硝酸酸化生物炭强化去除水中Pb(Ⅱ)和Cd(Ⅱ)的特性  

Enhanced removal of Pb(Ⅱ)and Cd(Ⅱ)from water by nitric acid treated biochar

作　　者：万顺利[1] 李燕[1] 陈卫旸 唐贵 王玉 Wan Shunli;Li Yan;Chen Weiyang;Tang Gui;Wang Yu(College of Life&Environmental Sciences,Huangshan University,Huangshan 245041,China)

机构地区：[1]黄山学院生命与环境科学学院,安徽黄山245041

出　　处：《工业水处理》2021年第8期58-64,共7页Industrial Water Treatment

基　　金：国家自然科学基金项目(22006047);污染控制与资源化研究国家重点实验室开放基金项目(PCRRF19028);安徽省自然科学基金项目(1908085QB86);安徽省高校自然科学研究项目(KJHS2020B05)。

摘　　要：采用常温硝酸酸化技术对茶叶渣生物炭(BC)进行改性,制备了酸化生物炭(A-BC),并用SEM、TEM、BET、Boehm滴定、FTIR对A-BC的表面物理化学特性进行表征。在此基础上,以BC为参照,考察A-BC对水中典型重金属离子Pb(Ⅱ)、Cd(Ⅱ)的吸附特性。结果表明,A-BC对Pb(Ⅱ)和Cd(Ⅱ)的吸附容量远高于BC,且吸附等温线符合Freundlich模型;吸附速度较快,在100 min内即可达到平衡,Pb(Ⅱ)和Cd(Ⅱ)在A-BC孔内的传质系数分别可达5.5×10^(-9)、1.0×10^(-8)cm^(2)/s。A-BC可在高浓度HA和碱金属共存条件下实现对Pb(Ⅱ)和Cd(Ⅱ)的靶向吸附。经历10次吸-脱附循环后,A-BC对Pb(Ⅱ)、Cd(Ⅱ)的吸附容量未出现明显下降。XPS结果显示,A-BC主要通过表面功能基团与Pb(Ⅱ)、Cd(Ⅱ)的外球络合作用实现吸附去除。在柱吸附装置内,A-BC可实现含Pb(Ⅱ)、Cd(Ⅱ)模拟废水的达标处理,具有广阔的应用前景。Teawaste biochar was modified using nitric acid at room temperature,and a new biochar A-BC was prepared.The physicochemical characteristic of A-BC was investigated by means of SEM,TEM,BET,Boehm titration,FTIR.Moreover,the adsorption behavior of Pb(Ⅱ)and Cd(Ⅱ)onto A-BC was evaluated with the pristine BC as reference.The research results showed that the adsorption capacities of Pb(Ⅱ)and Cd(Ⅱ)onto A-BC were much higher than that onto BC,and the isotherms met well with Freundlich model.The adsorption processes of two metals onto A-BC were relatively quick with equilibrium time within 100 min.The intra-particle diffusivities of Pb(Ⅱ)and Cd(Ⅱ)on A-BC were predicted to be 5.5×10^(-9) cm^(2)/s and 1.0×10^(-8) cm^(2)/s.A-BC could preferably remove Pb(Ⅱ)and Cd(Ⅱ)in the coexisting of high concentration of HA and Mg^(2+),Na+with high levels.More importantly,after 10 cycles of adsorption-desorption tests,there were no obvious decline for the adsorption capacities of Pb(Ⅱ)and Cd(Ⅱ)onto A-BC.XPS results showed that the A-BC were mainly through surface functional groups’complexation with outer sphere for Pb(Ⅱ)and Cd(Ⅱ)for their adsorption removal.Additionally,A-BC could be successfully used in column setting and treat the simulated Pb(Ⅱ)and Cd(Ⅱ)wastewater to satisfy their discharge standards which has great potential.

关 键 词：茶叶渣 生物炭 重金属 吸附 

分 类 号：X703[环境科学与工程—环境工程] TL941.21[核科学技术—辐射防护及环境保护]