改性膨润土作为垃圾渗透液防渗层的实验研究

本文以天然钠基膨润土为原料，采用水溶液聚合法，在室温条件下，通过改性聚丙烯酰胺对膨润土进行直接插层改性，制备了一种新型聚丙烯酰胺改性膨润土防渗材料。以此防渗材料作为防渗层，选用沈阳大辛填埋场的垃圾渗透液为处理对象，在动态实验下，就其对实际垃圾渗滤液中主要污染物去除的有效性和控制垃圾渗滤液渗透的可行性进行研究。抗渗性能测试结果表明，改性膨润土防渗性能较好，渗透系数为1．0×10^-7cm/s，达到固体废物填埋场的防渗材料国家标准1．0×10^-7cm／s的使用要求。改性膨润土防渗层对COD、氨氮、重金属离子去除效果较好，吸附作用较强，COD和氨氮最大去除率分别达到81％和91％，TFe、Zn^2＋和TCr的最大去除率分别达到71％、58％和73％。实验结果验证了本研究所制备的改性膨润土防渗材料具有优良的抗渗、截污性能。

Experimental study on landfill liners made from modified bentonite

In this study, a new type of polyacrylamide-modified impermeable bentonite material was pre- pared by direct intercalation polymerization of modified polyacrylamide at room temperature with natural bentonite as raw material. With this impermeable material as impervious layer and landfill leachate from Shenyang Daxin Landfill as treatment object, the validity of the actual landfill leachate pollutant removal and the feasibility of landfill leachate seepage control were studied under dynamic experiments. The dynamic tests show that anti-seep- age capability of modified bentonite material is good, and the permeability coefficient is 1.0 x 10 -7 cm/s, which reaches the national standard （ 1.0 x 10 -7 cm/s） for impermeable materials used in solid waste landfills. During the dynamic test, the removal effect of modified bentonite on COD, ammonia nitrogen and heavy metallic ions is better, and the adsorption effect is stronger, with the maximum removal rates of COD and ammonia nitrogen be- ing 81% and 91% ,and the maximum removal rate of Tve, Zn2＋ and Tcr being 71% , 58% and 73% , respective- ly. The test results indicate that the type of polyacrylamide modified bentonite impermeable material holds excel- lent impermeability and decontamination performance.