Photocatalytic degradation of dyes in aqueous solution operating in a fluidised bed reactor.

This work reports a preliminary design of a new photochemical reactor and its application to photochemical degradation of two dyes, Crystal Violet and Azure B, operating in both batch and continuous processes. A novel kind of photocatalyst, consisting of ZnO immobilised in alginate gel beads, which is able to photodegrade organic dyes effectively, has been employed in the present study. When this photocatalyst, at a concentration of 1 g of ZnO per litre of alginate gel at 3%, was employed in batch process, almost total decolourisation of Crystal Violet in reaction times lower than 120 min was observed. Operating in continuous process at different residence times, it was possible to achieve a total decolourisation of both Crystal Violet and Azure B. Moreover, the total organic carbon content (TOC) was reduced to 90% in the former and to 52% in the latter. These results indicated that the photoreactor developed in the present work was able to degrade effectively dyes of different structures, revealing the non-specificity of the system.     

Inhibition of laccase activity from Trametes versicolor by heavy metals and organic compounds

Due to the numerous biotechnological applications of laccase enzyme, it is essential to know the influence of different agents usually present in the natural environment on its enzymatic action, especially for in situ treatment technologies. In the present work, a simple and rapid method to determine the inhibitory or inducer effect of different compounds on laccase activity was developed. The compounds tested were copper-chelating agents and heavy metals. It was found that using syringaldazine as a substrate, all copper-chelating agents (except EDTA) highly inhibited laccase activity (around 100%) at an inhibitor concentration lower than 20 mM. Moreover, 40% of inhibition, which was detected at a concentration of 20 mM for both Cd(2+) and Cu(2+) increased with concentration until nearly complete inhibition at 80 mM.     

Estimation of the critical effect level for pollution prevention based on oyster embryonic development toxicity test: the search for reliability

In spite of the consideration that toxicity testing is a reduced approach to measure the effects of pollutants on ecosystems, the early-life-stage (ELS) tests have evident ecological relevance because they reflect the possible reproductive impairment of the natural populations. The procedure and validation of Crassostrea rhizophorae embryonic development test have shown that it meets the same precision as other U.S. EPA tests, where EC(50) is generally used as a toxicological endpoint. However, the recognition that EC(50) is not the best endpoint to assess contaminant effects led U.S. EPA to recently suggest EC(25) as an alternative to estimate xenobiotic effects for pollution prevention. To provide reliability to the toxicological test results on C. rhizophorae embryos, the present work aimed to establish the critical effect level for this test organism, based on its reaction to reference toxicants, by using the statistical method proposed by Norberg-King (Inhibition Concentration, version 2.0). Oyster embryos were exposed to graded series of reference toxicants (ZnSO(4) x 7H(2)O; AgNO(3); KCl; CdCl(2)H(2)O; phenol, 4-chlorophenol and dodecyl sodium sulphate). Based on the obtained results, the critical value for C. rhizophorae embryonic development test was estimated as EC(15). The present research enhances the emerging consensus that ELS tests data would be adequate for estimating the chronic safe concentrations of pollutants in the receiving waters. Based on recommended criteria and on the results of the present research, zinc sulphate and 4-chlorophenol have been pointed out, among the inorganic and organic compounds tested, as the best reference toxicants for C. rhizophorae ELS-test.     

Endocrine disruptors in the Leça River and nearby Porto Coast (NW Portugal): presence of estrogenic compounds and hypoxic conditions

The Leça River and two beaches close to the north and south margins of the estuary, nowadays an important seaport harbor, show signs of contamination. However, the chemical nature of that contamination is uncertain. Therefore, this study checked for the presence of 11 endocrine disrupting compounds (EDCs) of animal (17β-estradiol and estrone), pharmaceutical (17α-ethynylestradiol), and industrial (alkylphenols, alkylphenol ethoxylates, and bisphenol A) origins in water samples collected from six points at the river gradient and at two sites in the coastline (Atlantic Ocean). Along with the EDCs, evaluated by gas chromatography – mass spectroscopy (GC-MS) during spring, summer, and autumn, physico-chemical parameters were also assessed and particular attention was given to dissolved oxygen (DO) levels. Data showed the presence of high amounts of estrogens (up to 10?ng?L^?1 for estrone) and industrial compounds (up to 2?µg?L^?1 for the nonylphenol ethoxylates) at both river and seacoast. Along with this, clear signs of hypoxia were found in the river (DO??1 at several sampling sites). Taking into account these issues, it was concluded that there are local conditions for the occurrence of endocrine disruption in aquatic animals.     

Carbon-optimised land management strategies for southern Amazonia

Regional Environmental Change -     

Testing differences in methods of preparing moss samples

The main objective of this research was to estimate the total mass of nitrogen discharged from various sources in Korea using the mass balance approach. Three different nitrogen mass balances were presented: (1) agricultural activities including raising crops and animal husbandry; (2) domestic activities, and (3) activities in forest and urban areas. These nitrogen balances were combined to estimate riverine discharge of nitrogen to the ocean in national scale. Nitrogen inputs include atmospheric deposition, biological nitrogen fixation, application of inorganic fertilizers/manures, animal feed/imported foodstuffs, and meat/fish. Nitrogen outputs include ammonia volatilization, denitrification, human/animal waste generation, crop/meat production, and riverine discharge to the ocean. The estimated total nitrogen input in Korea was 1,194.5 × 10³ tons N/year. Nitrogen discharged into rivers was estimated as 408–422 × 10³ tons N/year, of which 66–71% was diffuse in origin. The estimated diffuse discharges for land uses were estimated as 82 × 10³ tons N/year from agricultural areas, 7 × 10³ tons N/year from forestry and 75 × 10³ tons N/year from urban and industrial areas.     

Mesocosm trials of bioremediation of contaminated soil of a petroleum refinery: comparison of natural attenuation,biostimulation and bioaugmentation

Purpose  

Contamination with petroleum hydrocarbons (PHC) is a global problem with environmental implications. Physico-chemical treatments can be used for soil cleanup, but they are expensive, and can have implications for soil structure and environment. Otherwise, biological remediation treatments are cost-effective and restore soil structure. Several remediation experiments have been carried out in the lab and in the field; however, there is the challenge to achieve as good or better results in the field as in the laboratory. In the ambit of a project aiming at investigating suitable biological remediation approaches for recovering a refinery contaminated soil, we present here results obtained in bioremediation trials. The approaches biostimulation and bioaugmentation were tested, in parallel, and compared with natural attenuation. For this purpose, mesocosm experiments were carried out inside the refinery area, which constitutes a real asset of this work.     

Bioavailable metals and cellular effects in the digestive gland of marine limpets living close to shallow water hydrothermal vents

The pressure exerted by shallow water hydrothermal vents on edible gastropods and their cellular responses triggered by these stresses are almost unknown. The aims of this study were to evaluate the bioavailability of metals in the Macaronesian endemic limpet Patella candei gomesii living close to shallow water hydrothermal vents, and the structural differences in their digestive gland as well as the levels of apoptosis in that organ. Limpets were sampled in four sites, two with the presence of hydrothermalism and the other two without it. Whole body concentrations of several metals (Ca, Cd, Cs, Co, Cu, Fe, Hg, Mg, Mn, Pb, Rb, Se, Sr, and Zn) were obtained, morphometry analysis of the digestive gland and TUNEL test for apoptosis were also performed. Results revealed that the presence of shallow water hydrothermal vents is a source of chronic metal stress to limpets, imposing modifications in the morphometry and cell composition of the digestive gland of those limpets that may constitute cell and tissue adaptations to the environment they live in. This study sets up new baseline data for further research on the influence of shallow water hydrothermal vents over communities living in these habitats.     

Phosphorus recovery from sewage sludge ash through an electrodialytic process

The electrodialytic separation process (ED) was applied to sewage sludge ash (SSA) aiming at phosphorus (P) recovery. As the SSA may have high heavy metals contents, their removal was also assessed. Two SSA were sampled, one immediately after incineration (SA) and the other from an open deposit (SB). Both samples were ED treated as stirred suspensions in sulphuric acid for 3, 7 and 14 days. After 14 days, phosphorus was mainly mobilized towards the anode end (approx. 60% in the SA and 70% in the SB), whereas heavy metals mainly electromigrated towards the cathode end. The anolyte presented a composition of 98% of P, mainly as orthophosphate, and 2% of heavy metals. The highest heavy metal removal was achieved for Cu (ca. 80%) and the lowest for Pb and Fe (between 4% and 6%). The ED showed to be a viable method for phosphorus recovery from SSA, as it promotes the separation of P from the heavy metals.     

Risk factors affecting injury severity determined by the MAIS score

Objective: Traffic crashes result in a loss of life but also impact the quality of life and productivity of crash survivors. Given the importance of traffic crash outcomes, the issue has received attention from researchers and practitioners as well as government institutions, such as the European Commission (EC). Thus, to obtain detailed information on the injury type and severity of crash victims, hospital data have been proposed for use alongside police crash records. A new injury severity classification based on hospital data, called the maximum abbreviated injury scale (MAIS), was developed and recently adopted by the EC. This study provides an in-depth analysis of the factors that affect injury severity as classified by the MAIS score.

Method: In this study, the MAIS score was derived from the International Classification of Diseases. The European Union adopted an MAIS score equal to or greater than 3 as the definition for a serious traffic crash injury. Gains are expected from using both police and hospital data because the injury severities of the victims are detailed by medical staff and the characteristics of the crash and the site of its occurrence are also provided. The data were obtained by linking police and hospital data sets from the Porto metropolitan area of Portugal over a 6-year period (2006–2011). A mixed logit model was used to understand the factors that contribute to the injury severity of traffic victims and to explore the impact of these factors on injury severity. A random parameter approach offers methodological flexibility to capture individual-specific heterogeneity. Additionally, to understand the importance of using a reliable injury severity scale, we compared MAIS with length of hospital stay (LHS), a classification used by several countries, including Portugal, to officially report injury severity. To do so, the same statistical technique was applied using the same variables to analyze their impact on the injury severity classified according to LHS.

Results: This study showed the impact of variables, such as the presence of blood alcohol, the use of protection devices, the type of crash, and the site characteristics, on the injury severity classified according to the MAIS score. Additionally, the sex and age of the victims were analyzed as risk factors, showing that elderly and male road users are highly associated with MAIS 3+ injuries. The comparison between the marginal effects of the variables estimated by the MAIS and LHS models showed significant differences. In addition to the differences in the magnitude of impact of each variable, we found that the impact of the road environment variable was dependent on the injury severity classification.

Conclusions: The differences in the effects of risk factors between the classifications highlight the importance of using a reliable classification of injury severity. Additionally, the relationship between LHS and MAIS levels is quite different among countries, supporting the previous conclusion that bias is expected in the assessment of risk factors if an injury severity classification other than MAIS is used.