Metals in Sediments from the Stockholm Region: Geographical Pollution Patterns and Time Trends

The city of Stockholm is intersected and surrounded by water.Freshwater flows eastward and mixes with slightly brackish water in central Stockholm to finally reach the Baltic Sea. Inorder to estimate the magnitude and geographical impact of Stockholm as a source of metals to the aquatic environments, sediments from 117 stations in the Stockholm region have beenanalysed for metals (As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn).This paper reports on the geographical pollution pattern and onthe time trends in metal pollution in Stockholm during the 20th century. Stockholm is a strong source of Cd, Cu, Hg,Pb and Zn whereas the Cr concentrations are moderately perturbed.In contrast, the concentrations of As, Co, and Ni are in generalclose to preindustrial levels. The concentrations of Cd, Cu, Hg,Pb and Zn are highest in central Stockholm and eastwards (i.e., in the water flow direction). Sediments upstream of Stockholm andin lakes that are not hydrologically connected to central Stockholm show a significantly lower impact. This may be indicative of metals emitted in Stockholm mainly being transported by the water route. Of Cd, Hg, Pb, and Zn, Cd showsthe most pronounced decline in accumulation rates over the lasttwo decades.     

Century Perspective of Heavy Metal Use in Urban Areas. A Case Study in Stockholm

The inflow and stock (amount in use) of heavy metals (cadmium(Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni) and zinc (Zn)) in goods in 1995 have been quantifiedin the anthroposphere of Stockholm, Sweden. Statistics on national, regional and local level were used. Contacts were established with representatives from production and constructionin the industrial sector and with authorities. The results show that the stock of Cd is 0,2 kg per capita. For the other heavymetals the corresponding result per capita is: Cr 8, Cu 170, Hg 0,01, Ni 4, Pb 73 and Zn 40 kg. The inflow varies between2–8%of the stock indicating the importance of the stock. The lowestlevels are for Cu and Pb. Heavy metal levels in solid waste are high, between 15–45% of the amount in the inflow (Hg excluded), the lowest values were for Cu and Pb. Thus, recyclingis incomplete. Long life expectancy goods form the majority of the stock but there is a tendency that short life expectancy goods increase their importance in the inflow. Concealedgoods are also more frequent in inflow than in the stock.     

Goods in the Anthroposphere as a Metal Emission Source A Case Study of Stockholm,Sweden

The aim of this study was to quantify the diffuse emissionsduring use of metal containing goods in the capital of Sweden,Stockholm. The following metals were studied: Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb), Mercury (Hg), Nickel (Ni) and Zinc (Zn).A major part of the metals are found in a protected environmentwhere degrading processes like corrosion are most limited. However, during the lifetime of some goods the metal release to the environment is significant. The quantitatively most dominant emissions were found for Cu and Zn. The tap water system and roofs/fronts (Cu) represent goods with large exposedareas but with relatively small release rates per unit. In contrast, brake linings, aerial lines and electrical grounding (Cu) and tyres, brake linings and chemicals (Zn) are allgoods with high release rates but mostly limited exposed stocks.High yearly emissions are also found for Pb, ammunition andsinkers dominate the calculated emissions totally. For Cr and Ni, stainless steel represent the major part of the stocks, butcorrosion was estimated to give only a minor contribution to the emissions. Potential emission sources, i.e. stabilisers,pigments and plated goods dominate the exposed Cd stock. Theseemissions were not quantified due to lack of data. Hg is currently phased out, but one major source of emission, i.e. the use of amalgam, will be continuously significant for several decades. The importance of the traffic sector is obvious. The emissionsfrom brake linings (Cu, Zn and Pb), tyres (Zn, Pb, Cr and Ni)and asphalt wear (Cu, Zn, Cr, Ni and Pb) are all of large importance for the total emission from respectively metal.     

Relationship Between the Sediment Geochemistry and Phosphorus Fluxes in a Great Lakes Coastal Marsh,Cootes Paradise,ON, Canada

Cootes Paradise is a coastal wetland, adjacent to Hamilton Harbour at the western tip of Lake Ontario. The marsh has been considerably degraded due to the excessive sediment and nutrient input from sewage treatment plants (STPs), marsh tributaries and Combined Sewer Overflows (CSOs). Although there has been reduction in nutrient loadings from external sources, high nutrient levels, and a prolific algal growth remain a problem in Cootes Paradise. To assess the importance of external versus internal nutrient loadings to the marsh, nutrient fluxes from sediments were estimated using porewater profiles at three locations from 2001 and five additional sites from 2002. The fluxes varied between 0.27 and 5.25 mg P m⁻² day⁻¹, with sites receiving outfalls of STP and CSO having highest fluxes (∼5 mg P m⁻² day⁻¹). Mean phosphorus release rate of 2.02 mg P m⁻² day⁻¹ was calculated from the spatial distribution of the non-apatite inorganic phosphorus (NAI-P) in sediments, employing a relationship between the NAI-P and P fluxes. The results confirm that sediment P geochemistry is important in regulating the P pool in porewater which, consequently, governs the P fluxes from sediments.     

Concentrations and Pools of Heavy Metals in Urban Soils in Stockholm,Sweden

The concentrations of heavy metals (Cd, Cr, Cu, Hg, Ni, Pb andZn) and arsenic (As) were surveyed and the metal pools estimatedin soils in Stockholm Municipality. The sampling sites were distributed all over the entire municipality with a higher sampling density in the city centre. Soils were sampled to a maximum depth of 25 to 60 cm. Soil texture, total-C content, electrical conductivity and pH were analysed. Heavy metal concentrations were determined after wet digestion with boiling7 M HNO₃.The results showed a wide range in heavy metal concentrations, as well as in other soil properties. The city centre soils constituted a rather homogeneous group whereas outside this areano geographical zones could be distinguished. These soils were grouped based on present land use, i.e. undisturbed soils, public parks, wasteland (mainly former industrial areas), and roadside soils. The city centre and wasteland soils generally hadenhanced heavy metal concentrations to at least 30 cm depth compared to park soils outside the city centre and rural (arable)soils in the region, which were used to estimate background levels. For example, the mean Hg concentration was 0.9 (max 3.3)mg kg^-1 soil at 0–5 cm and 1.0 (max 2.9) at 30 cm depth in the city centre soils, while the background level was 0,04 mg kg^-1. Corresponding values for Pb were 104 (max 444) and135 (max 339) mg kg^-1, at 0–5 and 30 cm, respectively, while the background level was 17 mg kg^-1.The average soil pools (0–30 cm depth) of Cu, Pb and Zn were 21,38 and 58 g m^-2 respectively, which for Pb was 3–4 timeshigher and for Cu and Zn 1.5–2 times higher than the backgroundlevel. The total amount of accumulated metals (down to 30 cm)in the city centre soils (4.5^*10 ⁶ m² public gardens and green areas) was estimated at 80, 1.1, 120 and 40 t for Cu, Hg, Pb and Zn, respectively. The study showed (1) thatfrom a metal contamination point of view, more homogeneous soilgroups were obtained based on present land use than on geographicdistance to the city centre, (2) the importance of establishing a background level in order to quantify the degree of contamination, and (3) soil samples has to be taken below the surface layer (and deeper than 30 cm) in order to quantify theaccumulated metal pools in urban soils.     

Urban Land-Use Influences on Transport of Heavy Metals to Lakes and Concentrations in Fish

Water, Air, &; Soil Pollution: Focus - To investigate the urban land-useinfluences on transport of heavy metals to lakesand metal concentrations in fish liver (perch andcrucian carp), ten lakes...     

无机稳定剂处理重金属污染土壤

以重金属污染土壤为研究对象,比较了铁屑、蒙脱石、碳酸钙和羟基磷灰石4种稳定剂对土壤中Pb,Zn,Cd,Cu 4种重金属的稳定效果。实验结果表明,4种稳定剂稳定效率的大小顺序为：羟基磷灰石﹥碳酸钙﹥蒙脱石﹥铁屑。当稳定剂质量分数为10%时,羟基磷灰石、碳酸钙、蒙脱石和铁屑对Pb,Zn,Cd,Cu 4种重金属的平均稳定效率分别为99.63%,98.53%,97.15%,86.95 %。未加稳定剂时,土壤中的Pb以残渣态为主,Zn以残渣态和可交换态为主,Cd以残渣态为主,Cu以残渣态和可交换态为主;加入稳定剂后,土壤中4种金属可交换态的所占比例（简称占比）均显著降低,还原态的占比明显增大,残渣态的占比略有增大,氧化态的占比基本保持不变。     

Solubility and Potential Mobility of Heavy Metals in Two Contaminated Urban Soils from Stockholm,Sweden

The solubility and potential mobility of heavy metals (Cd, Cu,Hg, Pb and Zn) in two urban soils were studied by sequential andleaching extractions (rainwater). Compared to rural (arable) soils on similar parent material, the urban soils were highlycontaminated with Hg and Pb and to a lesser extent also with Cd,Cu and Zn. Metal concentrations in rainwater leachates were related to sequential extractions and metal levels reported fromStockholm groundwater. Cadmium and Zn in the soils were mainly recovered in easily extractable fractions, whereas Cu and Pb were complex bound. Concentrations of Pb in the residual fractionwere between two- and eightfold those in arable soils, indicatingthat the sequential extraction scheme did not reflect the solidphases affected by anthropogenic inputs. Cadmium and Zn conc. inthe rainwater leachates were within the range detected in Stockholm groundwater, while Cu and Pb conc. were higher, whichsuggests that Cu and Pb released from the surface soil were immobilised in deeper soil layers. In a soil highly contaminatedwith Hg, the Hg conc. in the leachate was above the median concentration, but still 50 times lower than the max concentration found in groundwater, indicating the possibilityof other sources. In conclusion, it proved difficult to quantitatively predict the mobility of metals in soils by sequential extractions.     

Release of Metals from Buildings,Constructions and Products during Atmospheric Exposure in Stockholm

This article presents results from investigations of run-off frommaterials used on buildings and other constructions obtained byshort term exposures of smaller model surfaces and one year exposures of larger materials surfaces on buildings and other constructions. Elevated concentrations of metals in run-off wereobserved for a wide range of different materials used on buildings and other constructions. Sources of metal emission tothe environment includes copper (Cu) surfaces, galvanized steel,impregnated wood, lead (Pb) surfaces, asphalt surfaces, paintedmaterial stainless steel and concrete. Metal emission rates fromsurfaces of copper and galvanized steel were measured from surfaces on buildings during 12 months exposure. The magnitude of metal emission form other surfaces was also estimated and theapplicability of these data for calculations of metal flows inan urban environment is discussed.     

Stockhome: A Spreadsheet Model of Urban Heavy Metal Metabolism

Computer models for analysis,visualising and decision support in environmentalresearch have become increasingly popular. TheStockhome project, where the urban metabolism ofheavy metals in Stockholm was studied, resultedin a database with historical data of the use ofgoods containing cadmium (Cd), chromium (Cr),copper (Cu), lead (Pb), mercury (Hg), nickel (Ni)and zinc (Zn). A spreadsheet model was developedto study flows and stocks of the metalconsumption process and emissions. The modelindicates uncertainties of the data, societalaspects such as field of use and rights ofdisposition of the goods. By considering goods asthe drivers of the emissions, the model would bewell suited for policy support.     

Metallic Composition and Sources of Airborne Atmospheric Particulates in the Industrial Belt of the City of Madrid

The characteristics of the airborne particulates in the industrial belt of the city of Madrid were studied and their metal content in Pb, Ca, Cu, Ni, Fe, Mn, Cr, Mg, Zn and K were determined, with the purpose of assessing any differences when compared to typical urban particulates. The object was to examine the sources of the trace metals analysed and to evaluate their spatial and temporal variations. Six sample collection points were chosen in the industrial belt of the city of Madrid and more than 320 samples were collected over a period of one year. Various forms of source identification were used in order to study the origins of each of the analysed metals. The data obtained indicates that the area studied has a different kind of pollution from that which typically occurs in urban or industrial areas. We were also able to explain a high percentage of the inorganic pollution investigated using a small number of sources: resuspended ground dust, vehicle exhaust, building, industrial combustion and metal processes, and fuel-oil combustion.     

污泥中重金属离子的电动力学去除技术

概述了国内外电动力学去除技术的研究现状以及污泥中重金属离子的存在形态、水解引起的pH变化、电极极化、外加酸和螯合剂、电流和电压等对该技术的影响。阐明了利用电动力学去除技术去除剩余污泥中重金属离子的可行性。指出了今后电动力学去除技术重点研究的方向。     

Sediment–Water Interactions in an Eroded and Heavy Metal Contaminated Peatland Catchment,Southern Pennines,UK

Atmospherically deposited lead in the upper layer of the heavily eroded peatlands of the Peak District, southern Pennines, UK, reaches concentrations in excess of 1,000 mg kg⁻¹. Erosion of the upper peat layer in this region is releasing lead, associated with eroded peat particles, into the fluvial system. Understanding the process mechanisms that control dissolved lead concentrations in contaminated peatland streams is vital for understanding lead cycling and transport in peatland streams. Many headwater streams of the southern Pennines recharge drinking water reservoirs. Measurements in the Upper North Grain (UNG) study catchment show that mean sediment-associated and dissolved lead concentrations are 102 ± 39.4 mg kg⁻¹ and 5.73 ± 2.16 μg l⁻¹, respectively. Experimental evidence demonstrates that lead can desorb from suspended sediments, composed of contaminated peat, into stream waters. In-stream processing could therefore account for the elevated dissolved lead concentrations in the fluvial system of UNG.     

水合肼改性淀粉去除废水中的重金属离子

以木薯淀粉为原料、硝酸铈铵为引发剂,合成丙烯酸甲酯接枝淀粉;用水合肼对其进行改性,合成了具有氨基功能团的改性淀粉。将改性淀粉用于对多种单一重金属离子和混合重金属离子的去除。在混合重金属离子溶液中,在室温、改性淀粉加入量为7.0g/L、重金属离子质量浓度为30mg/L、反应时间为120min的条件下,混合液pH为3～7时,改性淀粉对Cu2+、Pb2+、Cd2+和Ni2+的去除率均达99.9%以上;混合液pH为4时,改性淀粉对Cr6+的去除率达73.2%。     

Selective Separation of Heavy Metals from Industrial Wastewater Streams by Means of Heavy Metal Bonding Agents

Industrial wastewater is often contaminated with heavy metals and must undergo expensive and elaborate treatment. A new, environmentally friendly process, which allows both metals and water to be reused, has been developed. It comprises the following three process stages: firstly, a metal bonding agent (BA) is added to the wastewater to bind the heavy metal; secondly, the loaded BA is separated by ultrafiltration/microfiltration or a new hybrid process involving flotation and membrane filtration; and thirdly, the BA is regenerated. The first results from the characterisation of selected BAs (synthetic hydrotalcites and synthetic zeolites) in terms of their bonding kinetics, maximum loading capacity and regeneration potential are presented.     

纳米铁氧化物吸附处理重金属废水的研究进展

概述了用于吸附重金属的主要纳米铁氧化物的种类及其吸附效果,介绍了常见的纳米铁氧化物制备方法及改性方法,讨论了影响纳米铁氧化物吸附重金属的主要因素,并对纳米铁氧化物在水环境保护领域中的研究方向提出了展望:如发展绿色、高效的纳米铁氧化物制备工艺,探讨纳米铁氧化物结构调控和表面功能化对其吸附性能的影响等。     

微生物降解重油的初步研究

丛石油污染的土壤中筛选出一株假单胞菌,考察了其对重油的降解效果。降解18d,重油的降解率达到42．8％,饱和烃、芳香烃、胶质、沥青质的降解率分别为42．95％,43．85％,44．5％,5．55％;质量浓度2．5g／L的表面活性剂Tween-80可使重油的18d降解率达到51．0％;弱碱性条件有利于重油的生物降解;生物泥浆法处理重油污染的土壤,1kg土壤中重油质量100g,降解45d,重油的降解率达到38．85％。     

Metal Contamination of the Natural Environment in Norway from Long Range Atmospheric Transport

Long range atmospheric transport is the most important sourceof contamination to the natural environment in Norway with manyheavy metals. Investigations based on aerosol studies, bulkdeposition measurements and moss analysis show that airborne transport from other parts of Europe is the major mode for supplyof vanadium, zinc, arsenic, selenium, molybdenum, cadmium, tin,antimony, tellurium, thallium, lead, and bismuth, whereas metalssuch as chromium, nickel, and copper are mainly derived from point sources within Norway and in northwestern Russia close tothe Norwegian border. Elements associated with long range transport show substantial enrichment in the humus horizon of natural soils in southern Norway, sometimes to levels suspected to cause effects on soil microbial processes. E.g. lead concentration values of 150–200 ppm are observed in the mostcontaminated areas in the south as compared to about 5 ppm inthe far north. Elements such as lead and cadmium also show enrichment in some terrestrial food chains. These elements alsoshow considerably elevated levels over background concentrationsin the water and sediment of small lakes in the southern part ofthe country. Retrospective studies based on ombrogenous peatcores indicate that long range transport has been a significantsource of heavy metal contamination in southern Norway for thelast couple of centuries. The deposition of most heavy metals inNorway has been considerably reduced over the last 20 yr, withthe exception of contributions in the north from Russian smelters.     

Effects of Decreased Atmospheric Heavy Metal Deposition in South Sweden on Terrestrial Birds and Small Mammals in Natural Populations

In southern Sweden, where exposure to long range distributedheavy metals is about the highest in Scandinavia, depositionsof cadmium (Cd) and lead (Pb) decreased about 20 and 70%,respectively, between mid-1980s and mid-1990s, as estimated bytheir concentrations in moss. Concentrations of Cd and Pb in tissues of the pied flycatcher (Ficedula hypoleuca) and bank vole (Clethrionomys glareolus) were also lower in 1996and 1997 compared to 1981 and 1982. It is concluded that the decreased deposition rate of these elements in southern Sweden had caused decreased exposure, and thus also to decreased potential risk of detrimental effects on insectivorous birds andherbivorous mammals. There was no indication that breeding results of pied flycatcher was influenced by the decreased deposition of toxic metals.     

重金属螯合剂的制备及镀铬废水中Cr3+的去除

以二乙烯三胺(DETA)、CS2、环氧氯丙烷和NaOH为原料合成了重金属螯合剂(HMCA),采用红外光谱对其结构进行了表征,通过SEM及电子能谱观察分析了螯合产物的形貌和组成.红外光谱谱图表明,HMCA分子中已成功接入-CSS-基团.采用HMCA处理镀铬废水,HMCA与Cr3+可形成稳定的螯合产物.电子能谱分析表明,HMCA螯合产物中S与Cr的摩尔比为4.097∶1,与理论值较接近,基本上按n(-CSS-)∶n(Cr3+)=2∶1形成螯合物.HMCA处理镀铬废水的最佳pH为8.5,最佳HMCA加入量为8.52 g/L,此时Cr3+去除率为99.94％,残余Cr3+质量浓度为0.16 mg/L.