Distribution,characteristics, and research status of microplastics in the trunk stream and main lakes of the Yangtze River: A review

Microplastic pollution has become an environmental issue of great concern owing to the persistence of microplastics and their potential adverse effects on biota.The Yangtze River is the longest river in China and the third-longest river in the world,and the microplastics in this river will affect the health of a large population living along with it.To ensure the survival safety of people,it is essential to plan ahead and investigate in advance in order to understand the microplastic pollution in the river and work out countermeasures.This paper reviews the literature concerning the microplastic pollution in the Yangtze River basin and analyzes the abundance,shapes,colors,and composition of microplastics in the water bodies and sediments in the trunk stream and main lakes of the Yangtze River.The results are as follows.Compared to other river basins in China and abroad,the microplastics in the Yangtze River basin have a moderate abundance and high spatial heterogeneity.Owing to the barrier effect of the Three Gorges Dam on microplastics,the abundance of microplastics in the Three Gorges Reservoir is generally an order of magnitude higher than that in other sections of the river.Most microplastics in the water bodies and sediments are less than 1 mm in size and are transparent and colorful.In terms of shapes,they are dominated by fibers,followed by fragments and films.In terms of composition,the microplastics in the source region of the Yangtze River are mainly composed of nylon and polyethylene,while the microplastics in the surface water from the lower reaches of the Jinsha River to the Yangtze River estuary are dominated by polypropylene and polyethylene.The microplastics are primarily derived from the secondary microplastics in the environment,and relatively intensive human activities increase the abundance of microplastics.These results serve as bases for understanding and preventing microplastic pollution in the Yangtze River.     

松花江上游表层沉积物中重金属元素时空分布特征

松花江是我国七大河流之一,研究其底泥重金属元素的时空分布特征对流域的水环境治理具有重要意义。本文对松花江（哈达山至松花湖段）底泥（表层沉积物）中元素As、Hg、Cr、Cd、Pb的分布特征进行了研究,并利用地累积指数分析了这些元素的污染状况。结果表明：研究区底泥几乎未受到As、Cr和Pb的污染,但多数地段内出现了Cd和Hg的污染,尤其是元素Hg,在个别地段的污染程度达到了极强;与10年前相比,一些重金属的污染得到了明显改善,但吉林市区段内Hg的污染仍非常严重。污染样品空间分布特征表明,松花江吉林市区段可能有来自工农业废水的重金属污染。     

城市垃圾的地质处置

城市固体废物（城市垃圾）是国际上现代化城市环境污染的主要污染源之一,发达国家非常注重固体废物地质处置的研究,这一领域是环境工程与水资源工作者研究的热点问题。我国城市垃圾对环境的污染非常严重,目前有三分之二的城市已形成“垃圾包围城市”的严重局面。随着经济的发展,我国城市固体废物的数量增长很快。如何处理庞大的城市垃圾将是关系到经济发展、水资源和环境保护的重大问题。本文介绍了我国城市垃圾的现状和目前国际     

扬-泰-靖地区地下水系统水力联系与硫酸盐污染特征

本文对长江三角洲扬-泰-靖地区第四系松散层地下水中环境同位素(D、18O、34S)的分布特征进行了分析,旨在揭示大气降水、长江水、潜水及承压水之间的水力联系,辨别地下水中硫酸盐的来源及其污染状况。研究结果表明潜水含水层接受大气降水及长江水的补给,硫酸盐主要为农业污染来源或与海源硫酸盐的混合。承压含水层主要接受大气降水的补给,与潜水含水层及长江之间的水力联系较差,硫酸盐来源不同。在研究区顶部和沿江地段的浅层孔隙承压水中,硫酸盐来源于硫化物的氧化;在东部的深层孔隙承压水中,硫酸盐主要来源于硫酸盐岩的溶解或海源硫酸盐的滞留,基本未受到潜水或地表水中硫酸盐的污染。     

Environmental Assessments of Trace Metals in Sediments from Dongting Lake, Central China

INTRODUCTIONFresh water lakes are one of the planet’s mosti mportant freshwater resources.They support life invarious forms,develop tourism and provide uniquerecreational opportunities.It is also a good source ofthe provision of drinking-water for local communi-ties.Studies on trace elements in rivers,lakes,andsedi ments(Zhou et al.,2004;Gray et al.,2000;Grosheva et al.,2000;Klavins et al.,2000;Aucoinet al.,1999;Bortoli et al.,1998;Elbaz-Poulichet etal.,1996;Johansson et al.,1995;F r…     

西南岩溶区矿山与水污染问题探讨及建议

我国西南石山连片分布的岩溶区,总面积约100万km2,其中裸露岩溶区面积约62万km2,这里虽然年降水量在1000 mm以上,但由于岩溶强烈发育,降水很快转化为地下径流,通过众多岩溶地下河排入位于深切峡谷的大江大河里。该区地形西高东低,西部为云贵高原,东部为低山丘陵区,中部是过渡的斜坡地带。云贵高原处于生态屏障区,是长江和珠江的分水岭。该区矿产资源丰富,如贵州的煤矿、稀有金属、磷矿等;广西的有色金属、锰矿、铝土矿等。采、选矿产生的尾砂及废水,如果处理不当,会污染地表水和地下水,北面影响长江流域,南面影响珠江流域。2008—2010年间,"西南岩溶石山地区重大环境地质问题及对策研究"项目专家组先后几次对岩溶石山区部分矿产开采点引发的水环境污染问题进行考察,认为由于不规范、不合理的矿产开发带来的水环境问题依然比较严重,是影响该地区可持续发展的重大环境地质问题之一。     

Technical Challenges to In-situ Remediation of Polluted Sites

Throughout the world, subsurface contamination has become a widespread and pervasive problem. Toxic chemicals such as heavy metals and organic compounds are commonly used in a myriad of industries. However, largely through inadvertent or accidental release, these chemicals are presently polluting sites across the United States. In order to protect public health and the environment, further pollution must be prevented and sites with existing contamination urgently need remediation. Unfortunately, remediating subsurface contamination has proved to be a daunting task. Heavy metals and organic compounds often coexist and their distribution within the subsurface is highly dependent on particle and macro-scale heterogeneities. Vast resources have been invested to develop efficient remediation technologies, yet very few of these technologies have been successful. In-situ remediation is often preferred due to minimal site disturbance, safety, simplicity, and cost-effectiveness. The effectiveness of in-situ remediation technologies depends largely on the contaminant chemistry and subsurface heterogeneities (including particle-scale heterogeneities such as fine-grained soils, soils with reactive minerals, and/or soils rich in organic matter as well as macro-scale heterogeneities such as irregular soil layers and/or lenses). Under such heterogeneous conditions, integrated electrokinetic remediation technology has great potential. As a safe and economical remedial option for so many contaminated sites, the application of integrated electrokinetic remediation offers enormous public health, environmental, and financial benefits.     

Use of Regional Geochemical Survey Data and exploratory statistics to estimate natural condition concentrations for trace metals in stream sediments: a case study for the Cook Inlet watershed,Alaska

The United States and other nations use the term natural conditions or reference conditions in legislation providing for the protection of aquatic ecosystems. Natural or reference conditions are generally used to describe environmental conditions in an aquatic resource before any human introduced pollution. The natural or reference conditions are used in establishing water quality criteria for protection of aquatic resources, helping classify aquatic resources within a regulatory category, and for assessing effectiveness of aquatic resource restoration actions. Regional scale geochemical mapping of stream sediments is available for many countries that when combined with exploratory data analysis and geospatial data can be used to establish screening level natural conditions for trace metals in stream sediments. This approach is applied to the Cook Inlet watershed in Alaska using the US Geological Survey National Geochemical Survey stream sediment trace metals data. Upper concentration limits are developed for As, Cr, Cu, Pb, Hg, Ni, and Zn in the Cook Inlet watershed to aid in screening sediments for potential anthropogenic contamination.     

Environmental quality assessment on a river system polluted by mining activities

In this study, adverse impacts of heavy metal pollution, originating from mining, smelting and panning activities, on the aquatic ecosystem of the Lean River in south China, were evaluated by integrating the chemical, toxicological and ecological responses of single and multiple metals in overlying water, surface sediment and floodplain topsoil. The assessment results indicated that a highly localized distribution pattern was closely associated with the pollution sources along the river bank. Based on the combined indices, deterioration of local environmental quality was induced mainly by two sources. One was strong acidity and a large amount of Cu in the drainage from the Dexing Cu Mine. Another was high concentrations of Pb and Zn in the effluents released from many smelters and mining/panning activities in the riparian zone. Some possible suggestions on source control may be effective in dealing with these issues.     

Estimation of environmental impacts on the water quality of the Tahtalıdam watershed in İzmir, Turkey

Water pollution is a widespread problem in different areas of the world. Some of these problems originated from point contamination sources and widespread contaminant outlet sources which are observed in every country. The major elements and chemical loads of surface water have been dominated by constituents derived directly or indirectly from human activities and/or industrial practices that have increased additives in the last several decades. The point sources of contamination may result from the direct wastewater discharges to the dam sites, which are considered to be the most commonly encountered water pollution problems. One of these problems is the eutrophication process which usually occurs in the static water mass of lakes and other surface water reservoirs. This process may be caused by the continuous increase of nitrogen and phosphorus contents and decrease of O₂ level in water causing an anaerobic condition which may stimulate algae-growth flow in these water bodies, consequently reducing the quality of water. Of course, there are many research methods for determining the various kinds of water pollution. In this research, the hydrochemical parameters were evaluated to estimate the types of pollution sources, the level of pollution, and its environmental impacts on the Tahtal dam reservoir.     

Assessment of heavy metal contamination in soils around Manali industrial area, Chennai, Southern India

The concentrations of heavy metals (As, Ba, Co, Cr, Cu, Ni, Mo, Pb, Sr, V and Zn) were studied in soils to understand metal contamination due to industrialization and urbanization around Manali industrial area in Chennai, Southern India. This area is affected by the industrial activity and saturated by industries like petrochemicals, refineries, and fertilizers generating hazardous wastes. The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor (EF), contamination factor and degree of contamination. Soil samples were collected from the industrial area of Manali from the top 10-cm-layer of the soil. Soil samples were analyzed for heavy metals by using Philips MagiX PRO-2440 Wavelength dispersive X-ray fluorescence spectrometry. The data revealed elevated concentrations of Chromium (149.8–418.0 mg/kg), Copper (22.4–372.0 mg/kg), Nickel (11.8–78.8 mg/kg), Zinc (63.5–213.6 mg/kg) and Molybdenum (2.3–15.3 mg/kg). The concentrations of other elements were similar to the levels in the earth’s crust or pointed to metal depletion in the soil (EF < 1). The high-EFs for some heavy metals obtained in the soil samples show that there is a considerable heavy metal pollution, which could be correlated with the industries in the area. Contamination sites pose significant environmental hazards for terrestrial and aquatic ecosystems. They are important sources of pollution and may result in ecotoxicological effects on terrestrial, groundwater and aquatic ecosystems. In this perspective there is need for a safe dumping of waste disposal in order to minimize environmental pollution.     

我国河流湖泊污染的防治技术及发展趋势

我国河流湖泊污染现状为V类和劣V类水质占七大水系(辽河、海河、淮河、黄河、松花江、珠江、长江)主要断面的50%以上,高中营养化湖泊占被调查湖泊的85%以上,河流湖泊污染状况十分严峻.目前河流湖泊采取的污染防治技术措施主要有:削减截流污染源、完善城市排水系统和建设污水处理厂、河流低泥疏浚、河道曝气技术、生物修复技术、水生植被恢复工程、引清冲淡等等.生物生态技术将在河流湖泊污染防治及生态恢复中发挥重要的作用.     

三峡库区澎溪河消落带土壤中重金属形态分布与迁移特征研究

消落带是水域与陆地的过渡地带,对水环境有着至关重要的影响。本文以三峡库区消落带面积最大的澎溪河流域作为研究区域,采集消落带土壤及其沿岸土壤样品,分析重金属形态分布特征,并使用地质累积指数法和风险评价准则(RAC)对重金属污染程度及生态风险进行评价。研究表明,消落带土壤中Pb、Cu、Cr、Cd、Zn和Ni平均含量分别为68.70、36.96、55.10、0.68、108.26、31.68 mg/kg,污染程度依次为CdPbZnCuNiCr,以Cd和Pb污染较为突出,普遍高于长江干流土壤,远高于重庆地区土壤。Cd的RAC值为20.62%,呈中等环境风险;其形态稳定性最差,以可还原态和酸提取态为主。Pb、Cu、Cr、Zn、Ni的RAC值为5.45%~10.0%,环境风险较低;且均以残渣态为主,占总量的54.69%~83.05%。以消落带沿岸土壤为对照,消落带形成后土壤中各重金属总量均有不同程度升高,且不同重金属在其增量部分的形态存在差异,Cr和Ni的增量部分以残渣态为主,Cd、Pb、Zn的增量以非残渣态为主。研究发现,由于受到水域与陆地污染源的双重影响,澎溪河流域重金属具有由沿岸向消落带沉积富集的趋势。     

铜陵矿区主要河流水质分析与污染评价

铜陵矿区是长江下游重要的铜铁资源基地,也是典型的含硫多金属矿区,矿山酸性废水是矿业开发活动不可避免的环境问题,对地表水体有很大影响。本文以铜陵矿区主要河流为研究对象,通过野外调查采样和室内测试分析,从常规理化性质、矿山酸性废水和重金属元素三方面分析了的水质现状,采用单因子指数和内梅罗水质指数法进行了污染评价。结果表明:(1)矿区河流污染成分以有机污染和矿山酸性废水污染为主,其次是重金属污染。(2)在检测的46个河段中, 按综合污染指数大小分级,共计有93.48%的河段受到不同程度的污染,其中,水质严重污染的河段占 4.35%,水质重污染的河段占13.04%,水质污染的河段占 65.22%,水质轻污染的河段占10.87%;共计有6.52%的河段水质较好,均为清洁状态。(3)3条河流按污染程度大小依次为新桥河>顺安河>红星河,除顺安河外,其他均受到了矿山酸性废水污染。今后应重点关注矿山酸性废水的污染机理与风险评估,加强矿区水环境保护与恢复治理工作。     

Petroleum pollution and evolution of water quality in the Malian River Basin of the Longdong Loess Plateau,Northwestern China

The possible sources of water pollution and the evolution of water quality in the Malian River Basin of China’s Longdong Loess Plateau were studied based on chemical analysis. Concentrations of major chemicals in the river were related to the distance downstream from the source of the river and the surface water in the upstream had good quality, while the river from Southern Huanxian County to Qingcheng County was seriously polluted. Groundwater quality was generally good in the phreatic aquifer beneath the loess plateau, with bicarbonate and calcium dominant, but salinity was high and petroleum pollution was present in many parts of the study area. Both surface water and groundwater quality have declined rapidly during the past 20 years, leading to much of the water unsafe to drink and unsuitable for use in irrigation. The substances released into the water included industrial wastes, domestic sewage, organic and inorganic fertilizers, and pesticides, as well as a range of other substances that are harmful to humans. However, petroleum contamination caused by the oil industry in the Longdong oilfield is the largest source of pollution that infiltrates surface water and groundwater, leading to deterioration of water quality. It is recommended that oilfield management must be improved and the petroleum products and wastes must be disposed carefully to reduce the risk of further spills and pollution.     

Ecological risk assessment of heavy metals sampled in sediments and water of the Houjing River,Taiwan

The Houjing River flows through Kaohsiung, the most industrialized city in southern Taiwan. In this study, heavy metal concentrations in water and sediments from samples along the river were investigated to illustrate metal contamination levels and call for the awareness of industrial pollution prevention. The heavy metal concentrations in the water samples were low and appear to pose little direct risk to aquatic life and irrigation, but heavy metal concentrations in the sediments are locally very high and present an environmental risk. Cadmium, Cu, and Zn were found in higher concentrations in the river sediments than those recommended in some sediment quality guidelines and findings of river sediments in similar studies worldwide. Hence, the ecological risk of heavy metal contamination in sediments was assessed using the pollution load index (PLI) and potential ecological risk index (RI). Three of the eleven sites sampled were found to have PLI values higher than 1 and 8 of them had ‘considerable’ to ‘very high’ RI values, suggesting a considerable ecological risk. These findings provide an insight into elemental metal contamination of the Houjing River and present a baseline data set, which will be critical for future development and environmental protection plans devised for the region.     

Distribution of heavy metals and pollution pathways in a shallow marine shelf: assessment for a future management

The spatial distribution and geoaccumulation indices of four heavy metals were investigated in very shallow marine sediments of southwestern Spain. Surface sediments were collected from 43 sites with water depth ranging from 3 to 20 m. High to very high pollution levels (I _geo > 4 for zinc, lead and copper) were detected near the end of the Huelva bank, whereas chromium shows a more hazardous distribution in the southwestern Spanish littoral. Low to moderate heavy metal contents (mainly zinc and lead) were also observed in other two areas at different water depths (Isla Cristina-Piedras River: 10–18 m water depth; Mazagón–Matalascañas: <10 m water depth), whereas unpolluted to moderately polluted sediments were detected in the very shallow zones (<8 m water depth) located between the mouths of the Guadiana and the Piedras Rivers. A regional scenario indicates a strong pollution of the adjacent marine areas by polluted inputs derived from the Tinto–Odiel rivers, with a partial transport of heavy metals by W–E littoral currents even 40 km eastward. The Guadiana River is an additional source of zinc–lead contamination near the Spanish–Portuguese border, mainly at water depths up to 10 m. All these rivers are affected by acid mine drainage processes, derived from millennial mining activities. This pollution affects the sediment quality even 40 km eastward.     

土壤元素污染等级划分方法及其应用

以土壤中有毒有害元素含量为依据,以元素污染叠加程度为准则,提出了土壤污染等级标准的确定方法。长江三角洲、福建沿海地区的试验研究表明,表、深层土壤成土母质具有同源性,元素含量具有较好的相关性,深层土壤基本不受人类活动的影响,基于深层土壤元素含量确定的地球化学基准值是土壤污染等级划分的基础依据,据此建立了长江三角洲地区土壤污染等级标准,取得了该地区土壤污染等级划分结果。根据土壤污染成因及其生态环境意义,厘定了不同土壤污染等级的内涵。研究认为土壤污染等级区的生态效应需综合各种因素进行分析。     

长江中华鲟栖息地适合度模型研究

对与水生生物生存栖息相关的河流底质、水深、水温、流速、水质等生态因子进行研究。提出水生生物的栖息地适合度模型,从生物生存栖息地影响角度对河流治理工程进行科学的评价。以长江珍稀动物中华鲟为研究对象,通过对影响中华鲟的各种生态因子的统计研究,分析整理出适宜其生存繁殖的河流水温、水深、底质、流速、含沙量及食卵鱼10个因子的临界指标,得出了这些因素的适合度曲线。发展了适合评价长江中华鲟栖息地的适合度方程,并用12组实测数据对模型进行了修改验证,提出了适合评价长江中华鲟栖息地适合度模型。     

长江中下游成矿带含稀散金属矿床特征初探

稀散金属是关键金属的重要部分,其矿化特点和成矿规律等方面受到矿床学界高度关注。文章总结了全球稀散金属矿化类型和分布规律,除了镓、镉和铊矿床外,其他锗、硒、铟、碲和铼5种稀散金属普遍伴生于斑岩-矽卡岩铜矿系统。笔者初步地绘制了全球斑岩型和矽卡岩型稀散金属的分布图、长江中下游成矿带含稀散金属矿床的分布图,指出长江中下游成矿带有2种不同类型含稀散金属矿床:一类呈伴生产于斑岩-矽卡岩铜铁金和铅锌矿床,以多种稀散金属为特征;另一类呈独立稀散金属矿床;以前者为主。文章以长江中下游矿成矿带鄂东南丰山矿田为例,介绍碲和铊的赋存状态,初步地建立了矽卡岩铜金碲矿床+远接触带低温金铊碲矿床组合模型。最后提出矽卡岩型稀散金属矿床重点关注的科学问题,建议加强氧化型含金矽卡岩矿床伴生的稀散金属矿床的成矿机制研究。