title: Effects of biochars on the availability of heavy metals to ryegrass in an alkaline contaminated soil.
abstract: A pot experiment was conducted to investigate the effects of biochars on the availability of heavy metals (Cd, Cu, Mn, Ni, Pb, and Zn) to ryegrass in an alkaline contaminated soil. Biochars only slightly decreased or even increased the availability of heavy metals assesses by chemical extractant (a mixture of 0.05 mol L-1ethylenediaminetetraacetic acid disodium, 0.01 mol L-1CaCl2, and 0.1 mol L-1triethanolamine). The significantly positive correlation between most chemical-extractable heavy metals and the ash content in biochars indicated the positive role of ash in this extraction. Biochars significantly reduced the plant uptake of heavy metals, excluding Mn. The absence of a positive correlation between the chemical-extractable heavy metals and the plant uptake counterparts (except for Mn) indicates that chemical extractability is probably not a reliable indicator to predict the phytoavailability of most heavy metals in alkaline soils treated with biochars. The obviously negative correlation between the plant uptake of heavy metals (except for Mn) and the (O + N)/C and H/C indicates that biochars with more polar groups, which were produced at lower temperatures, had higher efficiency for reducing the phytoavailability of heavy metals. The significantly negative correlations between the plant uptake of Mn and ryegrass biomass indicated the "dilution effect" caused by the improvement of biomass. These observations will be helpful for designing biochars as soil amendments to reduce the availability of heavy metals to plants in soils, especially in alkaline soils.
authors.affiliation: College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan, 030024, Shanxi Province, China.
authors.forename: Guixiang
authors.initials: G
authors.lastname: Zhang
authors.affiliation: College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan, 030024, Shanxi Province, China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Guo
authors.affiliation: College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan, 030024, Shanxi Province, China.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan, 030024, Shanxi Province, China. Electronic address: heqs@tyust.edu.cn.
authors.forename: Qiusheng
authors.initials: Q
authors.lastname: He
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China; Analytical and Testing Center, Beijing Normal University, Beijing, 100875, China.
authors.forename: Shuifeng
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Environment and Resources, Shanxi University, Taiyuan, 030006, Shanxi Province, China.
authors.forename: Yuen
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan, 030024, Shanxi Province, China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
authors.forename: Xitao
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China. Electronic address: sunke@bnu.edu.cn.
authors.forename: Ke
authors.initials: K
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan, 030024, Shanxi Province, China.
authors.forename: Tianwei
authors.initials: T
authors.lastname: Qian
mesh_terms: D002606:Charcoal / Q000737:chemistry*; D004787:Environmental Pollution / Q000032:analysis*; D052918:Environmental Restoration and Remediation / Q000379:methods; D008129:Lolium / Q000378:metabolism*; D019216:Metals, Heavy / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal
keywords: Alkaline soil; Biochar; Heavy metal; Phytoavailability; Remediation; Soil contamination