ABSTRACT

Acid mine drainage (AMD) has continued to be a major threat leading to the destruction of the ecosystem and contamination of soil and waterbodies. The high sulfate concentration of AMD lowers the soil pH, making the soil more acidic and less productive which contributes to a reduction in the availability of arable land for agricultural purposes. Biological treatment has offered a cost-effective and eco-friendly approach through the introduction of organic substrates, aeration, or genetically modified microorganism to stimulate the contaminated environment and enhance sulfate reduction as opposed to previously used physicochemical methods which were criticized due to their inefficient and non-ecofriendly nature. This study focused on the evaluation of biological treatment through the application of wastewater (biostimulation) and air-injection (bioventing) for sulfate removal from AMD-contaminated soils. AMD-contaminated soil was amended with brewery (BWW) and municipal wastewater (MWW) at varying loading ratios to investigate the possible synergy while atmospheric air was supplied to bioventing treatments only. All treatments were conducted at mesophilic conditions for 28 days. The inability to improve sulfate removal rate through air-injection can be attributed to biosulfidogenesis preference for anoxic as against (high) oxic conditions for optimum performance. The BST and BVT treatment resulted in 34–53% and 27–42% sulfate removal efficiency, respectively. This study showed the efficacy of wastewater biostimulations and bioventing as a promising approach for sulfate and heavy metal removal from AMD-contaminated soils. The techniques have the potentials as vital tools for the mitigation of pollution aftermath in affected communities.

摘要

酸性矿山排水 (AMD) 一直是导致生态系统破坏和土壤和水体污染的主要威胁。AMD 的高硫酸盐浓度降低了土壤的 pH 值，使土壤更酸、生产力更低，从而导致可耕地用于农业用途的减少。生物处理通过引入有机底物、曝气或转基因微生物来刺激受污染的环境并增强硫酸盐还原，提供了一种具有成本效益和生态友好的方法，这与以前使用的物理化学方法相反，后者因效率低下而受到批评。不环保的性质。本研究的重点是通过应用废水（生物刺激）和空气注入（生物通风）从 AMD 污染的土壤中去除硫酸盐来评估生物处理。AMD 污染的土壤用啤酒厂 (BWW) 和市政废水 (MWW) 以不同的负载比进行修正，以研究可能的协同作用，而大气仅用于生物通风处理。所有处理均在中温条件下进行 28 天。无法通过空气注入提高硫酸盐去除率可归因于生物硫化偏爱缺氧而不是（高）有氧条件以获得最佳性能。BST 和 BVT 处理分别导致 34-53% 和 27-42% 的硫酸盐去除效率。这项研究表明，废水生物刺激和生物通风的功效是从 AMD 污染的土壤中去除硫酸盐和重金属的一种有前途的方法。这些技术有可能成为减轻受影响社区污染后果的重要工具。