China-UK Low-carbon College, Shanghai Jiao Tong University, Shanghai 200240, PR China.
School of Environmental Science and Engineering, State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Sci Total Environ. 2022 Jul 1;828:154440. doi: 10.1016/j.scitotenv.2022.154440. Epub 2022 Mar 8.
Food waste is a challenging biomass resource due to its high moisture content, low calorific value, and complex composition. Natural humification of animal and plant residues is highly related to microorganism activity, but natural hydrothermal conditions are also speculated to play a significant role. In this work, a novel method for the conversion of food waste into artificial humic acid (HA) under hydrothermal conditions is proposed. The results revealed that an optimum HA yield of 43.5% from food waste was successfully obtained at 215 °C for only 1 h. Detailed analyses, including elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and Fourier transform infrared (FT-IR) spectroscopy, showed that the produced HA had similar structures and compositions with natural HA extracted from minerals. Moreover, the proteins contained in the food waste significantly promoted HA formation through the reaction of saccharides with amino acids, in which Maillard-like reactions were the key steps. These results not only provide experimental evidence for verifying the role of hydrothermal reactions in transforming food waste into humic acid but also provide insight into effective resource utilization of food waste.
由于食物废弃物水分含量高、热值低且成分复杂，因此它是一种具有挑战性的生物质资源。动植物残体的自然腐殖化与微生物活性密切相关，但也有人推测自然水热处理条件也发挥了重要作用。在这项工作中，提出了一种在水热条件下将食物废弃物转化为人工腐殖酸（HA）的新方法。结果表明，在 215°C 仅 1 小时的条件下，成功获得了 43.5%的最佳食物废弃物 HA 产率。详细分析，包括元素分析（EA）、X 射线光电子能谱（XPS）、核磁共振（NMR）和傅里叶变换红外（FT-IR）光谱表明，所产生的 HA 与从矿物质中提取的天然 HA 具有相似的结构和组成。此外，食物废弃物中的蛋白质通过糖与氨基酸的反应显著促进了 HA 的形成，其中美拉德反应是关键步骤。这些结果不仅为验证水热反应在将食物废弃物转化为腐殖酸中的作用提供了实验证据，而且为有效利用食物废弃物提供了新的思路。
