活性炭比例对四合土隔离层重金属阻滞能力的影响

Effects of activated carbon ratio on heavy metal blocking ability of isolation layer

为探究活性炭比例对四合土隔离层重金属阻滞能力的影响,在三合土中添加不同量的活性炭构建四合土隔离层,测定重金属离子穿透隔离层时间并运用两区模型拟合重金属离子在隔离层内的弥散扩散系数(D)和阻滞系数(R)。结果表明,随着隔离层中活性炭比例的增加,隔离层饱和导水率增大;隔离层材料黄土、熟石灰、活性炭、细沙比例为5∶2∶1∶2时,重金属Zn、Cd、Hg、Pb、Cu穿透时间分别延长了20.0%、16.0%、5.0%、8.0%、6.0%;隔离层材料黄土、熟石灰、活性炭、细沙比例为5∶1.5∶1.5∶2时,重金属Zn、Cd、Hg、Pb、Cu穿透时间分别延长了25.5%、19.8%、7.4%、7.2%、2.7%;添加活性炭的隔离层可以不同程度提高重金属Zn、Cd、Cu的阻滞系数。

To investigate the effect of different ratios of activated carbon on heavy metal blocking ability of isolation layer,different amount of activated carbon were put in soil mixture to measure the penetrate time of heavy metal ions to isolation layer.Two-region Model(TRM)was also used to fit the diffusion coefficient(D)and retardation coefficient(R)of heavy metal ions in the separator.The results showed that:Saturated hydraulic conductivity increased with activated carbon ratio increased.Penetrating time of Zn,Cd,Hg,Pb,Cu increased 20.0%,16.0%,5.0%,8.0%,6.0% respectively in isolation layer(loess∶slaked∶activated carbon∶fine sand=5∶2∶1∶2)compare tothat in isolation layer(loess∶slaked∶fine sand= 5∶3∶2).Penetrating time of Zn,Cd,Hg,Pb,Cu increased 25.5%,19.8%,7.4%,7.2%,2.7% respectively in isolation layer(loess∶slaked∶activated carbon∶fine sand=5∶1.5∶1.5∶2)compare to that in isolation layer(loess:slaked:fine sand= 5∶3∶2).Retardation coefficient of Zn,Cd,Cu were increased when activated carbon was put into tabia.