Dynamic change and diagnosis of physical, chemical and biological properties in bauxite residue disposal areas

赤泥堆场土壤性状的动态变化及诊断研究（英文）

Vegetation encroachment occurred in bauxite residue disposal area(BRDA)following natural weathering processes,whilst the typical indicators of soil formation are still uncertain.Residue samples were collected from the BRDA in Central China,and related physical,chemical and biological indicators of bauxite residue with different storage years were determined.The indicators of soil formation in bauxite residue were selected using principal component analysis,factor analysis,and comprehensive evaluation to establish soil quality diagnostic index model on disposal areas.Following natural weathering processes,the texture of bauxite residue changed from silty loam to sandy loam.The pH and EC decreased,whilst porosity,nutrient element content and microbial biomass increased.The identified minimum data set(MDS)included available phosphorus(AP),moisture content(MC),C/N,sand content,total nitrogen(TN),microbial biomass carbon(MBC),and pH.The soil quality index of bauxite residue increased,and the relative soil quality index decreased from 1.89 to 0.15,which indicated that natural weathering had a significant effect on improveing the quality of bauxite residue and forming a new soil-like matrix.The diagnostic model of bauxite residue was established to provide data support for the regeneration on disposal area.

以华中某赤泥堆场为研究对象,分析不同堆存年限的赤泥物理、化学、生物学特性,运用主成分分析、综合评价法等方法建立赤泥堆场土壤质量诊断模型。结果表明:在自然风化过程中,赤泥质地由类粉质壤土转变为类砂质壤土,孔隙度增加,pH、EC降低,养分含量增加,微生物量碳(MBC)升高;确定的最小数据集(MDS)为:速效磷(AP)、含水率(MC)、C/N、砂粒含量、全氮(TN)、MBC、pH;建立了赤泥堆场土壤化诊断模型,随着赤泥堆存年限的延长,综合质量指数上升,相对质量指数从1.89下降到0.15,逐渐形成一种新的类土基质。赤泥堆场土壤化诊断模型的建立,为赤泥生态化处置及堆场生态修复提供理论依据。