改性纤维球滤料对农田灌溉水中低浓度Cd^(2+)的吸附作用

Adsorption Effect of Modified Fiber-Ball Filter Media on Low Concentration of Cd^(2+) in Farmland Irrigation Water

采用化学氧化法对纤维球滤料进行改性,制成一种能够用来处理农田灌溉水中低浓度Cd^(2+)的吸附剂。用5 g/L的高锰酸钾溶液对纤维球滤料进行改性,制成改性纤维球滤料,并进一步就该吸附剂对水中重金属离子Cd^(2+)的吸附去除性能进行了考察。结果表明,该反应的最适pH值为7.0,吸附在10 h后基本达到平衡。在Cd^(2+)浓度为50μg/L、pH值为7.0、吸附剂投加量为1 g/L、溶液体积为1000 mL的条件下,改性纤维球滤料对Cd^(2+)的吸附去除率达到了99%。通过吸附动力学研究发现该吸附剂对Cd^(2+)的吸附符合一级动力学方程和Langmuir单分子层吸附规律。

The fiber-ball filter media was modified by chemical oxidation method to make a kind of adsorption material for removal of low concentration of Cd^2＋ in farmland irrigation water. As a high velocity filter material, the fiber-ball filter media was modified by 5 g/ L KMnO4. The adsorption capacity of this modified adsorbent to remove Cd^2＋ from aqueous solution was investigated under different conditions. Results showed that the optimum initial solution pH values for adsorption were 7.0. The adsorption could reach equilibrium in about 10 h. Under the condition that concentration of Cd^2＋ was 50 μg/L, pH value was 7.0, dosage of adsorbent was 1 g, and solution volume was 1 000 mL, the removal rate of the modified fiber-ball filter media for the adsorption of Cd^2＋ achieved 99%. The adsorption isotherm of the modified adsorbent could be described by Langmuir adsorption model and first-order kinetics equation.