黄河泥沙吸附砷污染物室内静态试验

Studies on Adsorption of Arsenic Pollutants onto Sediments of the Yellow River Using Laboratory Static Experiments

黄河是典型的多沙河流,其水体中砷的来源有自然本底砷和外来砷2种.随着砷污染的日益加剧,给黄河流域生态环境和饮用水安全构成巨大威胁.黄河泥沙对砷污染物具有吸附能力,其吸附量取决于砷污染物在水、沙两相间的分配比例.为了研究自然状态下黄河泥沙对砷的吸附规律,以黄河原型沙为对象,采用静态吸附微污染含砷废水试验,考察了接触时间、含沙量、泥沙粒径对泥沙吸附砷能力的影响.结果表明:①当含沙量在200 kg/m3以下时,泥沙对砷的吸附在5 min以内基本达到吸附平衡;②相同含沙量情况下,细沙对砷的吸咐量最大,中沙次之,粗沙最小;③同一颗粒级配下,泥沙对砷的吸咐量随含沙量的增加呈对数增长.

The Yellow River is a typical sediment-laden river, in which the arsenic is from both the river itself and from the outside. With the increase of arsenic pollution, the ecological environment and drinking water sources in the valley have been seriously threatened. Sand in the Yellow River adsorbs arsenic, with the adsorption amount dependent on the distribution proportion of arsenic in water and in the sediment. To study the mechanism of arsenic adsorption by sand in the Yellow River, the effects of contact time, sediment concentration and sediment gradation on the adsorption ability of prototype sand of the Yellow river sand were tested. The results showed that： 1 ） adsorption equilibrium of arsenic was reached within five minutes when the sediment concentration was less than 200 kg/m3 ; 2） under the same sediment concentration, the adsorption amount of arsenic decreased in the order of fine sediment 〉 medium granular sediment 〉 coarse sediment ; 3） with the same sediment gradation, adsorption of arsenic to sand showed a logarithmic increase with increase of sand concentration.