While copper is known to be neurotoxic, effects on behavior and especially on group behavior have received much less attention. Yet such behavioral effects can have important ecological consequences. This study determined whether shoaling behavior could be used as an indicator of acute copper toxicity and as an endpoint in studying acclimation in the least killifish (Heterandria formosa). For acute toxicity, least killifish were exposed to 0, 25, 50, or 100 μg/L of Cu for a 2-h duration and then tested for changes in shoaling behavior. The occurrence of copper acclimation was tested by pre-exposing fish to either 0 or 15 μg/L of Cu for a 7-day duration, then exposing them to 25, 50, or 100 μg/L of Cu to assess whether the two pre-exposure groups differed in their behavioral responses to high Cu levels. Behavioral responses were tested in a subdivided aquarium, with one side containing a group of conspecific fish and the other side the focal fish whose behavior was recorded for 3 min. Shoaling was based on the proximity of the focal fish to the divider separating it from the group of conspecific fish. Acute copper exposure resulted in significant decreases in both the time to first shoaling and in the total amount of time spent shoaling. Experiments assessing the occurrence of copper acclimation using shoaling as the toxicity endpoint did not detect a difference between the pre-exposure groups. Overall, this study demonstrated that acute copper exposure can alter shoaling behavior. However, least killifish shoaling behavior appears to be relatively insensitive as an endpoint to assess copper acclimation. © 2013 Springer Science+Business Media Dordrecht.

A pilot-scale anaerobic bioreactor with high levels of microbial sulfate reduction, known to be capable of removing cationic metals from a metal- and acid-contaminated waste stream, was utilized to determine if the system would be effective in removing metals in the form of oxyanions such as arsenate and chromate. The system removed 90 % to >99 % of the arsenic and between 86 % and 94 % of the chromium from a waste stream containing 5 mg/L of each. Cadmium, copper, iron, lead, and zinc also were removed. An equilibrium geochemistry computer modeling code, MINTEQAK, modified from MINTEQA2, was used for the chemical modeling of processes in the bioreactor. Experimental evidence on the chemical and biological reduction of arsenic and chromium and fluorescent diffraction analysis of precipitates support the following hypotheses: the primary removal process for chromium was the reduction of Cr(VI) to Cr(III) by sulfides, followed by precipitation of chromium hydroxide [Cr(OH) 3(s)]; removal of arsenic was by direct microbial enzymatic reduction of As(V) to As(III) followed by precipitation of arsenic sulfides (As 2S3 or AsS). Experimental evidence and modeling with MINTEQAK confirmed that 90 % to 95 % of the removal of arsenic and chromium occurred in the first quarter volume of the bioreactor. Additional removal of arsenic and chromium occurred in the remaining volume of the bioreactor. The use of a sulfate reduction-based anaerobic treatment system was effective for metal-laden wastewater with elevated concentrations of arsenic and chromium. © 2013 Springer Science+Business Media Dordrecht.

The release of heavy oil from laboratory-contaminated sediments was studied in a series of kinetic and equilibrium experiments. The kinetic curves could be interpreted by a two-compartment first-order equation including rapid and slow release steps. The slow step was dominant and the rate constant was 3 orders of magnitude smaller than for the rapid step. Equilibrium experiments for the slow step revealed that the isotherms could be described by the Freundlich equation. The release of heavy oil was found to correlate with higher contamination level, larger particle size, lower salinity, and higher temperature. The effect of coexisting surfactant on the release was also investigated and the results showed that the presence of Tween-20 promoted the process. The oil release process was endothermic and the randomness at the solid–liquid interface increased during the desorption process. The values of activation energy and standard enthalpy change indicated that this process was a physical one.

The catalytic effect of Cu(II) on the formation of disinfection by-products (DBPs) and chlorine degradation during chlorination of humic acid (HA) solutions was comparatively investigated under different experimental conditions. The experimental results showed that the total organic halogen (TOX) and trihalomethane (THM) formation increased with increasing Cu(II) concentration during chlorination, while haloacetic acids (HAAs) increased insignificantly. Accelerated chlorine decay and increased TOX and HAA formation were observed at high pH in the presence of 1.0 mg/L Cu(II) compared with that observed at low pH but THM formation decrease. Furthermore, the Cu(II) effect catalyzed the formation of brominated DBPs as it did for chlorine analogues in the presence of bromide ion. The microcalorimetry analysis demonstrated that more DBPs were formed in the Cu(II)-catalyzed chlorination, in which second-order rate constants obtained from reaction of HA with chlorine under given experimental conditions were 0.00256 M⁻¹ s⁻¹ (without Cu(II)) and 0.00865 M⁻¹ s⁻¹ (with Cu(II)), respectively. To discriminately examine the role of Cu(II) in greater detail, nine model compounds, which approximately represent the chemical structural units of HA, were individually oxidized by chlorine. It was demonstrated that carboxylic acids significantly enhanced the formation of TOX, THMs, and HAAs in the presence of Cu(II). Based on the previously published information and our experimental results, the possible pathway for Cu(II)-catalyzed TOX, THM, and HAA formation from chlorination of carboxylic acids were tentatively proposed.

Bottom slag and sewage sludge discharged from municipal solid waste incineration and sewage treatment plants were co-sintered for use as a cost-effective adsorbent for phosphate removal from aqueous solutions. The Langmuir isotherm model (which gives a better description of phosphate sorption than the Freundlich model) was adopted to describe the action of the synthesized adsorbent and also for phosphate sorption by either zeolite or ironstone. The model showed that the maximum sorption capacity of the synthesized adsorbent (27,030 mg kg-1) was 38.2 greater than for zeolite and 70.6 times greater than for ironstone. Desorption of phosphate from the synthesized adsorbent at different initial concentrations was about 4.98 %, which was several times lower than for zeolite. The phosphate removal capacity of the synthesized adsorbent remained constant for solution pH values ranging from 3 to 10, which was an improvement on the capacity of the other two adsorbents; its buffering capacity was also superior. The immobilization of phosphate on the synthesized adsorbent might be attributed mainly to complexation with Fe, Al, and Ca ions. Heavy metal ion concentrations in the leachate of the synthesized adsorbent were negligible. © 2013 Springer Science+Business Media Dordrecht.

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.

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.

Approximately 1.1 million deer–vehicle collisions occur in the United States each year. The predominant methods of disposing of these carcasses (landfill and burial) have several costly disadvantages, including long travel distances to landfills, increasing landfill restrictions, and lack of viable burial areas. Some states have found static compost windrows to be an easy and cost-effective carcass management technique. This type of composting involves the construction of passively aerated static piles, which do not require the materials turning needed with more traditional composting methods. In this study, deer mortality static compost windrows were monitored for 1 year. Windrows were analyzed for pathogen destruction and the degree to which underlying soil filtered leachate contaminants. In response to high windrow temperatures, indicator pathogens Escherichia coli and Salmonella were reduced by 99.99 % the first sampling day (day 7) and ascarids were deemed non-viable by day 77. Soil filtration of leachate was effective in reducing concentrations of ammonia, chloride, and total organic carbon. Nitrate, a contaminant of particular regulatory concern, had an estimated mass contaminant loss of 2.1 kg/ha, compared to the estimated 9 to 50 kg/ha loss from fertilizer application of common agronomic crops. Results of this study indicate that with properly constructed static compost windrows, (1) high temperatures effectively destroy indicator pathogens; (2) the natural filtration of leachate through soil reduces deer mortality contaminant concentrations; and (3) the low volume of leachate (i.e., two percent of the precipitation that fell on windrows) results in nominal losses of nitrate and other contaminants.

In this study, the performance of a laboratory-scale soil aquifer treatment (SAT) system was investigated and treatability studies were done in order to determine organic matter removal from synthetic wastewater (SWW) and secondary treated real wastewater (RWW). The SAT system was constructed in laboratory conditions and treatability studies were conducted using soil columns, which were packed with silt loam soil samples. Each column was equipped with a series of ports at multiple depths from soil surface (10, 20, 30, 50, and 75 cm) to collect water samples. Two operational cycles were applied to represent the influence of different wetting and drying periods during wastewater application. Dissolved oxygen, chemical oxygen demand (COD), and total organic carbon (TOC) concentrations were measured in all samples. Average removal values of 61.4 % (COD) and 68.2 % (TOC) were achieved by in SWW and of 58.3 % (COD) and 51.1 % (TOC) in RWW in 55 and 25 weeks of operation, respectively. These results indicated that the performance of the columns operated with SWW was better than the performance of the columns operated with RWW. In essence, the easily biodegradable portion of organic matter was quickly consumed by microorganisms in the first 10 cm of the columns where oxygen levels peaked. Complex organic compounds that are likely to be found in RWW could thus be removed when longer residence times were achieved through the columns. When the removal performances achieved with different operating cycles were compared for each wastewater, it could be seen that longer wetting and longer drying periods yielded higher removal efficiencies in RWW and vice versa in SWW. © 2013 Springer Science+Business Media Dordrecht.

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.