Vulnerability of Catalan (NW Mediterranean) ports to wave overtopping due to different scenarios of sea level rise

The overtopping of port breakwaters may affect the assets located at the breakwater lee side. If adaptation measures are not taken, the sea level rise will increase the overtopping discharges putting those assets at significant risk. This study compares, at a regional scale, overtopping discharges over port breakwaters for three storm conditions (return periods of 1, 5 and 50 years) under present climate as well as for three scenarios of sea level rise based on recent projections. The results indicate that, for the worst storm and sea level rise conditions, the overtopping discharge would not be negligible (larger than 1 l/s/m) in 35 ports (84 %), in contrast to only 18 ports (42 %) being affected under present conditions. In addition, in 28 ports (65 %) the overtopping would be at least one order of magnitude larger than for present conditions. In the case of large storms, in 2 ports the overtopping discharge exceeds 200 l/s/m (the discharge that can initiate breakwater damage) under present conditions, while in the worst scenario of sea level rise the number of ports exceeding this value would be 7. On the other hand, the vulnerability of each port for which overtopping flow is greater than an acceptable discharge flux is assessed, and regional maps of vulnerability are plotted. For the worst storm conditions, 23 % of the Catalan ports have risks associated with overtopping under present climate conditions. This percentage would increase to 47 % in the worst sea level rise scenario.     

Climatic drivers of potential hazards in Mediterranean coasts

This paper studies climatic drivers (air and water temperature, precipitation rates, river discharge, sea level and storm patterns) in four Mediterranean regions: the Catalan-Valencia Coast (Spain), the Oran (Algeria) and Gabès (Tunisia) Gulfs and the western Nile Delta (Egypt). The paper also considers the potential hazards that these drivers can induce. It first analyses climatic trends in the drivers, taking into account the available time series of recorded and simulated meteo-oceanographic data from different sources. Next, it presents the general framework to assess biogeophysical hazards (flooding, erosion, droughts and water quality), followed by a simple and yet robust evaluation of those hazards for the four studied coastal sites. Assuming climate change projections under different scenarios and considering the observed trends in drivers, the resulting erosion rates due to sea-level rise and wave storm effects have been estimated. The Nile and Ebro Deltas, together with the Oran Gulf, are more vulnerable than the Gulfs of Valencia and Gabès. Regarding water quality in terms of (a) precipitation and dissolved oxygen in the water column and (b) sea surface temperature, the results show that the most vulnerable zones for the projected conditions (a) are the Gulfs of Oran, Valencia and Gabès, while the Nile Delta is the region where the decrease in water quality will be less pronounced. For the projected conditions (b), the most vulnerable zone is the Ebro Delta, while the impact in the other three cases will be smaller and of comparable magnitude. Finally, the overall future impact of these hazards (associated to climatic change) in the four sites is discussed in comparative terms, deriving some conclusions.     

4-Ethylphenol and 4-ethylguaiacol in wines: Estimating non-microbial sourced contributions and toxicological considerations

Analyses of commercially available wines suggested non-Brettanomyces sources of 4-ethylphenol and 4-ethylguaiacol. Grapes, enological additions, exposure to plastics, and oak-barrel aging were potential inputs considered. Investigations of whole grape bunch samples from two major red wine Vitis vinifera cultivars (L. cv. Cabernet Franc and Pinot Noir), a commercial mannoprotein additive, and three commercial enological tannin additions indicated they are not likely significant sources of these compounds. Studies on 15 commercial oak barrelled red wines from six Vitis vinifera cultivars (L. cv. Cabernet Franc, Cabernet Sauvignon, Dunkelfelder, Merlot, Pinot Meunier, and Pinot Noir), and a review of volatile phenol extraction from toasted oak wood, suggested that oak-aging may produce concentrations of up to 50 μg L^?1 4-ethylphenol and 4-ethylguaiacol. Thus, following potential Brettanomyces-sourced aroma impacts in wine using 4-ethylphenol and/or 4-ethylguaiacol concentrations as proxies should only be considered reliable at analyte levels > 100 μg L^?1. A review of worldwide 4-ethylphenol and 4-ethylguaiacol concentrations in wine, consumption patterns, and available toxicological data also suggested that levels of 4-ethylphenol being observed in wines worldwide do not warrant concerns about acute or long-term effects. While little is known about the toxicology of 4-ethylguaiacol, it is unlikely that elevated concentrations will pose any health-related concerns.     

Fluorescence fingerprint of fulvic and humic acids from varied origins as viewed by single-scan and excitation/emission matrix techniques

Excitation/emission matrix (EEM), single-scan excitation and synchronous fluorescence spectra of a series of FA and HA from distinct environments are presented. The EEM plots show at least four spectral features whose corresponding Ex/Em pairs relate to the alpha', alpha, beta and gamma (or delta) fluorophores previously found in natural waters spectra. The alpha' and alpha peaks, which identify typical humic-like components, are present in all samples, independently of the organic matter (OM) source. In FA, their Ex/Em pairs are approximately 260 nm/460 nm and approximately 310 nm/440 nm, respectively. In HA their excitation and emission maxima are red-shifted, the corresponding Ex/Em pairs being located at approximately 265 nm/525 nm and approximately 360 nm/520 nm, respectively. The appearance of beta and gamma (or delta) peaks is dependent both on the OM origin and on HS aging. The former (Ex/Em approximately 320 nm/430 nm), that has been associated with the incidence of marine humic-like material, is present only in a few marine and estuarine HA. It emerges as a shoulder on the alpha peak and its detection is dependent on a balance between its magnitude and the magnitude and emission maxima location of the alpha peak. The gamma (or delta) peak (Ex/Em approximately 275 nm/315 nm in FA, and approximately 275 nm/330 nm in HA), on the other hand, is better visualized in FA than in HA diagrams. It has typical protein-, mainly tryptophan-like, fluorescence properties and appears with varied significance in a few marine and estuarine samples being hardly detected in samples from exclusively terrestrial environments. It is also shown in this study that with selected lambda(ex), lambda(em) and (delta)(lambda) values, regular emission, excitation and synchronous spectra can, together, provide a good picture of the OM sources and aging for extracted HS.     

Presence of diclofenac,estradiol, and ethinylestradiol in Manzanares River (Spain) and their toxicity to zebrafish embryo development

Environmental Science and Pollution Research - Diclofenac (DCF), 17-β-estradiol (E2), and 17-α-ethinylestradiol (EE2) are emerging pollutants included in the first watch list agreed by...     

Modelling the impact of thermal adaptation of soil microorganisms and crop system on the dynamics of organic matter in a tropical soil under a climate change scenario

No consensus currently exists about how climate change should affect the status of soil organic matter (SOM) in the tropics. In this study, we analyse the impact of climate change on the underlying mechanisms controlling SOM dynamics in a ferralsol under two contrasting tropical crops: maize (C4 plant) and banana (C3 plant). We model the effect of microbial thermal adaptation on carbon (C) mineralisation at the crop system scale and introduce it in the model STICS, which was previously calibrated for the soil-crop systems tested in this study. Microbial thermal adaptation modelling is based on a reported theory for thermal acclimation of plant and soil respiration. The climate is simulated from 1950 to 2099 for the tropical humid conditions of Guadeloupe (French Antilles), using the ARPEGE model and the IPCC emission scenario A1B. The model predicts increases of 3.4 °C for air temperature and 1100 mm yr⁻¹ for rainfall as a response to an increase of 375 ppm for atmospheric carbon dioxide concentration in the 2090-2099 decade compared with the 1950-1959 decade. The results of the STICS model indicate that the crop affects the response of SOM to climate change by controlling the change in several variables involved in C dynamics: C input, soil temperature and soil moisture. SOM content varies little until 2020, and then it decreases faster for maize than for banana. The decrease is weakened under the hypothesis of thermal adaptation, and this effect is greater for maize (−180 kg C ha⁻¹ yr⁻¹ without adaptation and −140 kg C ha⁻¹ yr⁻¹ with adaptation) than for banana (−60 kg C ha⁻¹ yr⁻¹ and −40 kg C ha⁻¹ yr⁻¹, respectively). The greater SOM loss in maize is mainly due to the negative effect of warming on maize growth decreasing C input from residues. Climate change has a small effect on banana growth, and SOM loss is linked to its effect on C mineralisation. For both crops, annual C mineralisation increases until 2040, and then it decreases continuously. Thermal adaptation reduces the initial increase in mineralisation, but its effect is lower on the final decrease, which is mainly controlled by substrate limitation. No stabilisation in SOM status is attained at the end of the analysed period because C mineralisation is always greater than C input. Model predictions indicate that microbial thermal adaptation modifies, but does not fundamentally change the temporal pattern of SOM dynamics. The vegetation type (C3 or C4) plays a major role in SOM dynamics in this tropical soil because of the different impact of climate change on crop growth and then on C inputs.     

Identification and quantitation of semi-crystalline microplastics using image analysis and differential scanning calorimetry

Environmental Science and Pollution Research - There are several techniques used to analyze microplastics. These are often based on a combination of visual and spectroscopic techniques. Here we...     

Photochemistry of a major commercial polybrominated diphenyl ether flame retardant congener: 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE153)

The photochemistry of a major commercial polybrominated diphenyl ether (PBDE) flame retardant congener, 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE153), was investigated in acetonitrile, distilled water, and seawater. After a short irradiation period in acetonitrile at 302 nm, the major photoproducts of BDE153 included 2,2',4,4',5-(BDE99), 2,2',4,5,5'-(BDE101), and 2,4,4',5,5'-(BDE118) substituted penta-BDEs as primary photohydrodebromination products, 2,2',4,4'-(BDE47), 3,3',4,4'-(BDE77), 2,3',4,4'-(BDE66), and 2,2',4,5'-(BDE49) substituted tetra-BDEs as secondary photohydrodebromination products, a suite of non-2,3,7,8-substituted mono- through penta-brominated dibenzofurans, and three tetrabrominated 2-hydroxybiphenyl congeners. By comparison, irradiation in distilled water and seawater gave increased relative photohydrodebromination contributions and no evidence for the formation of brominated dibenzofurans or 2-hydroxybiphenyls. In all solvent systems, subsequent degradation of primary and secondary photoproducts under continuing irradiation led to a steadily decreasing reaction mass balance. The results suggest a short photochemical half-life for BDE153 in aquatic systems, with rapid photohydrodebromination to some of the most prevalent penta- and tetra-brominated diphenyl ether congeners typically observed in environmental matrices.     

Influence of particle size distribution on anaerobic degradation of phenol and analysis of methanogenic microbial community

Sludge morphology considerably affects the mechanism underlying microbial anaerobic degradation of phenol. Here, we assessed the phenol degradation rate, specific methanogenic activity, electron transport activity, coenzyme F420 concentration, and microbial community structure of five phenol-degrading sludge of varying particle sizes (i.e., < 20, 20–50, 50–100, 100–200, and > 200 μm). The results indicated an increase in phenol degradation rate and microbial community structure that distinctly correlated with an increase in sludge particle size. Although the sludge with the smallest particle size (< 20 μm) showed the lowest phenol degradation rate (9.3 mg COD·gVSS−1 day−1), its methanogenic activity with propionic acid, butyric acid, and H2/CO2 as substrates was the best, and the concentration of coenzyme F420 was the highest. The small particle size sludge did not contain abundant syntrophic bacteria or hydrogenotrophic methanogens, but contained abundant acetoclastic methanogens. Moreover, the floc sizes of the different sludge varied in important phenol-degrading bacteria and archaea, which may dominate the synergistic mechanism. This study provides a new perspective on the role of sludge floc size on the anaerobic digestion of phenol.