School of Earth and Environment, University of Western Australia , 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
Environ Sci Technol. 2013;47(21):12089-96. doi: 10.1021/es402924g. Epub 2013 Oct 24.
The spontaneous colonization of a bauxite residue (alumina refining tailings) deposit by local vegetation in Linden, Guyana, over 30 years, indicates that natural weathering processes can ameliorate tailings to the extent that it can support vegetation. Samples were collected from vegetated and unvegetated areas to investigate the relationships between bauxite residue properties and vegetation cover. Compared to unvegetated areas, bauxite residue in vegetated areas had lower pH (mean pH 7.9 vs 10.9), lower alkalinity (mean titratable alkalinity 0.4 vs 1.4 mol H(+) kg(-1)), lower electrical conductivity (mean EC 0.3 vs 2.1 mS cm(-1)), lower total Al (mean Al2O3 19.8 vs 25.8% wt) and Na (mean Na2O 0.9 vs 3.7% wt), and less sodalite and calcite. Accumulation of N, NH4(+), and organic C occurred under vegetation, demonstrating the capacity for plants to modify residue to suit their requirements as a soil-like growth medium. Aeolian redistribution of coarse grained tailings appeared to support vegetation establishment by providing a thin zone of enhanced drainage at the surface. Natural pedogenic processes may be supplemented by irrigation, enhanced drainage, and incorporation of sand and organic matter at other tailings deposits to accelerate the remediation process and achieve similar results in a shorter time frame.
圭亚那林登的一处铝土矿残渣（氧化铝精炼尾矿）矿床在 30 多年间自然被当地植被定殖，表明自然风化过程可以改善尾矿，使其足以支持植被生长。采集了植被覆盖区和无植被覆盖区的样本，以研究铝土矿残渣特性与植被覆盖之间的关系。与无植被覆盖区相比，植被覆盖区的铝土矿残渣具有更低的 pH 值（平均值 pH 7.9 对 10.9）、更低的碱度（平均值可滴定碱度 0.4 对 1.4 mol H(+) kg(-1)）、更低的电导率（平均值 EC 0.3 对 2.1 mS cm(-1)）、更低的总铝（平均值 Al2O3 19.8 对 25.8% wt）和钠（平均值 Na2O 0.9 对 3.7% wt），以及更少的钠沸石和方解石。在植被下，氮、NH4(+)和有机碳的积累表明植物有能力改变残渣以适应其作为土壤状生长介质的要求。粗粒尾矿的风成再分配似乎通过在表面提供增强排水的薄带，支持植被的建立。自然成土过程可以通过灌溉、增强排水以及在其他尾矿库中添加沙子和有机物来补充，以加速修复过程并在更短的时间内取得类似的结果。
