生物炭负载石墨相氮化碳与固定化微生物对土壤石油烃协同降解机理

本项目针对土壤中石油烃的难生物降解特性，结合我国东北油田开采区土壤石油烃污染严重与强盐碱化的实际问题，以东北地区主要农业生物质材料玉米秸秆、玉米棒芯、大豆秸秆等制备的生物炭为载体，在对生物炭负载g-C3N4改性催化剂与固定化石油烃优势降解菌制备的多功能复合材料的物理结构表征与化学性质分析的基础上，采用13C同位素分析技术，揭示可见光/微波条件下生物炭负载催化剂对烷烃、芳香烃与BTEX等主要石油烃污染物的化学催化降解过程与关键影响因子；探究生物炭固定化石油烃优势降解菌对土壤石油烃的生物降解机理与主要影响因子；重点阐明生物炭负载催化剂与固定化微生物对土壤石油烃化学催化与生物降解的协同作用及土壤理化、生物学性质调控机理。通过生物炭负载催化剂与固定化微生物实现土壤石油烃污染物的协同降解与农业废弃物资源化利用，并同时有效调控土壤理化、生物学性质，为石油烃污染土壤修复提供科学依据。

Petroleum hydrocarbons have high resistance to biodegradation and cause severe soil pollution and salinization in the northeast oilfield in China. The aim of our study is to reclaim the petroleum-hydrocarbon-contaminated soil using multifunctional composite materials to enhance the synergistic effects of chemical and biological degradation. The composite materials were obtained by preparing biochar from corn straw, corn cob, and soybean straw, doped with graphitic carbon nitride (g-C3N4), and then immobilized dominant petroleum degrading bacteria. The physical and chemical properties of the composite materials were evaluated. 13C isotope analysis was used to investigate the mechanism and key controlling factors of chemical degradation of alkanes, aromatic hydrocarbons and BTEX using the biochar-loaded catalyst under the condition of visible light or microwave. The biodegradation mechanism and its key controlling factors by biochar immobilized dominant petroleum degrading bacteria were examined as well. Finally, the mechanism of synergistic degradation and the regulating mechanism among physical, chemical, and biological characteristics of soil were illustrated, which provided scientific basis for the petroleum-contaminated soil remediation.