Preliminary Analysis Of Heavy Metals In The Kahrizak Landfill Leachate: A Conceptual Approach

No data have been published on the leachate quality for the Kahrizak landfill site, including heavy metal concentrations. Therefore concentrations of Cu, Zn, Pb, Cd, Ni, Co, Fe and Mn were measured in four fresh and older leachate samples during a 10 months period. Conceptually, heavy metals can be considered to be present in three phases: ( a ) Dissolved; ( b ) adsorbed onto suspended solids; and ( c ) adsorbed onto the suspended solids with particle sizes less than 0.45 w m. A method is proposed in this paper to measure the concentrations of heavy metals in each of the three phases. Other samples were analyzed for phases ( a ) and ( b ). Fresh leachate samples with lower pH values had higher dissolved concentrations of heavy metals than the older leachate samples with higher pH values. Particulate heavy metal concentrations were slightly lower at higher pH values.     

Methods of removing external metal contamination from hair samples for environmental monitoring

Human exposure to trace elements has become a major environmental issue with the growing industrialization and urbanization around the world. Hair samples are the most conveniently obtainable biopsy material and they have been identified as good indicators of the metal pollution in an environment. For their effective use, however, it is necessary to exclude the effect of external contamination of the hair surface by metals. The present investigation compares the different methods of washing hair samples prior to further treatment for elemental analysis. Deionized water, solvents (acetone, ether and carbon tetrachloride), non-ionic detergent, ionic detergent (sodium lauryl sulfate), chelating agent (EDTA-2Na), ultrasonics and combinations of these agents were used in the experiments. EDTA was found to be the most suitable of these washing agents for removing external contaminant metals. Further elucidation, however, is needed before a standard method of hair washing can be established.     

Graphene oxide nanosheets modified with trithiocyanuric acid for extraction and enrichment of Pb (II) and Cu (II) ions in seawater

Trithiocyanuric acid (TTC) is a robust chelating ligand for extracting divalent and univalent heavy metals from water samples. In this method, graphene oxide nanosheets (GO) was modified with TTC, to produce a new nano‐adsorbent (GO‐TTC), for extraction and preconcentration of Pb (II) and Cu (II) ions from seawater samples. The concentrated analytes were measured by a flame atomic absorption spectrometry. The detection limits of the method for Pb (II) and Cu (II) ions were 0.32 ng/mL and 0.13 ng/mL, respectively. The relative standard deviations of analytes for six successive extractions were below 1.64%. The maximum adsorption capacity of GO‐TTC for Pb (II) and Cu (II) ions was 750 µg/g and 460 µg/g, respectively. The recoveries of the spiked analytes in artificial and natural seawater samples were above 90%, pointing out that the method is not affected by the major coexisting ions in seawater matrices.     

Metals in ambient air-polluted and unpolluted areas

A method has been developed to differentiate between the addition of metals to the ambient air environment as a result of man's activities, from metals characteristic of the natural background of suspended particulates. Annual, 1971 and 1972, arithmetic mean metal concentration data supplied by the Houston Department of Public Health were utilized as examples for the method. These data were obtained from atomic absorption analysis of suspended particulate samples. Trend-surface maps of metal concentrations were constructed from the data. Natural variation and sampling error could explain part of the deviations so revealed even though area sources for metals such as manganese and nickel are clearly associated with the high particulate concentrations found there. A ratio of metals to suspended particulates in adjacent rural areas establishes the natural ratio. This ratio, R_background, is then compared to the analogous urban ratios, R_Houston, to establish the enrichment ratio. Trend-surface maps of the enrichment ratios clearly delineate area sources of metals originating from man's activities.     

Short-term variations in the occurrence of heavy metals in Antarctic snow from Coats Land since the 1920s

Short-term variations in heavy metals concentrations in Antarctic snow have been investigated by analysing 13 metals (Al, V, Cr, Mn, Co, Cu, Zn, Ag, Cd, Ba, Pb, Bi and U) in a series of ultraclean samples collected from two snow pits in Coats Land in the Atlantic sector of Antarctica. The samples covered a approximately 70 years time period from the 1920s to 1990. They were analysed by inductively coupled plasma sector field mass spectrometry and graphite furnace atomic absorption spectrometry. The results conclusively show that there is a pronounced short-term (intra- and inter-annual) variability of heavy metal in Antarctic snow, with the highest concentrations being up to 100 times higher than the lowest ones for metal such as Cr, Mn, Pb and U. Contributions from the different possible natural and anthropogenic sources are found to be extremely variable. This is especially due to the large variability in the transport patterns of heavy metals from Southern America, Southern Africa and Australia to the Antarctic continent. Inputs from several volcanic events were identified in our samples from non-seasalt sulfate concentrations profiles. The only ones that gave clear signals for heavy metals were eruptions at Deception Island the proximity of which allowed for tropospheric transport to Coats Land.     

Concentrations of selected metals in honey consumed in Nigeria

The concentration of metals, cadmium (Cd), lead (Pb), nickel (Ni), chromium (Cr), copper (Cu), cobalt (Co), iron (Fe), manganese (Mn), and zinc (Zn) was measured in selected samples of honey in Nigeria with a view to providing information on the regional concentration profile of metals in these honeys. The honey samples were digested with a mixture of acids and analysed for metal concentrations using atomic absorption spectrophotometry. The concentrations of metals (mg kg^?1) in these honeys ranged from < 0.3 for Cd,<0.50–39.75 for Pb,<0.25–6.98 for Ni,<0.25–55.25 for Cr,<0.25–71.25 for Cu,<0.25–3.50 for Co,<5.0–163.15 for Fe,<11.0–31.75 for Mn and 1.0–31.0 for Zn. The concentrations of metals were relatively high but lower than their respective permissible limits in food except for Pb and Cu in some samples. The regional distribution patterns of metals indicated that honey samples from the Niger Delta region of Nigeria had higher mean concentrations of Ni, Cr, Co, Fe and Zn than honey samples from other regions. The honey samples from the northern region had higher mean concentrations of Pb and Cu.     

Quantities and associations of lead, zinc, cadmium, manganese, chromium, nickel, vanadium, and copper in fresh Mississippi delta alluvium and New Orleans alluvial soils

The topic of this study is the effect of anthropogenic metals on the geochemical quality of urban soils. This is accomplished by comparing the metal contents and associations between two alluvial soils of the lower Mississippi River Delta, freshly deposited alluvial parent materials and alluvial soils collected from a nearby urban environment. Fresh alluvium samples (n = 97) were collected from the Bonnet Carré Spillway. The urban alluvial soil samples (n = 4026) were collected from New Orleans and stratified by census tracts (n = 286). The Spillway samples tend to have less Pb and Zn than generally noted for the baseline of natural soils. Except for Mn and V, Spillway alluvium contains significantly less metal than urban soils. For Spillway samples, the median metal content (in microg g(-1)) is 4.7 Pb, 11.1 Zn, 0.7 Cd, 164 Mn, 0.8 Cr, 3.9 Ni, 3.2 V, and 3.9 Cu. For urban soils, the median metal content (in microg g(-1)) is 120 Pb, 130 Zn, 3.2 Cd, 138 Mn, 2.1 Cr, 9.8 Ni, 3.8 V, and 12.7 Cu. Metal associations also differ between Spillway alluvium and urban alluvial soils. Fresh alluvium correlation coefficients between individual metals vary from 0.87 to 0.99 (P < 10(-13)) except for Cr which ranges from 0.57 to 0.68 (P < 10(-7)). The urban soil correlation coefficients for metals and the index value are 0.40-0.98. In urban soils, Pb, Zn, Cr, and Cu are dominant metals and highly associated, with a correlation coefficient ranging from 0.83 to 0.98 (P < 10(-25)). Their strong association justifies the use of GIS to map the integrated soil metal index (sum of the medians of metals by census tract) of New Orleans. Although also positively correlated (0.40-0.68, P < 10(-10)), Cd, Mn, Ni and V differ in their distribution in the city compared to Pb, Zn, Cr and Cu. Overall, significantly higher metal values occur in the inner city and lower values occur in outlying areas. The human health impact of the mixture of metals is not well understood. This study provides empirical data about the mixture and distribution of metals in New Orleans alluvial soils. Given common technical development, especially of traffic flows in cities, similar patterns of soil metals are expected for all US cities and probably international cities as well. Primary prevention of urban metal accumulations is necessary to enhance and sustain the development of urban culture.     

Mass balance and distribution of sludge-borne trace elements in a silt loam soil following long-term applications of sewage sludge

Soil samples were collected at 15-cm increments to a depth of 75 cm from plots on a silt loam soil where until several years earlier and for 14 years, anaerobically digested sewage sludge had been annually applied by furrow irrigation. The study protocol consisted of four replications of 6.1 x 12.2-m plots with 0 (T0), 1/4-maximum (T1), 1/2-maximum (T2) and maximum (T3) sludge application rates randomized within blocks. When sludge applications were terminated, maximum sludge-treated plots had received 765 Mg ha-1 (dry weight equivalent) of sludge solids. Total soil concentrations of Cd, Cr, Cu, Ni, Pb and Zn had been significantly enhanced by all sludge application rates to a soil depth of 30 cm. Below the 30-cm depth, total soil Cd was increased to 75 cm, total Zn to 45 cm (T2 and T3 only), total Cr to 60 cm (T2 and T3 only), but total Cu, Pb, and Ni were not increased at depth. Despite the lack of significant increases in subsoil concentrations for some metals, mass balance calculations showed a relatively high proportion of all the above sludge-borne heavy metals to be unaccounted for in the soil profile for each application rate. Mass balance calculations of losses ranged from a high of 60% for Ni to a low of 36% for Cu and Pb. Similar losses were calculated from metal concentrations measured in soil samples taken at the time the sludge was applied. In soil surface samples (0-15 cm) from maximum sludge-treated plots, percentages of total metal concentration extracted with 4.0 M HNO3 ranged from a low of 31 for Zn to a high of 75 for Cu. Efficiency of metal extraction by HNO3 was inconsistent, depending on the soil horizon and sludge treatment, so that evaluation of HNO3-extractable metals is not a reliable method of estimating total metal retention in the profiles. In soil surface samples from maximum sludge-treated plots, the percentage of total metal contents extracted with DTPA ranged from a low of 0.03 for Cr to a high of 59 for Cd. The DTPA extractable levels of Cu, Ni, and Pb were higher in the subsoils of the sludge-treated soils, indicating that these metals had been redistributed from the surface layer to deeper zones in the profile of sludge-amended soil, despite the absence of elevated total concentrations of these three metals in the deeper subsoil.     

PAH and metal mixtures in New Orleans soils and sediments.

The purpose of this study is to determine the degree of PAH contamination and the association of PAHs with inorganic substances in soils and sediments of New Orleans. Bonnet Carré Spillway (BCS) (n = 5) provides modern baseline data, while urban soil samples (CTY) (n = 27) and sediment samples from Bayou St. John (BSJ) (n = 11) provide experimental data for New Orleans. Soil samples were collected from the top 2.5 cm of the surface, air-dried, and sieved (2 mm). Sediments samples were collected with a Wildco-Ekman bottom dredge, air-dried and finely ground. Accelerated solvent extraction (ASE) was used to release PAHs from the samples and analysis was conducted with gas chromatography-mass spectrometry (GC-MS). Metals were extracted using a 5:1 ratio of 1 mol/L nitric acid (room temperature) for soil and sediment samples, shaken for 2 h, centrifuged (1000 x g for 15 min) and filtered. Metal analysis was done by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Mann-Whitney tests show PAH differences (P < 0.001). Ranking of total PAHs is, BSJ sediments (10.3 mg/kg) > CTY soils (3.7 mg/kg) > BCS alluvium (0.28 mg/kg). The sum of the metals are similar for BSJ sediments (698 mg/kg) and CTY soils (679 mg/kg) and significantly lower for BCS (189 mg/kg). Manganese of these samples is similar for each site. For paired samples, Pearson Product Moment Correlation tests reveal that many PAHs are strongly associated with each other at all locations. For BCS alluvium and BSJ sediments, total PAHs are not significantly associated with total metals. For CTY, most pairs of metals are significantly associated, and total soil PAHs are strongly associated with total soil metals (correlation 0.78, P = 4.9 x 10(-4)). The linear model, total soil PAH = 136.3 + 6.25 (total soil metals) forms the basis for a predicted PAH map of New Orleans. Previous empirical research demonstrates an association between soil lead and children's lead exposure. This study indicates that PAHs are part of the soil mixture of accumulated substances and by-products of industrial society that presents exposure potential in cities.     

Heavy metals in human bones in different historical epochs

The concentration of the metals lead, copper, zinc, cadmium and iron was determined in bone remains belonging to 30 individuals buried in the Region of Cartagena dating from different historical periods and in eight persons who had died in recent times. The metals content with respect to lead, cadmium and copper was determined either by anodic stripping voltammetry or by atomic absorption spectroscopy on the basis of the concentrations present in the bone remains. In all cases, zinc and iron were quantified by means of atomic absorption spectroscopy. The lead concentrations found in the bone remains in our city are greater than those reported in the literature for other locations. This led to the consideration of the sources of these metals in our area, both the contribution from atmospheric aerosols as well as that from the soil in the area. Correlation analysis leads us to consider the presence of the studied metals in the analysed bone samples to be the consequence of analogous inputs, namely the inhalation of atmospheric aerosols and diverse contributions in the diet. The lowest values found in the studied bone remains correspond to the Neolithic period, with similar contents to present-day samples with respect to lead, copper, cadmium and iron. As regards the evolution over time of the concentrations of the metals under study, a clear increase in these is observed between the Neolithic period and the grouping made up of the Bronze Age, Roman domination and the Byzantine period. The trend lines used to classify the samples into 7 periods show that the maximum values of lead correspond to the Roman and Byzantine periods. For copper, this peak is found in the Byzantine Period and for iron, in the Islamic Period. Zinc shows an increasing tendency over the periods under study and cadmium is the only metal whose trend lines shows a decreasing slope.     

某金矿尾矿库土壤重金属污染特征及来源分析

尾矿中含有的重金属通过介质向环境缓慢释放,重金属进入土壤后,会对周围土壤、生态环境造成影响,危害人类身体健康和安全。本文以某金矿尾矿库为研究对象,对尾矿库流域内土壤重金属进行取样调查,确定尾矿库及周边土壤重金属污染现状,分析重金属来源及污染特征。对尾矿库及周边的土壤进行pH、氰化物、锑、砷、镉、铜、铅、锌、汞等元素含量测试,采用单项污染指数与内梅罗指数法进行重金属污染程度分析与评价;同时运用主成分分析法,探究尾矿库及周边区域土壤重金属形成原因和污染特征。研究结果表明：尾矿库流域内地表土样处于重污染状态,污染区主要集中在尾矿库东北侧,污染范围较大;氰化物、锑、镉、铜、铅、锌存在着不同程度的相关性,表明研究区内存在这6种元素不同程度的复合污染或这些元素具有同源性,重金属污染主要来源为矿石开采和工业活动等人为来源;土壤中砷的吸附、迁移与土壤pH值关系密切。调查和分析尾矿库土壤污染情况,查明尾矿库污染形成原因和污染特征,对尾矿库的综合治理具有重要意义。     

Lead,iron, chromium and zinc in road runoff at Pullman,Washington

The inputs of iron, lead, chromium and zinc to a 0.6 acre road surface were investigated. The selection of a viaduct in Pullman, Washington as a study area permitted the exclusion of metal input from non-road surfaces. Dust and precipitation metal deposition rates were measured at the viaduct as well as at a control location. It was found that the primary source of metals at the road surface was the operation of motor vehicles. For three separate storm events, runoff samples were collected, flow was measured and runoff samples were analyzed for total solids, total metals and dissolved-colloidal metals. Less than 5 percent of each metal in the runoff samples existed in the dissolved-colloidal fraction. Mean concentrations of total metals in road runoff were 1.86, 89, 0.139 and 19.1 mg/l for Pb, Fe, Cr, and Zn, respectively. A mathematical model was developed allowing the estimation of metal loadings for a storm event typical of the area, given the total runoff volume for the particular storm event. It was also found that a residual amount of metals remains on the road surface after each storm.     

Do heavy metals prevent the agricutlural use of municipal sludge?

The chemical binding of heavy metals on different samples of soil was found. It was shown that the distribution between undissolved metals and metals in solution was dependent upon pH, clay-and humus content. Requiring a concentration of metals in soil water corresponding to WHO's standard for drinking water, it was possible to calculate on the basis of the results obtained, how much sludge can be applied per ha. It was shown that lead in most cases is the metal limiting the amount of sludge, which can be used.     

Rapid screening of DOM's metal-binding ability using a fluorescence-based microplate assay

This note describes the development of a method to rapidly quantify the metal-binding ability of low-volume DOM samples based on their fluorescence properties. The method uses 96-well microplates to screen the fluorescence quenching observed when increasing concentrations of various metals are added to the pH-buffered DOM sample. Only 1.6 mL of DOM sample is required to quantify the binding affinity for each metal and the result is obtained in a few minutes. This study presents results for a surface soil DOM sample for which binding was assessed for Cu2+, Fe2+, Ni2+ at pH 5 and 9.     

The influence of heat treatment on the metallic and polycyclic aromatic hydrocarbon content of sewage sludge

Heat treatment followed by vacuum filtration or filter pressing is one method of dewatering sewage sludge. The concentrations of certain heavy metals and polynuclear aromatic hydrocarbons in raw sewage sludge, treated sludge cake and the resultant liquors have been determined in samples collected from three sewage treatment works in the United Kingdom utilising heat treatment. Mass balances have been calculated using the results obtained and the degree of resolubilisation of these materials which occurs during the treatment process has been determined.     

Effectiveness of wetlands in retaining metals from mine water,South Africa

Wetlands are effectively used to treat mine water effluent in South Africa, where they retain toxic metals that can potentially contaminate the environment. Wetlands that are located close to the abandoned tailings dams were chosen and solidified substrate samples were collected for thin section microscopy, X‐ray fluorescence (XRF) and X‐ray diffraction (XRD) analyses. In order to determine the concentration of selected metals in the tailings dams, fine grained samples were collected and leached with a diluted nitric acid and deionised water to simulate leaching by rainwater. The results from the substrate analysis revealed an overall oxide abundance of 71.76 weight percent (%) and an elevated metal concentration, which suggest a crucial role played by pH, redox, wetland sediments and wetland plants in maintaining oxygen circulation and triggering reactions. The study confirmed the efficiency of wetlands in the attenuation of toxic metals from the mine water.     

Trace metals in the bones of scaup ducks (Aythya marila L.) wintering in Gdańsk Bay, Baltic Sea, 1982-83 and 1983-84

The concentrations of Fe, Zn, Mn, Cu, Pb, Cd, Co, Ni, Cr and Ag in 88 samples of various bones and five samples of trachea prepared from scaup ducks (Aythya marila L.) have been determined. With the exception of lead, no significant sex-related differences were observed for the concentration of metals. However, there were significant differences in the concentrations of most metals for different bones.     

Toxicity assessment of heavy metal mixtures by Lemna minor L

The discharge of untreated electroplating wastewaters directly into the environment is a certain source of heavy metals in surface waters. Even though heavy metal discharge is regulated by environmental laws many small-scale electroplating facilities do not apply adequate protective measures. Electroplating wastewaters contain large amounts of various heavy metals (the composition depending on the facility) and the pH value often bellow 2. Such pollution diminishes the biodiversity of aquatic ecosystems and also endangers human health. The aim of our study was to observe/measure the toxic effects induced by a mixture of seven heavy metals on a bioindicator species Lemna minor L. Since artificial laboratory metal mixtures cannot entirely predict behaviour of metal mixtures nor provide us with informations relating to the specific conditions in the realistic environment we have used an actual electroplating wastewater sample discharged from a small electroplating facility. In order to obtain three more samples with the same composition of heavy metals but at different concentrations, the original electroplating wastewater sample has undergone a purification process. The purification process used was developed by Orescanin et al. [Orescanin V, Mikeli? L, Luli? S, Nad K, Rubci? M, Pavlovi? G. Purification of electroplating wastewaters utilizing waste by-product ferrous sulphate and wood fly ash. J Environ Sci Health A 2004; 39 (9): 2437-2446.] in order to remove the heavy metals and adjust the pH value to acceptable values for discharge into the environment. Studies involving plants and multielemental waters are very rare because of the difficulty in explaining interactions of the combined toxicities. Regardless of the complexity in interpretation, Lemna bioassay can be efficiently used to assess combined effects of multimetal samples. Such realistic samples should not be avoided because they can provide us with a wide range of information which can help explain many different interactions of metals on plant growth and metabolism. In this study we have primarily evaluated classical toxicity endpoints (relative growth rate, Nfronds/Ncolonies ratio, dry to fresh weight ratio and frond area) and measured guaiacol peroxidase (GPX) activity as early indicator of oxidative stress. Also, we have measured metal accumulation in plants treated with waste ash water sample with EDXRF analysis and have used toxic unit (TU) approach to predict which metal will contribute the most to the general toxicity of the tested samples.     

The Development of Ion Chromatography for Metals Analysis in Saline Waters

Previous attempts to utilize ion chromatography for the analysis of sea water samples have failed through chronic interference by the major ions (na, Mg, Ca) during the preconcentration stage. As part of ongoing research into ion chromatography, a technique has been developed to overcome these interferences, using a two-stage preconcentration step, prior to separation on a cation-exchange column. This has made it possible to detect μg/l quantities of trace metals in samples containing g/l concentrations of sodium, magnesium and calcium. A modified commercially-available ion chromatographic system was used to analyse copper, nickel, zinc, cobalt and manganese in saline waters. Detection limits were typically less than 1 μg/l, with relative standard deviation of less than 10%. Hence this new method has the potential to provide an inexpensive multi-elemental sea water analysis with the minimum of handling. In addition, the simplicity and sensitivity of the technique may make it suitable for unattended use as a remote monitor of metals.