Lin Chuanjin, Xin Zhenhua, Yuan Shijie, Sun Jing, Dong Bin, Xu Zuxin
College of Environmental Science and Engineering, Tongji University, No. 1239, Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Tongji University, No. 1239, Siping Road, Shanghai 200092, China.
College of Environmental Science and Engineering, Tongji University, No. 1239, Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Tongji University, No. 1239, Siping Road, Shanghai 200092, China; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing 100038, China; College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541006, China.
Water Res. 2024 Mar 1;251:121133. doi: 10.1016/j.watres.2024.121133. Epub 2024 Jan 13.
Sludge hydrothermal carbonization demonstrates potential for converting sludge into multifunctional carbon materials for soil remediation. However, the influence of dissolved organic matter (DOM) with unclear molecular characteristics in sludge-based hydrothermal carbon on plant growth has not been sufficiently investigated. Herein, the effects of hydrothermal temperature on the molecular transformation pathways and plant-growth-promoting properties of DOM were investigated via FT-ICR MS-based molecular network analyses and seed germination experiments. Results indicated that the highest DOM yield was achieved at 220 °C. During low-temperature (180 °C) hydrothermal treatment, the hydrolysis of biopolymers, as well as the partial condensation and cyclization of small-molecule intermediates, occurred in the sludge. This process produced unsaturated CHNO compounds containing one or two N atoms, which promoted seed germination. Further, the toxicity of DOM to plants increased with rising hydrothermal temperature. This was accompanied by S doping and aromatization reactions, which mitigated the effects of plant growth hormones. This study provides theoretical support for the optimization of sludge hydrothermal treatment and production of plant growth hormones, enhancing the ecological value of sludge-based hydrochar.
污泥水热碳化显示出将污泥转化为用于土壤修复的多功能碳材料的潜力。然而，基于污泥的水热碳中分子特征不明的溶解有机物（DOM）对植物生长的影响尚未得到充分研究。在此，通过基于傅里叶变换离子回旋共振质谱（FT-ICR MS）的分子网络分析和种子萌发实验，研究了水热温度对DOM分子转化途径和促进植物生长特性的影响。结果表明，在220°C时DOM产量最高。在低温（180°C）水热处理过程中，污泥中发生了生物聚合物的水解以及小分子中间体的部分缩合和环化。这一过程产生了含有一个或两个氮原子的不饱和CHNO化合物，促进了种子萌发。此外，DOM对植物的毒性随水热温度升高而增加。这伴随着硫掺杂和芳构化反应，削弱了植物生长激素的作用。本研究为优化污泥水热处理和生产植物生长激素提供了理论支持，提高了基于污泥的生物炭的生态价值。
