改性膨润土作为防渗层材料的性能研究及影响因素分析

以十六烷基三甲基溴化铵(HDTMA)为改性剂,对天然膨润土进行了有机改性.研究了改性后的有机膨润土防渗层去除污染物和控制渗滤液渗透的有效性及可行性,以及有机膨润土的吸附规律和影响因素.结果表明:改性后有机膨润土的吸附能力和容量均得到了提高,渗透系数在一定时间后可达到1×10-7cm/s以下,对苯酚有极强的衰减能力,对Fe3 的去除率也达到了98%.有机膨润土可显著延缓苯酚穿透防渗材料的速度,与未改性的天然膨润土相比,苯酚穿透防渗材料的时间推迟了近25倍,因此,改性后的有机膨润土可作为防渗材料.pH,改性剂的浓度和吸附时间等对防渗层污染物的去除有重要影响.

Study on Modified Bentonite Performance and the Analysis of Its Influencing Factors

Hexadecyltrimethylammonium(HDTMA) was used as denaturant to perform organic modification on the natural bentonite,and investigations conducted into availability and feasibility of the modified-layer to contaminants removal and leachate leaking control.The various influencing factors on the performance of the modified-layer were analyzed.Experimental results indicated that the sorption ability of the modified bentonite was improved,and the permeability of the liner was less than 1×10^-7cm/s after some time.The penetration tests showed that modified bentonite significantly retarded the transport of phenol,with the penetration time postponed to nearly 25 times,compared to natural bentonite.Besides,the removal rate of Fe³⁺ was 98%.Therefore,modified clay used as the material of the liners is feasible.The pH,concentration of the denaturant and time,etc.have significantly influenced on the contaminants removal efficiency of liners.