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.

A photochemical puff-trajectory model (Fotoplume) has been applied to simulate emissions, atmospheric transport and chemical transformations of pollutants from offshore oil and gas production in the North Sea. The above model was used in conjunction with the European Monitoring and Evaluation Programme (EMEP) regional Lagrangian oxidant model. The Fotoplume and EMEP models were used to evaluate the effects of the atmospheric emissions from the oil and gas exploration activity in the Norwegian sector of the North Sea. Deposition of nitrogen and formation of boundary level ozone in Southern Norway due to North Sea emissions of nitrogen oxides (NOₓ), carbon monoxide (CO) and volatile organic compounds (VOC) have been studied. The petroleum activity in the North Sea is calculated to contribute approximately 20% of the nitrogen deposition in the coastal areas of Norway in 1992. In addition, the models were used to estimate the AOT40 ozone exposure levels. The results indicate that emissions from British and Norwegian oil and gas exploitation sector separately contribute to less than 5% each of the AOT40 values for coniferous forests and meadows. Comparison of model calculations with experimental measurements is quite satisfactory and the models show realistic results for both the nitrogen deposition and AOT40 values.

Attempt has been made to study the treatability of printing ink wastewatergenerated from an Indian currency printing press using coagulation-flocculation process. Coagulant agents, viz. ferrous sulphate, ferric chloride, aluminium sulphate and polyaluminium chloride were studied to select the most suitablecoagulant for effective treatment, and attain the optimum coagulant concentration. Cationic polyeletrolyte in conjunction with the most effective coagulant was also studied to assess its effect on floc settleability. Polyaluminium chloride (PAC) was found to be the most efficient coagulant, achieving removals of colour, suspended solids (SS), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of 95.9–96.5%, 96.5–97.0%, 61.3–65.8%and 54.8–61.8%, respectively at an optimum concentration of 1500 mg L⁻¹. Other coagulants, viz. ferrous sulphate, ferric chloride and aluminium sulphate did not show substantial removals of colour, BOD and COD, except suspended solids in comparison to the performance of PAC. Cationic ploylectrolyte in combination with PAC at an optimum concentration of 1500 mg L⁻¹of PAC and 1.0 mg L⁻¹of polyelectrolyte further improved the removal efficiency of various parameters studied, in addition to improving the floc settling rate, and reduction in quantity of sludge generation.Effect of rapid mixing intensity expressed as mean temporal velocity gradient (G), and mixing time (t) on flocculation was also investigated. Rapid mixing at an impeller rotational speed (n) of 300 rpm and mixing time (t) of 60 sec indicated good floc formation, which resulted in achieving velocity gradient of 821 s⁻¹, and was found to be an optimum combination. This was also indicated by relatively high settling velocity of sludge formed and low residual colour in the supernatant. However, slow mixing beyond 5 min, adopted after initial optimum rapid mixing, indicated negligible effect on flocculation.

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.

In Zacatecas, Mexico, four plants are operating to extract Ag, Au, and Hg using CaS₂O₃solution from surface soil containing tailings from the amalgamation method used during 1550–1900. The metal ions extracted are cemented by scrap Cu wires. Hg is separated by evaporation from the cemented amalgam and Ag and Au are obtained from the residue. A part of the soil to be leached was separated and leached as in the industrial process. Only 121 ppm of Hg was freed from 168 ppm of extractable Hg. About a half of the remaining Hg in the soil evaporated during 18 months. This confirms that the Hg in the soil is metallic. Pb and As are also freed in the same process. It is estimated that 13 000–34 000 t of Hg had been discarded in the extraction of Ag.

The contributions of different acidifying processes to the total protonload (TPL) of the soil in control plots (C) and ammonium sulphate treatedplots (NS) were studied in a Norway spruce stand in Southwest Sweden during 1988–1998. The annual deposition of inorganic nitrogen and sulphate was on average 18 kg N and 20 kg S ha⁻¹. In addition the NS treated plots received 100 kg N and 114 kg S ha⁻¹annually. The amounts of nutrients added to the ecosystem by wet and dry deposition and the leaching at 50 cm depth were calculated. The net atmosphericproton load, the proton load by nitrogen transformations in the soil, the sulphate sorption/desorption in the soil and the excess base cation accumulation in biomass were calculated. There was no leaching of inorganic nitrogen from control plots during the study period. The net atmospheric proton deposition, originating from sulphuric and nitric acid deposition, was the main contributor to TPL in control plots. The addition of ammonium sulphate increased the leaching of ammonium, nitrate, sulphate, magnesium and calcium but not of potassium. The TPL in NS plots was about ten times that in control plots. The nitrogen transformation processes were the main contributors to TPL to NS soil, in the beginning by ammonium uptake and later also by nitrification. The pH decreased by 0.4 units in the mineral soil. The between-year variation in TPL during the eleven year period in C plots (200–1500 molcha⁻¹yr⁻¹) and in NS plots (1000–13000 molcha⁻¹yr⁻¹) was mainly dependent on the sorption or release of sulphate. Both in C and NS, the TPL was buffered mainly by dissolving solid aluminium compounds, most probably some Al(OH)₃phase.

Emissions in East Asia for 1993 by administrative units and source types are estimated to support regional emission assessments and transport modeling studies. Total emission of SOₓ, NOₓ, soil NOₓ, N₂O, and NH₃are 24 150, 12 610, 1963, 908, and 8263 kton yr⁻¹, respectively.China's emission contribution is the highest for every species.The area sources are the most significant source type for SOₓand NOₓ, but the fraction due to mobile source is highest for NOₓ. Major LPSs are located from the middle to the east part of China, south and middle-west part of South Korea, and the east part of Japan. The area sources of SOₓshow a pattern similar to population density, whereas NH₃shows a strong landuse dependency. Detail emissions analysis reveals higher SOₓemission `cores' within each province. The estimated emissions are used to estimate sulfur deposition in the regions. The seasonal average sulfur distribution amounts are estimated from the ATMOS2 chemical transport model. The results showed anti-correlation with temperature for sulfur (SO₂+ SO₄⁻²) concentrations and a positive correlation with rainfall for deposition.

More than 600 arable soils from Flanders (Northern-Belgium) were analysed for their total acid extractable contents of As, B, Be, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn in order to determine any increase in the natural background values. Samples were taken at random in several municipalities throughout Flanders. Areas with known historical or actual sources of trace element emissions were omitted although in some cases the distance between those sources and the sampling locations was not more than 20 km. The main soil types were, ranging from north to south: sand, loamy sand, light sandy-loam, sandy-loam and loam. In the coastal area, clay soils (sea polders) were sampled. In addition to the analysis of trace elements, the soil texture class, the pH and the carbon content were determined. Macro- or mesonutrients, Ca, K, P, Mg and Na, were determined from a weak acid extract of the soil samples. Correlations between trace elements and macronutrients provide some information about fertilisation practices and heavy metal sources.A limited number of soils showed slightly enhanced levels for As, Be, Cu, Co, Cr Mn, Ni Pb and Zn. In most cases, this could be linked to the regional industrial activities. However, a clear increase for Cu and Zn, above the natural background could be distinguished in areas with low atmospheric heavy metal deposits. In these cases, the excessive use of animal manure in the past may be the reason for this enrichment. However there was no indication that the Cd content of the soil was raised by the use of large amounts of pig slurry and/or by other common agricultural activities.

To determine the importance of Al-availability for soil micro-organisms 95 forest soils from Tyrol/Austria with comparable topography, vegetation, climatic conditions, soil type and with low soil pH (median = 3.9) were investigated for their physical (percentage of stable aggregates, water holding capacity), chemical (pH, electrical conductivity, contents of organic matter, concentrations of easily extractable aluminium, calcium, potassium, magnesium and phosphorus) and microbiological characteristics (microbial biomass and respiration, metabolic quotient, content of ATP, activities of protease and CM-cellulase, cfu-values of total and Al-tolerant bacteria and fungi). A highly significant negative correlation was detected between concentrations of KCl-extractable aluminium and soil pH. By the application of multivariate statistical methods, the effect of the concentration of KCl-extractable aluminium on abundance and activities of soil micro-organisms could be revealed. Al turned out to be of great importance for micro-organisms and often outmatched the significance of other well known soil properties like organic matter, pH or water holding capacity. However, due to very healthy trees at the sites under investigation no effect of Al or soil acidification on forest decline could be detected.