生态环境学报2025，Vol.34Issue(10)：1519-1531,13.DOI:10.16258/j.cnki.1674-5906.2025.10.003
微塑料对滨海湿地中污染物行为和元素循环的影响研究进展
Research Progress on the Effects of Microplastics on Pollutant Behavior and Element Cycling in Coastal Wetlands
摘要
Abstract
Although coastal wetlands account for less than 0.2％of the ocean area,their carbon storage accounts for 50％of ocean carbon(blue carbon)storage;therefore,they are regarded as important blue carbon ecosystems.In recent years,the invasion of microplastics has profoundly affected the geochemical cycling of carbon(C),nitrogen(N),sulfur(S),and phosphorus(P)nutrients in coastal wetlands by changing their elemental proportions,soil porosity,oxygen content,and microbial community structure.In addition,the high specific surface area,strong adsorption,and rich surface functional groups of microplastics have a profound impact on the toxicity,migration,and transformation of other organic pollutants and heavy metals in coastal wetlands.Although some progress has been made in the research and review of microplastics in wetlands in recent years,there is still a lack of comprehensive review and summary of the impact of microplastics on pollutant behavior and element cycling in coastal wetlands.In this review,the distribution characteristics of microplastics in coastal wetlands and their influence and mechanisms on the environmental behavior of pollutants,soil organic matter transformation,and elemental cycling are comprehensively summarized.The results showed that the main types of microplastics in coastal wetlands are polyethylene(PE),polypropylene(PP),polystyrene(PS),polyvinyl chloride(PVC),polyethylene terephthalate(PET),polyamide(PA),polylactic acid(PLA),and polymethyl methacrylate(PMMA).The generally high abundance of microplastics in coastal wetlands,especially in the economically developed coastal zones of Southeast Asia and some European countries,may be attributed to the high use of plastics and imperfect management.In addition,natural factors effect the abundance of microplastics in coastal wetlands.For example,the distribution of microplastics is relatively dense at latitudes of 0°‒30°,indicating that the tropical region has a high concentration of microplastics,perhaps due to ultraviolet radiation,oxidation,and heating,which increase the abundance of microplastics in the tropical region.The distribution and abundance of microplastics in coastal wetlands are affected by different factors,including wetland type,environmental medium,soil depth,and plant type.Microplastics entering coastal wetlands significantly changes the soil physical structure,chemical properties,microbial community structure,and enzyme activity owing to their high specific surface area,strong adsorption,high carbon content,and rich surface functional groups.It is important to note that soil aggregates exposed to microplastics may be affected differently because of differences in the shape and amount of microplastics as well as soil properties.Exposure to microplastics alters the soil cation exchange capacity of coastal wetlands and the free exchange capacity of protons,thereby changing the soil pH.Microplastics can also indirectly affect pH by altering the microbial structure and metabolic function in coastal wetlands.On the one hand,the large specific surface area of microplastics can provide good survival sites for microorganisms;on the other hand,microplastics increase the content of dissolved organic matter,provide carbon sources for microorganisms,and regulate microbial communities.In addition,microplastics can regulate soil microbial respiration and carbon emission rates by changing the electron transfer properties of soil and sediment.In complex coastal wetland environments,some organic pollutants exhibit significant refractory degradation characteristics.Microplastics posses unique physical and chemical properties that enable them to establish close adsorption relationships with organic pollutants,such as polybrominated diphenyl ethers,polycyclic aromatic hydrocarbons,polychlorinated biphenyls,PPCPs,and other endocrine-disrupting substances.The adsorption of organic pollutants by microplastics is not a simple physical process but has a non-negligible impact on the toxicity of organic pollutants in the ecosystem,which can produce both combined and antagonistic toxicities.Microplastics in coastal wetlands are effective heavy metal carriers.Microplastics can adsorb a variety of heavy metals,such as Cu,Cd,As,Zn,Pb,and Mo,through surface complexation,intra-particle diffusion,electrostatic interactions,and other mechanisms.When organism directly ingest microplastics,the accumulation of heavy metals in their bodies increases significantly.More critically,the presence of microplastics not only increases the accumulation of heavy metals but also affects the toxic effects of heavy metals in living organisms.As a high-carbon substance,microplastics entering coastal wetlands not only directly increase their carbon content but also indirectly affect their carbon content by changing soil physical and chemical properties and microbial metabolic activities.The changes in soil carbon content caused by microplastics in coastal wetlands are affected by many factors,such as the abundance,type,and aging degree of microplastics,and the vegetation type of coastal wetlands.Microplastics affect the transformation and mineralization of soil organic matter in coastal wetlands and the emission of greenhouse gases.Studies have shown that microplastics can increase CO2 emissions by 54.3％and CH4 emissions by 9.7％,and that aged microplastics have a greater increase in greenhouse gas emission rate than unaged microplastics.In terms of nitrogen transformation,microplastics lead to changes in the soil C/N ratio,affect the utilization and demand of microorganisms for nitrogen,and interfere with microbial community structure,such as affecting the growth of different types of bacteria,thereby changing the process of nitrogen transformation and accumulation.Microplastics ultimately lead to changes in soil sulfur content by enhancing the sulfate reduction.In terms of phosphorus transformation,microplastics,on the one hand,reduce soil phosphatase activity and hinder the mineralization of organic phosphorus,and on the other hand,change the adsorption capacity of soil for polyphosphate,thus affecting the availability and transformation of phosphorus in soil.The effects of microplastics on organic matter conversion and C,N,S,and P cycling in coastal wetlands are affected by the type,abundance,aging degree,exposure time,and wetland type of the microplastics.There is still much room for progress in understanding the impact of microplastics on coastal wetlands.For example,the research methods for microplastics need to be standardized;there is a lack of systematic in situ studies on the effects of microplastics on carbon transformation in different types of coastal wetlands;and studies on the interaction mechanism between various pollutants and microplastics and their influence on element cycling should be strengthened.This review will not only deepen the understanding of the impact of microplastics on the environmental behavior of pollutants in coastal wetlands,but will also be of great significance for a comprehensive understanding of blue carbon transition and element cycling caused by microplastic pollution in coastal wetlands.关键词
微塑料/滨海湿地/污染物/蓝碳/环境行为/元素循环Key words
coastal wetlands/blue carbon/microplastics/contaminants/environmental behavior/element cycle分类
资源环境引用本文复制引用
汪彩琴,杨潜英,周名玉,张道勇,潘响亮..微塑料对滨海湿地中污染物行为和元素循环的影响研究进展[J].生态环境学报,2025,34(10):1519-1531,13.基金项目
浙江省领雁项目(2025C02216) （2025C02216）
国家自然科学基金项目(42107238) （42107238）
浙江省自然科学基金项目(LQ22D030004) （LQ22D030004）
