Leachability of elements from sub-bituminous coal fly ash from India

Environmental concerns regarding the potential contamination of soil, surface and ground water due to the presence of soluble metal species in the ash pond leachate is of great importance. Serial batch leaching was carried out simulating the rainwater condition of the study area to understand the behaviour of elements during leaching. The leachates were analysed for the elements Al, Ca, K, Mg, Na, P, S, Si, As, Ba, Fe, Mn, Mo, Ti, V, Pb, Zn, Co, Cr, Cu, Ni and Cd by inductively coupled plasma optical emission spectrometer (ICP-OES). It was found that Cd, Co, Cr and Ni did not leach from the ash while Cu and Pb concentrations were insignificant in the leachate regardless of liquid to solid (L/S) ratio. Most of the elements showed maximum concentrations at lower L/S ratio and then decreased with increasing L/S. The total cumulative concentrations of As, Mn and Mo were found to be higher than the World Health Organization (WHO) recommended values for drinking water while the concentrations of Fe, Mn and As exceeded the maximum allowable concentrations prescribed by the United States Environmental Protection Agency (USEPA). The pre and the post leached ash samples were analysed for morphology, specific surface area and mineralogical changes. Analysis of post-leached fly ash indicated changes in the specific surface area and morphology but no change in mineralogy.     

Strategies of heavy metal uptake by plants growing under industrial emissions

Total concentrations of Al, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Pb and Zn have been estimated in soil (A-horizon) and in leaves and stem samples of two Mediterranean species (Nerium oleander L. and Pinus pinea L.) growing in an industrial area in Spain (Huelva). Both species showed a different behaviour for the elements studied. Bark and leaves of both species acted as excluders of Al, Ba, Cr, Fe and Pb, N. oleander acted as indicator of Cu and Zn and, needles and bark of P. pinea behaved as accumulators of Cu. The enrichment ratio data indicated that Cu in soil and plant was enhanced with anthropogenic activities, with industrial activities being the primary contributor for Cu. All the other elements studied were controlled by natural source variations, but Pb could also be anthropogenically enhanced. Wood did not accumulate pollutants, with the translocation from bark being rather reduced. Uptake patterns of metals into foliage and bark tissues were more or less the same in both species for almost all the studied elements, which indicates that both plant parts could be indifferently used as biomonitors.     

Distribution of Cd,Cu, Fe,Mn, Pb and Zn in selected tissues of juvenile whales stranded in the SE Gulf of California (Mexico)

With the aim of knowing the concentration and distribution of essential and nonessential metals in selected tissues of whales, analysis of Cd, Cu, Fe, Mn, Pb and Zn were carried out in kidney, liver and muscle of the gray whale Eschrichtius robustus and the sperm whale Physeter catodon. Whales were found stranded in the southeast Gulf of California. Individuals were in a juvenile stage; mean length of whales was 9.3 m for E. robustus and 7 m for P. catodon. Sequence of metal concentrations was Fe>Zn>Cu>Mn>Cd>Pb in E. robustus, and Fe>Zn>Cu>Cd>Mn>Pb in P. catodon. In E. robustus, highest concentrations of Cu, Mn, Pb and Zn (17.2, 19.6, 0.9 and 388 microg g(-1), respectively) were measured in liver, Cd (5.7 microg g(-1)) in kidney and Fe (1009 microg g(-1)) in muscle. In P. catodon, the highest levels of Cu, Fe and Pb (48.6, 5200 and 4.2 microg g(-1), respectively) were found in liver, Cd and Zn (94 and 183 microg g(-1)) in kidney and Mn (8 microg g(-1)) in muscle. Metal concentrations reported here were not considered to contribute to the stranding of specimens.     

Speciation of heavy metals in marine sediments from the East China Sea by ICP-MS with sequential extraction

Twelve elements (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Sn, Cd and Pb) in 24 sediment samples at eight sites (S1-S8) from the East China Sea were analyzed with the BCR sequential extraction (SE) protocol to obtain the metal distribution patterns in this region. The results showed that the heavy metal pollutions in S4 and S8 were more severe than in other sampling sites, especially Cd and Pb pollution. In the top sediments at S4 and S8, both the total contents and the most dangerous non-residual fractions of Cd and Pb were extremely high. More than 90% of the total concentrations of V, Cr, Mo and Sn existed in the residual fraction. Fe, Co, Ni, Cu and Zn mainly (more than 60%) occurred in the residual fraction. While Mn, Pb and Cd dominantly presented in the non-residual fractions in the top sediments. The metal distribution patterns with depth and the correlations between total organic carbon (TOC) and the total Fe-Mn content were also investigated. The results showed that, for most of the elements except Fe, the concentration of elements in fraction A in the top sediments was higher than that in other depth. The similar rule was also found in fraction B but not in fraction C. Besides, the distributions of V, Cd in fraction B and Pb, Cd, Cu in fraction C might be affected by TOC.     

Heavy metal contents of epiphytic acrocarpous mosses within inhabited sites in Southwest Nigeria

The levels of the metals Pb, Zn, Cu, Cd, Ni, Mn, and Fe accumulated in acrocarpous mosses within inhabited parts of villages and towns in the southwest region of Nigeria were determined, and then used for a classification of the area into relative pollution zones. Ibadan City was found to be the most polluted in the study area. Other zones of “low” and “medium” polluted villages and towns were identified. The zonations based on metal levels in these mosses were to some extent similar to that already obtained in a separate study of the same area with epiphytic forest mosses. The enrichment factors show that the gradients between zones of different pollution levels were higher in mosses within the inhabited sites.     

Environmental geochemistry and pollution studies of Aliaga metal industry district

The Aliaga metal industry district located 50 km northwest of Izmir City, in Turkey, includes many metal factories. The geology of the area is represented by Mesozoic flysch deposits and Cenozoic volcano sedimentary rocks. Tectonic elements are NE-SW and NW-SE trending faults and a W-NW trending fault direction that is important for water supply. Rock, soil, stream sediment, and water samples taken at various distances from the industrial area were analyzed for Fe, Ti, Mn, Cr, Pb, Cu, Ni, Zn, and Mo. According to the results, the elements in rocks are reasonable for the range of "Clarke" values, but in the soils and stream sediment, they comprise higher values than are acceptable for agricultural activities. Toxicity analyses were carried out in the drinking artesian water of Cakmakli village and wastewater samples of the factories and river water both of which are used for irrigation of the agricultural areas in and around the investigated area. The people should, however be made aware that this waste and river water is unacceptable for agriculture. Additionally, the contamination of seawater in Nemrut Bay is probably caused by contaminated river and underground water running to the sea. The chemical and toxicity analysis of drinking water samples show that they are above accepted standards and harmful. Previous air pollution studies (funnel gas emission analyses) also show that gas emission contains high amount of dust particles with high Fe, Zn, Pb, and Cu concentrations. As a result, all elements analyzed are of great importance relative to problems concerning contamination of the soil, stream sediment, ground surface water, and air by individual metals from uncontrolled processing of some metal factories.     

Heavy metals in water, sediments, plants and fish of Kali Nadi U.P. (India)

The distribution of heavy metals viz., Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in the water, sediments, plants and fish samples collected from the Kali Nadi (India) have been determined. The studies have shown that there was considerable variation in the concentration of heavy metals from one sampling station to the other which may be due to the variation in the quality of industrial and sewage wastes being added to the river at different places. The orders of the concentration of heavy metals in water, sediments, plants (Eicchornia crassipes) and fish (Heteropnuestes fossilis) were Fe > Zn > Cu > Mn > Cr > Ni > Pb > Co > Cd; Fe > Zn > Mn > Ni > Cr > Co > Cu > Pb > Cd; Fe > Mn > Zn > Cu > Ni > Co > Pb > Cr > Cd and Fe > Zn > Mn > Ni > Pb > Co > Cr > Cu > Cd, respectively.     

Impact of different pollutant sources on Shiraz air pollution using SPM elemental analysis

Weekly average suspended particulate matter (SPM) concentrations were measured in four locations in Shiraz, Iran. Sampling was carried out from July 1999 and continued until July 2000. Instrumental neutron activation analysis (INAA) and atomic absorption spectrometry (AAS) methods were employed to obtain the weekly concentrations of Pb, Br, V, Ca, Al, Fe, Cu, Cr, Mn, Sc and Zn. The mean annual concentrations (in microg/m(3)) of 11 elements were found to be: Pb 0.545 (+/- 33.8%), Br 0.413 (+/- 34.1%), V 0.009 (+/- 28.2%), Ca 13.36 (+/- 24.5%), Al 2.56 (+/- 46.3%), Fe 2.62 (+/- 38.7%), Cu 0.122 (+/- 41.4%), Cr 0.015 (+/- 35.8%), Mn 0.053 (+/- 35.5%), Sc 0.0008 (+/- 37.5%) and Zn 0.085 (+/- 25.2%). The results of the study show that vehicle (traffic) pollution in Shiraz is higher than WHO and EPA standards and natural and industrial pollution is exceeding international guidelines in some seasons. The findings of the study confirm that the nearby cement factory has a major pollution impact on Shiraz air.     

Speciations of trace metals in the Danube alluvial sediments within an oil refinery

A sequential extraction procedure was applied to identify forms of Ni, Zn, Pb and Cu with Fe- and Mn-oxides associated in alluvial sediments of the River Danube within Pancevo Oil Refinery (Serbia). The five steps of the sequential extraction procedure partitioned metals into: CH(3)COONH(4) extractable (S1); NH(2)OH.HCl carbonate extractable and easily reducible (S2); (NH(4))(2)C(2)O(2)/H(2)C(2)O(2) moderately reducible (S3); H(2)O(2)-HNO(3) organic extractable (S4); and HCl acid soluble residue (S5). Extracted concentrations of trace metals, analyzed after all five steps, were found to be (mg kg(-1)) for Mn: 656, Fe: 26734, Ni: 32.3, Zn: 72.8, Pb: 13.4 and Cu: 27.0. Most of the elements were found in acid soluble residue, characterizing stable compounds in sediments. Non-residual fractions of trace metals (sum of the first four fractions) were analyzed because they are more bioavailable than the residual amount. Correlation analysis and two multivariate analysis methods (principal component and cluster analysis) were used to understand and visualize the associations between the non-residual fractions of trace metals and certain forms, more or less crystalline of Fe- and Mn-oxides within the analyzed sediments, since Fe- and Mn-oxides play an important role in trace metal sorption within aquatic systems, especially within the Danube alluvium where the fluctuations of groundwater are very frequent and the level of groundwater could come close to surface.     

Heavy metals in organisms and sediments from Turkish Coast of the Black Sea, 1997-1998

During the period 1997-1998, macroalgae, sea snail, mussel, fish and sediment samples were collected at different stations of the Turkish Black Sea coast in order to establish the concentration of selected heavy metals. Heavy metals analyzed were Cd, Co, Cr, Ni, Zn, Fe, Mn, Pb and Cu. The results showed that the Turkish Black Sea coast is facing heavy metal pollution. The metal concentrations in macroalgae, sea snail, mussel and sediment samples are very high. However, Cd, Pb and Cu concentrations in anchovy fish decreased, while Co, Fe, Zn, Cr, Mn and Ni contents had changed when compared previous data. The metal levels in macroalgae did not follow the same pattern as concentrations in sediments at the same station. On the other hand, concentrations of Cd, Co, Cr, Zn, Fe, Mn and Cu in sea snail, mussel and fish samples were related to sediment data in the examined stations.     

Heavy metal contamination of brown seaweed and sediments from the UK coastline between the Wear river and the Tees river

The concentration of Fe, Mn, Zn, Cu, Pb, Ni, Cr, Cd, and Ag were determined in the brown alga Fucus vesiculosus and intertidal surface sediments from coastal locations of northeast England. Levels of heavy metals similar to those of polluted areas of the British coastline were detected. There is evidence of contamination (especially with Zn and Pb) in sediments from sites affected by colliery spoil and from the Wear estuary. The pelitic fraction ( < 63 microm) is usually more enriched in heavy metals, but it represents a very small percentage of the bulk samples. The fine-grained sand is a very important repository of contaminants especially where particles of colliery spoil, secondary mineral, and amorphous phases are present. Aqua regia-extracted Zn, Cu, and Pb in sediments are significantly correlated with those in seaweed. Despite the closure of all base metal and coal mines, and the cessation of many industrial activities in the region, sediments and brown algae are contaminated with heavy metals. The control site (Holy Island) and the Tees estuary appear to be the least affected.     

上海城郊土壤重金属含量的空间变异与分布特征

为揭示城市化、工业化等人为活动对土壤环境质量的影响,选择上海城郊结合部为研究区域,采用地统计学方法对表层土壤样品Cu、Zn、Pb、Cr、Mn 5种重金属的空间变异结构和分布特征进行了分析。结果表明：土壤Cu、Cr、Mn、Pb、Zn均属中等变异,土壤Mn含量服从正态分布,土壤Cr、Cu、Pb、Zn含量服从对数正态分布;半方差函数模型拟合结果显示土壤Mn符合指数模型,土壤Cr、Cu、Pb、Zn符合线性模型、其中土壤Cu、Pb、Zn为纯块金效应模型,反映了城郊结合部土壤污染空间变异的复杂性。通过泛克里格插值可直观反应表层土壤重金属含量空间分布特征,发现土壤Cr、Mn呈岛状,土壤Cu、Pb、Zn呈多岛状分布的特点,工业和交通污染源是影响土壤重金属空间分布的重要因素     

Speciation of elements in sediment samples collected at lakes Volvi and Koronia, N. Greece

A five-step sequential extraction procedure was applied for the determination of the distribution of seven elements (Cd, Pb, Cr, Cu, Mn, Zn, Fe) in sediment samples collected at two lakes, Volvi and Koronia, located in N. Greece. Samples were taken in two seasons, and the average concentration of the elements was calculated. The accuracy evaluated by comparing total trace metal concentrations with the sum of the five individual fractions proved to be satisfactory. Based on the results determined at one sampling point in Koronia and two sampling points along the lake Volvi, it seems that the two lakes have not yet been polluted. There were no significant changes in the individual seasonal concentrations of elements in this monitoring period. Cd, Pb, Cu and Cr are associated with the oxidizable, carbonates and residual fractions. Zn and Fe are associated with residual and reducible fractions. The metals that we most easily extracted in the samples analysed in both lakes are Pb, Cr, Cd, Cu and also Mn in the case of Koronia lake.     

Intra-urban biomonitoring: Source apportionment using tree barks to identify air pollution sources

It is of great interest to evaluate if there is a relationship between possible sources and trace elements using biomonitoring techniques. In this study, tree bark samples of 171 trees were collected using a biomonitoring technique in the inner city of São Paulo. The trace elements (Al, Ba, Ca, Cl, Cu, Fe, K, Mg, Mn, Na, P, Rb, S, Sr and Zn) were determined by the energy dispersive X-ray fluorescence (EDXRF) spectrometry. The Principal Component Analysis (PCA) was applied to identify the plausible sources associated with tree bark measurements. The greatest source was vehicle-induced non-tailpipe emissions derived mainly from brakes and tires wear-out and road dust resuspension (characterized with Al, Ba, Cu, Fe, Mn and Zn), which was explained by 27.1% of the variance, followed by cement (14.8%), sea salt (11.6%) and biomass burning (10%), and fossil fuel combustion (9.8%). We also verified that the elements related to vehicular emission showed different concentrations at different sites of the same street, which might be helpful for a new street classification according to the emission source. The spatial distribution maps of element concentrations were obtained to evaluate the different levels of pollution in streets and avenues. Results indicated that biomonitoring techniques using tree bark can be applied to evaluate dispersion of air pollution and provide reliable data for the further epidemiological studies.     

Transfer of metals from soil to vegetables in an area near a smelter in Nanning, China

A field survey was conducted to investigate the metal contamination in soils and vegetables, and to evaluate the possible health risks to local population through foodchain transfer near a smelter in Nanning, southern China. Contamination levels in soils and vegetables with cadmium (Cd), lead (Pb), zinc (Zn) and copper (Cu) were measured, and transfer factors (TF) from soils to vegetable plants and its health risk (risk index, RI) were calculated accordingly. Results showed that both soils and vegetables from villages 1 and 2 (V1 and V2, 1500 m and 500 m from the smelter) were heavily contaminated, compared to a village 50 km from the smelter. Geometric mean of Cd and Pb concentrations in vegetables for V1 and V2, respectively, were 0.15 and 0.24 mg Cd kg(-1) and 0.45 and 0.38 mg Pb kg(-1) (on fresh weight basis). Oral intake of Cd and Pb through vegetables poses high health risk to local residents. Risk indices for V1 and V2, respectively, were 3.87 and 7.42 for Cd, and 1.44 and 13.5 for Pb. The complexity of metal contamination and their health risks are also discussed.     

Ecological-biogeochemical role of macrophytes in aquatic ecosystems of urbanized territories (an example of small water bodies of St. Petersburg)

The accumulation of heavy metals (Fe, Mn, Zn, Cu, Cr, Ni, Pb, Cd) and biogenic elements (P, S, K, Ca, Na) in leaves has been studied in macrophytes of different ecological groups growing in small water bodies of St. Petersburg. The ecogeological and biogeochemical role of macrophytes in the water-aquatic plants-bottom sediments system and their contribution to the stability of aquatic ecosystem functioning under conditions of a megalopolis are considered. Prospects for using macrophytes for bioindication and phytoremediation of polluted aquatic ecosystems are discussed.     

Sediment quality in Rio Guadiamar (SW, Spain) after a tailing dam collapse: contamination, toxicity and bioavailability

An integrated assessment of sediment quality in the Guadiamar River after a mining spill was conducted. The concentration of different metals and other conventional parameters were measured in sediments located along the river. Four sediment toxicity tests (Hyalella azteca 28-day survival and growth test; Chironomus riparius 10-day survival and growth test; Hexagenia spp. 21-day survival and growth test; and Tubifex tubifex 28-day reproduction and survival test) were carried out to determine the effects associated with the accidental spill. The geochemical fractions of 6 metals (Fe, Mn, Zn, Cu, Pb, and Cd) were determined to establish the bioavailability of the metals. The relationship found in the concentrations of metals associated with the mobile fractions of the sediments in the sites studied is similar to the toxic mud from tailing pond and confirms that the toxic effects are associated with the metals Zn and Cd originating from the spill.     

Trace element and radionuclide mass balances at a coal-fired electric generating station

Coal, bottom ash, and fly ash from Milliken Station, a coal-fired 270 MW power plant, were analyzed for 20 elements (Ag, Al, As, Be, Cd, Co, Cr, Cu, Ga, Hg, Mn, Ni, Pb, Sb, Se, Sn, Te, Tl, V, and Zn) and the major natural radionuclides (²³⁸U series, ²³²Th series, and ⁴⁰K). Mass balance calculations showed that most of the Hg, and some of the Sb and Se, were unaccounted for by ash collection, suggesting their possible discharge into the atmosphere. Silver, As, Hg, Pb, Cd, and Zn were more concentrated in the fly ash than in the bottom ash while all of the other elements were equally distributed, by concentration, between the ash fractions. The radionuclides showed a 46% higher concentration in fly ash than in bottom ash, and ²¹⁰Pb was enriched in the fly ash relative to the other radionuclides by a factor of 2.4. Mass balance calculations indicated a balance within statistical error for the radionuclides, except for ²¹⁰Pb.     

Biologically available trace metals in Mytilus edulis from the coast of Northeast England

The concentrations of Fe, Mn, Zn, Cr, Cu, Pb, Ni, Cd, and Ag were determined in soft tissue and shell material of mussel Mytilus edulis collected in the winter season from five coastal sites in the northeast of England. The trace metal levels observed were significantly high, particularly at locations affected by past coal mining activities (Blackhall) and present industrial sources (Middleton). The mussels from the chosen control site (Holy Island), a shellfish-designated area, were particularly enriched in Cu and Ag. The metal pollution index for the Bran Sands site, a heavily industrialised area on the Tees Estuary, was relatively low. At four sites out of five, the levels of Fe and Cu were negatively correlated with mussel size. No significant correlation with size was found for the other metals. With few exceptions, the elements Fe, Zn, and Mn accumulated preferentially in the soft tissue, whereas Pb, Cd, Cr, Ag, and Ni were more abundant in the hard part of the mussels. The Ag values in shell material were remarkably similar (about 6 mg kg⁻¹ – 7 mg kg⁻¹, dry wt) at all sites studied. In general, the data show that the mussels from the coastline studied accumulate metal concentrations comparable to or higher than the most contaminated sites reported in the literature.     

Effects of readily dispersible colloid on adsorption and transport of Zn, Cu, and Pb in soils

Soil colloids (<0.002 mm) were extracted from three types of soils to make the colloid-bound forms of Zn, Cu, and Pb solution. The clay mineral types and composition of the colloids, the adsorption characteristics of the colloids, and the effect of readily dispersible colloid on the transport of metals and the quality of the soils and groundwater were studied. The results showed that the adsorption capacity of Cu, Zn, and Pb was greater for the Aquic Vertisols (Shajiang Black soil) as compared to the Udic Luvisols (Brown soil) and Usdic Luvisols (Cinnamon soil), due to the difference of clay content and clay mineral composition in the different soils. The adsorption capacity of Pb was much higher than that of Zn and Cu for the same soils, which would contribute to the chemical properties of metals and specific adsorption characters of the colloids. The mobility of Zn in soils was greater than that of Cu and Pb, while similar trend was found in the transportation processes for Zn and Cu. The concentration of Zn and Cu in leachates increased as the leaching solution volume increased, but the migration of Pb was negligible, and the concentration of Pb could not been detected in leachates even after 7.5 pore volume leaching solution. The influence of mobility on Zn and Cu transport was different for different type of colloids. The mobility caused by readily dispersible colloids from Aquic Vertisols was greater as compared to that of Udic Luvisols and Usdic Luvisols. Analysis of soils after column leaching indicated that Zn was distributed much deeper than Cu, but Pb was almost not migrated, and mainly accumulated in the soil surface. Therefore, Zn had greater tendency for the groundwater pollution than Cu and Pb, and Pb tends to contaminate the surface soils.