The behaviour of heavy metals from the Guadalquivir estuary after the Aznalcóllar mining spill: field and laboratory surveys

The spill at `Los Frailes caused a large input of metals intothe riverine, estuarine and coastal ecosystems. Metal behaviourin natural waters can be studied both by performing fieldmeasurements, and by undertaking laboratory simulationexperiments. Here is described the behaviour of the heavymetals Zn, Cd, Pb and Cu in the Guadalquivir estuary usingincubation experiments and the results compared to thoseobtained during field assessments. If the toxic waste water hadbeen discharged untreated into the environment, it could haveraised the heavy metal concentrations in the estuary water tohigh values, such as 20.65 M for Zn and 40 × 10^-3 M for Cd. These values are several times higher than thoseobtained in samples collected in the area during the monitoringof the early impact. The metals present a non-conservative behaviour, with a high loss to waters of low salinity values.     

Heavy metal pollution in surface soils of Pearl River Delta,China

Heavy metal pollution is an increasing environmental problem in Chinese regions undergoing rapid economic and industrial development, such as the Pearl River Delta (PRD), southern China. We determined heavy metal concentrations in surface soils from the PRD. The soils were polluted with heavy metals, as defined by the Chinese soil quality standard grade II criteria. The degree of pollution decreased in the order Cd?>?Cu?>?Ni?>?Zn?>?As?>?Cr?>?Hg?>?Pb. The degree of heavy metal pollution by land use decreased in the order waste treatment plants (WP)?>?urban land (UL)?>?manufacturing industries (MI)?>?agricultural land (AL)?>?woodland (WL)?>?water sources (WS). Pollution with some of the metals, including Cd, Cu, Ni, and Zn, was attributed to the recent rapid development of the electronics and electroplating industries. Cd, Hg, and Pb (especially Cd) pose high potential ecological risks in all of the zones studied. The soils posing significantly high and high potential ecological risks from Cd covered 73.3 % of UL, 50 % of MI and WP land, and 48.5 % of AL. The potential ecological risks from heavy metals by land use decreased in the order UL?>?MI?>?AL?>?WP?>?WL?>?WS. The control of Cd, Hg, and Pb should be prioritized in the PRD, and emissions in wastewater, residue, and gas discharges from the electronics and electroplating industry should be decreased urgently. The use of chemical fertilizers and pesticides should also be decreased.     

Freshwater aquatic macrophytes as heavy metal monitors — the Ottawa River experience

The ability of freshwater aquatic vascular plants to accumulate heavy metals was examined in some detail during a five year study. Differences in uptake rate were found to depend on the species of plant, the seasonal growth rate changes and the metal ion being absorbed. Lead and mercury were concentrated to a greater extent than the lighter nickel and copper. Laboratory experiments were designed to establish uptake rate constants which were used to calculate water concentrations of mercury from the analyses of plant samples from the river. Background levels of mercury in aquatic plants of 35–50 ng g^-1 dry weight corresponded to a water concentration near 15 ng L^-1 of total mercury of which 25–30% was methylmercury. Higher concentrations of mercury in the plants indicated a proportional increase in the mercury level in the water.     

大宝山采矿活动对环境的重金属污染调查

调查了大宝山铁铜多金属矿床固体废弃物-水相互作用对环境的重金属污染,结果表明,矿床固体废弃物导致了水、土壤的重金属污染,污染元素主要有Cd、Cu、Pb、Zn等;重金属元素的水迁移强度由大至小顺序为Cr、Cu、Zn、Ni、Cd、As、Pb、Hg;元素的生物吸收系数由大至小顺序为Cd、Zn、Hg、Ni、Cu、Cr、As、Pb,虽然水稻糙米中的重金属含量未超过国家标准,但Cd、Cr两种元素含量已远远超出了植物中毒量的下限值.     

Non-radiological contaminants from uranium mining and milling at Ranger,Jabiru, Northern Territory,Australia

Protection from the hazards from radioactivity is of prime importance in the management of uranium mine and mill wastes. Such wastes also contain non-radiological contaminants (heavy metals, acids and neutralising agents) which give rise to potential long-term health and environmental hazards and short-term hazards to the aquatic ecosystem, e.g. as a result of release of waste water. This study seeks to identify non-radiological contaminants (elements) transferred to waste water at the Ranger uranium mine/mill complex at Jabiru, which are likely to hazardous to the aquatic environment. The two principal sources of contaminants are:

1. ore and waste rock mobilised from mining; and
2. process reagents used in the milling and mineral extraction process.

These substances may or may not already be present in the natural environment but may lead to deleterious effects on the aquatic environment if increased above threshold levels. Rhenium, derived from the ore body, was found to be significantly enriched in waste water from Ranger, indicating its suitability as an indicator element for water originating from the mining and milling process, but only uranium, likewise derived from the ore, and magnesium, manganese and sulfur (as sulfate) from the milling process were found to be significant environmental contaminants.     

Study on the law of heavy metal leaching in municipal solid waste landfill

Comparative leaching experiments were carried out using leaching medium with different pH to municipal solid waste in the landfill columns in order to investigate the mobility of heavy metals. The leachate pH and oxidation–reduction potential were measured by oxidation–reduction potential analyzer; the contents of heavy metals were measured by inductively coupled plasma mass spectrometry. It is very different in leaching concentrations of heavy metals; the dynamic leaching of heavy metals decreased with the rise of the leaching amount on the whole. Acid leaching medium had definite influence on the leaching of heavy metals in the early landfill, but it had the obvious inhibition effect on the leaching in the middle and late period of landfill; the neutral and alkaline leaching medium are more beneficial to the leaching of heavy metals. Due to the influence of the environment of landfill, the differences of the results in cumulative leaching amount, leaching rate, and leaching intensity of heavy metals are very big. The calculation results of the release rates of heavy metals prove that the orders of the release rates are not identical under different leaching conditions. Acid rain made heavy metals migrate from municipal solid waste to soil and detain in soil more easily; approached neutral and alkaline leaching mediums are more beneficial to leaching of heavy metals in the municipal solid waste and soil with leachate. The field verification of experimental data showed that the law of heavy metal leaching in municipal solid waste revealed by the experiment has a good consistency with the data obtained by municipal solid waste landfill.     

电镀废水中重金属的回收处理技术

电镀企业产生的漂洗水中含有大量的重金属,处理后生成的电镀重金属污泥属于危废,国家有相关的处置规定,若处置不当,会对环境造成二次污染,并且造成重金属的流失。介绍了利用离子交换法、电解法、膜分离技术、电去离子法等相关方法回收电镀漂洗废水中重金属的国内外的研究进展;从源头抓起,减少了电镀企业重金属元素的排放量,同时对废水的合理回用提供一些可行性方案。     

土壤中有效态重金属的化学试剂提取法研究进展

土壤重金属污染是国内外关注的热点问题，针对采用全量重金属评价土壤污染存在的问题，本文综述了近年来土壤有效态重金属的化学提取方法研究进展，比较分析了各种单一提取法和影响土壤重金属提取率的因素。在此基础上，评价了各类提取方法的特点及其在应用上的优势和局限，指出了筛选通用提取剂的原则和依据。结合实验初步提出以去离子水作为通用提取剂的可行性及尚需研究解决的问题。     

Assessment of the impact of landfill on groundwater quality: A case study of the Pirana site in western India

In present study focus has been given on estimating quality and toxicity of waste with respect to heavy metals and its impact on groundwater quality, using statistical and empirical relationships between different hydrochemical data, so that easy monitoring may be possible which in turn help the sustainable management of landfill site and municipal solid waste. Samples of solid waste, leachate and groundwater were analyzed to evaluate the impact of leachates on groundwater through the comparison of their hydrochemical nature. Results suggest the existence of an empirical relationship between some specific indicator parameters like heavy metals of all three above mentioned sample type. Further, K/Mg ratio also indicates three groundwater samples heavily impacted from leachate contamination. A good number of samples are also showing higher values for and Pb than that of World Health Organization (WHO) drinking water regulation. Predominance of Fe and Zn in both groundwater and solid waste samples may be due to metal plating industries in the area. Factor analysis is used as a tool to explain observed relation between numerous variables in term of simpler relation, which may help to deduce the strength of relation. Positive loading of most of the factors for heavy metal clearly shows landfill impact on ground water quality especially along the hydraulic gradient. Cluster analysis, further substantiates the impact of landfill. Two major groups of samples obtained from cluster analysis suggest that one group comprises samples that are severely under the influence of landfill and contaminated leachates along the groundwater flow direction while other assorted with samples without having such influence.     

Bioaccumulation of heavy metals and two organochlorine pesticides (DDT and BHC) in crops irrigated with secondary treated waste water

Four crop plants Oryza sativa (rice), Solanum melongena (brinjal), Spinacea oleracea (spinach) and Raphanus sativus (radish) were grown to study the impact of secondary treated municipal waste water irrigation. These plants were grown in three plots each of 0.5 ha, and irrigated with secondary treated waste water from a sewage treatment plant. Sludge from the same sewage treatment plant was applied as manure. Cultivated plants were analyzed for accumulation of heavy metals and pesticides. Results revealed the accumulation of six heavy metals cadmium (Cd), chromium (Cr), iron (Fe), copper (Cu), nickel (Ni), and zinc (Zn) as well as two pesticides [1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane; DDT] and benzene hexa chloride (BHC). Order of the plants for the extent of bioaccumulation was S. oleracea > R. sativus > S. melongena > O. sativa. The study has shown the secondary treated waste water can be a source of contamination to the soil and plants.     

Validation of plant based bioassays for the toxicity testing of Indian waters

Plant-based bioassays have recently gained remarkable popularity among the toxicological/eco-toxicological assessment procedures. The reasons for their wide use are comparative simplicity, sensitivity, and cost-effectiveness as well as a good correlation with other toxicity tests. The present study describes the use of two plant bioassays, Allium cepa test and seed germination test in the evaluation of the toxicity/genotoxicity of industrial waste water and river water and standardization with the commonly occurring pollutants in Indian waters namely heavy metals and phenolics. Both tests were standardized to suit the Indian conditions, and the local varieties were used. Both bioassays responded significantly with the test range of heavy metals and phenolics. The toxicity of heavy metals was in the order of Cu > Ni > Cd in both the tests whereas 2,4-dinitrophenol was the most toxic among the phenolic compounds. Cabbage, millet, and cucumber, respectively, were found to be the most sensitive in the seed germination test for the test heavy metals and phenols. Significant amounts of chromosomal abnormalities including bridges, stickiness, and fragmentations were recorded with both the industrial waste water and the XAD concentrated river water samples by A. cepa test.     

Topsoil and Housedust Metal Concentrations in the Vicinity of a Lead Battery Manufacturing Plant

The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g> ^-1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees.     

Environmental Monitoring of Heavy Metals in Bulgarian Black Sea Green Algae

Fe, Mn, Cu, Pb and Cd concentration distribution in six green macroalgae species from the Bulgarian Black Sea coast were determined. The measurement of these metals was carried out during six seasons from 1996 to 2002 using atomic absorption spectrometry (AAS). Samples were collected from eight different sites–Shabla, Kaliakra, Tuzlata, Ravda, Ahtopol and Sinemoretz. The obtained heavy metal (HM) data (mean values g/g) for all algae are: 650 ± 100 for Fe, 184 ± 15 for Mn, 5.6 ± 0.5 for Cu, 3.3 ± 0.3 for Pb and 1.1 ± 0.2 for Cd. The obtained HM contents indicate that different species demonstrate various degree of metal accumulation and the obtained higher values in the northern sector of the studied zone can be attributed to the discharge influence of the big rivers, entering the Black Sea–Danube, Dnyepr, Dnester and local pollutant emissions. All data show that there is no serious contamination in green macroalgae with heavy and toxic metals along the whole Bulgarian Black Sea coast.     

Atrazine and Alachlor Inputs to Surface and Ground Waters in Irrigated Corn Cultivation Areas of Castilla-Leon Region, Spain

The inputs of atrazine and alachlor herbicides to surface and ground waters from irrigated areas dedicated to corn cultivation in the Castilla-León (C-L) region (Spain) as related to the application of both herbicides were studied. Enzyme-linked immunosorbent assays (ELISA) were used for monitoring the atrazine and alachlor concentrations in 98 water samples taken from these areas. Seventy-nine of the samples were of ground waters and 19 were of surface waters. The concentration ranges of the herbicides detected in the study period (October 1997–October 1998) were 0.04–25.3 g L^–1 in the surface waters and 0.04–3.45 g L^–1 in the ground waters for atrazine, and 0.06–31.9 g L^–1 in the surface waters and 0.05–4.85 g L^–1 in the ground waters in the case of alachlor. The highly significant correlation observed between the concentrations of both herbicides in the surface waters (r = 0.89, p < 0.001) pointed to a parallel transport of atrazine and alachlor to these waters. A study was made of the temporal evolution of the concentrations of both herbicides, and it was found a maximum recharge of atrazine in the ground waters for April 1998 and of alachlor in October 1997 and October 1998. The temporal evolution of the concentrations of both herbicides in surface waters was parallel. The highly significant correlations observed between atrazine concentrations determined by ELISA and by HPLC (r = 0.92, p < 0.001) and between alachlor concentrations also determined by both methods (r = 0.96, p < 0.001) confirmed the usefulness of ELISA for monitoring both herbicides in an elevated number of samples. Using HPLC, the presence in some waters of the alachlor ethanesulfonate (ESA) metabolite was found at a concentration range of 0.52–4.01 g L^–1. However the interference of ESA in the determination of alachlor by ELISA was negligible. The inputs of atrazine and alachlor to waters found in this study, especially the inputs to ground waters, could pose a risk for human health considering that some waters, though sporadically, are even used for human consumption.     

The use of marine sponge, Haliclona tenuiramosa as bioindicator to monitor heavy metal pollution in the coasts of Gulf of Mannar, India

The results of the present research study indicate that the heavy metal accumulation in the marine sponges provide evidence as an excellent bioindicators for monitoring heavy metal pollution between near and offshore environments of Mandapam coast of "Gulf of Mannar (GoM), India". The heavy metal concentrations in sea water and accumulation in the tissues of Haliclona tenuiramosa were analyzed by ICP-MS (inductively coupled plasma-mass spectrometry). The concentrations of metals in the coastal waters of nearshore (< 0.5 km from shore) were always higher than those in the offshore waters (2-5 km away from shore). Likewise, sponges living in the nearshore accumulated greater concentrations of heavy metals (As, Cd, Co, Cu, Fe, Mn and Ni) ranging from 2 to 17 times higher concentration than the sponges located away from the shore. A positive correlation between concentration levels in water and bioaccumulation in tissues was observed. The bioaccumulation of heavy metals in sponge tissue were in order of Fe > Mn > Ni > Cu > As > Co > Cd in both the near and offshore stations. The present results justified that a more comprehensive monitoring of presence of heavy metals in H. tenuiramosa of surrounding GoM, is necessary to help a better mitigation of the problem.     

Speciation of heavy metals in biosolids of wastewater treatment plants at Mysore,Karnataka, India

Urban wastewater treatment leads to the generation of large quantities of biosolids. Accumulation of biosolids is a problem of environmental relevance due to the existence of heavy metals in the biosolids. Determination of total metal in biosolid provides information relating pollution levels. Determination of their mobilization capacity and behaviour in the environment is an important task. An experimental approach commonly used for studying the mobility, transport and bioavailability of metal in biosolids is the use of selective sequential extraction procedure. In the present study an attempt has been made to study the heavy metal properties in biosolid samples collected from urban wastewater treatment plants located at Mysore, Karnataka. Few heavy metals selected for the present study are cadmium, chromium, copper, iron, nickel and zinc. The concentration of these metals in biosolids and their partition in different fractions are studied. The speciation of metals based on the sequential extraction scheme was carried out. The concentration of heavy metals is lower than that established by European legislation. The residual fraction has the maximum percentage of heavy metals whereas, only a small fraction of heavy metals (Fe, Zn and Cd) are extracted in the most soluble fractions, exchangeable and carbonate fractions.     

Determination of Background Concentrations of Inorganics in Soils and Sediments at Hazardous Waste Sites

Hazardous waste sites may pose a threat to human health and the environment when toxic substances are released. However, the contaminants present at a waste site may have originated on-site (i.e., resulting from releases attributable to site activities) or off-site (i.e., resulting from sources not on-site). Off-site substances may result either from natural sources (e.g., erosion of naturally occurring mineral deposits) or anthropogenic sources (e.g., widespread contamination from automobile exhaust in urban areas). To determine the appropriate action to take at a hazardous waste site, the U.S. Environmental Protection Agency (EPA) must distinguish between substances directly attributable to the hazardous waste site (i.e., site contaminants) and those attributable to natural background concentrations. The most important factor to consider when determining background concentrations is to ensure that the physical, chemical, and biological aspects of the media to be sampled at both the contaminated site and the background site are as similar as possible. Inorganics, in particular metals, are addressed. Radionuclides are not specifically addressed; however, metals with radioactive isotopes that may be encountered at hazardous waste sites are included. There are references and data included in this paper that provide average concentrations and reference values for selected soils and sediments in the United States. Suggested sampling and monitoring design approaches that could be used by scientists and engineers faced with how to determine background concentrations are identified. The issues discussed include the selection of background sampling locations, considerations in the selection of sampling procedures, and statistical analyses for determining whether contaminant levels are significantly different on a potential waste site compared with a background site.     

Studies on heavy metals in the ground waters of the city of Aligarh U.P. (India)

A study was conducted to determine the levels of heavy metals Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn along with physico-chemical parameters in ground waters of Aligarh city, U.P. (India). Twenty seven samples of hand pump water and twenty three samples of municipal water supply were collected from different localities of the Aligarh city, five times during the period of two months at intervals of 12 days. The samples were analysed for physico-chemical characteristics (pH, electrical conductivity, chlorides, sulphates, total hardness, total alkalinity, nitrate-nitrogen, fluoride, calcium and magnesium) and heavy metal contents. The concentrations of heavy metals in the hand pump water samples were found in the ranges of Cd (ND-5.00); Cr (ND-30.00); Cu (ND-82.50); Fe (16.80–460.00); Mn (ND-425.00); Ni (ND-25.00); Pb (ND-25.00) and Zn (28.60–775.00) g l^–1. The heavy metal concentrations in the municipal water supply samples were found to be Cd (ND-5.00); Cr (ND-25.00); Cu (ND-37.50); Fe (8.00–37.50); Mn (ND-320.00); Ni (ND-25.00); Pb (ND-25.00) and Zn (2.00–271.87) g l^–1.It appears from the results of these studies the concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the ground waters of the Aligarh City were found to be lower than the prescribed limits of World Health Organisation (1984), whereas the values of Fe and Mn were found above the prescribed limits in some localities. The chloride total hardness and nitrate-nitrogen were comparatively higher in the hand pump water than the municipal supply water. The reason of higher values of these parameters may be ascribed to the surface disposal of sewage wastes, wastes from metal processing industries and other house hold refuses.     

Environmental indicators for long-range atmospheric transported heavy metals based on national moss surveys

Environmental indicators for long-range atmospheric transported heavy metals have been developed. The indicators are based on data for Pb and Cd from national moss surveys which are performed regularly in Norway. The interpolation programme kriging has been used to transform the data from irregular grids to regular grids. Contour maps have been produced, and areas above estimated background levels for Pb and Cd in mosses have been calculated. The indicators are used to characterise the atmospheric deposition of long-range atmospheric transported heavy metals and monitor the changes with time.     

Heavy metal concentration in the moss Pleurozium schreberi in the Niepołomice Forest,Poland: changes during 20 years

The Niepoomice Forest is a large forestcomplex (110 km²) situated in southern Poland 10 to 30 kmto the east of the urban industrial Kraków agglomeration andsteelworks, which was built up on the outskirts of the city in1950. Due to prevailing westerly winds, the forest is affectedby pollutants emitted by both the steelworks and the city. Thelevel of heavy metal contamination in the Niepoomice Forestwas described using a sensitive bioindicator – the moss Pleurozium schreberi. Mean concentrations of metals in mosscollected in the Niepoomice Forest were Cd – 0.71, Cr – 2.4,Cu – 8.6, Fe – 673, Pb – 12.7, and Zn – 61 mg/kg.Concentrations of heavy metals in moss in the NiepoomiceForest decreased in time. As compared with the relatively cleanarea in north-eastern Poland (Puszcza Biaowieska), the concentration of Fe was 2–9 fold and Pb 4–6 fold higher in theNiepoomice Forest in 1975, while in 1998 4 fold and 2 fold,respectively. In both 1975 and 1998 the most polluted by heavymetals was the western part of the Niepoomice Forest (closestto the pollution sources) and the area along the roads insidethe forest complex.