Onodera Takashi, Takemura Yasuyuki, Aoki Masataka, Syutsubo Kazuaki
Regional Environment Conservation Division, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan E-mail:
Regional Environment Conservation Division, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan; Present address Department of Civil Engineering, National Institute of Technology, Wakayama College, 77 Noshima, Nada, Gobo, Wakayama 644-0023, Japan.
Water Sci Technol. 2024 Dec;90(11):3029-3040. doi: 10.2166/wst.2024.383. Epub 2024 Nov 22.
Anaerobic treatment of sulfur-rich wastewater is challenging because sulfide greatly inhibits the activity of anaerobic microorganisms, especially methanogenic archaea. We developed an internal phase-separated reactor (IPSR) that removed sulfide prior to methanogenesis by gas stripping using biogas produced in the reactor. The IPSR was fed with synthetic wastewater containing a very high sulfide concentration of up to 6,000 mg S L with a chemical oxygen demand (COD) of 30,000 mg L. The IPSR was operated at an organic loading rate of 5-12 kg COD m day at 35 °C. The results show that the sulfide concentration was reduced from 6,000 mg S L in the influent to <700 mg S L in the first-stage effluent. The second-stage effluent contained <400 mg S L. As a result of effective sulfide removal by its gas stripping function, the IPSR had a COD removal efficiency of >90% over the entire experimental period. High-throughput 16S rRNA gene sequencing revealed that the major anaerobic archaea were Methanobacterium and Methanosaeta, which are frequently found in high-rate anaerobic reactors. Thus, the IPSR maintains these microorganisms and achieves high-process performance even when fed wastewater with very high sulfide concentrations
富含硫的废水的厌氧处理具有挑战性，因为硫化物会极大地抑制厌氧微生物的活性，尤其是产甲烷古菌。我们开发了一种内部分相反应器（IPSR），该反应器利用反应器中产生的沼气通过气提在产甲烷之前去除硫化物。IPSR 被投喂含有高达 6000 mg S/L 的非常高硫化物浓度且化学需氧量（COD）为 30000 mg/L 的合成废水。IPSR 在 35℃下以 5-12 kg COD/m²·天的有机负荷率运行。结果表明，硫化物浓度从进水的 6000 mg S/L 降低到一级出水的<700 mg S/L。二级出水含有<400 mg S/L。由于其气提功能有效地去除了硫化物，IPSR 在整个实验期间的 COD 去除效率>90%。高通量 16S rRNA 基因测序表明，主要的厌氧古菌是甲烷杆菌属和甲烷八叠球菌属，它们在高速厌氧反应器中经常被发现。因此，即使投喂硫化物浓度非常高的废水，IPSR 也能维持这些微生物并实现高工艺性能。
