巯基化稻壳炭吸附废水中Zn(Ⅱ)试验研究

Adsorption of Zn(Ⅱ) from wastewater by sulfhydryl rice husk carbon

通过巯基乙酸改性稻壳炭去除废水中的Zn(Ⅱ),研究溶液的p H、反应温度和时间以及解吸对巯基化稻壳炭(RD350)吸附效果的影响,并对改性材料进行扫描电镜(SEM)和X射线能量色散谱(EDS)分析。结果表明:通过化学改性向稻壳炭引入巯基,改性稻壳炭的表面变得更加光滑,孔隙增大,且表面功能基团—SH含量增加,有利于提高对Zn(Ⅱ)的吸附能力。RD350适用的p H范围较宽(6~8),25℃时在300 min达到吸附平衡,吸附过程符合假二级动力学方程,为吸热反应。通过阿伦尼乌斯(Arrhenius)经验方程计算其活化能可知,吸附为活性化学吸附。由Langmuir吸附等温线方程计算可得,RD350对Zn(Ⅱ)的理论饱和吸附量为11.26 mg/g,结合解吸可知该吸附剂对Zn(Ⅱ)的吸附有较好的固持性,具有一定的吸附效果。

Removal of zinc ions from the wastewater by mercapto acetic acid modified rice husk carbon was studied. The effects of p H, reaction temperature and time, and desorption on the adsorption effect of thiol based rice husk carbon were studied. Scanning electron microscopy and X ray energy spectrum analysis of modified materials were carried out. The results showed that the surface of modified rice husk carbon was more smooth and porous, and the surface functional group —SH content increased by the chemical modification to rice husk carbon,and the adsorption capacity of Zn（ Ⅱ） was improved. The modified rice husk carbon has a wide range of p H（ 6-8）,and the adsorption equilibrium is reached at 300 min at 25 ℃. The adsorption process conforms to the pseudo two kinetic equation and is an endothermic reaction. According to the activation energy calculation by Arrhenius empirical equation, the adsorption belongs to active chemical adsorption. Based on the Langmuir adsorption isotherm equation, the theoretical saturated adsorption capacity of the thiol rice husk carbon to Zn（ Ⅱ） is 11. 26 mg/g. When combined with desorption, it is known that the adsorbent has good immobilization on Zn（ Ⅱ） and has certain adsorption effect.