Abstract

The acid mine drainage (AMD) can causes negative impacts to the environment. Physico-chemical methods to treat AMD can have high operational costs. Through passive biological methods, such as anaerobic reactors, sulfate reduction, and recovery of metals are promoted. This study evaluated the performance of a horizontal anaerobic immobilized biomass (HAIB) reactor for the treatment of synthetic AMD using polyurethane foam as support material, and anaerobic sludge as inoculum. Ethanol was used as an electron donor for sulfate reduction, resulting in an influent chemical oxygen demand (COD) in the range of 500–1,500 mg/L and COD/sulfate ratio at 1. A gradual increase of sulfate and COD concentration was applied that resulted in COD removal efficiencies higher than 78%, and sulfate removal efficiencies of 80%. Higher sulfate and COD concentrations associated with higher hydraulic retention times (36 h) proved to be a better strategy for sulfate removal. The HAIB reactor was able to accommodate an increase in the SLR up to 2.25 g SO₄²⁻/L d⁻¹ which achieved the greatest performance on the entire process. Moreover, the reactor proved a suitable alternative for reaching high levels of metal removal (86.95 for Zn, 98.79% for Fe, and 99.59% for Cu).

摘要

酸性矿山排水（AMD）会对环境造成负面影响。治疗AMD的物理化学方法的运营成本可能很高。通过被动生物方法，例如厌氧反应器，促进了硫酸盐的还原和金属的回收。这项研究评估了卧式厌氧固定生物质（HAIB）反应器在以聚氨酯泡沫为载体材料，以厌氧污泥为接种物的情况下处理合成AMD的性能。乙醇用作硫酸盐还原的电子供体，导致进水化学需氧量（COD）在500–1,500 mg / L的范围内，COD /硫酸盐比为1。逐渐增加硫酸盐和COD的浓度，导致COD去除效率高于78％，硫酸盐去除效率达到80％。较高的硫酸盐和COD浓度以及较高的水力停留时间（36小时）被证明是一种较好的硫酸盐去除策略。HAIB反应器能够容纳高达2.25 g SO的SLR增加₄ ^2- / L d ^-1在整个过程中获得了最佳性能。此外，该反应器被证明是实现高水平金属去除的合适选择（锌为86.95，铁为98.79％，铜为99.59％）。