不同浊度下的泥沙对水体镉、铅、砷去除的影响分析

针对流域突发性重金属污染,不同浊度下的泥沙对重金属有一定的去除效果。以浊度为指示指标,通过试验研究了常温(25 ℃)和低温(5 ℃)条件下浊度50～650 NTU(Nephelometric Turbidity Unit)范围内泥沙对重金属镉、铅、砷吸附去除的影响。试验结果表明:泥沙对重金属镉、铅、砷的去除效果为铅＞镉＞砷,其中铅的去除率达到99%。浊度与能处理达标的最高重金属浓度呈线性关系,常温下浊度与能处理达标的最高镉、铅、砷浓度关系曲线的相关系数分别为0.996、0.998、0.999,低温下其相关系数分别为0.999、0.996、0.998。常温较低温更利于泥沙对重金属镉、铅、砷的去除,能去除更高浓度的重金属,达到生活饮用水卫生标准。

Influence of Turbidity on Removing Cadmium,Lead and Arsenic in Water

Water body with various turbidity has some mitigating effect in treating emergent heavy metal contamination in drainage basin. In this experiment, turbidity was used as indicator to study the influence of turbidity ranging 50 NTU~650 NTU (Nephelometric Turbidity Unit) on the removal of heavy metals (cadmium, lead, and arsenic) at room temperature (25 ℃) and low temperature (5 ℃). Results suggested that sediment had the best removal effect on lead, followed by cadmium and arsenic in sequence, among which the removal rate of lead amounted to 99%. Turbidity was in a linear relationship with the highest concentration of heavy metal that could be treated to be meeting standard after treatment. At room temperature, the correlation coefficients of the highest concentration of cadmium, lead, and arsenic against turbidity were 0.996, 0.998 and 0.999 respectively, whereas at low temperature, the coefficients were 0.998, 0.996 and 0.998 respectively. Compared with low temperature, room temperature is more conducive to the removal of heavy metals cadmium, lead, and arsenic by sediment. Also at room temperature, heavy metals of high concentrations can be removed to meet the sanitary standards of drinking water.