考虑生物降解作用时GCL+AL 衬垫中有机污染物的扩散规律

为研究有机污染物在土工复合膨润土衬垫(GCL)+土体保护层(AL)衬垫中的运移规律,建立了考虑AL中生物降解作用的GCL+AL衬垫中有机污染物一维扩散模型,并得到该模型的解析解。通过与Pollute v7的计算结果进行比较,验证了模型的合理性。基于该模型,分析了生物降解作用对有机污染物在GCL+AL衬垫中运移的影响,探讨考虑生物降解时GCL+AL与压实黏土衬垫(CCL)之间的等效性。结果表明,减小有机污染物在AL中的降解半衰期可以减少GCL+AL衬垫底部有机污染物通量。在文中计算条件下,GCL+1m以上的AL复合衬垫可代替标准的0.75m CCL。

Rule of diffusion of organic pollutants through GCL+AL liners considering biodegradation

clay liner (GCL) and attenuation liner (AL) was developed to investigate the transport of organicpollutants in the composite liners. Degradation of the organic pollutants in AL is considered. The analytical solutionto the model was obtained, and the results are in good agreement with those from Pollute v7 software, showing thereasonability of the proposed model. The effect of biodegradation on diffusion of organic pollutants was investigatedon the basis of the proposed model. The equivalence between GCL+AL and the compacted clay liner (CCL) isdiscussed with consideration of biodegradation. The results show that the bottom flux of the GCL+AL compositeliners is reduced when the degradation half-life of organic pollutants in AL decreases. The standard 0.75 m CCLcan be replaced by a combination of a GCL and an AL with a thickness of more than one meter under thecalculation conditions described in this paper.