Hydraulic conductivity of seven geosynthetic clay liners (GCLs) to synthetic coal combustion product (CCP) leachates were evaluated in this study. The leachates are chemically representative of typical and worst scenarios observed in CCP landfills. The ionic strength (I) of the synthetic CCP leachates ranged from 50 mM to 4676 mM (TCCP-50, LRMD-96, TFGDS-473, LR-2577, HI-3179 and HR-4676). One of the GCLs contained conventional sodium bentonite (Na–B) and the other six contained bentonite-polymer (B–P) mixture with polymer loadings ranging from 0.5% to 12.7%. Hydraulic conductivity tests were conducted at an effective confining stress of 20 kPa. The hydraulic conductivity of the Na–B GCLs were >1 × 10⁻¹⁰ m/s when permeated with all six CCP leachates, whereas the B–P GCLs with sufficient polymer loading maintained low hydraulic conductivity to synthetic CCP leachates. All the B–P GCLs showed low hydraulic conductivity (<1 × 10⁻¹⁰ m/s) to low ionic strength leachates (TCCP-50, I = 50 mM and LRMD-96, I = 96 mM). B–P GCLs with P > 5% showed low hydraulic conductivity (<1 × 10⁻¹⁰ m/s) up to HI-3179 leachates. These results suggest that B–P GCLs with sufficient polymer loading can be used to manage aggressive CCP leachates.

本研究评估了七种土工合成粘土衬垫 (GCL) 对合成煤燃烧产物 (CCP) 渗滤液的水力传导率。渗滤液在化学上代表了 CCP 垃圾填埋场中观察到的典型和最坏情况。合成 CCP 浸出液的离子强度 (I) 范围为 50 mM 至 4676 mM（TCCP-50、LRMD-96、TFGDS-473、LR-2577、HI-3179 和 HR-4676）。其中一种 GCL 含有常规的钠基膨润土 (Na-B)，另外 6 种含有膨润土-聚合物 (B-P) 混合物，聚合物负载量为 0.5% 至 12.7%。水力传导率测试是在 20 kPa 的有效围压下进行的。Na-B GCLs 的水力传导率 >1 × 10 ^-10 m/s 当用所有六种 CCP 浸出液渗透时，而具有足够聚合物负载的 B-P GCL 保持对合成 CCP 浸出液的低水力传导率。所有 B-P GCL 对低离子强度浸出液（TCCP-50，I = 50 mM 和 LRMD-96，I = 96 mM）都显示出低导水率（<1 × 10 ^-10 m/s）。P > 5% 的 B–P GCL 显示出低导水率 (<1 × 10 ^-10  m/s)，直至 HI-3179 渗滤液。这些结果表明，具有足够聚合物负载的 B-P GCL 可用于管理侵蚀性的 CCP 浸出液。