摘要
采用白腐菌和纳米零价铁(nZVI)联合体系强化去除水中Cd(Ⅱ),并考察pH值、Cd(Ⅱ)初始浓度、温度、nZVI投加量对Cd(Ⅱ)去除的影响,分析n ZVI对白腐菌胞内外富集镉的影响特性,同时结合扫描电镜、红外光谱、X射线光电子能谱、三维荧光光谱等手段分析联合体系对Cd(Ⅱ)的强化去除机制.结果表明,在pH=6,Cd(Ⅱ)初始浓度为50mg/L,温度为30℃,nZVI投加量为0.1g/L的条件下反应180min后,Cd(Ⅱ)的去除率可达到99.5%以上.联合体系对Cd(Ⅱ)的去除过程符合准二级动力学,主要去除机制为白腐菌对Cd(Ⅱ)的胞外络合吸附,添加n ZVI能促进白腐菌对Cd(Ⅱ)的胞外吸附,FTIR和XPS分析表明,羟基、羧基和氨基参与了Cd(Ⅱ)的吸附,白腐菌胞外聚合物(EPS)能与铁发生内层配位形成P-O-Fe键,加速富含羟基官能团的纤铁矿、磁铁矿等铁矿物形成,从而促进对溶液中Cd(Ⅱ)的吸附去除.
A combined system of white rot fungus and nanoscale zero-valent iron(nZVI) was used to enhance the removal of Cd(Ⅱ)from water. The effects of pH, Cd(Ⅱ) initial concentration, temperature and nZVI dosage on Cd(Ⅱ) removal were examined, and the impact of nZVI on intracellular and extracellular accumulation of cadmium by white rot fungus was investigated. The removal mechanism was analyzed by scanning electron microscopy(SEM), Fourier-transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS) and three-dimensional excitation emission matrix fluorescence spectroscopy(3D-EEM). The results showed that the removal efficiency of 50mg/L Cd(Ⅱ) reached 99.5% after 180 minutes at the conditions of pH 6, nZVI dosage of 0.1g/L and 30℃. The removal process of Cd(Ⅱ) was found to follow the pseudo second-order kinetic model, and the extracellular adsorption by white rot fungus accounted for the main removal. The addition of nZVI promoted the extracellular adsorption of Cd(Ⅱ)by white rot fungus. FTIR and XPS analysis showed that the hydroxyl, carboxyl and amino were involved in the adsorption of Cd(Ⅱ),and the extracellular polymeric substances(EPS) of white-rot fungus could coordinate with iron in the inner layer to form a P-O-Fe bond, accelerating the formation of iron minerals such as lepidocrocite and magnetite that are rich in hydroxyl functional groups,thereby promoting the adsorption and removal of Cd(Ⅱ) from the solution.
作者
曾峤婧
周鑫
黄超
王平
程豪
郑小雨
王梦欣
刘昊
ZENG Qiao-jing;ZHOU Xin;HUANG Chao;WANG Ping;CHENG Hao;ZHENG Xiao-yu;WANG Meng-xin;LIU Hao(College of Environmental Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China;Hunan Engineering Laboratory for Control of Rice Quality and Safety,Changsha 410004,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2022年第7期3174-3183,共10页
China Environmental Science
基金
国家自然科学基金资助项目(51809293)
中国博士后基金面上资助项目(2018M633004)
湖南省教育厅优秀青年基金资助项目(19B588)
湖南省重点研发计划(2019SK2191)
湖南省高新技术产业科技创新引领计划(2020SK2039)
湖南省大学生创新创业训练计划(湘教通[2021]197号)。
关键词
白腐菌
纳米零价铁
胞外聚合物
镉
white rot fungus
nanoscale zero-valent iron
extracellular polymeric substances
cadmium
