固废再利用的填埋场土质覆盖系统防渗与隔氧性能

The Anti-seepage and Oxygen Barrier Performance of a Landfill Soil Cover System Using Recycled Waste

为了促进固废资源化利用,提出了一种中和渣固废再利用的新型三层土质覆盖系统。采用自主研发的土柱试验系统和数值模拟方法,研究了所提出的覆盖系统的防渗隔氧性能。研究结果表明:为期75 d的监测期内,中和渣防渗层含水率无明显变化(<2%),在50年一遇的强降雨作用下未发生底部渗漏;中和渣层饱和渗透系数ks和初始饱和度S0对覆盖层防渗隔氧效果有显著影响,随着ks从3.5×10^(-10)m/s增加到3.5×10^(-7)m/s,降雨条件下累积渗漏量增加了339倍,随着S0从0.4增加到0.95,干燥条件下累积氧通量减少了94%。所提出的覆盖系统在无需土工膜的情况下可有效阻隔雨水渗入和氧气入侵,在湿润气候区年降雨量高达1820 mm条件下,累积渗漏量仅为27 mm,全年累积氧通量为5.5 g/m^(2)。

To promote the utilization of solid waste resources,a new three-layer landfill cover system using neutralized slag was proposed.The anti-seepage and oxygen barrier performance of the proposed cover system was investigated by using the self-developed soil column test system and numerical simulation.The results show that the water content of the neutralized slag layer has no obvious change(i.e.,<2%),and no leakage occur under the heavy rainfall(i.e.,with a 50-year return period).The saturation permeability coefficient(k s)and initial saturation(S 0)of the neutralized slag layer have significant effects on the performance of the cover system,with k s increasing from 3.5×10^(-10) m/s to 3.5×10^(-7) m/s,the cumulative percolation under rainfall conditions increase by 339 times,and the cumulative oxygen flux under dry condition reduces by 94%as S 0 increasing from 0.4 to 0.95.The proposed cover system can be effective in minimizing percolation and oxygen intrusion without geomembrane,under the condition of annual rainfall of 1820 mm in humid climate zone,the cumulative percolation is only about 27 mm,and the cumulative oxygen flux is about 5.5 g/m^(2).