The adsorption characteristics of heavy metals: cadmium(II), chromium(III), copper(II), nickel(II), lead(II), and zinc(II) ions by kaolin (kaolinite) and ballclay (illite) from Thailand were studied. This research was focussed on the pH, adsorption isotherms of single-metal solutions at 30–60 °C by batch experiments, and on ion selectivityin mixed and binary combination solutions. It was found that, except Ni, metal adsorption increased with increased pH of the solutions and their adsorption followed both Langmuir and Freundlich isotherms. Adsorption of metals in the mixture solutions by kaolin was: Cr > Zn > Cu ≈ Cd ≈ Ni > Pb, and for ballclay was: Cr > Zn > Cu > Cd ≈ Pb > Ni. The adsorption of metals was endothermic, with the exception of Cd, Pb and Zn for kaolin, Cu and Zn for ballclay. Kaolin and ballclay exhibited relatively hard Lewis base adsorption site. The presence of other metals may reduce or promote the adsorption of heavy metals. The presence of Cr³⁺induced the greatest reduction of metal adsorptiononto kaolin, as did the presence of Cu²⁺for ballclay.

Urban transportation activities generate a wide gradation of anthropogenic solids with varying physical and chemical properties. These solids accumulatein urban highway snow and remain as residual deposition material after the melting and recession of the snow from the pavement shoulder. This study analyzed the physical characteristics of these residuals and the associatedheavy metals for 10 urban highway sites located throughout metropolitan Cincinnati. Results from the residuals analyses indicate that for all sites particle gradations ranged from greater than 5000-μm to less than 25-μm with a mean d₅₀of 1225-μm. Specific gravity (ρₛg) of residual solids ranged from 2.5 to 3.2 as evaluated for intervals across thegradations, with the lower specific gravity associated with particles less than 100-μm. For each gradation, specific surface area (SSA) generally increased with decreasing particle size while the predominance of total surface area (SA) was associated with the coarser size fractions. Cumulativeanalysis for Pb, Cu, Cd and Zn associated with snow residuals indicated that more than 50% of the heavy metal mass was associated with particles greaterthan 250-μm and more than 80% was associated with particles greater than 50-μm. Results provide guidance for management of urban snow residuals and design of treatment strategies focused on these residuals.

Assessing metal contamination of sediments requires knowledge of the geochemical partitioning of trace metals at the sediment-water interface. Under controlled laboratory conditions, sequential extraction was conducted to determine the associations of metals (Cd, Cr, and Zn) and radiotracers (¹⁰⁹Cd,⁵¹Cr, and⁶⁵Zn) with various geochemical phases and the different partitioning and mobility of metals for two types of surface sediments collected from the Huanghe and Changjiang Rivers in Eastern China. The residual phase was the major phase for stable metal binding, indicating that these sediments had little subjection to recent anthropogenic influences. Fe–Mn oxides were the next important binding phases for metals. The partitioning of metals in various geochemical phases as a function of the duration of the radiolabeling was also examined. Trace metals transferred among the different geochemical phases over the 30 days radiolabeling period, particularly between the carbonate and Fe–Mn oxides phases. The freshwater-sediment distribution coefficients (Kd) of three metals were investigated in batch experiments using the radiotracer technique. The decreasing Kdwith increasing metal concentration(from 0.5 to 200 μg L⁻¹) may be explained by competitive adsorption. The metal Kdin sediments from the Changjiang River was greater than those from the Huanghe River, presumably because of the higher Fe/Mn and organic carbon contents in Changjiang River sediment. The Kddecreased with increasing total suspended solid load from 3 to 500 mg L⁻¹, and was Cr > Zn > Cd. For Cd and Zn, increasing the pH from 5 to 8 resulted in an increase in Kddue to the reduced H⁺competition and increasing sorptionpotential. However, the Kdfor Cr in the sediments from both rivers showed no relationship with pH, presumably becauseof the complexity of the Cr species and environmental behavior.

The threshold friction velocities for dust rises in inland China are examined using WMO synoptic station data and the soil types in the source region to estimate dust emission amounts for a dust event occurred from 13 to 24 April 1998 in China. The dust-rise reports in the WMO synoptic data are used for the delineation of dust source regions that are found to be composed of the Gobi, Sand and Loess regions according to soil types in inland China. The estimated threshold friction velocities with the use of wind speeds observed in the Gobi, Sand and Loess regions are found to be about 60, 50, and 40 cm s⁻¹, respectively. The estimated dust-rise occurrencegrids by both the grid interpolated observed wind and the MM5 model wind well coincide with the areas of strong wind speeds. However, the dust-rise areas estimated by the model are larger than those estimated by the observed wind, whereas the friction velocities estimated by the model in the dust-rise areas are much smaller than those estimated by the observed wind, which result in less amount of dust emission by the model in all source regions. The 10-day accumulated total dust emission estimated by the observed wind during the dust storm event is found to be 4.64 × 10⁸ton in the whole source region of 3.29 × 10⁶km². Of which 85, 9 and 6% are, respectively, contributed by the Gobi, Sand and Loess regions,suggesting the dominant emission from the Gobi region for this event.The model estimated total dust emission is found to be about 56% of that estimated by the observed wind, indicating some improvement of the model being required.

In this study, the adsorption of phosphate on gas concrete from aqueous solutions has been studied as functions of temperature, mixing rates and suspension pH. Over 99% of phosphate removal was found. The chemical composition of the gas concrete has been defined by X-ray analysis. Experimental data was fitted to the Langmuir equation in order to Langmuir coefficients. After calculating Langmuir coefficients, adsorption free energy (Δ G⁰ₐdₛ.) has been determined. In order to gather information about adsorption mechanism, electrophoretic mobilites of particles were measured at various pHs by using Zeta meter 3.0+. It has been found that the adsorption is driven by the interactions between the ionizations of CaO and Al₂O₃and the formation of AlPO₄. According to the BET (N₂) measurements, the specific surface area of gas concrete was found as 22 m²g⁻¹. The surface area after adsorption has been found as 17 m²g⁻¹. The surface area covered by adsorbate has been found as 5.23 m²g⁻¹by usingaₛ= nˢₘ. aₘ. NA. These two areas determined by BET and Langmuir model were close to each other (BET: 22 m²g⁻¹–17 m²g⁻¹).

This paper is devoted to the assessment of the impact of the Upper Silesian Industrial Region on greenhouse gases emissions in Poland. Detailed analysis will cover emissions of methane and carbon dioxide which are characteristic for the mining and power engineering industry prevailing in this region. The industries of Silesia emit 16.2% of CO₂, and about 30% of methane emissions in Poland come from coal seams. The leading strategy to counteract this situation, not only in Upper Silesia, should involve the improved efficiency of energy use and decreased use of primary energy carriers.

We studied the environmental effects of the mining activity of Troya Mine on the fluvial ecosystem, in the Basque Country, Spain, from 1993 to 1995. The multivariate analysis of the physicochemical conditions shows that the main abiotic factors of variation are: (i) in the water column, a significant increase in the content of heavy metals and conductivity, and (ii) an intense accumulation of heavy metals in the bottom sediments. We studied the effects of these factors on density, richness, dominance, similarity coefficient and composition of the benthic macroinvertebrate community (BMI).We observed a de-structuring of the community. Richness decreases (from 25 to 11 different number of families), but it does not suitably value the impact. Density oscillates radically (255–1548 individuals m⁻²) and reflects changes occurred in sediments. Dominance, which oscillates from 0 to 1, increase from 0.16 upstream from the mine, to 0.42 downstream, fundamentally due to oscillations of Chironomidae, Tubificidae, Baetidae and Simuliidae. The similarity coefficient indicates the physicochemical variations both in the sediment and in the water column; this index is therefore suitable for the follow-up of the evolution of the disturbance studied. The families sensitive to disturbance in the water column are: Ephemeridae, Athericidae, Sericostomatidae, Leptophlebiidae, Baetidae, Gammaridae, Perlidae, Heptageniidae, and Leptoceridae; the tolerant ones are: Coenagrionidae, Hydrobiidae, Lumbricidae, and Polycentropodidae.With regard to the metal content in sediments, the sensitive families are: Gammaridae, Ephemeridae and Ceratopogonidae; the tolerant ones are: Simuliidae, Culicidae, Hydrophilidae, Dolichopodidae, Chironomidae, Psychodidae, Tipulidae, and Chrysomelidae.We thus synthesized the complexity inherent to this type of pollution, in which large amounts of variables are normally involved.