人工合成铁、铝矿对As(V)吸附的研究

采用批实验方法研究了人工合成铁、铝矿物对As(V)的吸附,考察吸附时间及溶液pH值对As(V)吸附的影响.结果表明,不同类型铁、铝矿对As(V)的吸附量均表现出随初始As(V)浓度(0.1~100mg/L)的增加而增加的趋势,其中水铁矿的吸附量在整个浓度范围内始终呈上升趋势,初始浓度为100mg/L As(V)时的吸附量为22.56mg/g,而针铁矿、水铝矿和赤铁矿的吸附量在低初始浓度时上升较快,随浓度升高上升幅度减缓直至平衡,其中赤铁矿的吸附量最小,100mg/L As(V)时的吸附量为4.75mg/g.Freundlich方程对吸附数据的拟合效果优于Langmuir方程,吸附能力表现为水铁矿最高,水铝矿和针铁矿相近,赤铁矿较低.随着吸附时间的增加,4种铁、铝矿物对As(V)的吸附量都逐渐增加,尤其是水铁矿,10min内即达到平衡吸附量的96.3%;水铝矿和针铁矿在48h时吸附量分别为平衡吸附量的97.2%和97.4%;赤铁矿则需96h才基本达到平衡.除水铁矿外,4种动力学方程对其他矿物动力学曲线的拟合均较好,尤其是双常数方程.pH值对矿物吸附As(V)的影响受As(V)初始浓度的影响,初始浓度较低时,铁、铝矿的吸附量仅在极碱条件下(pH>10)降低,而初始浓度较高时则表现为随pH值升高直线下降的趋势.

Study on arsenate adsorption by synthetic iron and aluminum oxides/hydroxides

Batch experiments were used to investigate arsenate adsorption by synthetic iron and aluminum oxides/hydroxides.The effects of adsorption time and pH on the adsorption behavior were also studied.The results showed that,As(V) adsorption by four iron and aluminum oxides/hydroxides increased with initial As(V) concentrations(0.1~100 mg/L),in which ferrihydrite showed a rising adsorption trend in the whole concentration range,with the adsorption amount of 22.56 mg/g at the initial As(V) of 100 mg/L.While the ra...