Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
Korea Biochar Research Center, APRU Sustainable Waste Management Program & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, South Korea.
Sci Total Environ. 2021 Jul 15;778:146142. doi: 10.1016/j.scitotenv.2021.146142. Epub 2021 Mar 1.
The formed Fe oxides (minerals) in the magnetic biochar production process can facilitate its recovery and carbon retention rate. However, the influence of Fe oxides on pyrolysis volatile-derived water-soluble organic matter (PVWSOM, also called wood vinegar) has been largely overlooked. Results demonstrated that in-situ formed Fe oxides (α-FeO and FeO) could obviously inhibit biomass cracking and accordingly reduce PVWSOM emissions, as indicated by decreased PVWSOM concentrations from 28.7 to 6.8 mg C/g biomass. FT-ICR MS results further indicated that Fe oxides suppressed the formation of large-molecular-weight PVWSOM compounds with high degree of unsaturation (DBE value > 5) and oxygen content (oxygen number > 5), leading to lower polarity and aromaticity. Therefore, the changes in PVWSOM molecular structures caused by Fe oxides relieved its toxicity on wheat seed growth, and reduced negative impact on soil microbial diversity and promoted soil bacterial Proteobacteria and Acidobacteria. These results indicate that molecular structures of PVWSOM from biomass pyrolysis also can be changed by Fe oxides to affect its application.
在磁性生物炭生产过程中形成的 Fe 氧化物（矿物质）可以促进其回收和碳保留率。然而，Fe 氧化物对热解挥发物衍生的水溶性有机物（也称为木醋液）的影响在很大程度上被忽视了。结果表明，原位形成的 Fe 氧化物（α-FeO 和 FeO）可以明显抑制生物质的裂解，从而减少 PVWSOM 的排放，PVWSOM 浓度从 28.7 降至 6.8mg C/g 生物质。傅里叶变换离子回旋共振质谱（FT-ICR MS）结果进一步表明，Fe 氧化物抑制了大分子量、高不饱和度（DBE 值>5）和高含氧量（氧原子数>5）的 PVWSOM 化合物的形成，导致其极性和芳香性降低。因此，Fe 氧化物引起的 PVWSOM 分子结构的变化减轻了其对小麦种子生长的毒性，降低了对土壤微生物多样性的负面影响，并促进了土壤细菌中 Proteobacteria 和 Acidobacteria 的生长。这些结果表明，Fe 氧化物也可以改变生物质热解产生的 PVWSOM 的分子结构，从而影响其应用。
