腐殖质吸附重金属钼(MoO_4~(2-))的性能研究

模拟研究了腐殖质对含钼废水中钼(Mo O2-4)的吸附作用。分别考察了p H值、时间、温度和吸附剂投加量,以及竞争离子对吸附过程的影响,并应用热力学和动力学方法对吸附机理进行研究。结果表明:腐殖质在p H30 min,投加量为1 g,温度为25~30℃时,钼去除率至少达到90%。在最佳条件下,平衡吸附量可达1.014 mg/g。PO3-4对Mo O2-4的吸附表现了较强的竞争性,去除率从90%以上降低至60%左右,而SO2-4和Si O4-4对Mo O2-4的去除率没有显著影响。腐殖质吸附Mo O2-4符合Langmuir等温吸附模型,吸附动力学符合准二级动力学模型。腐殖质吸附钼属于化学吸附,受化学反应控制。结论表明,腐殖质在含钼废水治理领域具有良好的应用前景。

ADSORPTION PERFORMANCE OF MOLYBDENUM ONTO HUMUS

The adsorption of molybdenum onto humus was studied by simulation． pH，time，temperature，dosing quantity and competitive anions were investigated during adsorption process． The adsorption mechanism was researched by the method of adsorption isotherm and kinetic model． The results showed that the removal efficiency of molybdenum from solution attached 90% at least，with pH ＜ 3，adsorptim time of 30 min，humus dosage 1 g，and a temperature of 25 ～ 30 ℃． The equilibrium adsorption capacity was 1. 014 mg/g at the optimum conditions． Phosphate appeared to compete strongly with MoO2 － 4 and the removal efficiency of molybdenum decreased from over 90% to 60% or so． Silicate and sulfate did a negligible effect on the sorption of MoO2 － 4 ． The Langmuir isotherm adsorption model and the pseudo second-order rate equation could fit the experimental data well． It meant that adsorption molybdenum onto humus was chemical adsorption and was controlled by chemical reactor． The conclusion showed that humus could be applied in adsorption of molybdenum in the future．