摘要
[目的]通过稻壳炭表面的—OH和巯基乙酸上的—COOH发生酯化反应,制备成一种新型吸附剂(RD550),去除废水中的锌。[方法]利用改性前、后吸附材料研究溶液的pH值、投加量、反应时间、反应温度以及解吸对吸附效果的影响,并采用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)和X-射线光电子能谱(XPS)等对改性前、后稻壳炭的外貌形态进行表征和官能团分析。[结果]通过SEM图谱、XPS和FTIR图谱可知,巯基已被成功嫁接在稻壳炭上,能够增大稻壳炭孔隙和提高S含量以及对锌的吸附性能。巯基改性稻壳炭吸附Zn(Ⅱ)的适用pH值为6.50,在360 min内达到吸附平衡,且符合拟二级动力学方程。从吸附效率和节约成本的角度考虑,吸附材料用量为0.10 g时,吸附效果最佳。整个吸附过程符合单分子Langmuir吸附模型,巯基改性稻壳炭吸附Zn(Ⅱ)的最大吸附量为68.03 mg·g^(-1),结合解吸试验可知相对于未改性的稻壳炭,巯基改性稻壳炭吸附Zn(Ⅱ)更加牢固,解吸率为2.91%～13.12%。[结论]通过化学改性可把功能基团—SH键合在稻壳炭上,并利用S对重金属的亲和性,可以有效提高吸附剂的吸附性能,对去除废水中的Zn(Ⅱ)具有重要意义。
[Objectives] A new adsorbent(RD550)was prepared by esterification of-OH on rice husk carbon and-COOH on thioglycolic acid to remove zinc from wastewater.[Methods] The effects of pH value,dosage,reaction time,reaction temperature and desorption on the adsorption were studied by using the adsorbent materials before and after modification.The morphology and functional groups of the modified rice husk carbon were characterized by scanning electron microscopy(SEM),fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).[Results] The results of SEM,XPS and FTIR showed that the sulfhydryl group had been grafted onto rice husk carbon successfully.The porosity of rice husk charcoal increased,and the content of S also increased,which was beneficial to the adsorption of zinc.The suitable pH for the adsorption of Zn(Ⅱ)by thioglycolated rice husk carbon was 6.50,and the adsorption equilibrium reached within 360 min,which accorded with the pseudo-second-order kinetic equation.From the perspective of adsorption efficiency and cost saving,when the amount of adsorption material was 0.10 g,the adsorption effect was the best.The adsorption process accorded with Langmuir adsorption model.The maximum adsorption capacity of Zn(Ⅱ)on sulfhydryl rice husk carbon was 68.03 mg·g^-1.Combined with desorption experiment,the adsorption of Zn(Ⅱ)on sulfhydryl rice husk charcoal was stronger than that on unmodified rice husk carbon,and the desorption rate was 2.91%-13.12%.[Conclusions] By chemical modification,the functional group-SH can be bonded to rice husk carbon,and the affinity of S to heavy metals can be used to improve the adsorption performance of the adsorbent,which is of great significance for the removal of Zn(Ⅱ)from wastewater.
作者
程德义
邵爱云
杜超
杜琪雯
黄兆琴
代静玉
CHENG Deyi;SHAO Aiyun;DU Chao;DU Qiwen;HUANG Zhaoqin;DAI Jingyu(College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China;The City Vocational College of Jiangsu,Nanjing 210036,China)
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2019年第2期308-315,共8页
Journal of Nanjing Agricultural University
基金
江苏省自然科学基金面上项目(15KJB610002)
关键词
巯基改性
吸附性能
Zn(Ⅱ)
稻壳炭
吸附等温线
sulfydryl modification
adsorption properties
Zn(Ⅱ)
rice husk carbon
adsorption isotherm
