Metal distributions in seawater,sediment and marine benthic macroalgae from the South Australian coastline

Algal species which are ubiquitous along the coastlines of many countries reflect the environmental conditions of the coastal seawater and may serve as useful biomonitors of anthropogenic pollution. Heavy metal concentrations of ten elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) of potential environmental concern were determined in seawater, sediments and twelve species of benthic marine macroalgae from four locations (Glenelg, Port Adelaide, Port Broughton and Port Pirie) along the South Australian coastline. The four sites chosen represented varying degrees of metal contamination, where the capacity for benthic macroalgae to accumulate heavy metals from the environment was evaluated. Spatial differences in heavy metal concentration in both seawaters and sediments were observed at all sites with the highest concentrations of heavy metals including Cd (125 μg g^?1), Pb (2,425 μg g^?1) and Zn (7,974 μg g^?1) found in the finer sediment fractions (<250 μm) of Port Pirie. While all algal species studied (Acrosorium polyneurum, Anotrichium tenue, Cystophora Cephalornithos Cystophora monillifera, Cystophora monilliformis, Dictyopteris australis, Gelidium micropterum, Gracilaria, Hormophysa Cuneiformis, Sargassum cinctum, Scaberia agardhii and Ulva lactuca) accumulated metals to varying degrees, Blindigia marginata was a good biomonitor species for a number of metals including Cd, Co, Cr, Fe, Pb and Zn, exhibiting both relatively high total metal concentrations and significant concentration factors.     

Germination and seedling growth of corn (Zea mays l.) under varying levels of copper and zinc

The heavy metal tolerance in corn (Zea mays L.) var. ‘Neelum’ was assessed at germination and seedling growth after having subjected it to different concentrations of CuSO₄ and ZnSO₄. Germination was not affected by any of the metal tested, whereas initial growth was strongly inhibited by increasing concentrations of ZnSO₄. Seedlings developed toxicity symptoms in the presence of both metals but more chlorotic and necrotic regions were observed at varying levels of ZnSO₄ than CuSO₄. The metal accumulation was concentration dependent. Z. mays seedlings accumulated more copper in roots but greater contents of zinc in their shoots. On the basis of results presented here, it can be concluded that the cultivar of the species tested has shown a marked sensitivity to the presence of small amounts of metals present in the growth medium. The data support the assumption that metal sensitivity is probably due to strong tendency of the species to accumulate them. This justifies that the corn variety ‘Neelum’ is not suitable for the cultivation under situations where water and soil suffer from occasional and/ or transitory metal pollution.     

Evaluation of heavy metal contamination in groundwater samples from Kapas Island,Terengganu, Malaysia

An attempt has been made to delineate the hydrochemistry for a small island based on the major ions and heavy metal concentrations. In this investigation, six sampling campaigns were conducted to measure the concentrations of major ions (Ca, Mg, Na, K, HCO₃, Cl, and SO₄) and heavy metals (Zn, Cr, Pb, Mn, As, and Cu) in groundwater samples collected from seven sampling stations (boreholes) located on Kapas Island, Terengganu, Malaysia. The distribution of major ions is illustrated by a piper plot where Ca–HCO₃ is the dominant type. In addition, the concentrations of heavy metals demonstrate that Mn shows as being the highest concentrated heavy metal in the groundwater sampled in the sampling campaigns; the average Mn content in groundwater sampled was 54.05 μg/L. However, a comparison of the heavy metal (Mn, Cr, Zn, As, Pb, and Cu) concentrations in groundwater samples with the Drinking Water Quality Standard prescribed by World Health Organization reveals that none of these heavy metals exceeded the recommended threshold limits. The principal component analyses (PCA) extracted four components that control the groundwater chemistry. Components 1 and 2 from the PCA analyses extracted approximately 52.11 % of the total variance, which represent the heavy metals (As and Mn) and physical parameters (pH, redox potential, electrical conductivity, temperature, and total dissolved solids). Based on the output of the PHREEQC hydrogeochemical software, several species of heavy metals exist, in which the dominant species found are Mn²⁺, PbCO₃, Cu(OH)₂, and Zn⁺.     

The impacts of common ions on the adsorption of heavy metal

Researches on the impact of common ions onto sediments are of great importance for the study of the heavy metal adsorption mechanisms. Considering the surface sediments from the relatively clean reach in the Baotou section of the Yellow River as the adsorbent, this work presents the impacts of common ions (Na⁺, Mg²⁺, K⁺, Ca²⁺, Cl⁻, SO₄ ²⁻, and NH₄ ⁺) on heavy metals (Cu²⁺, Zn²⁺, Cd²⁺, and Pb²⁺) adsorption. The experimental results reveal that the adsorptive capacities of the heavy metals are controlled by different adsorption mechanisms in different ion concentration ranges. With the increase of the ionic strength, the adsorption of the heavy metals increases for the compression of the electric double layer, whereas decreases for the decreasing of the ionic activities of the heavy metals. The competitive adsorption and complexations between the heavy metals and common ions are also important factors controlling the heavy metal adsorption. According to the experimental results and the real concentration of common ions in the Baotou section of the Yellow River, the increase of the concentrations of Na⁺, Mg²⁺, K⁺, and Ca²⁺ would cause the increase of Zn²⁺ adsorption and reduce the Zn pollution. The NH₄ ⁺ from the industrial discharge of the tributaries has a strong impact on the heavy metal adsorption.     

Sorption and distribution of adsorbed metals in three soils of India

The mobility and bioavailability of heavy metals depends on the metal retention capacity of soil and also on the geochemical phases with which metals are associated. Laboratory batch experiments were carried out to study the sorption and distribution of Cd, Ni and Pb in 3 soils differing in their physicochemical properties from India: Oxyaquic Haplustalf (SL1), Typic Haplustalf (SL2) and Typic Haplustert (SL3). The heavy metal adsorption was studied by isotherms and the distribution coefficient (K_D) for each metal was obtained from the linear regressions of the concentration of metal remaining in equilibrium solution and the amount adsorbed. In general, the sorption capacity for all the metals decreased in the order: SL3>SL2>SL1. Among metals, the sorption capacity in all the soils decreased in the order: Pb>>Ni>Cd. Distribution of sorbed metals at various equilibrating concentrations was studied by sequential extraction. Results showed significant differences in the distribution of metals in these soils. At higher additions (such as 200 μM l⁻¹) most of the metals were extracted in their more mobile fractions, exchangeable and/or inorganic in contrast to their original partitioning in soils, where they were preferentially associated with the less mobile residual fraction. Largest percentages of metals extracted in the exchangeable fraction corresponded to those soil–metal systems with smaller K_D values, e.g. Cd, Ni and Pb in SL1 and Cd and Ni in SL2. In neutral and alkaline soils (SL2, pH=7.1, and SL3, pH=8.6) Pb was predominantly extracted from the inorganic fractions and this corresponded to higher K_D values for Pb in these soils. The predominance of metals associated with the exchangeable fraction together with low K_D values indicates higher mobility of metals retained in the acidic soil (SL1, pH=5.2) compared with the others.     

Adsorption of copper and cobalt from fresh and marine systems

The adsorption of copper and cobalt from aqueous solution on to illite and other substrates has been studied as a function of pH, solution composition and solid phase concentration. The results are interpreted in terms of a model whereby the trace metals are adsorbed in exchange for surface bound H⁺ ions. Adsorption varies with solution ionic strength and the concentrations of complex forming ligands; both of these parameters tend to reduce the trace metal adsorption. The Cu²⁺ is two orders of magnitude more reactive toward solid surfaces than Co²⁺ , which is consistent with the general reactivities of these two metal ions. It is also found that Mg₂₊ interferes with adsorption, presumably by competing with the trace metals for the surface sites. A quantitative model was developed which describes adsorption of these metals from natural waters ranging from river water to sea water as a function of pH, complexing ligands and magnesium activity.     

Metal release from dolomites at high partial-pressures of CO2

The potential for metal release associated with CO₂ leakage from underground storage formations into shallow aquifers is an important consideration in assessment of risk associated with CO₂ sequestration. Metal release can be driven by acidification of groundwaters caused by dissolution of CO₂ and subsequent dissociation of carbonic acid. Thus, acidity is considered one of the main drivers for water quality degradation when evaluating potential impacts of CO₂ leakage. Dissolution of carbonate minerals buffers the increased acidity. Thus, it is generally thought that carbonate aquifers will be less impacted by CO₂ leakage than non-carbonate aquifers due to their high buffering potential. However, dissolution of carbonate minerals can also release trace metals, often present as impurities in the carbonate crystal structure, into solution. The impact of the release of trace metals through this mechanism on water quality remains relatively unknown. In a previous study we demonstrated that calcite dissolution contributed more metal release into solution than sulfide dissolution or desorption when limestone samples were dissolved in elevated CO₂ conditions. The study presented in this paper expanded our work to dolomite formations and details a thorough investigation on the role of mineral composition and mechanisms on trace element release in the presence of CO₂. Detailed characterization of samples from dolomite formations demonstrated stronger associations of metal releases with dissolution of carbonate mineral phases relative to sulfide minerals or surface sorption sites. Aqueous concentrations of Sr²⁺, CO²⁺, Mn²⁺, Ni²⁺, Tl⁺, and Zn²⁺ increased when these dolomite rocks were exposed to elevated concentrations of CO₂. The aqueous concentrations of these metals correlate to aqueous concentrations of Ca²⁺ throughout the experiments. All of the experimental evidence points to carbonate minerals as the dominant source of metals from these dolomite rocks to solution under experimental CO₂ leakage conditions. Aqueous concentrations of Ca²⁺ and Mg²⁺ predicted from numerical simulation of kinetic dolomite dissolution match those observed in the experiments when the surface area is three to five orders of magnitude lower than the surface area of the samples measured by gas adsorption.     

The long-term fate of Cu, Zn, and Pb adsorption complexes at the calcite surface: An X-ray absorption spectroscopy study

In this study, the speciation of Zn²⁺, Pb²⁺, and Cu²⁺ ions sorbed at the calcite surface was monitored during a 2.5-year reaction period, using extended X-ray absorption spectroscopy to characterize metal speciation on the molecular scale. Experiments were performed using pre-equilibrated calcite-water suspensions of pH 8.3, at metal concentrations below the solubility of metal hydroxide and carbonate precipitates, and at constant metal surface loadings. The EXAFS results indicate that all three metals remained coordinated at the calcite surface as inner-sphere adsorption complexes during the 2.5-year ageing period, with no evidence to suggest slow formation of dilute metal-calcite solid solutions under the reaction conditions employed. All three divalent metals were found to form non-octahedral complexes upon coordination to the calcite surface, with Zn²⁺ adsorbing as a tetrahedral complex, Cu²⁺ as a Jahn-Teller distorted octahedral complex, and Pb²⁺ coordinating as a trigonal- or square-pyramidal surface complex. The non-octahedral configurations of these surface complexes may have hindered metal transfer from the calcite surface into the bulk, where Ca²⁺ is in octahedral coordination with respect to first-shell O. The use of pre-equilibrated calcite suspensions, with no net calcite dissolution or precipitation, likely prevented metal incorporation into the lattice as a result of surface recrystallization. The results from this study imply that ageing alone does not increase the stability of Zn²⁺, Pb²⁺, and Cu²⁺ partitioning to calcite if equilibrium with the solution is maintained during reaction; under these conditions, these metals are likely to remain available for exchange even after extended sorption times.     

Assessment of contamination load on water,soil and sediment affected by the Kongjujeil mine drainage,Republic of Korea

Environmental pollution in the Kongjujeil mine creek was determined on the basis of physicochemical and mineralogical properties for various kinds of waters, soils, precipitates and sediments collected in August and December 1998. The hydrochemistry of water is characterized by an enrichment in concentrations of Ca ²⁺, Si, alkali ions, NO ₃ ^- and Cl ^- in ground and surface water, where relatively the mine waters are significantly enriched in Ca ²⁺+Mg ²⁺, Al, heavy metals and SO ₄ ^2- concentrations. The mine waters have lower pH (3.24) and higher EC (613 µS/cm) compared with those of ground and surface water. The ranges of dD and d ¹⁸O values (SMOW) in the water are -50.2 to -61.6‰ and -7.0 to -8.6‰. Using a computer code, the saturation indices of albite, calcite and dolomite in the mine water show that it is undersaturated, and has progressively evolved toward the equilibrium state. Ground and surface water are nearly saturated. The gibbsite, kaolinite and smectite are supersaturated in the surface and groundwater. Geochemical modeling shows that mostly toxic metals exist largely in the form of metal sulfates and free metals in mine water. These metals in the surrounding fresh water could be formed of carbonate or hydroxide complex ions. Minerals within the soil and sediment near the mining area were partly variable consisting of quartz, mica, alkali feldspar, plagioclase, chlorite, vermiculite, berthierine and clay minerals. The separated heavy minerals, soil and sediment are composed of some pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, malachite, goethite and various hydroxide minerals. Some potentially toxic elements (As, Cd, Cu, Pb, Sb and Zn) are found in extremely high concentrations in the surface soils in the vicinity of the mine. The enrichment index of heavy metals in sediment and surface soil of the mine drainage was very severe, while it was not so great in the cultivated soil.     

Leaching experiments on trace element release from the arsenic-bearing tailings of Khovu–Aksy (Tuva Republic,Russia)

The study of inactive As-bearing tailings impoundments at the Khovu-Aksy mine-site (Russia) revealed high concentrations of As in the porewater of tailings solids and in their aqueous extracts, as well as in adjacent soils. In these investigations, experimental leaching of As-containing tailings was performed in the laboratory. The three types of solutions which were used in the leach experiments to model natural waters and waters of anthropogenic origin were H₂O, HNO₃ and NH₄HCO₃, and during leaching with these solutions As concentrations were maintained at 10±2, 16±1 and ∼20 mg/l. No low-pH waters were observed at the end of the leach experiments, where pH varied between 8.3 and 9.1. These alkaline pH conditions are attributed to the effect of acid consuming carbonate mineral dissolution reactions, which are also indicated by increased concentrations of Mg and Ca. Also, the solution of certain heavy metals (Co, Ni, Fe) was negligible compared to that of As, and these metals were assumed to have been conserved in the solid phase. Analysis of the leach solutions, and modeling of the results showed that As could be removed from the surface of different particles where it had been adsorbed, and also its concentration could increase with time from the breakdown of Ca(Mg)- and Ni(Co)-arsenate phases. In the absence of an effective remediation program, As release will continue to be an environmental problem.     

Mathematical models to predict soil heavy metal toxicity in the 2012 Olympic site

Heavy metal concentrations in samples collected from the London 2012 Olympic Village were determined using a three-step sequential extraction and a rapid extraction method. Metal toxicity was measured by employing the Microtox^? solid phase analysis. Both extraction methods produced comparable results (p?=?0.996), but the rapid method produced higher readings. A number of heavy metals were detected using the two extraction methods, including aluminum, arsenic, cadmium, chromium, copper, iron, nickel, lead and zinc; beryllium, molybdenum, niobium and titanium were also found in low concentration ranging between 0.16 and 27.10?mg/kg in the total acid digestion. The total metal levels in all the soil samples were within the UK Soil Guideline Value (SGV) except for lead which ranged between 62.9 and 776.2?mg/kg. The 30?min EC₅₀ of different soil fractions was 2?C5.8?g/L. In the absence of any of heavy metals in the SGV, the Dutch Guideline values were referred. Mathematical models for a number of metals were generated based on the changes in EC₅₀ values between each (F1, F2 and F3) soil fractions and the initial toxicity in the non-fractionated samples. The resulting models produced good R² values (>96%) for predicting the change in toxicity of lead, cadmium, zinc and copper by measuring their changes in concentrations. These models could substantially reduce the time requires to determine the toxicity in the samples; they would be a useful tool in the clean up process where monitoring of metal toxicity is required.     

Removal of Lead,Copper, Zinc and Cadmium from Water Using Phosphate Rock

Removal of Pb^2＋, Cu^2＋, Zn^2＋ and Cd^2＋ from aqueous solutions by sorption on a natural phosphate rock （FAP） was investigated. The effects of the contact time and initial metal concentration were examined in the batch method. The percentage sorption of heavy metals from solution ranges generally between 50% and 99%. The amount of sorbed metal ions follows the order Cu〉Pb〉Cd〉Zn. Heavy metal immobilization was attributed to both surface complexation of metal ions on the surface of FAP grains and partial dissolution and precipitation of a heavy metal-containing phosphate. The very low desorption ratio of heavy metals further supports the effectiveness of FAP as an alternative and low-cost material to remove toxic Pb^2＋, Cu^2＋, Zn^2＋ and Cd^2＋ from polluted waters.     

Contents of hepatic and renal metallothioneins in Hyposarcus pardalis: for construction of biomarker for heavy metal contamination in environments

The pollution of water by heavy metals is one of the most serious problems in the developing countries, where watercourses play important roles in transport and economic activities. The aim of this study was to examine whether Hyposarcus pardalis, a fish species widespread in the freshwater environment in Indonesia, could be used as a biomarker for environmental pollution by metals. To this effect, the concentrations of metallothioneins and metals in the livers and kidneys of H. pardalis were measured. In addition, to clarify the relationship between metallothionein concentrations and metal exposure, the concentrations of metallothioneins and metals were determined in the liver and the kidney of fish exposed to 50 and 500 ppb Cu and 500 ppb Mn, compared with those kept in clean water. Sufficient concentrations of metallothionein were detected in fish captured from Lake Rawakalong located in an industrial area in the suburbs of Jakarta. The results of exposure experiments suggested that H. pardalis retained a history of pollution in its organs for a long duration, and the metals bound to metallothioneins in the liver and kidney could be replaced with Cu following exposure. In conclusion, the hepatic and renal metallothioneins in H. pardalis are a useful candidate biomarker for monitoring heavy metal contamination.     

Retention of strontium,cesium, lead and uranium by bacterial iron oxides from a subterranean environment

Bacteriogenic Fe oxides (BIOS) and groundwater samples were collected 195 m underground at the Stråssa Mine in central Sweden. Ferrous iron oxidizing bacteria, including stalked Gallionella ferruginea and filamenous Leptothrix sp., were prominent in the BIOS samples. The BIOS samples were found to contain only poorly ordered (amorphous) hydrous ferric oxide, as determined by X-ray diffraction. Inductively coupled plasma mass spectroscopy revealed hydroxylamine-reducible Fe and Mn oxide contents that ranged from 55 to 85% on a dry weight basis. Concentrations of Sr, Cs, Pb and U in filtered groundwater ranged from 0.002 to 1.8 μM. Solid phase concentrations of these heavy metals in the BIOS spanned the 0.04–2.23 mmol/kg range. Distribution coefficients (K_d values), calculated as the ratio between BIOS and dissolved heavy metal concentrations, revealed solid phase enrichments that, depending on the heavy metal and Fe oxide content of the sample, extended from 10^3.0 to 10^4.7. At the same time, however, a strong inverse linear relationship was found between log K_d values and the corresponding mass fraction of reducible oxide in the samples, implying that metal uptake was strongly influenced by the relative proportion of bacterial organic matter in the composite solids. Based on the metal accumulation properties of the BIOS, an important role can be inferred for intermixed Fe oxides and bacterial organic matter in the transport and fate of dissolved metals in groundwater systems.     

Influence of the Yangtze River and grain size on the spatial variations of heavy metals and organic carbon in the East China Sea continental shelf sediments

Bulk heavy metal (Fe, Mn, Zn, Cu, Pb, Cd), Al, organic carbon and carbonate concentrations, grain sizes, and δC¹³ of the organic carbon distributions were studied in sediments collected throughout the East China Sea continental shelf and the Yangtze River Delta. The results demonstrated that terrigenous sediments from the Yangtze River is a dominating factor controlling the spatial variations of heavy metals and organic carbon concentrations on the East China Sea continental shelf. In addition, grain size and recent anthropogenic influences are also major factors modifying the spatial and vertical variations of heavy metals.Large spatial variations with a band type distribution of heavy metals, grain size, organic carbon and carbonate were observed. Higher concentrations of heavy metal and light δC¹³ of the organic carbon were found primarily in the Deltaic and inner shelf sediments. The band type distribution generally followed the coastline with little variations in the north–south direction. Away from the Delta and inner shelf (west–east direction), most heavy metal concentrations decreased rapidly with the exception of Cd where high concentrations of Cd were also found in the carbonate-rich shelf break sediments. Coarse-grained relict sediments and biogenic carbonate are two primary diluting agents for the fine-grained aluminosilicate sediments from the Yangtze River with high concentrations of heavy metals.Unusually high concentrations of Cu, Pb, and Cd showed both spatially and vertically that more pollution prevention measures are needed in the Yangtze River drainage basin in order to prevent further heavy metal pollution of the East China Sea inner continental shelf.     

Rates of zinc and trace metal release from dissolving sphalerite at pH 2.0–4.0

High-Fe and low-Fe sphalerite samples were reacted under controlled pH conditions to determine nonoxidative rates of release of Zn and trace metals from the solid-phase. The release (solubilization) of trace metals from dissolving sphalerite to the aqueous phase can be characterized by a kinetic distribution coefficient, (D_tr), which is defined as [(R_tr/X(tr)_Sph)/(R_Zn/X(Zn)_Sph)], where R is the trace metal or Zn release rate, and X is the mole fraction of the trace metal or Zn in sphalerite. This coefficient describes the relationship of the sphalerite dissolution rate to the trace metal mole fraction in the solid and its aqueous concentration. The distribution was used to determine some controls on metal release during the dissolution of sphalerite. Departures from the ideal D_tr of 1.0 suggest that some trace metals may be released via different pathways or that other processes (e.g., adsorption, solubility of trace minerals such as galena) affect the observed concentration of metals.     

Heavy metal adsorption by sulphide mineral surfaces

The adsorption of aqueous Hg²⁺, Pb²⁺, Zn²⁺ and Cd²⁺ complexes on a variety of sulphide minerals has been studied as a function of the solution pH and also as a function of the nature of the ligands in solution. Sulphide minerals are excellent scavengers for these heavy metals. The adsorption is strongly pH dependent, i.e. there is a critical pH at which the adsorption increases dramatically. The pH dependence is related to the hydrolysis of the metal ions. Indirect evidence suggests that the hydrolyzed species are adsorbed directly on the sulphide groups, probably as a monolayer. The results also suggest the presence of MCI_n²⁻ⁿ species physisorbed on the adsorbed monolayer. A positive identification of the adsorbed species was not possible using ESCA/XPS.     

Sorption of trace metals on calcite: Applicability of the surface precipitation model

Published Sorption isotherm data of Cd²⁺, Mn²⁺, Zn²⁺, and Co²⁺ on calcite are adequately described by the surface precipitation model which was originally developed by FArley et al. (1985) for the sorption of cations on metal oxides. In addition to monolayer adsorption, the model accounts for the formation of a surface phase with a composition that is described by a solid solution having as end members the sorbent calcium carbonate mineral and a pure carbonate precipitate of the sorbing trace metal. The model thus specifies a continuum between adsorption and precipitation. This feature is supported in the literature by observations on the reaction kinetics and the amount of surface coverage during trace metal sorption on calcite. The apparent adsorption constants of these trace metals, as derived from the model, can be ranked according to the degree to which their ionic radii match the ionic radius of Ca²⁺.     

Removal of lead(II) from aqueous stream by hydrophilic modified kapok fiber using the Fenton reaction

A hydrophilic kapok fiber was prepared by a chemical process of the Fenton reaction and used as an adsorbent to remove Pb(II) from aqueous solution. The effects of experimental parameters including pH, contact time, Pb(II) concentration, and coexisting heavy metals were estimated as well as evaluated. The optimum concentrations of FeSO₄ and H₂O₂ for the Fenton reaction-modified kapok fiber (FRKF) were 0.5 mol L^?1 and 1 mol L^?1, respectively. The adsorption kinetic models and isotherm equations of Langmuir and Freundlich were conducted to identify the most optimum adsorption rate and adsorption capacity of Pb(II) on FRKF. The FRKF displayed an excellent adsorption rate for Pb(II) in single metal solution with the maximum adsorption capacity of 94.41?±?7.56 mg g^?1 at pH 6.0. Moreover, the FRKE still maintained its adsorption advantage of Pb(II) in the mixed metal solution. The FRKF exhibited a considerable potential in removal of metal content in wastewater streams.     

A comparison of metal attenuation in mine residue and overburden material from an abandoned copper mine

The metal attenuation capacities of secondary acid mine water precipitates is dependent upon such factors as pH, ionic strength, the presence of competing ions, and tailings mineralogy. At the abandoned Spenceville Cu mine in Nevada County, California, approximately 6800 m³ of jarosite overburden and 28,000 m³ of hematite residue are potential sources of heavy metals loading to infiltrating surface waters. A column study was performed to assess the ability of the overburden and the residue to attenuate heavy metals from acidic mine drainage. The study information was needed as part of a remedial design for the abandoned mine, and was designed to simulate a worst-case scenario to examine the plausibility of backfilling a large open pit with the waste materials. Ten pore volumes of acidic mine drainage were allowed to pass through the materials, and the column effluents were analyzed for dissolved Fe, Al, Ca, Mg, Na, K, Mn, Cu, Zn, Pb and Ni using ICP-AES. The oxidation-reduction potential (Eh) was measured with a combination PtAg/AgCl electrode and also calculated from Fe(II) and Fe(III) measurements using the Nernst equation. Ion activities in solution and saturation index (SI) values for various solid phases were calculated using the geochemical speciation model MINTEQA2, and mineralogical compositions of fine (< 2 mm) and coarse ( > 2 mm) fractions were determined by XRD. Geochemical modeling of the column effluent compositions indicate that goethite, jarosite, jurbanite and gypsum are potential solid phases that may control metal solubilities in the column effluents. Excellent agreement was observed between the measured Eh values and those calculated from the activity ratio of Fe²⁺(aq) to Fe³⁺(aq). The large attenuation capacities for Cu and Zn exhibited by the jarosite overburden also suggest that solid solution substitution plays a large role in controlling metal concentrations in the pore waters. Relatively little metal attenuation, however, was provided by the hematite residue.