一种新型改性吸附剂对水中痕量磷的吸附特征

Adsorptive characteristics of trace phosphorus in water on a new adsorption

采用碱液-超声波对小麦秸秆预处理后,在高温下用环氧氯丙烷和铝盐进行化学改性,制备了改性秸秆吸附剂.分别对改性前后秸秆的性质表征和吸附性能研究,探讨了改性和吸附机理.表征分析结果表明,改性后秸秆的有序度和结晶度都得到明显提高,并且成功引入了铝离子.改性秸秆吸附水体磷的主要机理包括:因改性而获得的凹凸有致状结构的物理吸附;表面羟基产生的氢键作用以及对磷酸根离子具有配位络合作用;带正电荷表面电位的改性秸秆,可与带负电荷的磷酸根离子之间产生静电吸附作用;改性秸秆对水体磷的空间网捕作用,生成混合磷酸盐晶体.

The adsorbent was obtained by wheat straw which was firstly chemical modified by alkaline solution under the ultrasonic pretreatment at high temperatures by epichlorohydrin and aluminum.The adsorbent were analyzed by characterizated technologies,and their adsorption capacities,adsorption isotherm in the adsorption process were evaluated in batch experiments.In the characterization analysis of the adsorbent,the modified straw in the degree of order and crystallinity had been significantly improved.Furthermore,the adsorbent structures had been successfully introduced aluminum ion.The summary in the main mechanism of removal of phosphate by the modified straw was physical adsorption depending on concave-convex shaped structure,chemical adsorption such as hydrogen bonds effect and coordination-complexation reaction because of hydroxyl groups,their surface potential was useful for phosphate anions adsorption.It also had spatial netting,which had the generation of mixed-phosphate crystals.