绿色絮凝剂PAS的性能及混凝机理探讨

Study on properties and coagu-flocculation mechanism of green flocculant PAS

通过向聚硅酸中加入一种高价亲生物环保的金属离子Ti^4＋,制备了一种适合处理长江水的绿色絮凝剂PAS,并且通过实验确定了其处理长江水的最佳处理条件：酸性聚硅酸与Ti金属盐溶液复合,nTi/nSi=0.3;投加量为10 mg/L（以Ti^4＋计）,pH=6～8,UV254的去除率〉61.7%,浊度去除率〉99%。PAS的混凝效果明显优于聚合铝和聚硅铝,而且矾花形成迅速,絮体密实、沉降快、出水更加清澈,无残留铝。Ti也是亲生物金属,健康环保。因此,PAS是绿色环保友好型絮凝剂,可作为饮用水专用絮凝剂。观察所形成絮体的形貌以及观测红外光谱图均发现,絮凝剂对胶体颗粒污染物有较好的架桥网捕与络合反应作用。

A green flocculant PAS is prepared by adding Ti metal-salt into polysilicic acid.Acidic PAS is more efficient than alkaline PAS.The best molar ratio is nTi/nSi=0.3.The optimum conditions are that the appropriate pH value is from 6 to 8,the adding amount of PAS is 10 mg/L by calculating the concentration of Ti^4＋in treating Yangtze River water.After treatment,UV254-removal efficiency is more than 61.7%,and the turbidity-removal efficiency is more than 99%.The coagulating property of PAS is higher than polyaluminum chloride＇s and ploysilicate-aluminum chloride＇s.The floccule is big and close-grained,having high sedimentation efficiency.Water drained is clearer,having zero content of Al.Ti is an environment-friendly green metal.PAS,an environment-friendly green flocculant,can be used as special flocculant for treating drinking water.The shapes and structure of sample flocs was investigated and analyzed using microscopy and FTIR.The results show that PAS have favorable ability of complexati...更多on,bridging and netting.