酸雨作用下含磷固化剂处理铅锌镉复合污染土的半动态浸出试验研究
发布时间：2019-07-22 19:48
【摘要】：酸雨pH可显著影响固化重金属污染土的浸出量。定量评价固化污染土在暴露条件下(例如酸雨)对周边水土体环境的影响,需要明确固化污染土的有效扩散系数和阻滞因子这两个关键参数。现有研究多集中在固化污染土的浸出特性和表观扩散系数,有关有效扩散系数和阻滞因子的研究很少。本次研究旨在研究改进的KMP固化剂固化重金属Pb、Zn、Cd复合污染土在酸雨作用下的有效扩散系数和阻滞因子。解吸附试验表明,随着污染土中重金属Pb、Zn、Cd浓度增加,固化污染土的解吸附量增大,且解吸附曲线满足Freundlich平衡吸附/解吸附方程。半动态浸出试验结果表明,污染土中重金属Pb、Zn、Cd浸出机制主要由扩散控制,且拟合曲线斜率分别为0.60,0.56和0.61,表观扩散系数Dobs为1.05×10~(-16),7.84×10~(-13)和2.11×10~(-12) m~2/s。结合解吸附试验和半动态浸出试验结果可知,Pb、Zn、Cd的阻滞因子Rd分别为17165.6,254.6和109.3,有效扩散系数De分别为1.82×10~(-12),1.96×10~(-10),2.34×10~(-10) m~2/s。与其他学者结果相比,固化污染土中Pb的有效扩散系数低于其他学者的两个数量级,而Zn和Cd的求算结果与其他学者一致。
[Abstract]:Acid rain pH can significantly affect the leaching amount of solidified heavy metal contaminated soil. To quantitatively evaluate the influence of solidified contaminated soil under exposure conditions (such as acid rain) on the surrounding water and soil environment, it is necessary to clarify the two key parameters of effective diffusion coefficient and blocking factor of solidified contaminated soil. Most of the existing studies focus on the leaching characteristics and apparent diffusion coefficient of solidified contaminated soil, but little on the effective diffusion coefficient and blocking factor. The purpose of this study was to study the effective diffusion coefficient and blocking factor of heavy metal Pb,Zn,Cd composite polluted soil cured by improved KMP curing agent under the action of acid rain. The desorption test shows that with the increase of the concentration of heavy metal Pb,Zn,Cd in the polluted soil, the desorption capacity of the solidified contaminated soil increases, and the desorption curve satisfies the Freundlich equilibrium adsorption / desorption equation. The results of semi-dynamic leaching test show that the leaching mechanism of heavy metal Pb,Zn,Cd in polluted soil is mainly controlled by diffusion, and the slope of fitting curve is 0.60,0.56 and 0.61, respectively, and the apparent diffusion coefficient Dobs is 1.05 脳 10 ~ (- 16), 7.84 脳 10 ~ (- 13) and 2.11 脳 10 ~ (- 12) m 鈮，
本文编号：2517849
[Abstract]:Acid rain pH can significantly affect the leaching amount of solidified heavy metal contaminated soil. To quantitatively evaluate the influence of solidified contaminated soil under exposure conditions (such as acid rain) on the surrounding water and soil environment, it is necessary to clarify the two key parameters of effective diffusion coefficient and blocking factor of solidified contaminated soil. Most of the existing studies focus on the leaching characteristics and apparent diffusion coefficient of solidified contaminated soil, but little on the effective diffusion coefficient and blocking factor. The purpose of this study was to study the effective diffusion coefficient and blocking factor of heavy metal Pb,Zn,Cd composite polluted soil cured by improved KMP curing agent under the action of acid rain. The desorption test shows that with the increase of the concentration of heavy metal Pb,Zn,Cd in the polluted soil, the desorption capacity of the solidified contaminated soil increases, and the desorption curve satisfies the Freundlich equilibrium adsorption / desorption equation. The results of semi-dynamic leaching test show that the leaching mechanism of heavy metal Pb,Zn,Cd in polluted soil is mainly controlled by diffusion, and the slope of fitting curve is 0.60,0.56 and 0.61, respectively, and the apparent diffusion coefficient Dobs is 1.05 脳 10 ~ (- 16), 7.84 脳 10 ~ (- 13) and 2.11 脳 10 ~ (- 12) m 鈮，
本文编号：2517849
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