摘要
聚多巴胺(PDA)辅助负载聚氨基噻唑(PAT)法制备了磁性颗粒吸附剂Fe3O4@SiO2@PDA-PAT.对吸附剂进行了XRD、VSM、TG、SEM、XPS、EDS和Zeta电位等表征分析,考察了吸附剂对Hg2+的吸附性能.结果表明,Fe3O4@SiO2@PDA-PAT具有超顺磁性,在pH小于2时Zeta电位为正,pH大于2时Zeta电位为负.在303 K和Hg2+浓度为50 mg/L模拟废水中,当pH为1.3和5.0时,Hg2+的平衡吸附量分别为121.9 mg/g和153.1 mg/g.在强酸(如pH 1.3)和弱酸(如pH 5.0)环境下Fe3O4@SiO2@PDA-PAT吸附Hg2+的过程均是自发过程,且符合二级动力学模型和Langmuir等温吸附模型.强酸环境下(如pH 1.3)Fe3O4@SiO2@PDA-PAT吸附Hg2+是焓驱动的放热过程,弱酸(如pH 5.0)环境下是熵驱动的吸热过程.用2 mol/L混酸(盐酸和硝酸摩尔比为1∶1)作为解吸液可使Hg2+解吸率达91%以上.在303 K、pH 1.3、Hg2+浓度20 mg/L条件下,当Na+、K+、Mg2+、Ca2+、Cu2+、Zn2+、Ni2+质量浓度为Hg2+的20倍时,Fe3O4@SiO2@PDA-PAT的Hg2+平衡吸附量分别下降了33.2%、32.1%、20.6%、26.7%、21.2%、29.6%、17.8%.在模拟海水下,Hg2+吸附量下降40.9%.Fe3O4@SiO2@PDA-PAT具有较好的Hg2+选择性,具有净化海水脱除重金属的应用潜力.
Abstract
In this study,magnetic particle adsorbent Fe3 O4@SiO2@PDA-PAT was prepared by using polydopamine(PDA)assisted loading polyaminothiazole(PAT)method.The adsorbent was characterized by XRD,VSM,TG,SEM,XPS,EDS,and Zeta potential analysis,and the adsorption performance of the adsorbent for mercury was investigated.The results showed that Fe3 O4@SiO2@PDA-PAT exhibited super paramagnetic behavior,and its Zeta potential was positive at pH<2 and negative at pH>2.At 303 K and a mercury ion concentration of 50 mg/L in simulated wastewater,the equilibrium adsorption capacities of Fe3 O4@SiO2@PDA-PAT were 121.9 mg/g and 153.1 mg/g at pH 1.3 and pH 5.0,respectively.The adsorption process of mercury ions by Fe3 O4@SiO2@PDA-PAT was a spontaneous process and followed the second-order kinetic model and Langmuir isotherm model at 303 K,as well as in strong acid(pH 1.3)and weak acid(pH 5.0)environments.The adsorption of mercury ions by Fe3 O4@SiO2@PDA-PAT in strong acid environment(pH 1.3)was an exothermic process driven by enthalpy,while in weak acid environment(pH 5.0)it was an endothermic process driven by entropy.The use of 2 mol/L mixed acid(hydrochloric acid and nitric acid in a molar ratio of 1∶1)as the desorption solution could achieve a mercury desorption rate of more than 91%.Under the conditions of 303 K,pH 1.3,and Hg2+concentration 20 mg/L,when the mass concentration of Na+,K+,Mg2+,Ca2+,Cu2+,Zn2+,and Ni2+were 20 times that of Hg2+,the Hg2+equilibrium adsorption capacities of Fe3 O4@SiO2@PDA-PAT for mercury ions decreased by 33.2%,32.1%,20.6%,26.7%,21.2%,29.6%,and 17.8%,respectively.In simulated seawater,the mercury adsorption capacity decreased by 40.9%.Fe3 O4@SiO2@PDA-PAT exhibited good mercury adsorption selectivity and had the potential to be used for purifying seawater and removing heavy metals.
基金项目
舟山市定海区科技项目(2021C31002)
大连理工大学基本科研业务项目(DUT23RC3044)
国家科技期刊平台
NSTL
万方数据