School of Water Conservancy and Environment, University of Jinan, Jinan, 250022, China.
School of Water Conservancy and Environment, University of Jinan, Jinan, 250022, China.
J Environ Manage. 2024 Nov;370:123026. doi: 10.1016/j.jenvman.2024.123026. Epub 2024 Oct 23.
The filling substrate is one of key factors influencing effectiveness of sulfate reducing packed-bed bioreactor (SRPB) treating acid mine drainage (AMD). The effects of four substrates (i.e. quartz sand, steel residue, biochar, and peanut shell) on remediation performance and sulfur transformation of SRPB treating AMD was studied. The results showed that steel residue and biochar improved sulfate reduction efficiency (61% and 49%) compared to quartz sand (32%), whereas peanut shell inhibited sulfate reduction efficiency (19%), attributed to its decomposition process leading to a severe accumulation of acetic acid. More amounts of sulfides generated in steel residue bioreactor were converted into acid volatile sulfide and elemental sulfur, resulting in a significant decrease in dissolved sulfide in the effluent. Metals (Fe, Al, Zn, Cd and Cr) except for Mn were effectively immobilized in the bioreactors, particularly for Al and Cd. Sulfate reducing bacteria and sulfide oxidizing bacteria lived symbiotically in all bioreactors which exhibited similar heterogeneity in microbial distribution and function, i.e. bacterial sulfate reduction mainly occurring in bottom-middle layers and photoautotrophic sulfide oxidation in upper layer close to outlet. The microbial response mechanism to various substrate environments was revealed through co-occurrence networks analysis. This study suggests that attention should be paid to the inhibitory effect of acetic acid accumulation on sulfate reduction when using sole lignocellulosic waste (peanut shell), and steel residue and biochar could be utilized as filling substances to promote sulfate reduction.
填充底物是影响硫酸盐还原填充床生物反应器（SRPB）处理酸性矿山排水（AMD）效果的关键因素之一。本研究考察了四种底物（石英砂、钢渣、生物炭和花生壳）对 SRPB 处理 AMD 的修复性能和硫转化的影响。结果表明，与石英砂（32%）相比，钢渣和生物炭提高了硫酸盐还原效率（61%和 49%），而花生壳抑制了硫酸盐还原效率（19%），这归因于其分解过程导致乙酸严重积累。钢渣生物反应器中生成的更多硫化物转化为酸可挥发性硫化物和元素硫，导致流出物中溶解的硫化物显著减少。除 Mn 以外的金属（Fe、Al、Zn、Cd 和 Cr）在生物反应器中得到有效固定，特别是 Al 和 Cd。硫酸盐还原菌和硫化物氧化菌在所有生物反应器中共生，微生物分布和功能表现出相似的异质性，即细菌硫酸盐还原主要发生在中下层，靠近出口的上层进行光自养硫化物氧化。通过共同发生网络分析揭示了微生物对各种底物环境的响应机制。本研究表明，在使用单一木质纤维素废物（花生壳）时，应注意乙酸积累对硫酸盐还原的抑制作用，而钢渣和生物炭可用作填充物质来促进硫酸盐还原。
