Assessing the Relative Contribution of Wastewater Treatment Plants to Levels of Metals in Receiving Waters for Catchment Management

The selection of control measures for reducing metal contamination in rivers has targeted point sources such as wastewater treatment plants (WWTPs) and industrial discharges without a proper evaluation of their relative contribution to metal loads at the catchment level. The necessity of controlling pollutant inputs in a sound and cost-effective way to prevent the deterioration of chemical and ecological quality of receiving waters has highlighted the need for appropriate source assessment. As metals in rivers emanate from a wide range of sources, it is necessary to understand their relative contribution in order to reduce effectively the concentrations in receiving waters. This study presents a simple method for calculating the relative contribution of WWTPs to levels of metals in receiving waters as applied to the Aire?CCalder catchment in the UK. In this catchment, the apportionments to WWTP effluents of metal levels in rivers were 37, 31, 36 and 60?% of total cadmium (Cd), lead (Pb), mercury (Hg) and nickel (Ni), respectively. Spatial metal distribution in rivers with maximum concentrations of 0.47???g?L^?1 for Cd, 8.54???g?L^?1 for Pb, 0.05???g?L^?1 for Hg and 10.17???g?L^?1 for Ni caused by the discharge of WWTP effluents was estimated. The findings demonstrate that the proposed approach using quantification of metal loads and estimation of concentrations in receiving waters could adequately calculate the relative contribution of WWTP effluents to metal levels in receiving waters. Applications to various river catchments using site-specific data would further validate the effectiveness of the approach proposed.     

Insecticide resistance status of Myzus persicae (Hemiptera: Aphididae) populations from peach and tobacco in mainland Greece

The susceptibility of 88 and 38 field samples of Myzus persicae (Sulzer) to imidacloprid and deltamethrin respectively was examined using the FAO dip test bioassay. The field samples were collected from tobacco and peach from various regions of Greece in the period from 2004 to 2006. In addition, 497, 349 and 370 clones originating from peach and tobacco were screened for the three known resistance mechanisms, elevated esterases, modified acetylcholinesterase (MACE) and knockdown resistance (kdr) respectively, using biochemical and DNA diagnostics. Most of the samples assayed with imidacloprid showed low resistance factors (RFs)-39% below 5 and 21% between 5 and 10. However, 9% of the samples (all from tobacco) showed relatively high RF values (24-73). Differences were found between crops, with higher RF values recorded in samples from tobacco than in those from peach. Bioassays with deltamethrin revealed the development of strong resistance in the populations examined. The RFs were mostly higher than 23, and in 29% of the samples they were extremely high (152-436). Finally, the three known resistance mechanisms were found in high frequencies in the populations examined, although some differences between crops and years were detected. The implications of the study for management schemes against M. persicae are discussed.     

Anthropogenic Heavy Metal Pollution in the Surficial Sediments of the Keratsini Harbor, Saronikos Gulf, Greece

The contents of ten elements [Cd, Pb, W, Zn, Mn, As, Se, Cr, Cu, and organic carbon (C_org)] have been determined in the surficial sediments of Keratsini harbor, Saronikos Gulf, Greece. The contamination of the sediments was assessed on the basis of geoaccumulation index and to corresponding sediment quality guidelines (SQGs) effects range low/effects range median. The results revealed highly elevated Cd, Pb, W, Zn, As, Se, Cr, Cu, and C_org values (Cd, 190–1,763 mg kg^?1; Pb, 521–1,263 mg kg^?1; W, 38–100 mg kg^?1; Zn, 409–6,725 mg kg^?1; Mn, 95–1,101 mg kg^?1; As, not detectable–1,813 mg kg^?1; Se, not detectable–58 mg kg^?1; Cr, 264–860 mg kg^?1; Cu, 195–518 mg kg^?1; and C_org, 0.69–4.41%). The enrichment of metals in the sediments results from the contribution of the central Athens sewage outfall through which the waste of the Attica basin ends up in Keratsini harbor as well as from industrial and ship contaminants.     

Influence of wine pH on changes in color and polyphenol composition induced by micro-oxygenation

The presence of oxygen in red wine leads to the transformation of ethanol into ethanal, which after capturing a proton will react with flavanols to start the process of forming ethyl bridges between flavanols and between flavanols and anthocyanins. Wine pH also conditions the equilibrium between the different anthocyanin structures and may thus affect anthocyanin reactivity. Consequently, the aim of this paper was to study how the pH can affect the changes induced by micro-oxygenation in two wines with different phenolic composition. The differences between micro-oxygenated wines and their controls were, in general, greater when the pH was more acidic. Specifically, the differences between micro-oxygenated wines and their corresponding controls in terms of color intensity, anthocyanin concentration, PVPP index, ethyl-linked pigments, B-type vitisins, polymeric pigments, and ethylidene-bridged flavanols were greater at lower pH. In contrast, the effects of micro-oxygenation when the pH was less acidic were much less evident and sometimes practically nonexistent. These results demonstrate for the first time that the pH of the wine has a great influence on oxygen-induced changes of color and phenolic compounds.     

Estimation of scavenging activity of phenolic compounds using the ABTS(*+) assay

Observations on the applicability of the ABTS(*+) assay to define structure-activity relationships (SARs) among phenols (AH) were based on experimental data and theoretical calculations. All AH examined (hydroxycinnamic derivatives, simple polyphenols, polyhydroxybenzoates, and flavonoids) were found to be active toward ABTS(*+). Moreover, known weak radical scavengers (i.e., coumaric and isoferulic acids) were found to be efficient or comparatively active to caffeic or rosmarinic acids in contradiction to the AH classification based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) data or the bond dissociation enthalpy values. This behavior was observed both in ethanol and in buffered (pH 7.4) environment. Resorcinol and phloroglucin were found to be more active than catechol and hydroquinone, whereas, among polyhydroxybenzoates, 2,4-dihydroxybenzoic acid was the least active, in line with the DPPH and theoretical data. Therefore, it can be argued that the ABTS(*+) assay may give an indication for the presence of antioxidants in a certain system but SARs cannot be readily inferred.     

To what extent are threatened European plant species conserved in seed banks?

The number of ex situ conservation facilities has grown dramatically in recent years, and they have become increasingly integrated under national and regional conservation initiatives. However, little information is available about the extent to which plant species are appropriately represented in ex situ collections. This paper assesses whether seed/spore collections stored in European seed banks cover or not, and to what extent, the species currently threatened with extinction in the wild. Although a substantial amount of the European flora (ca. 70%) is currently stored in seed banks, we highlight the relatively poor representation of threatened species: only 27% of the taxa listed on the European threatened plant list and 44% of the taxa listed in Annex II of the EU Habitat Directive are stored in European seed banks. Some taxonomical groups most at risk, e.g. Pteridophytes and Orchidaceae, are also under-represented in European seed banks. By examining the number of accessions per species and the number of seeds per accession, this study also gave some insight on how well species are conserved, considering that these two variables are surrogates for genetic diversity. We have highlighted that at least two thirds of the threatened species stored in European seed banks likely suffer from too low genetic diversity in the collections. These analyses were essential to identify those collections and additionally the standards needed to maximize the usefulness of future collections.     

Estimating Levels of Micropollutants in Municipal Wastewater

The evolution of microbial communities with increasing carbon tetrachloride concentrations was studied in two anaerobic columns containing sand and two different clay soils, one of which contained high levels of iron. Microbial communities were characterized through analysis of column effluents with denaturing gradient gel electrophoresis and quantitative polymerase chain reaction for archaea and eubacteria as inlet carbon tetrachloride concentrations were increased from 0.8 to 29 μM. Inhibition of microbial activity was observed in both columns, and was associated with the accumulation of chloroform at concentrations of 0.2 to 0.4 μM as inlet CT concentrations were increased to 2.4–3.0 μM in the low-iron clay column and approximately 16 μM in the iron rich clay column. Inhibition was indicated by decreasing rates of methanol and carbon tetrachloride degradation, decreases in effluent levels of DNA, and shifts in microbial communities of the columns. Even with the inhibition observed, in the iron-rich clay column CT degradation continued to the end of the study with inlet CT concentrations of 29 μM, in contrast to the low-iron clay column in which minimal CT degradation occurred once CT inlet concentrations exceeded 3 μM. The greater capacity for CT degradation in the column containing the iron-rich clay was hypothesized to be the result of reaction with biogenic ferrous iron produced by biological dissimilatory iron reduction.     

Seasonal size distribution,condition status and muscle yield of Mediterranean horse mackerel <Emphasis Type="Italic">Trachurus mediterraneus</Emphasis> from the North Aegean Sea,Greece

ABSTRACT:   The seasonal intrinsic variability of the North Aegean Sea Mediterranean horse mackerel Trachurus mediterraneus population has been studied from monthly samples taken from the Greek purse-seine fishery over a 4-year period (2001–2005). The length and weight frequency distributions differed significantly by season, the highest mean lengths and weights attained in spring and the lowest in autumn. Length-weight relationships were determined on a monthly and annual basis, and monthly variations on the allometry coefficient were found. The differences between the coefficient obtained for annual data and the coefficients for each month were not significant in 50% of the cases. The b -values obtained both in this study and some of the previously reported in the Mediterranean Sea and other Greek waters were compared, showing basic similarities and minor spatial variation. The seasonal cycle in Mediterranean horse mackerel condition appears to be related to the reproductive cycle of the fish. Values of muscle yield ranged between 23.33% and 33.07% (mean value 28.48 ± 2.49%), but variations within seasons were not significant.