School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
Chemosphere. 2018 May;199:402-408. doi: 10.1016/j.chemosphere.2018.02.058. Epub 2018 Feb 9.
Biochar improves soil fertility and promotes long-term terrestrial carbon sequestration. However, biochar seems not to be stable enough due to physical, chemical and biological reactions. In this study, a novel, stable, and magnesium (Mg)-impregnated biochar was prepared from cow dung and applied to decrease P leaching from soil. XPS, FTIR, XRD, SEM and EDS were used to evaluate the effect of modification and phosphorus(P) sorption on the oxidation resistance of biochar. The results showed that the oxidation resistance of the Mg-impregnated biochar was improved by the formation of MgO on its surface. The soil column experiment indicated that the Mg-impregnated -biochar decreased P loss from leaching by 89.25%. In addition, the available P content of the soil surface layer under Mg-impregnated biochar treatment increased by 3.5-fold relative to that under the control treatment. P sorption also enhanced the oxidation resistance of biochar. The relative contents of CO, CO, and COOH on the surface of P-laden biochar was 20.97% and was lower than those on the surface of biochar without P sorption (33.15%). Oxidation resistance was enhanced by the formation of new MgP crystals, which prevented the oxidation of CC, CC, and CH into CO, CO, and COOH, respectively, by acting as a physical barrier between the biochar surface and oxygen. The results of XRD, SEM and EDS provided evidence for the formation of MgP crystals. Overall, results indicated that the Mg-impregnated biochar can reduce P leaching loss from soil and has enhanced stability.
生物炭可以提高土壤肥力并促进陆地碳的长期封存。然而，由于物理、化学和生物反应，生物炭似乎不够稳定。在这项研究中，我们从牛粪中制备了一种新型、稳定的镁（Mg）浸渍生物炭，并将其应用于减少土壤中磷的淋失。XPS、FTIR、XRD、SEM 和 EDS 用于评估改性和磷（P）吸附对生物炭抗氧化性的影响。结果表明，表面形成 MgO 提高了镁浸渍生物炭的抗氧化性。土柱实验表明，镁浸渍生物炭可将磷的淋失损失减少 89.25%。此外，镁浸渍生物炭处理下土壤表层的有效磷含量比对照处理增加了 3.5 倍。磷吸附也增强了生物炭的抗氧化性。与未吸附磷的生物炭（33.15%）相比，吸附磷的生物炭表面的 CO、CO 和 COOH 的相对含量为 20.97%。新形成的 MgP 晶体增强了氧化阻力，其充当了生物炭表面和氧气之间的物理屏障，分别阻止了 CC、CC 和 CH 氧化成 CO、CO 和 COOH。XRD、SEM 和 EDS 的结果为 MgP 晶体的形成提供了证据。总之，结果表明，镁浸渍生物炭可以减少土壤中磷的淋失损失，并提高稳定性。
