College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
Yunnan Provincial Key Laboratory of Rural Energy Engineering, Kunming, 650500, China.
Bioprocess Biosyst Eng. 2024 Mar;47(3):417-427. doi: 10.1007/s00449-024-02974-w. Epub 2024 Feb 29.
The anaerobic treatment of sulfide-containing organic wastewater (SCOW) is significantly affected by pH, causing dramatic decrease of treatment efficiency when pH deviates from its appropriate range. Fe has proved as an effective strategy on mitigating the impact of pH. However, systematic analysis of the influence mechanism is still lacking. To fill this gap, the impact of different initial pH values on anaerobic treatment efficiency of SCOW with Fe addition, the change of fermentation type and methanogens, and intra-extracellular electron transfer were explored in this study. The results showed that Fe addition enhanced the efficacy of anaerobic treatment of SCOW at adjusted initial pH values, especially at pH 6. Mechanism analysis showed that respiratory chain-related enzymes and electron shuttle secretion and resistance reduction were stimulated by soluble iron ions generated by Fe at pH 6, which accelerated intra-extracellular electron transfer of microorganisms, and ultimately alleviated the impact of acidic pH on the system. While at pH 8, Fe addition increased the acetogenic bacteria abundance, as well as optimized the fermentation type and improved the F420 coenzyme activity, resulting in the enhancement of treatment efficiency in the anaerobic system and remission of the effect of alkaline pH on the system. At the neutral pH, Fe addition had both advantages as stimulating the secretion of respiratory chain and electron transfer-related enzymes at pH 6 and optimizing the fermentation type pH 8, and thus enhanced the treatment efficacy. This study provides important insights and scientific basis for the application of new SCOW treatment technologies.
含硫有机废水（SCOW）的厌氧处理受 pH 值影响显著，当 pH 值偏离适宜范围时，处理效率会大幅下降。铁已被证明是缓解 pH 值影响的有效策略。然而，其影响机制的系统分析仍存在不足。为了填补这一空白，本研究探讨了不同初始 pH 值对添加铁的 SCOW 厌氧处理效率、发酵类型和产甲烷菌变化以及胞内外电子传递的影响。结果表明，添加铁可增强调整初始 pH 值下 SCOW 的厌氧处理效果，尤其是在 pH 值为 6 时。机理分析表明，铁在 pH 值为 6 时生成的可溶性铁离子刺激了呼吸链相关酶和电子穿梭体的分泌以及电子还原抗性的降低，从而加速了微生物的胞内外电子传递，最终缓解了酸性 pH 值对系统的影响。而在 pH 值为 8 时，添加铁增加了产乙酸菌的丰度，优化了发酵类型并提高了 F420 辅酶活性，从而提高了厌氧系统的处理效率，并缓解了碱性 pH 值对系统的影响。在中性 pH 值下，添加铁同时具有在 pH 值为 6 时刺激呼吸链和电子传递相关酶的分泌以及在 pH 值为 8 时优化发酵类型的优势，从而增强了处理效果。本研究为新型 SCOW 处理技术的应用提供了重要的见解和科学依据。
