湿地植物对镉和抗生素单一及复合污染物的去除机制

Removal Mechanisms of Single and Combined Pollutants of Cadmium and Antibiotics by Wetland Plants

本文对镉和抗生素残留的湿地植物体内体外2条去除途径、镉-抗生素复合污染的湿地植物去除研究进展进行综述。湿地植物根系是植物去除镉的主要部位——镉在湿地植物根际微环境的迁移转化受根际分泌物有机酸、土壤理化性质、微生物群落等影响,植物体内螯合素的螯合/络合作用对镉的植物体内去除起重要影响,而植物根表铁膜是重要的植物体外螯合物,是植物根际-微生物共同体发挥去除效应的场所。湿地植物-微生物协同效应能有效去除抗生素残留污染,但抗生素残留对根际微生物群落组成和结构影响显著,存在产生抗生素抗性细菌和抗性基因的风险。镉和抗生素复合污染因污染物母体种类、浓度不同而表现出不同的络合物行为特征,进而影响对湿地植物的毒性作用;也同时带有污染物母体的毒性特征,呈现复杂的毒性机制。相较于环境中的综合性污染现状,目前仅对少数种类重金属和抗生素复合污染的湿地植物去除进行研究。结合近年来国内外研究进展,我们提出湿地植物去除抗生素及其重金属抗生素复合污染物现有研究的不足及未来发展方向,以期为重金属和抗生素复合污染的湿地植物修复技术提供理论支撑。

In this review,we summarized the in vitro and in vivo removal approaches of cadmium and antibiotics residues and the combined removal methods of cadmium and antibiotics in wetland plants.The roots of wetland plant is the main part for cadmium removing,the migration and transformation of cadmium in wetland plant rhizosphere microenvironment were affected by organic acids in rhizosphere secretions,soil physical and chemical properties,and microbial community.Chelation/complexation of chelates in plant played an important role in the removal of cadmium in plant body,and iron film on plant root surface was an important chelate in vitro to exert its removal efficiency.The synergistic effect of plant-microorganisms in wetlands could effectively remove antibiotic residues.However,antibiotic residues significantly affected the composition and structure of the rhizosphere microbial community,with the risk of producing antibiotic-resistant bacteria and antibiotic-resistant genes.Combined-pollution by cadmium and antibiotics showed different complex behavior characteristics due to their various type and the concentration of the pollutants show,leading to toxic effects on wetland plants.Complex pollutants exhibit the toxic properties of their parent pollutant and entail intricate mechanisms of toxicity.Recently,there are a few studies on the synergic removal of heavy metals and antibiotics using wetland plants.Given that,we proposed the deficiencies and future development directions of the current research on the removal of heavy metal and antibiotics by wetland plants,to provide theoretical support for wetland phytoremediation technology of heavy metal and antibiotic pollution.