The bracket-like polypore fungus, Ganoderma australe, was selected for its potential to degrade lindane in liquid agitated sterile cultures. An orthogonal central composite design based on response surface methodology was used to find the optimum biodegradation and biosorption conditions of this pesticide and the growth conditions of the fungus. The factors tested include nitrogen content, initial concentration of lindane, incubation time, and temperature. The optimization parameters investigated were fungus biomass, fungus growth rate, final pH, specific biodegradation, specific biosorption, specific biodegradation rate, biodegraded to biosorbed ratio. The results of the experiments were statistically analyzed and the significance and effect of each factor on responses was assessed. The optimum (maximum) lindane biodegradation (3.11 mg biodegraded lindane per gram biomass) was obtained with nitrogen content of 1.28 g/L, lindane concentration of 7.0 ppm, temperature of 18.0°C, and 5 days of cultivation time.

pH monitoring data for public water bodies in Niigata and Gifu prefectures in central Japan were tested by the nonparametric seasonal Mann-Kendall method to evaluate long-term acidification. A significant long-term declining trend in river water pH was found in several watersheds in Niigata and Gifu prefectures. In Niigata, the declining trend was observed only in areas receiving drainage from granitic rocks, and the acid neutralizing capacity of the river waters was in fact low in those areas. In Gifu, a declining trend was observed in some remote watersheds, where there was no clear relationship between the geology and the long-term trends. Since Niigata and Gifu receive the highest level of acid loading from the atmosphere in Japan, river water acidification in several watersheds may be attributable to the effects of the acid deposition. Other factors, such as hot spring drainage, changes in land use, and natural sea salt deposition, cannot adequately explain the acidification phenomena observed in this study.

Petroliferous activities in Brazil have an accelerated development in the last years. As a consequence, the incidence of environmental accidents such as oil spills and contamination of soils has increased significantly. Therefore, it is extremely necessary to develop remediation techniques with lower costs, decontamination efficiency and impact minimisation. The aim of this work was to evaluate Sebastiania commersoniana phytoremediation potential in soil contaminated by petroleum. This species, which is a native tree, was selected due to its proven capacity for surviving in areas contaminated by petroleum. Experiments were carried out with soils that were vegetated but non-contaminated, soils that were freshly contaminated (25, 50 and 75 g kg⁻¹) but non-vegetated, and soils that were vegetated and contaminated, samples were collected 60 and 424 days after contamination with the purpose of evaluating the percentage of petroleum degradation in relation to the time. The results obtained in the present study allow us to state that S. commersoniana proves to be tolerant to petroleum contamination with respect to plant's growth. The degradation of petroleum hydrocarbons was evaluated by gas chromatography with a flame ionisation detector (GC-FID) equipped with a capillary column HP-5 (5% phenyl-methylpolysiloxane, 30 m; 0.25 mm; 0.25 μm). According to chromatographic analysis, samples in contact with S. commersoniana showed a significant area reduction of the hydrocarbon peaks. Analysis of the 60-day samples showed a reduction of petroleum hydrocarbons area higher than 60% and the 424-day samples showed a reduction higher than 94%, which demonstrates that a petroleum degradation process is occurring.

Extended persistence of enteric bacteria in coastal sediments and potential remobilization of pathogens during natural turbulence or human activities may induce an increased risk of human infections. In this study, the effect of sediment characteristics such as particle grain size and nutrient and organic matter contents on the survival of fecal indicator bacteria (FIB) including total coliforms, Escherichia coli, and Enterococcus was investigated. The experimentation was carried out for 50 days in microcosms containing lake water and different contaminated freshwater sediments in continuous-flow and batch conditions. Results of this study revealed: (1) extended FIB survival in sediments up to 50 days, (2) higher growth and lower decay rates of FIB in sediments with high levels of organic matter and nutrients and small (mainly silt) grain size, and (3) longer survival of Enterococcus sp. compared to E. coli and total coliforms. FIB survival in sediments and possible resuspension are of considerable significance for the understanding of permanent microbial pollution in water column and therefore human risk during recreational activities.

As part of the Rain In Cumulus over the Ocean Experiment (RICO) and the Puerto Rico Aerosol and Cloud Study (PRACS), cloud water was collected at East Peak (EP) in Puerto Rico. The main objective of this study was to determine the concentrations of water-soluble species (Cl⁻, NO₃ ⁻, SO₄ ²⁻, NH₄ ⁺, Ca²⁺, H⁺, Mg²⁺, K⁺, and Na⁺) in water samples taken from clouds influenced by tropical trade winds. The most abundant inorganic species were Na⁺ (average 465 μeq l⁻¹) and Cl⁻ (434 μeq l⁻¹), followed by Mg²⁺ (105 μeq l⁻¹), SO₄ ²⁻ (61 μeq l⁻¹), and NO₃ ⁻ (25 μeq l⁻¹). High concentrations of nss-SO₄ ² (28 μeq l⁻¹), NO₃ ⁻ (86 μeq l⁻¹), and H⁺ (14.5 μeq l⁻¹) were measured with a shift in air masses origin from the North Atlantic to North American continent, which reflected a strong anthropogenic influence on cloud chemistry at EP. Long-range transport of particles and acid gases seems to be the factor responsible for fluctuations in concentrations and pH of cloud water at East Peak. When under trade wind influences the liquid phase concentrations of all inorganic substances were similar to those found in clouds in other clean maritime environments.

Risk assessment of trace-metal contamination in soils requires predictive models that take into account the interaction of metal ions with other cations (e.g., H⁺ and Ca²⁺) that can change the speciation of trace metals in solution and compete for binding sites on plant roots thus affecting metal uptake and toxicity. Acid-base titrations were used to estimate the types and quantity of cation-binding sites on fresh pea (Pisum sativum L. cv. Lincoln) roots and their binding strength with protons. The roots were found to have three types of cation-binding sites with site densities of 190, 382, and 347 μmolc g⁻¹ (dry weight), respectively. The binding strength with H⁺ was indicated by the equilibrium formation constants (K HLj ). The logK HLj values under different ionic strengths were determined. At zero ionic strength, the logK HLj values are estimated to be 2.5, 5.5, and 8.3, respectively. Complementary experiments were used to validate the titration results. These included an ion exchange experiment, an experiment with HCl extractions, and a KOH neutralization method. Estimates from all four methods were consistent under the experimental conditions. The quantification of the binding capacity and the characteristics of these binding sites will assist in the development of more appropriate solution speciation models that incorporate biotic ligands. The derived parameters will provide the basis on which further development of a biotic ligand model is dependent.

Naphthenic acids (NAs) are a complex group of naturally occurring oil sands constituents that constitute a significant portion of the dissolved organic carbon (DOC) pool available for microbial degradation in the process-related waste water associated with oil sands mine sites. One approach to understanding the biological fate of oil sands process-derived carbon and nitrogen in aquatic reclamation of the mine sites involves the use of stable isotope analyses. However, for stable isotope analyses to be useful in such field-based assessments, there is a need to determine how microbial degradation of a complex mixture of NAs might change the stable isotope values (δ ¹³C, δ ¹⁵N). In batch cultures and semi-continuous laboratory microcosms, utilization of a commercial mixture of NAs by oil sands-derived microbial cultures resulted in microbial biomass that was similar or slightly ¹³C enriched (1.4[per thousand] to 3.0[per thousand]) relative to the DOC source, depending on the length of incubation. Utilization of a NA-containing extract of oil sands processed water resulted in greater ¹³C enrichment of microbial biomass (8.5[per thousand]) relative to the DOC source. Overall, the δ ¹³C of the DOC comprised of complex mixtures of NAs showed minimal change (-0.5[per thousand] to -0.1[per thousand]) during the incubation period whereas the δ ¹³C of the dissolved inorganic carbon (DIC) was more variable (-5.0[per thousand] to +5.4[per thousand]). In tests where the concentration of available nitrogen was increased, the final biomass values were ¹⁵N enriched (3.8[per thousand] to 8.4[per thousand]) relative to the initial biomass. The isotope trends established in this study should enhance our ability to interpret field-based data from sites with hydrocarbon contamination, particularly in terms of carbon source utilization and ¹⁵N enrichment.

A box-core 3576 (PO287-26-1B) collected from the Tagus Prodelta in 2002 was analysed for organic carbon, ²¹⁰Pb, ²²⁶Ra, major (Al, Fe, Ca, Ti, Mg and Mn) and trace elements (Ba, Hg, Cr, Cu, Li, Ni, Pb, Sb, Sn, Sr, and Zn). Maximum concentrations of contaminants in ²¹⁰Pb-dated samples were reached in the decades between 1960 and 1980, followed by a slightly decrease in up-core metal trends. Trace metal concentrations increased in the bottom of the core (²¹⁰Pb dated as 1925) to maximum values during the 1970s. Factor analysis of geochemical data was used to reduce the 18 variables into four factors that reveal distinct origins or accumulation mechanisms controlling the chemical composition in the study area. Changes in the dominance of these factors through the time indicate not only changes in industrial activity, but also the increase of biological productivity towards the present.

To evaluate the phytoremediation capability of some poplar and willow clones a hydroponic screening for cadmium tolerance, accumulation and translocation was performed. Rooted cuttings were exposed for 3 weeks to 50 μM cadmium sulphate in a growth chamber and morpho-physiological parameters and cadmium content distribution in various parts of the plant were evaluated. Total leaf area and root characteristics in clones and species were affected by cadmium treatment in different ways. Poplar clones showed a remarkable variability whereas willow clones were observed to be more homogeneous in cadmium accumulation and distribution. This behaviour was further confirmed by the calculation of the bio-concentration factor (BCF) and the translocation factor (Tf). Mean values of all the clones of the two Salicaceae species showed that willows had a far greater ability to tolerate cadmium than poplars, as indicated by the tolerance index (Ti), calculated on the dry weight of roots and shoots of plants. As far as the mean values of Tf was concerned, the capacity of willows to translocate was double that of poplars. On the contrary, the mean values of total BCF in poplar clones was far higher with respect to those in willows. The implications of these results in the selection of Salicaceae clones for phytoremediation purposes were discussed.