摘要
铵氮在砷的生物地球化学循环过程中发挥着重要作用,但铵氮输入对藻类介导的As(Ⅲ)生物氧化机理尚不清楚.以固氮蓝藻鱼腥藻(Anabaena sp.)为研究对象,通过室内模拟实验,研究在不同浓度As(Ⅲ)条件下,鱼腥藻对As(Ⅲ)的毒性响应和氧化作用,并研究了外源铵氮输入对鱼腥藻的生长以及氧化As(Ⅲ)的影响.结果表明,鱼腥藻的半抑制浓度(IC_(50))值为15.59 mg/L,当As(Ⅲ)的浓度为0.1 mg/L、1 mg/L和10 mg/L时,分别在1 d、2 d和7 d内被完全氧化为As(V),并且随着As(Ⅲ)浓度增加,鱼腥藻的固氮作用增强.NH_(4)^(+)浓度在234 mg/L以内时,对鱼腥藻(Anabaena sp.)的生长有促进作用,随着NH_(4)^(+)浓度从0 mg/L增加至1 mg/L、45 mg/L和234 mg/L,1 mg/L As(Ⅲ)分别在48 h、36 h、24 h和12 h被完全氧化.随着NH_(4)^(+)浓度增加,鱼腥藻对砷的吸附量增加,As(Ⅲ)的氧化加速.研究结果有助于阐释天然水体中铵氮在砷生物转化过程中的作用.
Ammonium plays an important role in the biogeochemical cycle of arsenic,but the mechanism of ammonium input on algae-mediated As(Ⅲ)bio-oxidation remains unexplored.The arsenic-resistant cyanobacteria Anabaena sp.was used in this study.Through laboratory simulation experiments,the toxicity,oxidation of different As(Ⅲ)concentrations mediated by Anabaena sp.was investigated.The influences of the input of exogenous ammonium on the growth of Anabaena sp.and the oxidation of As(Ⅲ)were also explored.The results show that the IC_(50) value of Anabaena sp.was 15.59 mg/L,and 0.1 mg/L,1 mg/L and 10 mg/L As(Ⅲ)were completely oxidized to As(V)within 1 d,2 d and 7 d,respectively,after inoculating Anabaena sp.,With the concentration of As(Ⅲ)increased,the nitrogen fixation effect of Anabaena sp.is enhanced.Furthermore,the growth of Anabaena sp.was promoted within 234 mg/L NH_(4)^(+).With the increase of NH_(4)^(+)concentration from 0 mg/L to 1 mg/L,45 mg/L and 234 mg/L,1 mg/L As(Ⅲ)was completely oxidized at 48 h,36 h,24 h and 12 h,respectively,as the concentration of NH_(4)^(+)increases,the adsorption of Anabaena sp.to arsenic increases,and the oxidation of As(Ⅲ)accelerates.The research results help to interpret the role of ammonium nitrogen in the process of arsenic biotransformation in natural waters.
作者
钟兆淇
谢作明
毛青
赵欣鑫
刘太坤
Zhong Zhaoqi;Xie Zuoming;Mao Qing;Zhao Xinxin;Liu Taikun(School of Environmental Studies,China University of Geosciences,Wuhan 430078,China;State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430078,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2024年第5期1920-1930,共11页
Earth Science
基金
国家自然科学基金面上项目(Nos.41572230,41172219)
国家自然科学基金创新研究群体项目(No.41521001)。
关键词
鱼腥藻
亚砷酸盐
铵氮
毒性
氧化
吸附
地球化学
anabaena sp.
arsenite
ammonium
toxicity
oxidation
adsorption
geochemistry
