粉煤灰对重金属钼的吸附效果及其影响因素

Study on Adsorptive Effect and Influencing Factors of Fly Ash on Heavy Metal Molybdenum

为了探讨粉煤灰对重金属钼的吸附影响因素及吸附机理,以粉煤灰为吸附剂,钼酸铵为吸附质,通过单因子试验分别考察粉煤灰粒径、粉煤灰投加量、吸附时间、pH和温度等因素对吸附效果的影响,确定了粉煤灰吸附的最佳条件(粒径为80～100目,投加量为2.5g,吸附时间为30min,pH为3,温度为30℃)。在此条件下,粉煤灰对钼酸铵的去除率达到80%～85%。分别用纯水以及0.01,0.05,0.10mol/L的NaOH和0.05mol/L的NaCl对最佳吸附条件下的粉煤灰进行解吸试验,结果表明,在粉煤灰的吸附过程中,化学吸附作用大于物理吸附。

In order to investigate the affecting factors and mechanism of fly ash＇s adsorption on heavy metal molybdenum, the factors of fly ash particle size, dosage, adsorption time, pH, and temperature were studied through single factor experiments with fly ash as adsorbent and ammonium molybdate as adsorbate. The optimum adsorption condition was obtained ： fly ash＇s particle size was 80-100 mesh, the dosage of adsorbent was 2.5 g, pH was 3, reaction time was 30 rain, and the temperature was 30 ℃. Under this condition, the removal rate of ammonium molybdate by fly ash was 80%-85%. Under the optimum adsorption condition, the desorption experiment of fly ash was carried out by pure water, NaOH with the concentrations 0.01, 0.05, 0.10 mol/L and NaCl with the concentration 0.05 mol/L. The conclusion was that chemical adsorption effect was greater than the physical adsorption effect in the adsorption process of fly ash.