土壤矿物质-可溶态生物炭的交互作用及其对碳稳定性的影响

发布时间：2019-01-04 11:29

【摘要】：将生物质转化为生物炭并输入土壤被认为是一种很有前景的碳封存技术.生物炭颗粒在土壤中会不断释放出可溶态生物炭,这部分生物炭不稳定,易被微生物分解.探明土壤组分矿物质对可溶态生物炭稳定性的影响对评估生物炭的碳封存作用具有重要意义.因此,本文以核桃壳生物炭为研究对象,通过批次吸附实验及微生物降解实验研究了2种代表性土壤矿物质高岭土和针铁矿与核桃壳生物炭可溶有机组分的结合机理,以及这种结合作用对可溶态生物炭稳定性的影响.结果表明:低浓度(如20 mg·L-1)可溶态生物炭条件下,高岭土与可溶态生物炭之间以Ca2+架桥作用为主,约占吸附总量的65%;高浓度(如80 mg·L-1)条件下,以范德华力为主,约占吸附总量的76%.随着可溶态生物炭初始浓度的升高,针铁矿对其吸附量先升高后下降,且以范德华力为主,Ca2+会抑制针铁矿对可溶态生物炭的吸附.被矿物质吸附后的可溶态生物炭,其微生物降解性显著下降,可降解的碳下降了47.9%~85.3%,土壤矿物质能够吸附保护可溶态生物炭,提高其在土壤中的稳定性.
[Abstract]:Converting biomass into biochar and importing it into soil is considered to be a promising carbon sequestration technology. Biochar particles release soluble biochar from soil, which is unstable and easy to be decomposed by microorganisms. It is of great significance to investigate the effect of soil component minerals on the stability of soluble biochar in evaluating the carbon sequestration of biochar. Therefore, the binding mechanism of two typical soil minerals kaolin and goethite to soluble organic components in walnut shell biochar was studied by batch adsorption experiment and microbial degradation experiment. And the effect of this binding on the stability of soluble biochar. The results showed that under the condition of low concentration (20 mg L-1) of soluble biochar, the bridging action between kaolinite and soluble biochar was mainly Ca2, accounting for about 65% of the total adsorption amount. At high concentration (such as 80 mg L ~ (-1), van der Waals force accounts for about 76% of the total adsorption. With the increase of the initial concentration of soluble biochar, the adsorption amount of goethite increased first and then decreased, and the van der Waals force was dominant. Ca2 could inhibit the adsorption of goethite to soluble biochar. The biodegradability of soluble biochar adsorbed by minerals decreased significantly, and the biodegradable carbon decreased by 47.9% and 85.3% respectively. Soil minerals can be adsorbed to protect soluble biochar and improve its stability in soil.
【作者单位】：上海交通大学环境科学与工程学院;
【基金】：国家自然科学基金重点项目(No.21537002)~~
【分类号】：X131.3

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