微生物-植物联合修复镉砷污染农田土壤技术与应用

Microbe-plant Combined Remediation of Cadmium and Arsenic Contaminated Agricultural Soils:A Review

农田土壤重金属污染严重,难以降解且通过食物链传递,影响农作物食品安全且具有潜在人体健康风险,其中以镉(Cd)、砷(As)污染尤为突出。重金属污染土壤修复技术主要包括固化稳定化、化学淋洗、电动修复、微生物修复和植物修复等,其中,基于超富集植物的重金属抗性、活化和超吸收机制以及根际微生物对植物修复效率的强化作用,微生物-植物联合生物修复已成为重金属污染土壤修复的研究热点,亦具有良好的应用前景。本文重点关注农田土壤及农作物中Cd、As污染与土壤修复技术,在阐述土壤Cd、As污染现状基础上,综述微生物(丛枝菌根真菌、植物内生菌和根际促生菌等)-植物(东南景天、龙葵、美洲黑杨、蜈蚣草和樟子松等)联合修复Cd、As污染农田土壤的研究进展,阐述联合修复的过程作用机制(重金属抗性、解毒、活化、转运及微生物-植物共生),重点讨论不同微生物-植物联合技术的修复效率、作用机制、应用条件、限制因素及应用前景。合理利用微生物-植物联合技术修复体系,可充分发挥微生物与植物效力优势,提高污染土壤修复效率,以期为提高Cd、As污染农田土壤生物修复效率和保障土壤种植安全及食品安全提供理论依据和技术参考。

Agricultural soils are seriously polluted by heavy metals especially by cadmium(Cd)and arsenic(As),which are difficult to be degraded thus being transferred and accumulated via the food chain,posing great risk to food safety and human health.Strategies for heavy metals contaminated soils remediation include solidification and stabilization,chemical leaching,electro-based remediation,microbial remediation,and phytoremediation.Specifically,based on high resistance,mobilization and efficient uptake of hyperaccumulating plants and the roles of rhizosphere microbes in enhancing phytoremediation,microbe-plant combined remediation attracts increasing attention and shows application potentials.This review focuses on Cd and As pollution in agricultural soils and crops and the associated remediation technologies,describes the pollution status of Cd and As in soils,illustrates the research progress of microbe(arbuscular mycorrhizal fungi,endophytes and rhizosphere growth promoting bacteria)-plant(Sedum alfredii,Solanum nigrum,Populus deltoids,Pteris vittata,Pinus sylvestris)combined remediation of Cd/As-contaminated farmland soils,discusses the remediation mechanisms(heavy metals resistance,detoxification,mobilization,translocation and microbe-plant symbiosis).In particular,the remediation efficiency,mechanism,application condition,affecting factors and application prospects of different microbe-plant combined remediation technologies are discussed.Reasonable use of microbe-plant combined remediation technologies can amplify the independent effects of the plant and the microorganism,thereby increasing the efficiency of phytoremediation.The information provides theoretical basis and technical supports for improving remediation efficiency of Cd/As contaminated agricultural soils to ensure soil planting safety and food safety.