College of Resources and Environment, Zunyi Normal University, Zunyi 563006, China.
Chengdu Drainage Co., Ltd., Chengdu 610000, China.
Int J Environ Res Public Health. 2022 Dec 11;19(24):16653. doi: 10.3390/ijerph192416653.
In view of the problem of Fe pollution in an iron sulfur mine, different layers of loess soil in the Bijie area were used for adsorption to alleviate the mine wastewater pollution by natural treatment. The effects of the initial concentration of Fe, adsorption time and pH value on the adsorption performance of top, core and subsoil layers of loess soils were studied by the oscillatory equilibrium method, and the adsorption mechanism of these three soils was analyzed through a kinetic adsorption experiment and infrared spectroscopy. The results showed that the adsorption capacity of Fe was improved by increasing the initial concentration and reaction time, but the adsorption rate of the adsorption capacity of Fe was reduced. The adsorption rate of Fe in the subsoil layer was faster than that in the other two layers. The higher the pH, the higher the adsorption capacity. After the pH was higher than 3.06, it had little effect on the adsorption capacity, but the adsorption rate increased. The first-order kinetic equation, second-order kinetic equation and Elovich equation were suitable for iron adsorption kinetics of three soils. The fitting correlation coefficient of the second-order kinetic equation was close to one, indicating the main role of chemical adsorption. The adsorption rate constant of the subsoil layer was about two times and three times that of the core soil layer and the topsoil layer. The Langmuir model can better fit the isothermal adsorption process. The results of infrared spectroscopy of soil showed that the content of soil organic matter played an important role in the adsorption capacity of Fe. The subsoil layer had a higher concentration of organic matter and more abundant functional groups, so the adsorption capacity of Fe was the highest. The results could provide a theoretical basis for the removal of iron in acid mine wastewater.
针对某铁硫矿山 Fe 污染问题，采用毕节地区不同层次的黄土土样进行自然处理吸附，以减轻矿山废水污染。通过振荡平衡法研究了初始 Fe 浓度、吸附时间和 pH 值对黄土土样表土层、心土层和底土层吸附性能的影响，并通过动力学吸附实验和红外光谱分析了这三种土壤的吸附机理。结果表明，随着初始浓度和反应时间的增加，Fe 的吸附容量提高，但 Fe 吸附容量的吸附速率降低。底土层对 Fe 的吸附速率比其他两层快。pH 值越高，吸附容量越大。当 pH 值高于 3.06 后，对吸附容量的影响较小，但吸附速率增加。一级动力学方程、二级动力学方程和 Elovich 方程均适用于三种土壤的铁吸附动力学。二级动力学方程的拟合相关系数接近 1，表明化学吸附起主要作用。底土层的吸附速率常数约为心土层和表土层的两倍和三倍。Langmuir 模型可以更好地拟合等温吸附过程。土壤红外光谱结果表明，土壤有机质含量对 Fe 的吸附容量起着重要作用。底土层的有机质浓度较高，官能团较丰富，因此对 Fe 的吸附容量最高。研究结果可为去除酸性矿山废水中的铁提供理论依据。
