Mine Waste Materials Research Articles

Geochemical and mineralogical assessment of sedimentary limestone mine waste and potential for mineral carbonation.

This paper attempts to evaluate the mineralogical and chemical composition of sedimentary limestone mine waste alongside its mineral carbonation potential. The limestone mine wastes were recovered as the waste materials after mining and crushing processes and were analyzed for mineral, major and trace metal elements. The major mineral composition discovered was calcite (CaCO3) and dolomite [CaMg(CO3)2], alongside other minerals such as bustamite [(Ca,Mn)SiO3] and akermanite (Ca2MgSi2O7). Calcium oxide constituted the greatest composition of major oxide components of between 72 and 82%. The presence of CaO facilitated the transformation of carbon dioxide into carbonate form, suggesting potential mineral carbonation of the mine waste material. Geochemical assessment indicated that mean metal(loid) concentrations were found in the order of Al > Fe > Sr > Pb > Mn > Zn > As > Cd > Cu > Ni > Cr > Co in which Cd, Pb and As exceeded some regulatory guideline values. Ecological risk assessment demonstrated that the mine wastes were majorly influenced by Cd as being classified having moderate risk. Geochemical indices depicted that Cd was moderately accumulated and highly enriched in some of the mine waste deposited areas. In conclusion, the limestone mine waste material has the potential for sequestering CO2; however, the presence of some trace metals could be another important aspect that needs to be considered. Therefore, it has been shown that limestone mine waste can be regarded as a valuable feedstock for mineral carbonation process. Despite this, the presence of metal(loid) elements should be of another concern to minimize potential ecological implication due to recovery of this waste material.

Are LCA Studies on Bulk Mineral Waste Management Suitable for Decision Support? A Critical Review

Bulk mineral waste materials are one of the largest waste streams worldwide and their management systems can differ greatly depending on regional conditions. Due to this variation, the decision-making context is of particular importance when studying environmental impacts of mineral waste management systems with life cycle assessment (LCA).We follow the premise that LCA results—if applied in practice—are always used in an improvement (i.e., decision-making) context. But how suitable are existing LCA studies on bulk mineral waste management for decision support? To answer this question, we quantitatively and qualitatively assess 57 peer-reviewed bulk mineral waste management LCA studies against 47 criteria. The results show inadequacies regarding decision support along all LCA phases. Common shortcomings are insufficient attention to the specific decision-making context, lack of a consequential perspective, liberal use of allocation and limited justification thereof, missing justifications for excluded impact categories, inadequately discussed limitations, and incomplete documentation. We identified the following significant issues for bulk mineral waste management systems: transportation, the potential leaching of heavy metals, second-order substitution effects, and the choice to include or exclude avoided landfilling and embodied impacts. When applicable, we provide recommendations for improvement and point to best practice examples.

Geochemical and Mineralogical Characterisation of Historic Zn–Pb Mine Waste, Plombières, East Belgium

Mine wastes and tailings derived from historical processing may contain significant contents of valuable metals due to processing being less efficient in the past. The Plombières tailings pond in eastern Belgium was selected as a case study to determine mineralogical and geochemical characteristics of the different mine waste materials found at the site. Four types of material were classified: soil, metallurgical waste, brown tailings and yellow tailings. The distribution of the mine wastes was investigated with drill holes, pit-holes and geophysical methods. Samples of the materials were assessed with grain size analysis, and mineralogical and geochemical techniques. The mine wastes dominantly consist of SiO2, Al2O3 and Fe2O3. The cover material, comprising soil and metallurgical waste is highly heterogeneous in terms of mineralogy, geochemistry and grain size. The metallurgical waste has a high concentration of metals (Zn: 0.1 to 24 wt.% and Pb: 0.1 to 10.1 wt.%). In the tailings materials, Pb and Zn vary from 10 ppm to 8.5 wt.% and from 51 ppm to 4 wt.%, respectively. The mining wastes comprises mainly quartz, amorphous phases and phyllosilicates, with minor contents of Fe-oxide and Pb- and Zn-bearing minerals. Based on the mineralogical and geochemical properties, the different potential applications of the four waste material types were determined. Additionally, the theoretical economic potential of Pb and Zn in the mine wastes was estimated.

Use of image processing algorithms for mine originating waste grain size determination

The utilization of mineral wastes from the mining industry is one of most challenging phases in the raw materials life cycle. In many countries, there are piles of mineral waste materials that date back to the previous century. There is also a constant stream of accompanying mineral matter excavated during everyday mine operation. This stream of waste matter is particularly notable for deep coal mining. Grain size composition of waste mineral matter is one of most important characteristics of coal originating waste material. This paper presents the use of image analysis for the determination of grain size composition of mineral matters. Three methods for edge identification have been tested: gradient magnitude, multiscale linear filtering and Statistical Dominance Algorithm (SDA). Images acquired in laboratory conditions were pre-processed using Gaussian, Median and Perona-Malik filtration. The image was segmented using a classic watershed algorithm; as a reference, manually segmented images were used. The results show that the SDA algorithm was the best in determining the grain edges. Therefore, the sizes determined after application of this algorithm were closest to the referenced ones. This method can be used for the assessment of the grain size composition of mineral waste material.

The Use of Mining Waste Materials for the Treatment of Acid and Alkaline Mine Wastewater

The mining of metal ores generates both liquid and solid wastes, which are increasingly important to manage. In this paper, an attempt was made to use waste rocks produced in the mining of zinc and lead to neutralizing acid mine drainage and alkaline flotation wastewater. Waste rock is a quartz-feldspar rock of hydrothermal origin. It is composed of, besides quartz and potassium feldspar (orthoclase), phyllosilicates (chlorite and mica), and sulfides (chiefly pyrite). To determine its physicochemical parameters and their variability, acid mine water and flotation wastewater were monitored for 12 months. Acid mine drainage (AMD) is characterized by a low pH (~3), high zinc concentration (~750 mg·L−1), and high sulfate content (~6800 mg·L−1). On the other hand, the determinations made for flotation wastewater showed, among others, a pH of approximately 12 and ca. 780 mg·L−1 of sulfates. AMD and flotation wastewater neutralization by the waste rock was shown to be possible and efficient. However, in both cases, the final solution contained elevated concentrations of metals and sulfates. Premixing AMD with alkaline flotation wastewater in the first step and then neutralizing the obtained mixture with the waste rock was considered the best solution. The produced solution had a circumneutral pH. However, the obtained solution does not meet the legislative requirements but could be further treated by, for example, passive treatment systems. It is noteworthy that the proposed approach is low cost and does not require any chemical reagents.

Characterization of modified mineral waste material adsorbent as affected by thermal treatment for optimizing its adsorption of lead and methyl orange

AbstractThermal treatment is one of the most common processes in mineral modification, and this process has been applied to the modification of mineral waste material to improve its adsorption ability of methyl orange (MO) and lead (Pb) in this study. The properties of modified mineral waste material (MMWM) before and after thermal modification were characterized by using the Brunauer–Emmett–Teller (BET) N2 adsorption/desorption measurement, field emission scanning electron microscope (FESEM) coupled with energy-dispersive X-ray (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Phase transformation was investigated related to the change in surface morphology and dehydroxylation that occurred in MMWM samples during the process of thermal treatment. To study adsorption performances of Pb and MO onto the newly modified MMWM, several experiments were carried out under different adsorption conditions and the results were determined using inductively coupled plasma optical emission spectrometry (ICP-OES) and UV-Vis spectrophotometry. The thermally treated MMWM samples showed morphological transformation and an increasing trend in BET specific surface area (SSA) up to 500 °C followed by a decreasing trend till 1000 °C. Thermal modification of MMWM successfully improved Pb adsorption from 349 to 515 mg/g, corresponding to the MMWM modified at 600 °C, and the methyl orange (MO) adsorption from 68 to 87.6 mg/g at 400 °C. The adsorptions of Pb and MO were mainly chemisorption and monolayer coverage, as the pseudo-second-order model and the Langmuir equation displayed good correlations for Pb and MO adsorption data.

Amendments to improve plant response under simulated water-limited conditions in diamond mine Anthroposols

Development of Anthroposols for land reclamation requires consideration of a variety of factors to support plant establishment and growth. Water limitation is a key challenge when using mine waste as a growth medium, and these materials also have poor structure and lack organic matter and nutrients. These greenhouse experiments assessed effectiveness of treatments composed of hydrogel and organic amendments to increase plant establishment and growth under water-limited conditions in mine waste materials (crushed rock, lakebed sediment, and processed kimberlite) from a diamond mine in northern Canada. Amendments were hydrogel, peat, sewage, and soil, mixed with waste materials (substrates) at four application rates, and seeded with slender wheat grass (Elymus trachycaulus). One experiment assessed germination response with limited watering during germination, and the other experiment assessed growth response with adequate water during germination followed by restricted water. Substrate had the greatest effect on germination, with processed kimberlite and crushed rock being most successful, at least 10% higher than lakebed sediment. Sewage amendment resulted in the largest plants (mean 0.22 g in lakebed sediment, 0.40 g in crushed rock and processed kimberlite, 0.05 g no amendment); sewage had a limited effect on germination. Highest organic amendment application generally improved plant response. Hydrogel did not improve plant growth, although it increased germination up to 63% in processed kimberlite. Type of mine waste, amendment, and rate of application impacted germination and plant growth and can be altered to build a suitable Anthroposol for reclamation.

Hydrogeochemical Behavior of Reclaimed Highly Reactive Tailings, Part 2: Laboratory and Field Results of Covers Made with Mine Waste Materials

The possibility of using mine wastes (low-sulfide tailings and waste rocks) as cover components to prevent acid mine drainage (AMD) generation from highly reactive tailings was previously investigated through a laboratory-based characterization of reactive tailings and cover materials (Part 1 of this study). Characterization results showed that the reactive tailings are highly acid-generating, and that the mine waste materials that were used in this study are non-acid-generating and have suitable hydrogeological and geochemical properties to be used in a cover with capillary barrier effects (CCBE). In order to further investigate the use of low-sulfide mining materials in the reclamation of highly reactive tailings, a large laboratory-based column and a field cell simulating a CCBE were constructed. The instrumented field cell used the same configuration and materials as the laboratory column. This paper presents the main findings from 504 days (column test) and three seasons (field test) of monitoring, and compares the hydrogeochemical behavior observed at the two scales. The results show that a CCBE made with low-sulfide mine wastes would be efficient at reducing oxygen fluxes and limiting AMD generation from highly reactive tailings at the laboratory and intermediate scale. However, at these two scales, the concentrations of some contaminants were not reduced to levels of the legally imposed environmental objectives. The results also showed differences in metal and sulfate concentrations in the drainage waters between the laboratory and field scales. The outcomes from this investigation highlight that the previous oxygen flux design targets and the typical configurations of multilayer covers developed for fresh non-oxidized tailings or pre-oxidized tailings may not always be directly applicable for fresh or pre-oxidized highly reactive tailings.

Assessment and Characterization of Mine Waste and Fly Ash Material for Effective Utilization in Opencast Coal Mines

Coal is a major source of nonrenewable energy in India. Most of the Industries depend on the coal to meet the energy demand of the country. Coal mining is invariably associated with the generation of voids. The voids so generated are often filled with overburden (OB) and waste materials. To enhance the utilization, fly ash (FA) is also being used for filling the voids. However, these operations inevitably require excessive planning and control to minimize the environmental impact of mining. In order to evaluate the impact of backfilling the voids with coal mine wastes and fly ash, Overburden and fly ash materials have been collected from Talcher coalfield. The geotechnical characterization study of overburden (OB) sample and OB+30% fly ash samples have been carried out separately for backfilling. After addition of fly ash, it is observed that the permeability is increased but liquid limit, plastic limit, and plasticity index (PI) of the OB are decreased. The maximum dry unit weight of OB mixture decreases while optimum water content increases with the fly ash. The angle of internal friction of OB decreases after addition of the fly ash. Cohesion value of OB sample has not changed much after addition of the fly ash. The grain size analyses results show OB sample is poorly graded. The OB soil type is found to be poorly graded sand of low compressible clay (SP-CL). Similarly, the OB+30% fly ash soil type is of poorly graded sand of low compressible silty (SP-ML) type. The OB and OB+ 30% fly ash contain heavy metals such as Fe and Al in high quantity, mild concentrations of Zn, Cr, and Mn and low amounts of Cu, Co, As, and Se. B and Pb are found below the detection level. The decreasing order of heavy metals in the leachate samples observed to be Fe>Mn>Ni>Cu>Zn>Se>Co>Cd>Cr>As. The major mineral phases in OB and OB+30% fly ash samples are found to be quartz, kaolinite, muscovite, dickite, zinnwaldite, and illite.

Modelling the hydrologic effects of vegetation growth on the long-term trajectory of a reclamation watershed

Reclamation watersheds that integrate fen peatlands into the design require the inclusion of uplands that are capable of supporting forest development while concurrently supplying sufficient groundwater recharge to downgradient wetland ecosystems. This necessitates selecting materials with suitable soil hydraulic properties and identifying the appropriate thickness and layering to fulfill the dual function of uplands as water storage, and water conveyance features. Currently, these systems incorporate tailings sand - a mine waste material - overlain by a cover soil of fine forest-floor material. The developmental pathway of these uplands is currently unknown, and it is unclear whether these landforms will provide enough groundwater recharge once a climax vegetation community establishes. Therefore, this research attempts to estimate the maximum density of vegetation, and associated water balance fluxes of a constructed upland integrated into a peatland watershed. The numerical modelling software HYDRUS-1D simulated soil moisture dynamics using a 65-year meteorological record, and a plant water stress algorithm was used to estimate the maximum sustainable leaf area index that the upland could support. Based on the thickness of the cover soil, the upland could support an average leaf area index of 1.2. Under this vegetation density, average annual groundwater recharge was 83 mm, and predominantly supplied by snowmelt (64%). Given this quantity of recharge, the model indicates that the upland will continue to provide enough groundwater to offset the anticipated water deficit in the downgradient fen ecosystem. However, by altering the design of the upland, specifically the spatial arrangement and thickness of cover soil, the same recharge could be supplied while also allowing for a higher average vegetation density. Such a design could allow for the creation of watersheds with a higher proportion of peatland.

Low Liquid-to-solid Ratio of Mining Waste and Slag Binary Alkali-activated Material

This study investigates the effect of the increasingly compressing pressures on the properties of the low liquid-to-solid (L/S) ratio binary alkali-activated binder to use as a binder for the manufacturing of engineered stones. The binders were a combination of two types of wastes (aluminosilicate source) as precursors (TMWM 50 Vt.% + EAF-Slag 50 Vt.%), blended with (11.11 wt.%) alkaline activator solution (NaOH/Na2SiO3 with weight ratio 4/1). The mixtures were molded in cube and exposed to five different pressures (20, 40, 60, 80 and 100 MPa) in order to obtain a compressed alkali-activated binder. The main evaluation techniques in this study were compressive strength, and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that the maximum compressive strength (50.57 MPa) was obtained at a pressing pressure 100 MPa at twenty-eight days of testing.

Laboratory study: durability characteristics of Asphalt concrete binder course utilizing Bantak and Clereng as aggregate and Asbuton Lawele as fine aggregate (using Marshall Methods)

Construction of roads and will continue and growing, while on the other side of the raw material reserves for the road less. Given this, the researchers tried to use the mining waste material at the bottom of Sabo Dam from Merapi which is bantak to substituted coarse aggregate and asbuton is substituted fine aggregate to tackle the lack of asphalt and to utilise local’s natural resources. This research carried out by using a mixture of 40% Bantak and 60% Clereng and substitute fine aggregate (substitution) with asbuton Lawele type 20/25 with the same amount. The asbuton concentrate variation that used in the test are (100%:0), (75%:25%), (50%:50%), (25%:75%), (0%:100%). All the specimens tested and analysed using Marshall Method as Public Work Department specification (2007), determined the optimum asphalt value of each specimen. All specimens with optimum value will immersed in water during half hour, 24 hours and 48 hours before Marshall test. Result of the test is used to know the asbuton substitution variation effects based on stability value, and residual strength index. The result shows that optimum asphalt value of asbuton specimens with percentage asbuton 0%, 25%, 50%, 75% and 100% are 6.2%; 5.6%; 5.25%; 5.1% and 5%. On standardise immersion asbuton variation of 0%, 25%, 50%, 75% and 100% the mix stability value are of 1498 kg, 1629 kg, 1405 kg, 1264 kg and 1258 kg respectively. While on 48 hour immersion, the residual strength indexs are 97.97%, 88.86%; 71.06%; 64.41% and 57%. In the conclusion optimum utilisation asbuton is 25% with optimum asphalt value 56% because has high stability, but has low durability.

Fluoride adsorption and photoreduction of Cr(VI) using heterogeneous Al3+ modified mine-waste, an in-situ approach

Herein, an in-situ ion-exchange mechanism of fluoride (F‒) uptake of the ore type present in Beldih (23°3'5"N 86°17'46"E, India) exhausted phosphate mines and fabrication of triclinic, pH-stable a cost-effective Al3+ modified nanocomposites using the phosphate mine-waste (MW) materials for F‒ adsorption and the photoreduction of Cr(VI) under Solar irradiation has been demonstrated. The materials were characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD), Furrier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), ξ-potential study, UV–vis diffuse reflectance spectra (UV–vis DRS), and Brunauer–Emmett–Teller (BET) surface area studies. The F‒ removal efficiency along with the photoreduction ability was highest for the MW2 (MW : Al3+ = 1:2, w/w %) with BET surface area 11.05 m2/g i.e. 80 % for 10 ppm F‒ solution and 81.89 % for 3 ppm Cr(VI) solution at pH 7 respectively. The F‒ removal occurred through chemisorption process revealed from the FTIR and BET isotherm studies. The photoreduction of Cr(VI) to Cr(III) followed the pseudo-1st-order kinetics and the mechanism established through the pH-controlled surface charge model.

Mineral carbonation of sedimentary mine waste for carbon sequestration and potential reutilization as cementitious material.

This study highlights the importance of mineralogical composition for potential carbon dioxide (CO2) capture and storage of mine waste materials. In particular, this study attempts to evaluate the role of mineral carbonation of sedimentary mine waste and their potential reutilization as supplementary cementitious material (SCM). Limestone and gold mine wastes were recovered from mine processing sites for their use as SCM in brick-making and for evaluation of potential carbon sequestration. Dominant minerals in the limestone mine waste were calcite and akermanite (calcium silicate) while the gold mine waste was dominated by illite (iron silicate) and chlorite-serpentine (magnesium silicate). Calcium oxide, CaO and silica, SiO2, were the highest composition in the limestone and gold mine waste, respectively, with maximum CO2 storage of between 7.17 and 61.37%. Greater potential for CO2 capture was observed for limestone mine waste as due to higher CaO content alongside magnesium oxide. Mineral carbonation of the limestone mine waste was accelerated at smaller particle size of < 38μm and at pH 10 as reflected by the greater carbonation efficiency. Reutilization of limestone mine waste as SCM in brick-making exhibited greater compressive strength and lower water absorption compared to the bricks made of gold mine waste. The gold mine waste is characterized as having high pozzolanic behaviour, resulting in lower carbonation potential. Therefore, it has been noticeable that limestone mine waste is a suitable feedstock for mineral carbonation process and could be reutilized as supplementary cementitious material for cement-based product. This would be beneficial in light of environmental conservation of mine waste materials and in support of sustainable use of resources for engineering construction purposes.

Analysis of the Thermophysical and Chemical-Technological Properties of Mining and Processing Waste Materials

Results of a system analysis of volumes and physical, chemical, granulometric, lithological, and thermophysical characteristics of waste materials of apatite–nepheline ores stored in tailing dumps of ore mining and processing works are presented to assess the economic viability of using such materials in energy- and resource-efficient and environmentally sustainable processing systems comprised of conveyor belt roasting machines and ore-thermal furnaces. The results allow the formulation of the principal engineering, technological, economic, and environmental requirements imposed on complicated chemical–power-engineering systems for the processing of apatite–nepheline ore waste materials at mining and processing works and the determination of the variability degree of the characteristics of waste batches from different dumps.

Incorporation of gold and limestone mining waste materials for carbon capture and storage in bricks

The industrial sector is the main contributor of carbon dioxide emissions which have an enormous impact on the planet’s weather. One of the approaches to sequester carbon dioxide permanently is through the utilization of potential mining waste to produce commercial materials such as bricks. This research emphasizes the use of gold and limestone mining waste as raw materials for carbon capture and storage in the manufacturing of bricks and to determine their physical and mechanical characteristics for construction purposes. The dimensions of the sand bricks in this research were 215×103×65 mm. Gold and limestone mining waste was used as a partial cement replacement in sand bricks. Findings showed that the gold mine waste bricks have an average of 1.8% higher water absorption value and hence are more permeable, compared to the average of 1.05% in limestone mine waste bricks. Compressive strength measurements indicated that bricks made up of limestone mine waste have an average of 34.72 N/mm2, which is greater than the average of 24.09 N/mm2 for gold mine waste bricks. Limestone mine waste bricks exhibit good durability of the bricks as compared to gold mine waste bricks, because of their low water absorption. Thus, they have greater strength for construction purposes. Limestone mine waste bricks are more appropriate for buildings because they are less permeable and have greater brick power than gold mine waste bricks. Thus, utilization of mining waste as a raw material for bricks production might increase the physical and mechanical properties of bricks and provide potential solutions for permanent carbon dioxide storage.

Soil moisture dynamics modelling of a reclaimed upland in the early post-construction period

Mine reclamation landscapes typically comprise layers of mine waste materials such as tailings sands, capped with a cover soil. In addition to the arrangement and placement of these materials, their hydraulic properties govern the performance of the built system. Soil evolution due to freeze–thaw cycling can result in dramatically altered soil hydraulic properties compared to the as-built material. Therefore, prediction of present and future hydrologic behaviour relies on understanding the nature and magnitude of this change and the elapsed time associated with stabilization. This research quantifies the transient hydraulic properties of mine reclamation materials at a constructed upland within a reclaimed watershed, and models the effect of this evolution on the partitioning of soil moisture between evaporation and groundwater recharge. Soil moisture dynamics were simulated using HYDRUS-1D for the ice-free period two, three, and five years after construction. A capillary barrier between the fine-grained cover soil and coarse-grained tailings sand regulated percolation past the interface. Soil evolution of the cover soil was responsible for an increase in saturated hydraulic conductivity by an order of magnitude, decrease in air-entry pressure by a factor of 4, and decrease in the van Genuchten n parameter by a factor of 2. The altered soil hydraulic properties associated with the weathered cover soil ultimately resulted in a 64% increase in groundwater recharge as a consequence of the capillary barrier weakening. The cover soil exhibited minor spatial heterogeneity in soil hydraulic properties, and did not contribute substantial uncertainty to the estimates of groundwater recharge and evaporation. Cover soil thickness exerted a strong influence on the partitioning of soil moisture. Reclaimed uplands will provide the most recharge to downgradient ecosystems in the period following the completion of soil evolution (~4 years) but preceding substantial vegetation development.

Thermal properties of fired clay bricks from waste recycling. A review of studies

The large waste volumes globally generated have increased environmental awareness, promoting waste recycling as a sustainable construction material. This study presents a review of researches that analyze the thermal behavior of eco-friendly clay bricks incorporating organic and mineral waste materials as an addition. Many of these works also provide data related to the composition of the material, and its physical, micro-structural and mechanical characteristics. Most of eco-friendly clay units increase the porosity of the ceramic, improving the energy efficiency of masonry enclosures, reducing the clay content and the energy consumption during the fire process. The positive effects of lightweight ceramics are an opportunity to improve the fire resistance inside green buildings.

Differences of Acer platanoides L. and Tilia cordata Mill. Response patterns/survival strategies during cultivation in extremely polluted mining sludge – A pot trial

The study aimed to evaluate the physiological mechanisms underlying differences in metals and metalloid uptake and tolerance of two tree species cultivated in mining waste material. Two-year old Acer platanoides L. and Tilia cordata Mill. were cultivated in mining sludge characterized by high pH, salinity and an extremely high concentration of As. Both species were able to develop leaves from leafless seedlings, however, their total biomass was greatly reduced in comparison to control plants, following the severe disturbances in chlorophyll content. Phytoextraction abilities were observed for T. cordata for Ba, Nb, Rb and Se, and phytostabilisation was stated for Pd, Ru, Sc and Sm for both species, Ba and Nd for A. platonoides and Be for T. cordata only. Metal exclusion was observed for the majority of detected elements indicating an intense limitation of metal transport to photosynthetic tissue. A diversified uptake of elements was accompanied by a species-specific pattern of physiological reaction during the cultivation in sludge. Organic ligands (glutatnione and low-molecular-weight organic acids) were suppressed in A. platanoides, and enhanced biosynthesis of phenolic compounds was observed for both species, being more pronounced in T. cordata. Despite its higher accumulation of key metabolites for plant reaction to oxidative stress, such as phenolic acids, flavonoids and organic ligands, T. cordata exhibited relatively lower tolerance to sludge, probably due to the increased uptake and translocation rate of toxic metal/loids to aerial organs and/or restricted accumulation of salicylic acid which is known to play a decisive role in mechanisms of plant tolerance.

Assessment of contribution of metal pollution sources to attic and household dust in Pb-polluted area.

Attic and household dusts from Pb-polluted area were investigated using various analytical techniques for source apportionment and assessment of source contribution of metal-bearing phases. Mineralogically, attic dust consists of gypsum, anhydrite, and metal-bearing phases, while household dust comprises C-bearing particles and only minor metal-bearing phases. Sulfur isotope composition of sulfides and sulfates in attic dust shows that they result from past primary smelting of local sulfide ore, while those in household dust originate directly from local mine-waste material. Pb isotope ratios show that Pb-bearing phases in both dust types mostly originate from mining and primary smelting of local Pb-ore. Individual metal-bearing particles were apportioned by their composition, morphology, and mineralogy to phases from past Pb-smelting, present-day Pb-recycling, and past mining/mine-waste mechanical processing. Calculated source contribution of metal-bearing phases to indoor dust showed that primary Pb-smelting was important pollution source in the past, while active Pb-recycling has contributed only negligible amount of material so far. However, material from mining/mine-waste processing is an important currently active pollution source. Study demonstrated that simultaneous investigation of characteristics and isotopic composition of metal-bearing phases in different indoor dust types serves as tool for assessment of source contribution of past and recent airborne metal pollution.