生物炭对脱碱赤泥理化性质及环境风险的影响

Effect of Biochar on Physical and Chemical Properties and Environmental Risks of De-alkalized Red Mud

生物炭作为一种绿色环境修复材料,不仅可用于污泥等固体废物的减量化、资源化,而且在改良土壤条件和修复等方面有巨大潜力。为探究其对脱碱赤泥理化性质与环境风险的影响,该文采用慢速热解法制备生物炭,取用赤泥与酸性矿山废水反应得到的脱碱赤泥。以不同质量百分比在脱碱赤泥中添加生物炭进行培养,对培养后样品的理化性质进行分析与表征。结果表明,生物炭能为脱碱赤泥提供有机质,但存在时间较短;能使样品的pH升高,添加量越多pH越高;样品的电导率随生物炭添加量增加而增加,随培养时间增长而增加;能增加样品的稳定性,降低重金属离子的浸出浓度,对重金属离子有较好的固定能力;能使脱碱赤泥达到填埋要求,降低其环境风险。

Biochar,as a green environmental remediation material,can be used not only for the reduction and resource utilization of solid waste such as sludge,but also has great potential for improving soil conditions and remediation.To investigate its effects on the physicochemical properties and environmental risks of de-alkalized red mud,biochar was prepared by slow pyrolysis method,and the de-alkalized red mud obtained by reacting red mud with acid mine drainage(AMD)was taken.The biochar was added to the de-alkalized red mud at different mass percentages for incubation,and the physicochemical properties of the incubated samples were analyzed and characterized.The results showed that biochar could provide organic matter for the de-alkalized red mud,but the presence time was short;it could increase the pH of the samples,and the higher the addition amount,the higher the pH.The electrical conductivity(Ec)of the samples increased with the addition amount of biochar,and increased with the increase of incubation time;it could increase the stability of the samples,reduce the leaching concentration of heavy metal ions,and had better fixation ability for heavy metal ions.It could make the de-alkalized red mud meet landfill requirements and reduce its environmental risk.