胶体类悬浮物的絮凝性能。结果表明，P(SAC-AM)可充分发挥电中和与吸附架桥的协同作用，在低投加量条件下，获得比市售絮凝剂单独或组合使用时均较优的絮凝效果，并可形成粒径较大且密实的絮体，有利于悬浮物后续的沉降与分离。此外，P(SAC-AM)可同时实现废水中COD, Ca2+, Mg2+等的少量去除。

关键词: 胶体类悬浮物, 煤气化废水, 无机-有机杂化材料, 絮凝