环糊精调控过硫酸钠预氧化联合土著微生物降解黑土PAHs的机制研究

东北黑土区遗留了大量多环芳烃（PAHs）污染场地，且以苯并[a]芘（BaP）污染最为突出。原位化学氧化（ISCO）联合原位生物修复（ISB）是PAHs污染土壤极具潜力的修复手段，但富有机质黑土中PAHs土水界面传质缓慢导致氧化剂需求量高及抑制土著微生物活性等问题亟待解决。环糊精作为增溶剂在土壤修复领域得到广泛关注，但围绕环糊精对ISCO-ISB体系的调控研究鲜见。本项目针对黑土BaP污染，选择代表性环糊精，研究环糊精对黑土中BaP土水界面分配行为的调控规律和机制；研究环糊精调控下，活化过硫酸钠预氧化BaP的影响因素、动力学规律及降解路径，探明环糊精促进BaP预氧化机制；研究预氧化后环糊精、BaP及土著微生物的互作关系，阐明环糊精的增效机制；通过揭示并优化环糊精对黑土中BaP界面传质-化学氧化-生物降解的全过程调控途径，为ISCO-ISB体系高效、经济及安全用于有机污染场地修复提供科学依据。

There are many PAHs contaminated sites remaining in the black soil region of Northeast China with benzo[a]pyrene as the most representative pollutant. In-situ chemical oxidation combining with in-situ bioremediation is a potential remediation method for PAHs contaminated soil. However, the problem that slow mass transfer of PAHs across soil-water interface of organic-rich black soil results in high demand for oxidant dosage with inhibition of indigenous microorganisms activity urgently needs to be addressed. Cyclodextrin as solubilizer has obtained widespread concern in the field of soil remediation, however, there have few studies on the cyclodextrin regulation of ISCO-ISB system. Therefore, this project focuses on BaP contaminated black soil, and selects representative cyclodextrins to (1) explore the cyclodextrin regulation law and mechanism of BaP interface distribution in soil-water environment; (2) study the influence factors, kinetics law and degradation pathway of the preoxidation of BaP by activated sodium persulfate under cyclodextrin regulation with its enhancing mechanism; (3) investigate the interactions among cyclodextrin, BaP and indigenous microorganisms after the preoxidation, and illuminate the synergistic mechanism of cyclodextrin. Overall, the cyclodextrin regulation pathways of interfacial mass transfer, chemical oxidation and biodegradation of BaP in black soil will be comprehensively revealed and optimized, in order to provide scientific basis for the efficient, economical and secure application of ISCO-ISB system in organic-contaminated sites remediation.