Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Fujian Key Laboratory of Digital Technology for Territorial Space Analysis and Simulation, Fuzhou 350108, China.
Water Res. 2024 Dec 1;267:122477. doi: 10.1016/j.watres.2024.122477. Epub 2024 Sep 18.
To speed up reaching UN Sustainable Development Goal 6 for safe sanitation by 2030, integrating high-solid anaerobic digestion (HSAD) into decentralized systems could recycle fecal slag (FS) and food waste (FW), aiding a circular economy and toilet revolution. In this study, a percolate recirculation system and conductive material were used to improve mass transfer, stability, and enhance methane production in HSAD of FS and FW. This setup consists of a percolate tank and a digester tank, where nano-zero valent iron (nZVI) was dosed in the percolate tank (P) and the digester tank (P) and compared with a control with no additive (P). The highest cumulative methane yield of 519.43 mL/gVS was achieved in P, which was 4.52 and 3.59 times higher than that of P (144.59 mL/gVS) and P (114.96 mL/gVS). This finding demonstrates that the dosing strategy of P facilitated effective interaction among organic matter, microbial communities, and nZVI, resulting in organics removal efficiencies of 67.42 % (total solid) and 77.22 % (volatile solid). Moreover, microbial community analysis supported the efficacy of the P strategy, revealing the enrichment of Clostridium sensu stricto 1 (46.91 %), which potentially engaged in interspecies electron transport (Interspecies hydrogen transfer (IHT) and direct interspecies electron transfer (DIET)) with Methanobacterium (81.19 %) and Methanosarcina (17.11 %). These interactions contribute to enhanced methane yield and stability maintenance in the HSAD system with percolate recirculation. The findings of this study demonstrate that the implementation of HSAD of FS and FW, coupled with percolate recirculation and the addition of nZVI, holds promise for enabling sustainable sanitation practices in developing regions. Moreover, this approach not only facilitates resource recovery but also eliminates the requirement for water.
为了加快实现联合国可持续发展目标 6 中关于到 2030 年提供安全环境卫生设施的目标，将高固体厌氧消化（HSAD）纳入分散式系统可以回收粪便渣（FS）和食物垃圾（FW），助力循环经济和厕所革命。在这项研究中，采用渗滤液循环系统和导电材料来提高 FS 和 FW 的 HSAD 中的传质、稳定性，并提高甲烷产量。该系统由渗滤液罐和消化罐组成，纳米零价铁（nZVI）添加到渗滤液罐（P）和消化罐（P）中，并与未添加任何添加剂的对照组（P）进行了比较。P 中获得了最高的累积甲烷产量 519.43 mL/gVS，比 P（144.59 mL/gVS）和 P（114.96 mL/gVS）分别高出 4.52 倍和 3.59 倍。这一发现表明，P 的投加策略促进了有机物、微生物群落和 nZVI 之间的有效相互作用，导致总固体去除效率为 67.42%，挥发性固体去除效率为 77.22%。此外，微生物群落分析支持 P 策略的有效性，揭示了梭菌属（Clostridium sensu stricto 1）的富集（46.91%），其可能与产甲烷菌（Methanobacterium）（81.19%）和产甲烷八叠球菌属（Methanosarcina）（17.11%）进行种间电子传递（种间氢转移（IHT）和直接种间电子转移（DIET））。这些相互作用有助于提高 HSAD 系统中渗滤液循环的甲烷产量和稳定性。本研究结果表明，FS 和 FW 的 HSAD 与渗滤液循环和 nZVI 投加相结合，有望在发展中地区实现可持续的环境卫生实践。此外，这种方法不仅促进了资源回收，而且还省去了用水需求。
