Chen Xuejiao, Zhang Jinhong, Lin Qimei, Li Guitong, Zhao Xiaorong
School of Food Science and Bioengineering, Xihua University, Chengdu, 610039, China.
College of Land Science and Technology, China Agricultural University, Beijing, 100193, China.
Environ Sci Pollut Res Int. 2023 Jan;30(2):4592-4602. doi: 10.1007/s11356-022-22359-4. Epub 2022 Aug 16.
Landfill of waste biomass not only poses a threat to environmental protection but also leads to a great waste of biomass resources. Hydrothermal carbonization (HTC) has been considered a promising method to convert the wet biomass into hydrochar, a high-value-added product with multiple application potentials. The cabbage waste, typical wet waste biomass with a huge production per year, was hydrothermally carbonized under 190 °C and 260 °C, respectively. The results indicated that the majority of nutrients from feedstock were dissolved in spent liquor during HTC, with only a few amounts retained on hydrochar. Temperature showed a more significant impact on hydrochar properties than retention time, which enables hydrochar to be potentially used as a soil conditioner. Particularly, the hydrochar produced at 190 °C could improve plant nutrition in the short term, while that produced at 260 °C may benefit in C sequestration. Moreover, the hydrochar dominated by meso/macropores (> 90%) would be conducive to the storage of plant-available water. But both BTX and VOCs may release during hydrochar application; thus, further field experiments are needed to test the environmental risks of hydrochar when applied as a soil amendment.
废弃生物质的填埋不仅对环境保护构成威胁，还会导致生物质资源的大量浪费。水热碳化（HTC）被认为是一种将湿生物质转化为水炭的有前景的方法，水炭是一种具有多种应用潜力的高附加值产品。白菜废弃物是典型的湿垃圾生物质，年产量巨大，分别在190℃和260℃下进行水热碳化。结果表明，在水热碳化过程中，原料中的大部分养分溶解在废液中，只有少量保留在水炭上。温度对水炭性质的影响比保留时间更为显著，这使得水炭有可能用作土壤改良剂。特别是，在190℃下产生的水炭可以在短期内改善植物营养，而在260℃下产生的水炭可能有利于碳固存。此外，以中/大孔（>90%）为主的水炭将有利于储存植物可用水分。但是在水炭应用过程中可能会释放BTX和挥发性有机化合物（VOCs）；因此，需要进一步的田间试验来测试水炭作为土壤改良剂时的环境风险。
