浮石负载壳聚糖吸附去除水中丙溴磷

通过浮石负载壳聚糖制备了吸附剂壳聚糖/浮石复合物,采用扫描电子显微镜(SEM)、热重分析(TGA)、元素分析、傅里叶红外光谱(FT-IR)、X射线衍射(XRD)和X射线荧光光谱(XRF)等技术手段表征了吸附剂性质,考察了吸附剂量、吸附时间、溶液pH值、离子强度和温度对该吸附剂吸附去除水中丙溴磷的影响,研究了再生吸附剂的吸附性能。结果表明,负载在浮石上的壳聚糖占吸附剂总量的8.69%;在p H值3.0~7.0内,壳聚糖/浮石对丙溴磷的吸附率大于90%;这种吸附剂对丙溴磷的吸附受溶液离子强度影响较小,随温度升高而稍微减小。在溶液温度25℃、pH=7.0、丙溴磷浓度40 mg/L、壳聚糖/浮石剂量为0.7 g/L和吸附平衡时间为90 min条件下,此吸附剂对丙溴磷最大吸附率为93.3%(最大吸附量为53.4 mg/g)。壳聚糖/浮石连续经过3次吸附/再生循环,每次循环对丙溴磷的吸附率下降约12%。可见壳聚糖/浮石通过吸附可有效地去除水中的农药丙溴磷。

Adsorptive Removal of Profenofos from Aqueous Solution by Chitosan/Pumice

An adsorbent named chitosan/pumice has been prepared for adsorptive removal of profenofos from aqueous solutions. The effects of solution pH, adsorbent dosage, contact time, ion strength and temperature on the adsorption of profenofos were investigated by batch experiments. The immobilization of chitosan was characterized by SEM, TGA, elemental analysis, FT-IR, XRD and XRF. The resultsshow that the chitosan loaded on pumice accounts for 8.69% of the amount of adsorbent; the adsorbent can be employed at pH 3.0~7.0 for quantitative adsorption rate(>90%); the adsorption for profenofos is hardly influenced by ion strength, and slightly decreases with temperature increase. Under the condition of 25 ℃, pH=7.0, 40 mg/L for the concentration of profenofos and 0.7 g/L for dose of chitosan/pumice, the adsorption equilibrium time is 90 min and the maximum adsorption rate of profenofos is 93.3%(53.4 mg/g for adsorbing capacity). The adsorbent can be reused at least three consecutive times with about 12% decrease on profenofos adsorption efficiency. This method for the adsorptive removal of profenofos from aqueous solution is simple, low cost, rapid and effective.