Organic contaminants in sediments and mussels from Thermaikos gulf,Greece

Thirteen surficial sediment samples, two sediment cores and mussels (Mytilus galloprovincialis) from six locations were collected from Thermaikos gulf, Greece and analyzed for herbicides, organochlorine compounds and aliphatic hydrocarbons. Herbicide concentrations were low in surface sediments (not detected‐0.8 ng/g dry wt) and undetectable in subsurface samples. Organochlorine concentrations ranged between 0.8 and 88.2 ng/g dry wt for the polychlorinated biphenyls (PCBs) and between 1.7 and 22.8 ng/g dry wt for the SDDTs, while aliphatic hydrocarbon values varied from 28.8 to 965.4 ng/g dry wt. The highest concentrations for all the pollutants were measured in the vicinity of the city of Thessaloniki. Petroleum‐related hydrocarbons were dominant in surface sediments, while were still detected till about 1 m depth in the sediment core. Mussels presented low organochlorine concentrations (3.6–10.5 ng/g dry wt for the PCBs, 12.2–34.0 ng/g dry wt for the DDTs), but petroleum hydrocarbon concentrations were rather increased, mainly in the samples collected along the east coastline of the gulf (aliphatic hydrocarbons 52.3–224.3 μg/g dry wt).     

Impact of dredged urban river sediment on a Saronikos Gulf dumping site (Eastern Mediterranean): sediment toxicity,contaminant levels,and biomarkers in caged mussels

Impacts of chemical contaminants associated with dumping of dredged urban river sediments at a coastal disposal area in Saronikos Gulf (Eastern Mediterranean) were investigated through a combined approach of sediment toxicity testing and active biomonitoring with caged mussels. Chemical analyses of aliphatic hydrocarbons (AHs), polycyclic aromatic hydrocarbons (PAHs), Cu, and Zn in combination with the solid phase Microtox® test were performed on sediments. Concentrations of PAHs, AHs, Cu, and Zn as well as multiple biomarkers of contaminant exposure and/or effects were measured in caged mussels. Sediments in the disposal and neighboring area showed elevated PAHs and AHs concentrations and were characterized as toxic by the solid-phase Microtox® test during and after dumping operations. Biomarker results in the caged mussels indicated sublethal effects mainly during dumping operations, concomitantly with high concentrations of PAHs and AHs in the caged mussel tissues. Cu and Zn concentrations in sediments and caged mussels were generally not elevated except for sediments at the site in the disposal area that received the major amount of dredges. High PAHs and AHs levels as well as sublethal effects in the caged mussels were not persistent after termination of operations. The combined bioassay–biomarker approach proved useful for detecting toxicological impacts of dredged river sediment disposal in sediments and the water column. Nevertheless, further research is needed to evaluate whether sediment toxicity will have long-term effects on benthic communities of the disposal area.     

The application of bioflocculant for the removal of humic acids from stabilized landfill leachates

The evaluation of bioflocculant, in comparison with traditional inorganic coagulants, for the removal of humic acids from landfill leachates stabilized by biological treatment, was performed using conventional jar-test coagulation experiments. The optimized conditions (pH and coagulant dosage) were identified for the treatment of synthetic solutions as well as for biologically pre-treated landfill leachates. It was found that the application of bioflocculant was quite efficient in the removal of humic acids from synthetic solutions as well as in the reduction of COD content from real landfill leachates. The optimal pH value was found to be between 7 and 7.5, while a 20 mg/l bioflocculant dosage was sufficient in providing more than 85% humic acid removal. The results were comparable with those obtained by the application of conventional coagulants such as alum or polyaluminum chloride; therefore, bioflocculant can be considered as a viable alternative in the treatment of landfill leachates applying coagulation.     

An empirical investigation of European drivers' self-assessment

PROBLEM: Evaluating motorists through self-assessment has attracted much interest in recent literature, which is mainly due to the profound impact various parameters of self-assessment can have on the way motorists deal with hazardous traffic situations. Much of the previous work in this area has been hampered both by the lack of adequate sample sizes and, because of the small samples, the evaluation methodologies used. METHOD: This paper extends previous research in two significant directions: (a) it uses the SARTRE 2 database, which provides more than 17,000 questionnaires from most European countries; and (b) it employs the ordered probit modeling approach, which recognizes the latent nature of self-assessment and explicitly links its dimensions to a set of relevant explanatory variables such as age, gender, region, and income. RESULTS: The results indicate that drivers who rate themselves as both more dangerous and faster than others are, generally, younger men, with higher incomes, break the speed limit more frequently, avoid wearing seat belts, and have been involved in more accidents in the past than other drivers. Interestingly, more experienced and more highly educated drivers assess their driving as less dangerous, but admit to driving faster than other drivers. IMPACT ON INDUSTRY: The methodology used and the results obtained can be a significant help in identifying drivers with high and low self-assessment ratings, which can be useful in planning and implementing road safety information campaigns.     

Screening of wood rotting fungi potentially useful for the degradation of organic pollutants

Many papers have shown that white rot fungi can degrade aromatic pollutants under laboratory conditions, but few report field scale trials. Here we report the first steps in the development of a remediation system for Greek conditions. A review of the available organochlorine compound pollution information in Greece is presented. White rot fungi isolated from sites in Greece have been screened for growth rate and ligninolytic activity, using decolourisation of the dye Poly R-478 as an indicator of enzyme activity. Use of white rot fungi under field conditions in Greece will require bioaugmentation to be effective at high temperatures and low water activity for much of the year. The most potent strains have been selected under a range of conditions and have been challenged with priority pollutants to determine their degradative ability under laboratory conditions and subsequently ex situ in soil.     

Potential use of lignite fly ash for the control of acid generation from sulphidic wastes

In the present paper, the potential use of lignite fly ash in the control of acid generation from sulphidic tailings disposed of at Lavrion, Greece was studied. Long-term laboratory column kinetic tests were performed on tailings containing 27% S, which were homogeneously mixed with various amounts of fly ash, ranging from 10 to 63% w/w. The drainage quality of the columns was monitored over a test period of 600 days. Chemical and mineralogical characterisation of column solid residues was performed after a 270-day test period. The hydraulic conductivity of the mixtures was also measured to evaluate the potential of fly ash to form a low permeability layer. Based on the results, the addition of fly ash to sulphidic tailings, even at the lower amount, increased the pH of the drainage at values of 8.6-10.0 and decreased the dissolved concentrations of contaminants, mainly Zn and Mn, to values that meet the European regulatory limits for potable water. Higher fly ash addition to tailings, at amounts of 31 and 63% w/w also reduced the water permeability of material from 1.2 x 10(-5) cm/sec to 3 x 10(-7) and 2.5 x 10(-8) m/s, respectively.     

Phytoplankton community structure changes during autumn and spring in response to environmental variables in Methana,Saronikos Gulf,Greece

Environmental Science and Pollution Research - Phytoplankton community was investigated during two contrasting periods using offshore plankton samples in the volcanic area of Methana peninsula...