【摘要】 沉积物对砷的吸附-解吸作用是控制砷在地下水中的迁移和转化的决定性因素。对砷中毒重病区大同盆地山阴县沉积物中砷的吸附行为和影响因素研究结果表明,沉积物对砷的吸附符合Freundlich吸附等温模式,吸附量主要与沉积物颗粒大小、黏土矿物质量分数和类型、铁铝氧化物质量分数以及沉积物中As的质量分数有关,有机质质量分数对砷的吸附量影响需进一步深入研究。铝硅酸盐、铁铝氧化物质量分数较高且颗粒较细的黏土和亚黏土类沉积物对砷的吸附性较强;而铝硅酸盐、铁铝氧化物质量分数较低且颗粒较粗的细砂和粉砂类沉积物对砷的吸附性较差,其所处的含水层也是形成高砷地下水的主要含水层。pH值为5.5~8.0时,砷的吸附量最大。大同盆地高砷地下水pH条件非常不利于沉积物中砷的吸附,易形成高砷地下水。该区地下水10℃左右的温度条件非常有利于沉积物对砷的吸附,但由于影响因素较多,且地下水的温度在不同季节会发生一定的变化,其产生的影响还有待进一步研究。更多还原

【Abstract】 Adsorption-desorption plays a predominant role in controlling the mobilization and transformation of arsenic in the sediments.This paper discusses an experiment on the arsenic adsorption behaviors in sediments of endemic arsenism diseased areas from Shanyin County,Datong Basin and the influence factors.The results show that arsenic adsorption by sediments is in accordance with the Freundlich adsorption isotherm.The adsorption capacity is mainly associated with the particle size,contents and types of clay,contents of iron-aluminum oxides and arsenic in the sediments,and with little relation to organic matter.Strong arsenic adsorption capacity is found with clay and silt clay of high content of alumina-silicate,iron-aluminum oxide,while the opposite is found with coarse-grained sand and silt with lower alumina-silicate,iron-aluminum oxide content.The high arsenic aquifers are mainly located in the sediments of fine sand and silt.When pH varied from 5.5 to 8,the maximum arsenic adsorption capacity will occur in the sediments.Pore groundwater in Datong Basin is weak alkaline,hence is unfavorable for arsenic adsorption.While the benefitial temperature for the arsenic adsorption is about 10℃.However,further research should be needed as many other factors will also affect the arsenic adsorption in the sediments.更多还原