This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
第 34 卷第 3 期2020 年 6 月
南华大学学报(自然科学版)Journal of University of South China(Science and Technology)
(1. School of Resource Environment and Safety Engineering,University of South China,Hengyang,Hunan 421001,China;2. Hunan Nuclear Industry Center Laboratory,Changsha,Hunan 410100,
China;3. Hengyang Key Laboratory of Soil Contamination Control and Remediation,Hengyang,Hunan 421001,China)
Abstract:Through isolating and expanding soil microorganisms,then extracting their extra-cellular secretions,the effects of different temperature on soil bacterial extracellular poly-meric substances (SB-EPS) yield and soil bacterial yield were studied. Study on the effectof reaction time on U(VI) removal by SB-EPS in solution at different temperatures were
第 34 卷第 3 期 董雪洁等:土壤细菌胞外聚合产物对溶液中 U(VI)的去除动力学研究
performed. Dynamics are analyzed using pseudo first-order kinetic equations and pseudosecond-order kinetic equations. The results showed that it was better to culture soil microor-ganisms and extract SB-EPS at 303 K. At temperatures of 298 K,308 K,and 318 K,theSB-EPS removed U(VI) reached a reaction equilibrium in about 120 minutes,and the e-quilibrium removal amounts were 4. 97 mg / g,8. 75 mg / g,and 6. 96 mg / g. The pseudo-second-order kinetic equation can better describe the reaction process than the pseudo-first-order kinetic equation,which indicates that the removal of U(VI) by the extracellularpolymeric products of soil bacteria is a chemical mechanism-based reaction.key words:soil bacteria;extracellular polymeric substances;uranium;kinetic analysis
0 引 言
铀是自然界中原子量最大的元素,随着核技
术的快速发展,铀的应用越来越广泛。 铀资源的
采冶和利用过程中产生了大量的含铀工业废水,对生态环境造成的影响不容忽视[1]。 如何解决
土壤重金属污染一直是研究热点问题。 微生物修
复土壤重金属污染因其经济、高效和无二次污染
等优势引发了关注[2]。胞外聚合产物 ( extracellular polymeric sub-
stances,EPS)是微生物在新陈代谢过程中产生的
成分复杂的生物聚合物质[3]。 EPS 的存在能保护
微生物,降低重金属对胞体的毒害[4]。 S. K. Kazy等人研究了铜绿假单胞菌胞外多糖结合铜,认为
参考文献:[1] PEREIRA W D S,KELECOM A G A C,DA SILVA A X,
et al. Assessment of uranium release to the environmentfrom a disabled uranium mine in Brazil[J]. Journal of en-vironmental radioactivity,2017,188:18-22.
[2] 刘家女,王文静. 微生物促进植物修复重金属污染土
壤机制研究进展[ J]. 安全与环境报,2016,16(5):290-297.
[3] SHENG G P,YU H Q,LI X Y. Extracellular polymericsubstances (EPS) of microbial aggregates in biologicalwastewater treatment systems:A review[J]. Biotechnologyadvances,2010,28(6):882-894.
[4] WEI X,FANG L,CAI P,et al. Influence of extracellularpolymeric substances (EPS) on Cd adsorption by bacteria[J]. Environmental pollution,2011,159(5):1369-1374.
[5] KAZY S K,SAR P,SINGH S P,et al. Extracellular poly-saccharides of a copper-sensitive and a copper-resistantPseudomonas aeruginosa strain:Synthesis,chemical natureand copper binding [ J]. World journal of microbiologyand biotechnology,2002,18(6):583-588.
[6] DANG C,YANG Z,LIU W,et al. Role of extracellular
polymeric substances in biosorption of Pb2+,by a highmetal ion tolerant fungal strain Aspergillus niger PTN31[ J ]. Journal of environmental chemical engineering,2018,6(2):2733-2742.
[7] CHUG R,GOUR V S,MATHUR S,et al. Optimization ofextracellular polymeric substances production using Azo-tobacter beijreinckii and Bacillus subtilis and its applica-tion in chromium (VI) removal[ J]. Bioresource tech-nology,2016,214:604-608.
法的比较[J]. 环境科学,2018,41(7):3306-3313.[13] LU M,ZHANG Y M,GUAN X H,et al. Thermodynamics
and kinetics of adsorption for heavy metal ions from a-queous solutions onto surface amino-bacterial cellulose[J]. Transactions of nonferrous metals society of China,2014,24(6):1912-1917.