Sulfur-modified organoclay promotes plant uptake and affects geochemical fractionation of mercury in a polluted floodplain soil

Jianxu Wang; Sabry M Shaheen; Ann-Christin Swertz; Thilo Rennert; Xinbin Feng; Jörg Rinklebe

doi:10.1016/j.jhazmat.2019.03.010

Sulfur-modified organoclay promotes plant uptake and affects geochemical fractionation of mercury in a polluted floodplain soil

J Hazard Mater. 2019 Jun 5:371:687-693. doi: 10.1016/j.jhazmat.2019.03.010. Epub 2019 Mar 4.

Authors

Jianxu Wang¹, Sabry M Shaheen², Ann-Christin Swertz³, Thilo Rennert⁴, Xinbin Feng⁵, Jörg Rinklebe⁶

Affiliations

¹ State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550082 Guiyang, PR China; University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, PR China. Electronic address: wangjianxu@vip.gyig.ac.cn.
² University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; University of Kafrelsheikh, Faculty of Agriculture, Department of Soil and Water Sciences, 33516 Kafr El-Sheikh, Egypt; King Abdulaziz University, Faculty of Meteorology, Environment, and Arid Land Agriculture, Department of Arid Land Agriculture, Jeddah 21589, Saudi Arabia. Electronic address: shaheen@uni-wuppertal.de.
³ University of Wuppertal, Faculty of Mechanical Engineering and Safety Engineering, Department of Safety Technology and Environmental Protection, Rainer-Gruenter-Straße, 42119 Wuppertal, Germany. Electronic address: swertz@uni-wuppertal.de.
⁴ Department of Soil Chemistry and Pedology, Institute of Soil Science and Land Evaluation, University of Hohenheim, Emil-Wolff-Str. 27, 70599 Stuttgart, Germany. Electronic address: t.rennert@uni-hohenheim.de.
⁵ State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550082 Guiyang, PR China. Electronic address: fengxinbin@vip.skleg.cn.
⁶ University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; University of Sejong, Department of Environment, Energy and Geoinformatics, 98 Gunja-Dong, Guangjin-Gu, Seoul, Republic of Korea. Electronic address: rinklebe@uni-wuppertal.de.

PMID: 30889465
DOI: 10.1016/j.jhazmat.2019.03.010

Abstract

We investigated effects of the application of a sulfur-modified organoclay (SMOC) at doses of 1%, 3% and 5% (w/w) on the geochemical fractionation of mercury (Hg) and its accumulation by pea and corn in a polluted floodplain soil. Soil Hg was fractionated sequentially to five operationally defined fractions as follows: F1: water soluble Hg; F2: "human stomach acid" soluble Hg; F3: organo-chelated Hg; F4: elemental Hg; and F5: Hg-sulfur-compounds/residual Hg. The high dosage of SMOC caused a decrease of Hg in F3 (18%) and F5 (36-63%), and 6.7 fold increase of Hg in the mobile fraction (MF = F1+F2) as compared to control soil. The transformation of Hg from F5 to the MF in SMOC-treated soil might be due to the associated decrease of soil pH. Pea accumulated more Hg than corn. Mercury contents were larger in roots than in shoots of both plants and increased significantly by a factor of up to 11 by SMOC addition. The potential transformation of Hg from the hardly soluble to the MF by SMOC addition and the associated increase of Hg accumulation by plants imply a great potential of the SMOC for enhancing Hg phytoremediation.

Keywords: Geochemical fractions; Hg bioavailability; Phytoremediation; Risk management.

Publication types

Research Support, Non-U.S. Gov't