土工合成黏土衬垫对煤矸石渗滤液中Zn^(2+)和Mn^(2+)的吸附特性

Adsorption performance of Zn^(2+) and Mn^(2+) from coal gangue leachate on geosynthetic clay liners

为验证土工合成黏土衬垫(GCL)作为煤矸石处置场衬垫层建设材料的可行性,采用批式吸附试验研究了GCL中膨润土对重金属Zn2+和Mn2+的吸附性能,分析了土悬液土水比和pH对膨润土吸附重金属性能的影响。结果表明:土悬液的土水比和pH对膨润土吸附重金属的性能产生重要影响,当土水比从1∶200升高至1∶20时,膨润土对重金属的吸附量降低了50%"90%;当土悬液pH从10降低至2时,膨润土对重金属的吸附量降低了50%"70%。即使是在最不利条件下,GCL中膨润土对Zn2+和Mn2+的吸附量仍大于其他黏土材料。研究结果表明GCL可以作为煤矸石处置场衬垫层的建设材料。

In order to verify the feasibility of geosynthetic clay liners （GCL） as liners material for coal gangue impoundment, batch tests were conducted to determine the adsorption capacity of bentonites sandwiched in GCL for Zn2＋ and Mn2＋ prior to using in situ. In this stud- y, the parameters evaluated were solid and solution ratio and the pH of solution. The test results showed that the solid and solution ratio and the pH of solution had a significant effect on the adsorption capacity of bentonite. The adsorption capacity of the bentonites decreased 50%- 90% when the solid and solution ratio increased from 1 ： 200 to 1 ： 20, and decreased 50% - 70% as the solution pH decreased from 10 to 2. However, while under most extreme conditions, the adsorption capacity of bentonite was higher than that of most other clay soils. All the test results indicated that GCL could be used as a liner material for the coal gangue impoundment.