Key Laboratory of Development and Application of Rural Renewable Energy (Ministry of Agriculture and Rural Affairs), Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041, China; Research Center for Rural Energy and Ecology, Chinese Academy of Agricultural Science, Chengdu, 610041, China.
Tarim Oilfield Company, PetroChina, Korla, 841000, China.
Chemosphere. 2024 Sep;364:142979. doi: 10.1016/j.chemosphere.2024.142979. Epub 2024 Aug 3.
Wet distillers grains, as a waste biomass with a large annual output, pose a threat to the environment and food industry. Herein, artificial humic acid (AHA) was first produced from wet distillers grains in a dual-stage microwave-assisted hydrothermal process. The influence of temperature on AHA's characteristics was investigated and compared with natural humic acid (NHA) and standard humic acid (SHA). A high yield of AHA at 20.6% was obtained at 200 °C with a total reaction time of 1 h, which is 1.8-3.1 times that obtained in traditional single-stage hydrothermal process. Increasing the reaction temperature induced the formation of phenolic hydroxyl in AHA. AHA was rich in aromaticity and carboxylic acid structure, showing similar spectral characteristics to NHA. The distribution of molecular weight of AHA was mostly 5797 Da, which decreased by 15% compared to SHA. The optimal concentration of AHA to promote seedling growth was 0.2 g/L, and the root length was 2.0 times that of the control. The microwave hydrothermal process is a facile and efficient approach to preparing AHA from waste biomass with high moisture content.
湿酒糟作为一种年产出量大的废弃生物质，对环境和食品工业构成了威胁。在此，首次采用两段式微波辅助水热法从湿酒糟中制备人工腐殖酸（AHA）。考察了温度对 AHA 特性的影响，并将其与天然腐殖酸（NHA）和标准腐殖酸（SHA）进行了比较。在 200°C 下总反应时间为 1 小时时，AHA 的产率最高可达 20.6%，是传统单段水热法的 1.8-3.1 倍。升高反应温度会促使 AHA 中形成酚羟基。AHA 富含芳构性和羧酸结构，表现出与 NHA 相似的光谱特征。AHA 的分子量分布主要为 5797 Da，与 SHA 相比降低了 15%。促进幼苗生长的 AHA 最佳浓度为 0.2 g/L，根长是对照的 2.0 倍。微波水热法是一种从高含水量的废弃生物质中制备 AHA 的简便、高效方法。
