In coastal marshy lands, halogen bromide concentration is reported to be generally higher than in the inland soils where, annual halophytic species naturally grow. The effect of bromide on plant responses is relatively less known. The objectives of this study were to assess the effect of sodium bromide (NaBr) on growth, photosynthetic pigments, tissue ions content and changes in enzymes activity in Salicornia brachiata, a salt marsh halophyte. Presence of NaBr in the root medium induced 200 percent increase in fresh mass and 30% increase in dry mass, compared to untreated control. Relative water content also increased significantly with NaBr treatment. Increase in fresh and dry mass was not associated with high photosynthetic efficiency as evidenced by decrease in photosynthetic pigments accumulation. However, inorganic ion analysis revealed that S. brachiata accumulated Na⁺ as a primary osmotica. The concentration of Na⁺ in NaBr treated plants was ~4 fold higher than that measured in untreated controls and this was associated with significant reduction in K⁺, Ca²⁺, Mg²⁺ contents. Bromide content also increased significantly and accounted for 20 to 50 percent of dry weight. In addition, significant differences in the activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT) and ATPase were observed in bromide treated plants. For the first time bromide tolerance in coastal halophyte was reported and the results suggest that bromide was not toxic to S. brachiata for growth and metabolism even at 600 mM. concentration and suggest that the species can be used in phytoremediation of bromide contaminated soils.

Historic lead mining, milling and smelting on the floodplain soils of the upper reaches of the Vils River, Eastern Bavaria, Germany has led to heavy metal contamination within the younger floodplain sediments downstream. This study aims to date the lead pollution and possible primary sources, display and quantify its spatial distribution within the Vils River floodplain in accordance to soil horizons and characterise the binding forms of lead. One hundred fifty profiles were sampled to detect total contents of heavy metals. Sequential extractions were carried out to determine the binding forms; thus, the potential of lead mobility was characterised. The contamination of the floodplain soils act as an alluvial archive, providing a stratigraphical indicator of mining activities and related sedimentation. The age of the sediments displaying the initial lead peak in the alluvial loams corresponds with sediment accumulations at the onset of the mining period and its first phase of prosperity in the sixteenth century. Enrichments of lead in the oxidic gleysols revealed that dissolved fractions of lead precipitate in the groundwater table fluctuation zone. The sequential extraction proved that lead mobility increases in the psammic and hypersceletic fluvial horizons below the flood loams due to the modest salt contents of the extractants and low pH given in these layers. Thus, the risk of the particulate transport of lead has to be extended to include the danger of potential lead solubility in ground and surface waters. Further, the polluted alluvial sediments also act as a source of contamination, leading to the grave danger of the further pollution of so far uncontaminated areas downstream, especially if the reworking and dredging of the material is allowed to occur.

In the present study, a comparative assessment of 2,4,6-T (2,4,6-Trichlorophenol) degradation by different AOPs (Advanced Oxidation Processes - UV, UV/ H₂O₂, Fenton, UV/Fenton and UV/TiO₂) in the laboratory scale is performed. The effects of different reactant concentrations and pH are assessed. 2,4,6-T removal, Total Organic Carbon mineralization (TOC) and dechlorination are monitored. Of all the AOPs, UV/Fenton process is more effective in degrading 2,4,6-T. The optimum conditions obtained for the best degradation with UV/Fenton are: pH = 3, Fe⁺² concentration of about 5 ppm, and peroxide concentration of 100 ppm for an initial 100 ppm of 2,4,6 T concentration at room temperature. In these conditions, a pseudo first-order rate constant is evaluated. The degradation rate of 2,4,6 T followed the order: {{{\text{UV}}} \mathord{\left/ {\vphantom {{{\text{UV}}} {{\text{TiO}}_{\text{2}} > {{{\text{UV}}} \mathord{\left/ {\vphantom {{{\text{UV}}} {{\text{H}}_{\text{2}} {\text{O}}_{\text{2}} > {\text{Feton}}}}} \right. \kern-\nulldelimiterspace} {{\text{H}}_{\text{2}} {\text{O}}_{\text{2}} > {\text{Feton}}}}}}} \right. \kern-\nulldelimiterspace} {{\text{TiO}}_{\text{2}} > {{{\text{UV}}} \mathord{\left/ {\vphantom {{{\text{UV}}} {{\text{H}}_{\text{2}} {\text{O}}_{\text{2}} > {\text{Feton}}}}} \right. \kern-\nulldelimiterspace} {{\text{H}}_{\text{2}} {\text{O}}_{\text{2}} > {\text{Feton}}}}}} > {\text{UV}} $$]]>

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.

The rate at which creosote-treated pilings release polycyclic aromatic hydrocarbons (PAHs) into the environment should diminish with structure age and weathering, and so, it may be assumed that PAH concentrations in the vicinity of old structures (>30 years) may approach background levels. However, this may not be true in cold environments where PAH release and degradation rates are slow and where pilings continue to experience significant physical damage. Moreover, PAHs will remain high in the vicinity of pilings if current and wave action is insufficient to disperse and dilute PAHs over a wider area and/or where PAHs do not become diluted and buried by uncontaminated sediments. This is demonstrated in our investigation of the sediments of the Grey Owl Marina, located in Prince Albert National Park, in central Saskatchewan, Canada. The marina, constructed in the early 1960s, consists of six piers and is protected from strong wave action by a breakwater. PAH concentrations were high in sediments collected under the piers and inside the boat slips, exceeding probable effect levels for several compounds. Various lines of physical and chemical evidence pointed to creosote as being the primary PAH source with a mixture of relatively undegraded and weathered PAHs being present. PAH concentrations decreased rapidly 2 m and further away from the pilings as a result of dilution with increasing dispersal over a broadening area. There was evidence of benthic community impairment, with total abundances negatively correlated with PAH concentrations. According to the Methods for Ranking Contaminated Aquatic Sites on Canadian Federal Properties, areas with the highest hazard scores were under the piers and inside the boat slips, while areas with the lowest hazard scores were >10 m from the pilings. Therefore, remedial actions based on piling and contaminated sediment removal may need to be conducted over only a small area, i.e., within 2 m of the pilings.

The aim of this survey was to assess metal concentrations in precipitation over the Aegean Sea and to identify possible source regions that contribute to their long-range transport to the northeastern Mediterranean. Total metal concentrations in 37 rainwater samples collected on the island of Lesvos showed a high variability depending mostly on the origin of the air masses influencing the rain events assessed by 4-day back trajectories. Concentrations of Al, Fe, Mn, Cu, Pb, Zn, Cr and Ni were rather similar to those found at other coastal sites in the Mediterranean basin, but Cd was significantly lower. The calculation of crustal enrichment factors of the metals along with the statistical analysis of the results showed that Saharan dust storms supply significant amounts of natural Al, Fe, Mn, Cr and Ni to the northern Aegean atmosphere, although some amounts of Cr and Ni are also contributed from anthropogenic sources. On the other hand, anthropogenic emissions largely determine Pb, Cu, Cd and Zn loads, although not all four metals follow the same enrichment and transportation pattern.

Impacts of heavy metal concentrations in sediments on the gastropod community structure were assessed in the coastal waters of Dumai, Sumatra, Indonesia. The objective of this study was to relate the levels of heavy metal pollution with the changes of gastropod community structure in the study area. Concentrations of Cd, Cu, Pb, Zn, Ni, and Fe in surface sediments collected from five sampling stations were analyzed and correlated with the abundance, species richness, and diversity of gastropod populations. Sediments at stations with more anthropogenic activities accumulated higher concentrations of heavy metals and consequently displayed lower abundances, lower species richness and diversity; while stations with lower heavy metal concentrations in sediments showed the opposite pattern in gastropod community metrics. The above findings are complemented by significant negative correlations p < 0.05-0.01) between concentrations of Cd, Cu, Pb, Zn, and Ni in the sediments and gastropod abundance and species richness. Among the metals analyzed, Cu and Zn had strongest negative correlations with the gastropod diversity which suggests that these metals may be the most detrimental to gastropod populations in the mangrove area of Dumai coastal waters.

The problem of air pollution is a frequently recurring situation and its management has social and economic considerable effects. Given the interaction of the numerous factors involved in the raising of the atmospheric pollution rates, it should be considered that the relation between the intensity of emission produced by the polluting source and the resulting pollution is not immediate. The aim of this study was to realise and to compare two support decision system (neural networks and multivariate regression model) that, correlating the air quality data with the meteorological information, are able to predict the critical pollution events. The development of a back-propagation neural network is presented to predict the daily PM₁₀ concentration 1, 2 and 3 days early. The measurements obtained by the territorial monitoring stations are one of the primary data sources; the forecasting of the major weather parameters available on the website and the forecasting of the Saharan dust obtained by the “Centro Nacional de Supercomputaciòn” website, satellite images and back trajectories analysis are used for the weather input data. The results obtained with the neural network were compared with those obtained by a multivariate linear regression model for 1 and 2 days forecasting. The relative root mean square error for both methods shows that the artificial neural networks (ANN) gives more accurate results than the multivariate linear regression model mostly for 1 day forecasting; moreover, the regression model used, in spite of ANN, failed when it had to fit spiked high values of PM₁₀ concentration.

Uptake of organic contaminants by plant roots consists of two consecutive steps: sorption to plant roots and entrance into root xylem tissues through epidermal and endodermic membranes. Most research pertaining to phytoremediation assumed that sorption to plant roots is linear and non-competitive. A growing body of evidence, however, is suggesting that sorption to plant roots is nonlinear and competitive. The objective of this study was to examine the concentration effects of chemical constituents on the competitive sorption of trichloroethylene (TCE) and tetrachloroethylene (PCE) to the roots of Typha latifolia. Competitive sorption was clearly demonstrated by the reduced sorption of TCE and PCE in bi-solute systems than in single-solute systems. Concentration is an important factor affecting the extent of competition. In bi-solute systems, the PCE/TCE ratio on root surface approximately reflected the contaminant footprints in solution. The result was attributed to limited high energetically favorable sorption sites on the root surface and similar sorption mechanisms of TCE and PCE. The results hold significant importance for the application of phytomonitoring of organic contaminant mixtures.

In this study, slurry photocatalytic oxidation process was investigated for natural organic matter removal from aqueous humic acid solutions by using different titanium dioxide (TiO₂) under UV-A irradiation. Bench scale experimental studies were conducted at different humic acid concentration at the range of 10-50 mg/L and different pH. Anatase and mixed-phase anatase-rutile TiO₂ nano particles used in the photocatalytic reactor. The results were evaluated in terms of the parameters that are specific to organic matter content such as dissolved organic carbon concentration, ultraviolet absorbance at 254 nm (UV₂₅₄), specific ultaviolet absorbance at 254 nm, and color (VIS₄₀₀). It was observed that increasing humic acid concentration decreases photocatalytic degradation efficiency. The reactivity of the mixed-phase anatase-rutile (Degussa P-25) TiO₂ was greater than individual anatase particles and the highest efficiency was observed at pH 3 for anatase TiO₂.