Regional-scale investigation of salt ions distribution characteristics in bauxite residue: A case study in a disposal area

赤泥堆场盐分分布及其盐碱土特性（英文）

Revegetation on bauxite residue disposal areas is the most promising strategy to reduce its potential ecological risk during stacking or disposing.Migration of salt ions in bauxite residue is one of the major issues to stimulate soil formation to support plant growth.21 residue samples were collected and the related parameters including exchangeable cations,soluble ions,total salt,pH,electrical conductivity(EC)and exchangeable sodium percentage(ESP)were selected to evaluate alkalization and salinization of bauxite residue.High levels of ions,cation exchange capacity(TOC),total salt,exchangeable sodium percentage(ESP)and cation exchange capacity(CEC)in bauxite residue were detected with greater coefficient of variation(CV),which indicated that distribution characteristics of salt ions varied significantly.The percentage of sulfate-chloride-soda type in the residues accounted for 71.43%.The mean value of pH was 10.10,whilst mean value of ESP was 52.05%.It indicated that the residues in this case study belonged to sulfate-chloride-soda saline and alkaline soil.The research results could provide theoretical basis for soil formation in bauxite residue.

盐分迁移转化是赤泥土壤化处置的主要影响因素之一。通过对堆场赤泥盐碱参数的测定,分析堆场赤泥盐分分布及其盐碱土特性。结果表明:赤泥总盐含量、主要盐分离子含量、交换性钠离子比、阳离子交换量的变异系数较大,赤泥堆场盐分分布具有显著性差异;赤泥总盐含量均值为9.61 g/kg,具有盐土类型特征,且以硫酸盐-氯化物-苏打型为主,占比达到71.43%;赤泥pH均值为10.10,可交换钠离子比均值为52.05%,具有碱土类型特征。研究结果为赤泥盐碱调控及土壤化处置提供了理论依据。