中文摘要：

通过红外光谱和X-射线衍射研究了镁铝复合絮凝剂（PMAS）的结构形态,通过对渗滤液生化出水的脱色效果和系统Zeta电位的测定,分析了絮凝机制.结果表明：①X-射线衍射和红外结果显示,PMAS是以羟基桥联的铝和镁的复杂多聚物;②PMAS的絮凝机制主要是电中和和网捕卷扫作用.在低投药量时,以吸附电中和作用为主;在高投药量时,随体系pH值不同其絮凝行为而有所变化：酸性条件下以电中和机制为主;碱性条件下以网捕卷扫机制为主;中性条件下则是两种机制共同发挥作用.

英文摘要：

Crystal structures and morphologic characteristics of poly-aluminum（Ⅲ）-magnesium（Ⅱ）-sulfate（PMAS） were discussed using X-radial diffraction and infrared spectrogram and the flocculation mechanism was explored here based on comparisons between decolorization effect of landfill leachate secondary effluent and the system Zeta potential.The results indicated that PMAS was a kind of macromolecular composite polymer of aluminum and magnesium based on —OH bonding.The flocculation mechanism of PMAS was mainly charge neutralization and co-precipitation netting.Charge neutralization was the main mechanism at low dose.Its flocculation behaviors were different along with different pH of wastewater at high doses,namely,it was mainly charge neutralization at low pH and co-precipitation netting at high pH and both of them work together at neutral condition.