School of Civil and Environmental Engineering, Nanyang Technological University, 639798 Singapore, Singapore; College of Environmental Science and Engineering, Tongji University, 200092 Shanghai, China.
School of Civil and Environmental Engineering, Nanyang Technological University, 639798 Singapore, Singapore.
Sci Total Environ. 2021 Apr 1;763:144550. doi: 10.1016/j.scitotenv.2020.144550. Epub 2020 Dec 18.
Freshwater sludge (FS) is generated in large quantities during the production of drinking water every day. It is largely underutilized, and has long been filter pressed to sludge cake and then disposed of in landfills. The search for more economical and sustainable disposal or reuse options is urgently needed. Biochar and hydrochar are increasingly popular wastes derived materials with huge potential for soil improvement, environmental remediation, and mitigation of climate change, but there is a lack of research on the production of FS derived biochar and hydrochar. In this study, biochar was produced by pyrolysis at 300, 500 or 700 °C for 1 h, and hydrochar was produced by hydrothermal carbonization (HTC) at 140, 160, 180 or 200 °C for 4 h. Proximate analyses show that the biochar has a higher carbon stability and is possibly suitable for carbon sequestration, while the hydrochar contains more labile carbon structures. The ultimate analysis indicates that the surface hydrophobicity is in the order of: biochar > hydrochar > FS. The phytotoxicity tests indicate their positive effects on germination of wheat seeds. This study provides a new treatment to reuse numerous FS and put forward the possible applications of its carbonaceous products, which is expected to facilitate a circular economy and realize the zero-waste target.
每天在生产饮用水的过程中会产生大量的淡水污泥（FS）。它的利用率很低，长期以来一直被压滤成污泥饼，然后被填埋处理。迫切需要寻找更经济和可持续的处置或再利用选择。生物炭和水热炭是越来越受欢迎的衍生废物材料，具有巨大的土壤改良、环境修复和减缓气候变化的潜力，但对于 FS 衍生生物炭和水热炭的生产研究还很少。在这项研究中，通过在 300、500 或 700°C 下热解 1 小时来生产生物炭，通过在 140、160、180 或 200°C 下进行水热碳化 (HTC) 4 小时来生产水热炭。 初步分析表明，生物炭具有更高的碳稳定性，可能适合碳封存，而水热炭则含有更多不稳定的碳结构。 最终分析表明，表面疏水性的顺序为：生物炭>水热炭>FS。 植物毒性测试表明它们对小麦种子发芽有积极影响。 本研究为再利用大量 FS 提供了一种新的处理方法，并提出了其碳素产品的可能应用，有望促进循环经济并实现零废物目标。
