近年来垃圾填埋场中越来越多的使用高密度聚乙烯(HDPE)膜与粘土组合作为复合防渗层,但是HDPE土工膜在填埋场中寿命如何以及它的降解规律国内研究甚少。针对这一问题,文章总结了国际上关于HDPE土工膜进行的室内老化降解试验研究并介绍Arrhenius模型预测抗氧化剂寿命,以期对国内的工程实践提供参考。HDPE膜的降解分三阶段,对其老化影响最大的是第一阶段即抗氧化剂耗散阶段。现有的室内试验主要通过将HDPE膜浸泡在空气,水及合成渗沥液中或通过模拟衬垫装置模拟进行升温老化,进而通过测量氧化诱导时间变化预测抗氧化剂寿命。然而室内试验均未能完全模拟实际条件,后续还需实地填埋场观察取样了解其降解情况。
In recent years,more and more landfills using high-density polyethylene(HDPE)geomembrane with clay layers as a composite liner,but the researches on the durability and degradation performance of HDPE geomembrane in landfill are rare in China.This article summarize the HDPE geomembrane ageing tests and introduce the Arrhenius model to predict the life time of anti-oxidants in order to provide references for further researches.Degradation of HDPE geomembrane is divided into three phases,the most critical phase is the first stage:the antioxidants depletion stage.The existing laboratory tests have two methods:immersion tests by immersing the HDPE geomembranes in the medium of air,water and synthetic leachate or simulated landfills to simulate the pressure and liner situation in landfills.The life time of antioxidants can be conducted by the OIT test.However,the real degradation performance needs the long-term observations and experiments in the landfills.