纳米聚硅氯化铝复合絮凝剂的制备、表征与应用研究

通过溶胶-凝胶法制备纳米聚硅氯化铝复合絮凝剂,运用傅立叶红外光谱、X-Ray粉末衍射、扫描电镜、透射电镜等对制得的产品进行了表征,研究了纳米聚硅氯化铝复合絮凝剂的分子结构与形态。结果表明,复合过程不是简单的物理混合,部分铝离子及水解络合铝离子可与共存的聚硅酸通过羟基结合,发生络合反应生成铝硅聚合物。为了检测样品的絮凝性能,采用镇江段长江水作为絮凝水样,选用传统的絮凝剂聚氯化铝和聚硅酸作对比实验。结果表明,在最佳絮凝条件下,纳米聚硅氯化铝的CODCr去除率和浊度去除率可分别达到83.6%和93.5%,比聚氯化铝和聚硅酸絮凝剂具有更好的絮凝性能。

Study on Preparation, Characterization and Application of Nanosized Polyaluminum Silicate Chloride Coagulant

Compound polymer coagulants, nanosized polyaluminum silicate chloride with different n(Si)/n(Al) molar ratios were prepared through sol-gel method . The characterization of the coagulant form was made with application of modern techniques of FT-IR spectrum, XRD, SEM and TEM. The results demonstrated that recombination was not only physical mixed, but also connected by hydrogen bond between silicic polymer and free or hydrolyze-polymerized aluminum ion and polysilic acid which could form aluminiferous during the process. To test the coagulating performance of the coagulant, polysilic acid and polyaluminum chloride were used to treat water sample of the Yangtze River. Experimental results demonstrated that under the optimum conditions, the rates of removal CODCr and turbidity were 83.6 % and 93.5 % respectively.The coagulating performance of nanosized polyaluminum silicate chloride was consistently superior to conventional coagulants.