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This content will become publicly available on November 21, 2018

Title: Modeling of Cd adsorption to goethite-bacteria composites

The accurate modeling of heavy metal adsorption in complex systems is fundamental for risk assessments in soils and associated environments. Bacteria-iron (hydr)oxide associations in soils and sediments play a critical role in heavy metal immobilization. The reduced adsorption of heavy metals on these composites have been widely reported using the component additivity (CA) method. However, there is a lack of a mechanism model to account for these deviations. In this study, we established models for Cd adsorption on goethite-Pseudomonas putida composites at 1:1 and 5:1 mass ratios. Cadmium adsorption on the 5:1 composite was consistent with the additivity method. But, the CA method over predicted Cd adsorption by approximately 8% on the 1:1 composite at high Cd concentration. The deviation was corrected by adding the site blockage reactions between P. putida and goethite. Both CA and “CA-site masking” models for Cd adsorption onto the composites were in line with the ITC data. These results indicate that CA method in simulating Cd adsorption on bacteria-iron oxides composites is limited to low bacterial and Cd concentrations. Thus the interfacial complexation reactions that occur between iron (hydr)oxides and bacteria should be taken into account when high concentrations of bacteria and heavy metals aremore » present.« less
Authors:
 [1] ;  [1] ;  [2] ;  [1] ;  [3] ;  [4] ; ORCiD logo [1]
  1. Huazhong Agricultural Univ., Wuhan (China). State Key Lab. of Agricultural Microbiology, Key Lab. of Arable Land Conservation
  2. Huazhong Agricultural Univ., Wuhan (China). State Key Lab. of Agricultural Microbiology
  3. Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Earth and Biological Sciences Directorate
  4. Huazhong Agricultural Univ., Wuhan (China). Key Lab. of Arable Land Conservation
Publication Date:
Grant/Contract Number:
41230854; 2662015PY016; 2662015PY116; AC0576RL01830
Type:
Accepted Manuscript
Journal Name:
Chemosphere
Additional Journal Information:
Journal Volume: 193; Journal Issue: C; Journal ID: ISSN 0045-6535
Publisher:
Elsevier
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; bacteria; cadmium; composite; geothite; modeling
OSTI Identifier:
1413472