摘要
The processes involved in the major steps of successful revegetation of bauxite residues are examined.The first phase is the natural physical,chemical and microbial ripening of the profile.This involves allowing the profile to drain,dry,shrink and crack to depth,leaching of soluble salts,alkalinity and Na down out of the surface layers,acidification by direct carbonation and natural seeding of tolerant vegetation with an accumulation of organic matter near the surface and an attendant development of an active microbial community.Following ripening,the surface layer can be tilled and gypsum and organic matter(e.g.manures,composts,biosolids)incorporated.These amendments result in a further decrease in pH,increase in Ca and other exchangeable cations,increased leaching of Na(with a reduction in exchangeable Na and ESP),improved physical properties,particularly aggregation,and a large increase in microbial activity.Other important considerations include the choice of suitable plant species tolerant to salinity/sodicity and local environmental conditions and the addition of balanced fertilizer applications.
本文探讨了赤泥堆场生态修复的主要过程。第一个重要过程就是赤泥物理、化学和微生物特性的自然熟化,主要包括:允许剖面排水、干燥、收缩和开裂至一定的深度;表面层可溶性盐、碱和钠的向下溶淋,并通过直接碳酸化进行酸化;抗性植被的自然播种、表层附近有机质的富集以及随之而产生的活性微生物群落的形成。堆场赤泥熟化后,表层施用石膏和有机特质(如粪肥、堆肥、生物固形物),这些改良剂的添加会进一步降低pH,提高钙和其他可交换阳离子的水平,促进钠的溶淋(降低可交换钠离子和ESP),改善赤泥的物理性质、提高微生物的活性。其他重要因素还包括选择合适的耐盐、耐碱及适应当地环境条件的植物种类、施用合适的肥料等。
