Potassium lignosulfonate as a washing agent for remediating lead and copper co-contaminated soils

Qianjun Liu; Yu Deng; Jiepeng Tang; Di Chen; Xiang Li; Qintie Lin; Guangcai Yin; Min Zhang; Huawen Hu

doi:10.1016/j.scitotenv.2018.12.228

Potassium lignosulfonate as a washing agent for remediating lead and copper co-contaminated soils

Sci Total Environ. 2019 Mar 25:658:836-842. doi: 10.1016/j.scitotenv.2018.12.228. Epub 2018 Dec 15.

Authors

Qianjun Liu¹, Yu Deng², Jiepeng Tang², Di Chen², Xiang Li², Qintie Lin², Guangcai Yin², Min Zhang³, Huawen Hu³

Affiliations

¹ School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China. Electronic address: lqjzhch@gdut.edu.cn.
² School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
³ School of Materials Science and Energy Engineering, Foshan University, Foshan 528000, China.

PMID: 30583179
DOI: 10.1016/j.scitotenv.2018.12.228

Abstract

Lignin is a renewable aromatic polymer which is present in large quantities in the cell walls of terrestrial plants and is the main binding agent for fibrous plant components. Potassium lignosulfonate (KLS), as a by-product of pulping processes, can be applied to agricultural fields as a soil conditioner and chelate fertilizer. In this study, based on its solubility and complexing ability, batch washing and column leaching was explored to evaluate the potential application of KLS in the washing remediation of soil contaminated with lead and copper. Under optimum conditions KLS concentration of 8%, pH of 5.24 and 6 h duration, the removal ratios for the simulated and mining area soils in the batch experiment were 67.40% and 52.87% respectively, for Pb and 73.42% and 55.20% respectively, for Cu. In the column leaching experiment, the removal efficiencies of Pb and Cu increased with solution volume and that the removal ratios of the simulated and mining area soils were 36.46% and 20.31%, respectively, for Pb and 39.74% and 22.76%, respectively, for Cu. KLS can reduce the ratio of acid-soluble and reducible fractions, which may have the most potential hazardous and poisonous for plants. Cation exchange capacity (CEC) and pH of soil were all stable after washing. However, the organic matter and available K, N, and P in the treated soil, which are important factors for plant growth increased significantly. This study showed that KLS can remove Pb and Cu from soil, while improve nutrient (ammonium nitrogen, available phosphorus and available potassium) levels of soil.

Keywords: Contaminated soil; Copper; Lead; Lignosulfonate; Washing.