Characterization of Pb2+ biosorption by psychrotrophic strain Pseudomonas sp. I3 isolated from permafrost soil of Mohe wetland in Northeast China. (1st July 2017)

• Record Type: Journal Article
• Authors: Li, Dandan; Xu, Xingjian; Yu, Hongwen; Han, Xuerong
• Is Part Of: Journal of environmental management. Volume 196(2017)
• Page Start: 8
• Page End: 15
• Publication Date: 2017-07-01
• Subjects: Pseudomonas sp. -- Biosorption -- Bioaccumulation -- Pb -- Psychrotrophic bacterium -- Metal resistance; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2017.02.076
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Due to the long and severe winter in Northeast China, wastewater containing lead (Pb) is treated inefficiently, resulting in irregular disposal. In order to solve this problem, a Pb-resistant psychrotrophic bacterium, Pseudomonas sp. I3, was isolated from permafrost soil of Mohe wetland and served as biosorbent for Pb 2+ removal under 15 °C. The minimum inhibitory concentration of strain I3 for Pb 2+ was 7.5 mM, which was higher than that of Escherichia coli DH5α (1.5 mM). However, acid digestion results showed that these two bacteria had a comparable biosorption capacity for Pb 2+, suggesting no direct relationship between biosorption ability of bacteria and their metal-resistance. Acid digestion results also proved that intracellular Pb accumulation was mainly contributed to the distinct performance between living and non-living biosorbents, which was further confirmed by the analyses of TEM-EDS. Results of FTIR revealed that functional groups including CH2, CO, CN, NH, COO and SO3 were participated in the biosorption process of the tested biosorbents no matter bacteria were living or not. The effects of environmental factors including pH, temperature, biomass dose, operation time and initial Pb 2+ concentration were investigated through a batch of biosorption experiments. The equilibrium data for living and non-living biosorbent were well fitted to Langmuir model with their maximum Pb 2+ biosorption capacities of 49.48 and 42.37 mg/g, respectively. The kinetic data for each biosorbent were well described by pseudo-second order kinetic model. Overall, Pseudomonas sp. I3 seemed to be an effective biosorbent for cleansing Pb 2+ from contaminated wastewater at low temperature. Highlights: A Pb-resistant psychrotrophic bacterium, Pseudomonas sp. I3, was isolated from permafrost soil. Both living and non-living strain I3 had good abilities to remove Pb(II) under cold condition. No direct relationship between biosorption ability of bacteria and their metal resistance.