北京大学学报(自然科学版)

• 北京大学学报 •

细菌对铅和铬在多孔介质中迁移行为的影响

原野;蔡荔;童美萍   

  1. 北京大学环境科学与工程学院, 北京 100871;
  • 收稿日期:2014-01-12 修回日期:2014-02-23 出版日期:2015-05-20 发布日期:2015-05-20
  • 通讯作者: 童美萍 tongmeiping@pku.edu.cn

Influence of Bacteria on the Transport Behaviors of Lead and Chromium in Porous Media

YUAN Ye;CAI Li;TONG Meiping   

  1. College of Environmental Sciences and Engineering, Peking University, Beijing 100871;
  • Received:2014-01-12 Revised:2014-02-23 Online:2015-05-20 Published:2015-05-20
  • Contact: TONG Meiping tongmeiping@pku.edu.cn

摘要: 选用石英砂和载铁石英砂两种介质模拟环境介质, 以大肠杆菌C3000 为代表细菌, 考察细菌对Pb(Ⅱ) 和Cr(Ⅵ)迁移行为的影响。研究发现, Pb(Ⅱ)和Cr(Ⅵ)在载铁石英砂中迁移的阻滞系数(分别为4.793 和 1.212)分别大于在石英砂中的阻滞系数(1.145 和0.427), 表明Pb(Ⅱ)和Cr(Ⅵ)在载铁石英砂中的迁移能力低于其在石英砂中的迁移。在石英砂中, Pb(Ⅱ)和Cr(Ⅵ)在无细菌时迁移的阻滞系数(分别为1.145 和0.427)与有细菌时迁移的阻滞系数(1.230 和0.369)相近, 表明Pb(Ⅱ)和Cr(Ⅵ)的迁移不受共存细菌的影响。在载铁石英砂中, Pb(Ⅱ)在有细菌时迁移的阻滞系数(6.360)明显大于其在无细菌时的阻滞系数(4.793), 而Cr(Ⅵ)在有细菌时迁移的阻滞系数(1.212)与其在无细菌时的阻滞系数(1.037)相近, 表明细菌的存在会抑制Pb(Ⅱ)的迁移, 而对Cr(Ⅵ)的迁移不产生影响。研究结果可为预测重金属在土壤地下水中的迁移行为提供理论依据。

关键词: 铅, 铬, 迁移, 饱和多孔介质, 细菌

Abstract: Escherichia coli C3000 was selected as model bacteria to evaluate the influence of bacteria on the transport of lead and chromium in two types of porous media (bare quartz sand and iron-oxide coated quartz sand (IOCS)). Experimental results showed that the retardation factors of lead and chromium in iron oxide-coated sand (4.793 for lead and 1.212 for chromium) are much greater than those in bare quartz sand (1.145 for lead and 0.427 for chromium), indicating that the transport of lead and chromium was lower in IOCS than that in bare quartz sand. In bare quartz sand, the retardation factors of lead and chromium in the absence of bacteria (1.145 for lead and 0.427 for chromium) are similar as those in the presence of bacteria (1.230 for lead and 0.369 for chromium), demonstrating that the transport of lead and chromium were not affected by the presence of bacteria; however, in IOCS, the retardation factor of lead in the presence of bacteria (6.360) is much larger than that in the absence of bacteria (4.793), whereas, the retardation factor of chromium in the presence of bacteria (1.212) is similar as that in the absence of bacteria (1.037). The results indicated that the presence of bacteria inhibited the transport of lead, whereas, the transport of chromium was yet not affected by the presence of bacteria in IOCS. These findings will help to predict the transport of heavy metals in variable soils and subsurface environment.

Key words: lead, chromium;transport;saturated porous media;bacteria