State International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, MOE Key Lab of Northwest Water Resource, Environment and Ecology, Shaanxi Provincial Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Provincial Key Lab of Environmental Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi 9808579, Japan.
State International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, MOE Key Lab of Northwest Water Resource, Environment and Ecology, Shaanxi Provincial Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Provincial Key Lab of Environmental Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China.
J Hazard Mater. 2024 Dec 5;480:136119. doi: 10.1016/j.jhazmat.2024.136119. Epub 2024 Oct 10.
Heavy metals contained in waste activated sludge (WAS), especially zinc ions, have an inhibitory effect on the anaerobic digestion. However, the effects of zinc ions on digester performance, antibiotic resistance genes (ARGs) reduction, and the microbial community involved in the anaerobic mesophilic co-digestion (AcoD) of WAS and food waste (FW) have not been fully characterized. Therefore, batch trials and continuous stirred tank reactors were used under different zinc-ion concentrations. Findings showed that the AcoD system can tolerate a maximum zinc ion of 540 mg/L in a short-term batch and 470 mg/L in a long-term AcoD system, promoting methane production of approximately 1.0-17.0 %. Metagenomic analysis revealed that syntrophic H transfer occurred between Syntrophomonas and Methanoculleus and the aceticlastic and hydrogenotrophic methanogenic pathways were both enhanced by 1.18- and 1.16 times, respectively. Moreover, the relative abundance of Methanosarcina increased from 58.4 % to 72.5 % at 470 mg/L to adapt to the high zinc ion concentration during long-term continuous operation. These results revealed that AcoD with a low zinc ion concentration can effectively increase the removal percentage of ARGs. The results provide guidance for biogas recovery and use of mesophilic AcoD with FW and WAS containing high zinc ion concentrations without pretreatment process.
废活性污泥（WAS）中含有的重金属，特别是锌离子，对厌氧消化有抑制作用。然而，锌离子对消化器性能、抗生素抗性基因（ARGs）减少以及参与 WAS 和食物废物（FW）的厌氧中温共消化（AcoD）的微生物群落的影响尚未得到充分表征。因此，在不同锌离子浓度下使用批试验和连续搅拌罐反应器进行了研究。研究结果表明，AcoD 系统在短期批处理中可以耐受高达 540mg/L 的最大锌离子浓度，在长期 AcoD 系统中可以耐受 470mg/L 的最大锌离子浓度，促进甲烷产量约为 1.0-17.0%。宏基因组分析显示，Syntrophomonas 和 Methanoculleus 之间发生了共氢转移，并且乙酸营养型和氢营养型产甲烷途径分别增强了 1.18 倍和 1.16 倍。此外，在 470mg/L 时，Methanosarcina 的相对丰度从 58.4%增加到 72.5%，以适应长期连续运行过程中高锌离子浓度。这些结果表明，在低锌离子浓度下进行 AcoD 可以有效地提高 ARGs 的去除百分比。这些结果为沼气回收和利用含高锌离子浓度的 FW 和 WAS 进行中温 AcoD 提供了指导，无需预处理过程。
