The interactions and mechanisms between sulfur and heavy metals are a growing focus of biogeochemical studies in coastal wetlands.These issues underline the fate of heavy metals bound in sediments or released into the...The interactions and mechanisms between sulfur and heavy metals are a growing focus of biogeochemical studies in coastal wetlands.These issues underline the fate of heavy metals bound in sediments or released into the system through sediments.Despite the fact that numerous published studies have suggested sulfur has a significant impact on the bioavailability of heavy metals accumulated in coastal wetlands,to date,no review article has systematically summarized those studies,particularly from the perspective of the three major components of wetland ecosystems(sediments,rhizosphere,and vegetation).The present review summarizes the studies published in the past four decades and highlights the major achievements in this field.Research and studies available thus far indicate that under anaerobic conditions,most of the potentially bioavailable heavy metals in coastal wetland sediments are fixed as precipitates,such as metal sulfides.However,fluctuations in physicochemical conditions may affect sulfur cycling,and hence,directly or indirectly lead to the conversion and migration of heavy metals.In the rhizosphere,root activities and microbes together affect the speciation and transformation of sulfur which in turn mediate the migration of heavy metals.As for plant tissues,tolerance to heavy metals is enhanced by sulfur-containing compounds via promoting a series of chelation and detoxification processes.Finally,to further understand the interactions between sulfur and heavy metals in coastal wetlands,some major future research directions are proposed.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.32071521,31800429,and 42067012)the Natural Science Foundation of Jiangsu Province(Nos.BK20170540 and BK20210751)+2 种基金the Scientific Research Foundation for Senior Talent of Jiangsu University,China(No.20JDG067)the Science and Technology Program of Gansu Province of China(No.20JR5RA532)the MEL Visiting Fellowship of Xiamen University and Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,China.
文摘The interactions and mechanisms between sulfur and heavy metals are a growing focus of biogeochemical studies in coastal wetlands.These issues underline the fate of heavy metals bound in sediments or released into the system through sediments.Despite the fact that numerous published studies have suggested sulfur has a significant impact on the bioavailability of heavy metals accumulated in coastal wetlands,to date,no review article has systematically summarized those studies,particularly from the perspective of the three major components of wetland ecosystems(sediments,rhizosphere,and vegetation).The present review summarizes the studies published in the past four decades and highlights the major achievements in this field.Research and studies available thus far indicate that under anaerobic conditions,most of the potentially bioavailable heavy metals in coastal wetland sediments are fixed as precipitates,such as metal sulfides.However,fluctuations in physicochemical conditions may affect sulfur cycling,and hence,directly or indirectly lead to the conversion and migration of heavy metals.In the rhizosphere,root activities and microbes together affect the speciation and transformation of sulfur which in turn mediate the migration of heavy metals.As for plant tissues,tolerance to heavy metals is enhanced by sulfur-containing compounds via promoting a series of chelation and detoxification processes.Finally,to further understand the interactions between sulfur and heavy metals in coastal wetlands,some major future research directions are proposed.
