The Upper Little Tennessee River (ULTR) possesses one of the most diverse assemblages of aquatic biota in North America, including the endangered Appalachian elktoe mussel (Alasmidonta raveneliana). Populations of the Appalachian elktoe declined significantly following a 2004 flood generated by hurricanes Frances and Ivan. Although the cause(s) of decline have yet to be determined, population declines may reflect exposure to contaminated sediment within the river system. The objectives of this study were to provide a preliminary assessment of the potential impact of sediment-associated trace metals on aquatic biota, particularly the Appalachian elktoe mussel, and to determine the source(s) of trace metals to the axial channel. Total sediment-associated Cu, Cr, Ni, and Zn concentrations within the ULTR locally exceeded threshold and probable effect guidelines for aquatic biota. These data are consistent with previous analyses that found particulate and dissolved concentrations of Cu in river waters periodically exceeded aquatic impact guidelines. However, the data conflict with (1) metal speciation analyses that show that Cu, Cr, and Zn are largely associated with the residual, non-available sediment phase, and (2) trace metal concentrations that are higher in mussel shells from the Tuckasegee River, a control site with intact populations, than in the ULTR. Moreover, the analyses suggest that most of the metals are derived from sulfide minerals contained within the underlying bedrock and, in the case of Cu, from locally used pesticides. The importance of the underlying bedrock as a significant long-term trace metal source suggests that Appalachian elktoe mussels were exposed to high levels of Cu, Cr, Ni, and Zn both before and after the 2004 event. Thus, it appears unlikely that the decline of Appalachian elktoe populations is related primarily to trace metals.

The occurrence, as well as the environmental fate and impact, of vegetable oil spills in freshwater wetlands have until now been unreported. Thus, the largest global vegetable oil spillage in a freshwater wetland, which occurred at the Con Joubert Bird Sanctuary wetland in 2007, presented an ideal opportunity to evaluate these impacts. Five post-spill sampling sites were selected within the wetland from which a variety of abiotic and biotic samples were collected bi-monthly over a period of 12 months. Abiotic variables included the sediment and water column oil concentrations, total nitrogen, total phosphorous, biochemical oxygen demand (BOD), silica, chlorophyll a, as well as in situ measurements of pH, electrical conductivity, and dissolved oxygen. Aquatic macroinvertebrates were chosen as biotic indicators in the study field due to their wide applicability as water quality indicators and were thus collected at each site. Spatial and temporal changes in total nitrogen, total phosphorous, and chlorophyll a concentrations as well as changes in pH were observed. The oil spillage also resulted in an increase in tolerant macroinvertebrate taxa, mainly Chironomidae and Psychodidae, at the sites closest to the source of the spillage. These two taxa, and to a lesser extent, Syrphidae, were identified as potentially useful indicators to determine the extent of vegetable oil contamination within a freshwater wetland. Furthermore, monitoring of these indicator taxa can be a useful management tool to determine the recovery of freshwater wetlands after vegetable oil spills. In the study, a static battery of bioassays of different biotic trophic levels was also employed to determine the adverse effects of the spilled vegetable oil on the biotic environment. It was evident from the result of the static battery of bioassay that adverse effects of the sunflower oil differ between trophic levels. The latter was in relationship with the data obtained from the field macroinvertebrate study, indicating that certain macroinvertebrate families were more tolerant to the adverse effects of sunflower oil than other families. © 2013 Springer Science+Business Media Dordrecht.

The aim of this study was to evaluate the presence of microcystin-LR, microcystin-RR, microcystin-YR, and the neurotoxin anatoxin-a in water samples collected monthly during 1 year in San Roque reservoir (Córdoba, Argentina) to identify the environmental factors that could promote the presence of these cyanotoxins. The HPLC-UV and MS/MS analysis showed the presence of microcystin in most of the sampling times, even when Cyanobacteria were subdominant. Microcystin concentrations varied from not detectable levels to 119.0 μg L⁻¹. Thus, they frequently surpassed the guidelines suggested by WHO for drinking water (1 μg L⁻¹) and recreational exposure (20 μg L⁻¹). To the extent of our knowledge, this is the first report of anatoxin-a in freshwaters in South America. Anatoxin-a concentrations varied from not detectable levels to 6.6 ng L⁻¹, a thousand times below the provisional guideline adopted by New Zealand for drinking water. Microcystin showed significant correlation with Microcystis and Pseudoanabaena while anatoxin-a correlated with Oscillatoria and Anabaena counts. Linear discriminant analysis showed that higher pH levels and more variable chlorophyll-a concentrations were measured in San Roque reservoir when cyanotoxins were present. Lower inorganic nitrogen concentrations were observed in autumn, when the prevalence of Anabaena became significant in Cyanobacteria composition and highest anatoxin-a levels were measured. The observed dynamic of phytoplankton going together with the cyanotoxins occurrence could be explained by the hypothesis of cyanotoxins acting as allelopathic compounds. The microcystin levels measured plus the presence of anatoxin-a show the need of stronger management efforts to preserve human and wildlife health.

In this study, we investigate the corrosion effects on modern materials at various sheltered and unsheltered locations in the Greater Athens Area (GAA) due to atmospheric pollution, since materials deterioration could emerge severe economic costs in the near future. The preselected materials are weathering steel, copper, bronze, zinc, and aluminum, which are mainly used in modern constructions in the GAA. The method applied in this study leads in the production of corrosion maps for GAA in the period 2000–2009 by using sophisticated geoanalytical methods together with dose–response functions for the selected materials. The corrosion effects are significant for weathering steel, moderate for copper and bronze and weak for zinc and aluminum. Also, a corrosion trend analysis is performed, which can be a very helpful tool for future protection of such materials from atmospheric pollution. The results show increasing corrosion trends for weathering steel and copper in the eastern regions of GAA, probably caused by the recent operation of the Athens International Airport at Spata, while no corrosion trends were observed to the other materials. The method applied in this work provides comprehensive results for the estimation of the impact of atmospheric corrosion on various construction materials.

Soil contamination by crude oil is a major environmental and health hazard. Extraction of the total petroleum hydrocarbons (TPH) sorbed to the clay soil (kaolin) was carried out using synthetic sorbent (Desmopan®) and 2-propanol as a mobilizing agent. The crude oil-loaded polymer beads were bioregenerated in a solid–liquid two-phase partitioning bioreactor (TPPB). A central composite design under response surface methodology was employed for the experimental design and analysis of the results. The independent variables were extraction phase to soil ratio, mobilizing agent to soil ratio, and initial concentration of crude oil in polluted soil. The influences of three independent variables on the TPH reduction efficiency were determined using a statistically significant quadratic model (R ² = 0.9673). Remediation was more efficient when the mobilizing agent to the soil ratio was equal to 3.00 ml g⁻¹, compared to the higher (4.00 ml g⁻¹) and lower (2.00 ml g⁻¹) levels. The results exhibited that the interaction between the extraction phase ratio and the initial concentration of crude oil in kaolin had significantly influenced the TPH removal. The bioregeneration studies showed a significant reduction (72.07 ± 0.63 %) of low-molecular-weight (two- to three-ring) polycyclic aromatic hydrocarbons and n-alkanes (97.75 ± 0.26 %) present in the crude oil-loaded solid polymers within a 10-day experiment. These findings show that solid polymer extraction followed by bioregeneration of sorbents in a TPPB is applicable to treat crude oil-contaminated kaolin.

This paper discusses the effects of breakwaters on the Rimini coastal environment over the last half century. Sediment cores of 50 cm thick were collected in various seasons from 2002 to 2005 and were subsampled at surface and subsurface levels at 20 inshore and offshore stations in order to take account of various freshwater and wastewater inputs. A 240-cm sediment core was collected in the most impacted area in order to reconstruct the evolution of the marine ecosystem since the time of the breakwaters’ construction. Sediment grain size, physico-chemical parameters, nutrients and inorganic and organic contaminants were determined. The breakwaters have stopped coastal erosion but have given rise to a worsening of environmental quality. No impacts were detected outside the breakwaters. The integrated approach, using biogeochemical markers to reconstruct spatial and historical environmental trends within the sheltered area, proved to be very useful in highlighting its capacity for recovery and providing indications for coastal management.

Static granular bed reactor (SGBR) and upflow anaerobic sludge blanket (UASB) reactor were demonstrated at mesophilic condition for the treatment of pulp and paper mill wastewater. The hydraulic retention times (HRTs) were varied from 4 to 24 h following 29-day start-up period. The overall chemical oxygen demand (COD) removal efficiency of the SGBR was higher than the UASB during this study. At 4 h HRT, the COD removal was greater than 70 % for the SGBR and 60 % for the UASB. Biomass yield and volatile fatty acids concentration of SGBR were slightly less than UASB at organic loading rates ranging from 1.2 to 5.1 kg/m³/day. The results indicated that the SGBR system can be considered a viable alternative system for anaerobic treatment for pulp and paper wastewater.

Four room temperature ionic liquids, [BMIM][PF₆], [BMIM][NTf₂], [PEGMIM][PF₆], and Aliquat, were investigated regarding their use in a two-phase partition bioreactor dedicated to remove two hydrophobic VOC, dimethyldisulfide and toluene. Aliquat and [PEGMIM][PF₆] cannot be further considered, owing to the toxicity of the former shown during glucose uptake inhibition tests and the water solubility of the latter. The partition coefficients of [BMIM][PF₆] and [BMIM][NTf₂] were found comparable to those recorded for typical liquid solvents used in multiphase bioreactors. They were also non-biodegradable, showed during long-term biodegradability tests. After 1 day of lag time, similar glucose biodegradation rates were recorded in the presence of 5 % [BMIM][PF₆] or [BMIM][NTf₂], if compared to controls deprived of ionic liquid. However, a clear inhibitory effect of the ionic liquids was observed during VOC biodegradation experiments. This phenomenon was significantly minimized after acclimation of activated sludge to VOC, since nearly similar consumption rates of toluene were recorded in the control deprived of IL and in the presence of 5 % bmimPF₆, 0.49 and 0.48 g m⁻³ h⁻¹, respectively. These promising results showed that more complex acclimation strategies, including microbial acclimation to both ionic liquids and VOC, will have to be considered.

An experiment in open-top chambers was carried out in summer 2008 in Curno (northern Italy) in order to study the effects of ozone and drought stress on net photosynthesis, growth and stable isotope partitioning on cuttings of an ozone-sensitive poplar clone (Oxford). The biomass (as dry weight) of stems, leaves and roots was assessed five times during the growing season on a set of plants intended for destructive measurements (set 1). Another set of plants (set 2) was used for repeated measurements (net photosynthesis) and then destroyed at the end of the experiment. The dry weight of the stems in set 1 plants was calculated using allometric relations. The results showed that drought stress had a strong effect on all the parameters assessed. Ozone did not have any effect on biomass allocation in woody stems and stable isotope composition but reduced root/shoot ratios and caused loss of leaves during the growing season. The loss of leaves in the lower part of the crown was partly recovered with the emission of new young leaves in the upper part, thus restoring the overall photosynthetic apparatus. We conclude that the metabolic costs suffered to repair damage and support growth, and the reduction in starch reserves in the roots can compromise growth and the capacity to cope with stress factors in subsequent years.

Constructed wetlands have been successfully used throughout the world for wastewater treatment. Nowadays, one of the most discussed questions is their long-term performance. The present study summarizes the performance of a constructed wetland designed to treat the municipal wastewater from a rural community in northwestern Spain during a period of 12 years. The monitoring of water quality for organic matter, suspended solids, nutrients, and indicator bacteria revealed that, in general, the effluent concentrations were significantly lower than influent concentrations. Moreover, differences among years were not statistically significant. Metals and metalloids were also monitored in wastewater, sediment, and vegetation. Results showed that these pollutants have mainly accumulated in the sediments, whereas only a minor fraction has been removed by plant uptake. © 2013 Springer Science+Business Media Dordrecht.