摘要
以花生壳(PH)和丙烯酸(AA)为原料,采用Fe^(2+)-H_2O_2引发接枝反应,制备了丙烯酸接枝改性花生壳(PH-g-AA)吸附材料,用热重分析(TG)、能谱分析(EDS)和零电荷点(pHpzc)的测定等对其结构进行表征。考察了pH值、吸附时间、Hg(Ⅱ)和Mn(Ⅱ)初始浓度、温度、共存离子等因素对Hg(Ⅱ)和Mn(Ⅱ)吸附效果的影响。结果表明:PH-g-AA对Hg(Ⅱ)和Mn(Ⅱ)的最佳吸附pH范围均为5.0~6.0,在金属离子的初始浓度为50mg·L^(-1)、温度为20℃时的吸附效率均超过95%。吸附量随温度升高而增大,热力学参数△G、△H的计算值表明是自发、吸热过程。吸附动力学可以用准二级动力学模型描述和预测,Freundlich方程能较好地描述PHg-AA吸附Hg(Ⅱ)和Mn(Ⅱ)的等温吸附过程。表面络合和离子交换作用是主要的吸附机制。
The modified peanuthull（ PH-g-AA） was prepared by grafting copolymerization ofacrylic acid（ AA） ontopeanuthull（ PH） using Fe^2＋-H2O2 as initiator. The adsorbent was characterized by the techniques of thermogravimetric analysis（TG） ,Energy dispersive spectrometry（ EDS） and pHp2C. The effect of various parameters on Hg（ II）/Mn（ II） adsorption process such as initial pH, contact time, initialconcentration of Hg（ II）/Mn（ II） , temperature and coexisting ions were measured and analyzed in detail through batch static experiments. The results indicated that the adsorption processes of Hg（ II）/Mn（ II） onPH-g-AA were much dependent on tem-perature and pH,the optimal pH values were at pH ranging from 5. 0 to 6. 0. Theadsorption efficiencies of PH-g-AA on Hg（ II）/Mn （II） weremore than 95% when the initial mental concentration was 50 mg＊L 1 and the temperature was 293 K. The adsorptioncapaci- tiesincreased withincreasing temperature. The thermodynamic parametervaluesof AH and AG revealed that the adsorption of H g （ I I ） / Mn（ II） ontoPH-g-AA was a spontaneous and endothermic process. The sorption kinetic experimental data were best described by the pseudo-second-order model,and the isotherm adsorption equilibriums ofHg（II）/Mn（II）werefollowed by Freundlich isotherm equation. The adsorption mechanisms were ion exchange and chelation between Hg（ II）/Mn（ II） andPH-g-AA.
出处
《化学研究与应用》
CAS
CSCD
北大核心
2016年第9期1287-1293,共7页
Chemical Research and Application
基金
四川省教育厅自然科学研究项目(16ZB0315)资助
国家自然科学基金项目(31300793)资助
