The decomposition of gaseous isopropanol (IPA) by UV/TiO₂ process in an annular photoreactor was studied under various conditions such as UV light intensity and inlet IPA concentrations. In order to impede the rapid electron/hole recombination during photoreaction, the Ag deposited on TiO₂ photocatalysts were prepared by a photodeposition process. This study was aimed at applying the photocatalytic oxidation using the Ag/TiO₂ and pure TiO₂ catalysts to remove gaseous IPA. The PL analyses indicated that the silver on the surface of TiO₂ could inhibit the electron/holes recombination. For experiments conducted with gaseous IPA under UV light irradiation, the photocatalytic activity of Ag deposited TiO₂ surface was significantly superior to that of TiO₂ only ones.

In this study, the occurrence of toxic heavy metals (As, Cd, Cr, Cu, Pb, and Zn) and relative bioaccumulation in biota samples were investigated in a freshwater ecosystem, the Basento river, one of the main aquatic systems in the south of Italy, which over the last years has been transformed into a sink of urban and industrial wastes. Therefore, the levels of arsenic, cadmium, chromium, copper, lead, and zinc were determined in water, sediments, and tissues of some macroinvertebrate--which are natural assessment endpoints for the evaluation of ecological risk in aquatic systems. Accumulation factors, as a ratio between the concentration of a given contaminant in biota and the one in an abiotic medium, were considered in order to estimate heavy metal contamination loads in biota. Statistical analysis was performed for a comparative evaluation of bioaccumulation among various macroinvertebrates, according to different feeding guilds. The Tukey honestly significantly different test showed significant differences in the bioaccumulation of As, Cd, and Cr among the considered biological receptors (collector-gatherer, predator, and filterer), suggesting that the biological uptake from immediate contact with the sediment or solid substratum (collector-gatherer), instead of the bioconcentration from water (filterer) or biomagnification along the biotic food webs (predators), is the more effective biological sequestering pathway for these metals. Biota-sediment accumulation factors, commonly used for the evaluation of sediment's role in aquatic systems contamination, were determined for the considered metals. A linear correlation between the concentrations of As, Cd, Cr, and Zn in macroinvertebrates and those in the sediments suggested that the metal uptake data in macroinvertebrates can provide useful information for the estimation of heavy metal exposure risk or bioavailability when making assessments of sediment toxicity in freshwater ecosystems.

Cadmium (Cd) pollution can alter soil flora and fauna, as well as the microbial community associated with the main biogeochemical cycles of a soil. The present study was conducted to investigate the effect of two different concentrations of Cd pollutant, 6.5 mg kg⁻¹ (low level) and 12.5 mg kg⁻¹ (high level) on microbial community activity, abundance, and structure in a semiarid soil after a 60-day incubation period at laboratory level. Available Cd, water soluble carbon (WSC), microbial biomass carbon (Cmic), adenosine triphosphate (ATP) content, and real-time polymerase chain reaction were used to measure the influence of Cd on the abundance and activity of the microbial community. Bacteria and fungi community structure and diversity based on denaturing gradient gel electrophoresis (DGGE) analysis were also analyzed. The percentage of Cd extracted by diethylenetriamine pentaacetic acid increased with the higher total concentration of Cd added to the soil, being 16.9% at low level and 77.9% at the high level. WSC, Cmic, and ATP content decreased significantly as soil Cd concentration increased (WSC 29% and 34%, Cmic 27% and 35%, and ATP 32% and 47%, at low and high levels, respectively). While fungal diversity already decreased with low levels of Cd concentration, and was even more negatively affected by the higher pollution levels, bacterial (acidobacteria, α-proteobacteria, and β proteobacteria) diversity only showed a decline with the higher Cd concentration. The fungi-to-bacteria ratio showed by the different treatments could imply that fungi abundance is less influenced by increased Cd pollution, although fungi diversity as revealed by DGGE analysis diminished as soil Cd concentration increased.

The paper presents the results of a study in the region Dübener Heide (Central Germany) testing the suitability of field measurements of magnetic susceptibility for the detection of historical fly-ash deposition. The measurements supported the verification of historically documented deposition zones along an emission gradient. Mean values, standard deviation, and coefficient of variation can be used to characterize the former deposition zones, although the study revealed several problems, which will be the subject of future work: (1) the volume susceptibility measurements used in the study do not allow the calculation of the actual fly-ash amount stored in the soil and thus must be calibrated with correction factors from laboratory measurements; and (2) measurements in regions with similar conditions but without fly-ash deposition are needed to obtain reference values for the natural range of magnetic susceptibility.

This work presents kinetic parameters for the degradation of petroleum hydrocarbons, under field conditions found in a biopile created for the remediation of soil which has been heavily polluted with aged oil and oil derivatives (27,600 mg kg⁻¹ of mineral oil, 41,400 mg kg⁻¹ total hydrocarbons and 3.57 mg kg⁻¹ of total polycyclic aromatic hydrocarbon, (PAH)). The kinetics of the biodegradation process can be described by two equations: [graphic removed] (1) and [graphic removed] (2). According to Eq. 1, biodegradation kinetics constant rates were in the range from 0.58 x 10⁻³ to 1.32 x 10⁻³ day⁻¹ for mineral oil and total hydrocarbons and 6.7 x 10⁻³ to 8.8 x 10⁻³ day⁻¹ for PAHs. According to Eq. 2, biodegradation kinetics constant rates were in the range from 1.6 x 10⁻² to 3.0 x 10⁻² day⁻⁰.⁵ for mineral oil and total hydrocarbons and 0.92 x 10⁻¹ to 1.3 x 10⁻¹ day⁻⁰.⁵ for PAHs.

The constructions of Cultural and Architecture Patrimony are influenced by pollutants. Many of degenerative processes in the materials which constitute them have their origin in pollutants. That is the reason why a physical-chemical characterisation of the particulate pollutants in the air has been carried out. The deposition and, as a consequence of that, the interaction of the pollutants with the different materials of the monuments depend on the reactivity of the chemical elements that form the atmospheric particulate. Studies of both, bulk dust deposition and total suspended matter, a mineralogical and chemical characterisation of them have been made. Lastly, starting from these data, it can be established that the interactions and degenerative processes are taking place in the monuments of the studied locations. In the present work, the methodology carried out in the study of the particulate atmospheric pollutants, which are capable of accumulating on monuments and buildings with artistic and historical interest in the area of Castellon, is displayed. By means of a network of captors, important samples of sedimentary and suspension atmospheric pollutants, total suspension particles (TSP) were obtained. Firstly, by gravimetric methods, we have obtained the concentration levels of these kinds of pollutants in milligrams per day in busk dust samples and micrograms per cubic meter in TSP. Due to the fact that the corrosivity of these pollutants fundamentally depends on their compositions, the study has been completed with a mineralogical and chemical characterisation. By X-ray diffraction and scanning electron microscopy, we have analysed the particles of the two kinds of samples. The chemical analysis was carried out by inductively coupled plasma-atomic spectroscopy and inductively coupled plasma-mass spectrometry (multielement analysis techniques) in TSP samples and in the soluble fraction of the depositing particulate matter. The results have shown as main compounds: clay minerals, calcite, and carbonaceous matter coming from non-perfect combustion of vehicles. The chemical analysis indicates a high Ca/S ratio and high levels of concentration in chemical elements associated to this representative industrial cluster of ceramics industry in Europe.

This paper examines the historical change in the pH of natural rainwater due to increased atmospheric CO₂ from 1800 until 2007, giving predicted change in 2100. During 1800-2007, the rainwater pH at 25°C and 1 atm is calculated to decrease by 0.06 units, from 5.68 to 5.62. In 2100, the predicted rainwater pH is calculated at 5.49 using the projected pCO₂ (700 ppmv; IS92a) at 25°C and 1 atm. Equilibrium calculations were made in an attempt to elucidate the calcium carbonate (calcite) dissolution by rainwater. From 1800 to 2007, the dissolution of calcite with pCO₂ of those time at 25°C and 1 atm increase the dissolved calcium concentration from 466 to 516 μmol kg⁻¹. This value is calculated to reach 633 μmol kg⁻¹ in the year 2100. Rainwater is found to become more acidic with decreasing temperature. In the year 2007 (pCO₂ = 384 ppmv), a total difference of 0.08 units in rainwater pH is calculated between areas at 0°C and 30°C. The equilibrium pH with respect to calcite was found to increase with decreasing temperature. At lower temperatures, rainwater pH is found to decrease, whilst CaCO₃ dissolution increases. Limestone landmarks and buildings might be affected through the dissolution of calcium carbonate by rainwater acidification. The effects of rainwater acidification on overall chemical weathering may result in influences on agriculture, forestry, landslides and flooding.

Surface runoff transporting sediment with high phosphorus (P) concentrations has been identified as a major hydrological pathway for sediment-associated P delivery to surface waters and is considered a major threat to water quality, due to the ability of P to cause eutrophication in fresh water. Not all P-rich sediment that is mobilised by erosion will however be delivered directly to the channel. Some may instead be deposited in intermediate storage away from its source area. The aim of this contribution was to determine the influence of land use and soil type on the P content of surface runoff sediment and sediment deposited in intermediate storage and was undertaken in the largely agricultural and rural catchments of the Rivers Frome and Piddle in Dorset, UK. The study formed part of a larger investigation of hydrological and hydrogeochemical processes and fluxes in lowland permeable catchments in the UK (LOCAR). Soil samples were collected from the main land use types; freshly deposited sediment was sampled from ditches, hedge boundaries and depressions in fields, and sediment-laden runoff was collected during heavy rainfall events. The concentrations of total phosphorus (TP) and the P fractions found in the surface runoff sediment were significantly different from those measured in the original source soils, with a greater degree of enrichment associated with surface runoff sediment from cultivated land than from pasture land. For cultivated land, concentrations of TP and the P fractions in deposited sediment were higher than those in the original source material, while for pasture soils, concentrations of TP and the P fractions tended to be lower than in the original source soils. The relative importance of the P fractions associated with surface runoff sediment and sediment deposits also differed from that for the original soil samples. Surface runoff sediment was finer than source pasture and cultivated soils, reflecting the particle size selectivity of sediment mobilisation and transport. Soil physical properties and land use can both influence the P content of surface runoff and deposited sediment.

An investigation of radioactivity and some heavy metal distribution in soil and sediment of the river basin (Bendimahi River, Van-Turkey) was conducted in two seasons of 2005. The samples of soil and sediment were collected from the basin and investigated for concentrations of some heavy metal and natural radioactivity. Concentrations of Pb, Cr, Mn, Fe, Co, Cu, Zn and Cd have been determined by Atomic Absorption Spectrometry (AAS), gross-alpha and gross-beta activity concentrations have been obtained by using gas-flow proportional counter in nuclear spectroscopic system. Correlation analysis was made for radioactivity and heavy metal concentrations and the Pearson correlation coefficients between gross-alpha and gross-beta radioactivity and heavy metal were determined.

Chemical remediation of soil and groundwater containing hexavalent chromium (Cr(VI)) was carried out under batch and semi-batch conditions using different iron species: (Fe(II) (sulphate solution); Fe⁰ G (granulated elemental iron); ZVIne (non-stabilized zerovalent iron) and ZVIcol (colloidal zerovalent iron). ZVIcol was synthesized using different experimental conditions with carboxymethyl cellulose (CMC) and ultra-sound. Chemical analysis revealed that the contaminated soil (frank clay sandy texture) presented an average Cr(VI) concentration of 456 ± 35 mg kg⁻¹. Remediation studies carried out under batch conditions indicated that 1.00 g of ZVIcol leads to a chemical reduction of ~280 mg of Cr(VI). Considering the fractions of Cr(VI) present in soil (labile, exchangeable and insoluble), it was noted that after treatment with ZVIcol (semi-batch conditions and pH 5) only 2.5% of these species were not reduced. A comparative study using iron species was carried out in order to evaluate the reduction potentialities exhibited by ZVIcol. Results obtained under batch and semi-batch conditions indicate that application of ZVIcol for the “in situ” remediation of soil and groundwater containing Cr(VI) constitutes a promising technology.