Spectroscopic changes on fulvic acids from a kraft pulp mill effluent caused by sun irradiation

Large volumes of wastewater with a high organic load are generated by the pulp and paper industry that negatively affect the quality of receiving waters. The main waste products in the pulp mill effluents are lignin derived macromolecular compounds, which are similar to natural humic substances and very resistant to wastewater treatments. Fulvic acids (FA) represent the higher percentage of these humic substances and it was observed that solar irradiation modify their properties. Several analytic tools, namely, UV–Visible, molecular fluorescence and FTIR spectroscopies, were used to assess the effect of solar exposition on fulvic acids from a kraft pulp mill effluent. It may be concluded that sun irradiation may alter to a high extent the physicochemical properties of macromolecular organic matter, namely fulvic acids, released by kraft pulp mill effluents. After solar exposition, the aromaticity decreases, the aliphatic structures become more oxygenated, and the fulvic acids from the pulp mill effluent remaining in solution are more similar to aquatic fulvic acids from non polluted sites.     

Mercury in salt marshes ecosystems: Halimione portulacoides as biomonitor

Mercury concentrations were quantified in Halimione portulacoides (roots, stems and leaves) as well as in sediments from eight Portuguese estuarine systems, covering seventeen salt marshes with distinct degrees of mercury contamination. The concentration of mercury in the sediments ranged from 0.03 to 17.0 microg g(-1). The results show that the accumulation of mercury differed according to the organ of the plant examined and the concentration of mercury in the sediments. Higher mercury concentrations were found in the roots (up to 12.9 microg g(-1)) followed by the leaves (up to 0.12 microg g(-1)), while the stems had the lowest concentrations (up to 0.056 microg g(-1)). A linear model explained the relation between the concentrations of mercury in the different plant organs: roots and stems (R(adj)(2)=0.75), stems and leaves (R(adj)(2)=0.85) and roots and leaves (R(adj)(2)=0.78). However, the results show that the variation of mercury concentration in the roots versus mercury concentration in the sediments was best fitted by a sigmoidal model (R(adj)(2)=0.89). Mercury accumulation in the roots can be described in three steps: at a low range of mercury concentrations in the sediments (from 0.03 up to 2 microg g(-1)), the accumulation of mercury in roots is also low reaching a maximum concentration of 1.3 microg g(-1); the highest rates of mercury accumulation in the roots occur in a second step, until the concentrations of mercury in the sediments reach approximately 4.5 microg g(-1); after reaching this maximum value, the rate of mercury accumulation in the roots slows down leading to a plateau in the concentration of mercury in the roots of about 9.4 microg g(-1), which corresponds to a mercury concentration in the sediments of about 11 microg g(-1). A linear model explained also the accumulation of mercury in leaves versus the mercury concentration in the sediments (R(adj)(2)=0.88). Differences in responses of roots and leaves are explained by the dynamics of the plant organs: old roots are mineralised in situ close to new roots, while leaves are renewed. Previous studies have already shown that H. portulacoides is a bioindicator for mercury and the results from this work sustain that H. portulacoides may also be used as a biomonitor for mercury contamination in salt marshes. Nevertheless, caution should be taken in the application of the models, concerning the life cycle of the species and the spatial variability of the systems.     

A review of regulatory decisions for environmental protection: part II - the case-study of contaminated land management in Portugal

This paper provides a case-study analysis of the challenges in the implementation of national soil policies, which was developed by the authors in Part I of the review of regulatory decisions for environmental protection [Rodrigues SM, Pereira ME, Ferreira da Silva E, Hursthouse A, Duarte AC. A review of regulatory decisions for environmental management: Part I-challenges in the implementation of national soil policies. Environ Int 2009. doi:10.1016/j.envint.2008.08.007]. The Portuguese case was selected as a case-study since specific regulatory decisions for contaminated land management are still in the early stages of development. Given the gap between the situation at the EU level and the state of Portuguese soil policy development, it is of merit to consider national contaminated land policy regimes already in place within the EU and to see if these provide a suitable basis to define the main challenges and research needs for the implementation of a Portuguese contaminated land management strategy. A framework combining the D-P-S-I-R (drivers-pressures-sources-impacts-responses) structure of policy evaluation with the Source-Pathway-Receptor approach to health risk assessment is proposed to derive an effective regulatory framework for managing contaminated land in Portugal, using available information and only to develop new data and research where knowledge gaps exist. Funding site clean-up and assigning liability were identified as relevant factors currently hampering site remediation. Most relevant research needs for the development of contaminated land management practices in Portugal are those associated to the definition of a risk assessment framework and setting guidelines for the evaluation of risks posed to both humans and ecosystems. Other relevant and innovative features are the integration of soil function analysis into site investigations and the definition of a framework that combines risk assessment with soil function analysis. The analysis of the Portuguese case also provides insight into the discussions needed for the effective development of regulatory decisions for contaminated land management in countries with no history of implementing specific soil policies.     

Extractability and mobility of mercury from agricultural soils surrounding industrial and mining contaminated areas

This study focussed on a comparison of the extractability of mercury in soils with two different contamination sources (a chlor-alkali plant and mining activities) and on the evaluation of the influence of specific soil properties on the behaviour of the contaminant. The method applied here did not target the identification of individual species, but instead provided information concerning the mobility of mercury species in soil. Mercury fractions were classified as mobile, semi-mobile and non-mobile. The fractionation study revealed that in all samples mercury was mainly present in the semi-mobile phase (between 63% and 97%). The highest mercury mobility (2.7 mg kg(-1)) was found in soils from the industrial area. Mining soils exhibited higher percentage of non-mobile mercury, up to 35%, due to their elevated sulfur content. Results of factor analysis indicate that the presence of mercury in the mobile phase could be related to manganese and aluminium soil contents. A positive relation between mercury in the semi-mobile fraction and the aluminium content was also observed. By contrary, organic matter and sulfur contents contributed to mercury retention in the soil matrix reducing the mobility of the metal. Despite known limitations of sequential extraction procedures, the methodology applied in this study for the fractionation of mercury in contaminated soil samples provided relevant information on mercury's relative mobility.     

Use of polyvinyl chloride pipes (PVC) as potential artificial shelters for amphibians in a coastal plain forest of southeastern Brazil

We studied the use of polyvinil chloride pipes (PVC pipes) by frogs as artificial shelters in a Coastal Plain forest in the Vale Natural Reserve, north of Espírito Santo state, southeastern Brazil from June 2015 to May 2016. We used 14 plots distributed in the Coastal Plain Forest following the RAPELD methodology of sampling. The frogs were sampled in transects along the plots, using the active search method, with visual and auditory sampling. We recorded two species of frogs (Aparasphenodon brunoi and Scinax argyreornatus) using PVC pipes as shelters in the plots in the Forest. Of the 468 PVC pipes established along plots, 38 of them (8.1%) were used as shelter by the frogs. For both frog species, about 33% of microhabitats used in the forest were the interior of PVC pipes. We concluded that the PVC pipes might constitute artificial shelters for at least two of the frog species living in the community of the Coastal Plain Forest, potentially being of relevance in conservation programs. In altered areas and those in which there has been the loss of types of microhabitats, the addition of these PVC pipes as artificial shelters may represent additional and complementary microhabitats to keep or increase the population stocks of arboreal and semi-arboreal frog species and having a size that allow them entering the shelter. These artificial shelters can play an important role in conservation of these frogs in fragmented areas where the availability of the microhabitats of these frog species were locally reduced.     

Core–shell magnetite-silica dithiocarbamate-derivatised particles achieve the Water Framework Directive quality criteria for mercury in surface waters

The sorption capacity of nanoporous titanosilicate Engelhard titanosilicate number 4 (ETS-4) and silica-coated magnetite particles derivatised with dithiocarbamate groups towards Hg(II) was evaluated and compared in spiked ultra-pure and spiked surface-river water, for different batch factors. In the former, and using a batch factor of 100 m³/kg and an initial Hg(II) concentrations matching the maximum allowed concentration in an effluent discharge, both materials achieve Hg(II) uptake efficiencies in excess of 99 % and a residual metal concentration lower than the guideline value for drinking water quality. For the surface-river water and the same initial concentration, the Hg(II) uptake efficiency of magnetite particles is outstanding, achieving the quality criteria established by the Water Framework Directive (concerning Hg concentration in surface waters) using a batch factor of 50 m³/kg, while the efficiency of ETS-4 is significantly inferior. The dissimilar sorbents’ Hg(II) removal efficiency is attributed to different uptake mechanisms. This study also highlights the importance of assessing the effective capacity of the sorbents under realistic conditions in order to achieve trustable results.     

Quantification of reef benthos communities and variability inherent to the monitoring using video transect method

Long-term monitoring program of organisms is the most recommended for understanding changing processes on reefs. The video transect method presents advantages for that. Specialists state that it is important to make sure that the recorded coverage is always the same between campaigns, so that differences in results may be entirely attributed to environmental changes. This study aimed to test the capability of implementing this requirement through tracking simulation and its validity for monitoring the benthic communities of reefs using the video transect method. Ten transects 20 m long were established in Todos os Santos Bay coral reefs. Subsequent to the first transect capture, a second diver repeated the same track, simulating two different monitoring campaigns. Data were transformed and a matrix of similarity was generated using Bray–Curtis’ Index. ANOSIM analysis was performed to test the similarity of the ten transects and its repetitions. The result, R = 0.08 (P = 0.928), shows that reef monitoring using video transect, the way it is described in the literature, is appropriate, but it is important to consider some premises discussed in this work.     

Evaluation of violations in water quality standards in the monitoring network of São Francisco River basin,the third largest in Brazil

The São Francisco River is the largest river located entirely within Brazil, and water scarcity problems have been a major concern of Brazilian society and government. Water quality issues are also a concern and have worsened with the recent intensification of urbanization and industrialization. In this study, violations to water quality standards established by local legislation were calculated as a percentage for 26 selected parameters over a monitoring period of 14 years. The violation percentages were analyzed spatially using the Kruskal-Wallis test, followed by multiple comparison analysis. Temporal analysis was performed using the Mann-Kendall test and Spearman correlation. Some parameters could be identified as cause for concern due to high violation levels, such as the fecal coliform indicator (FCI) and phosphorus—both related to domestic and effluent disposal without treatment or with insufficient treatment—and color, turbidity, manganese, and total suspended solids—which can be affected by erosive processes of natural and anthropogenic causes. The study found that these violations are concentrated in the most urbanized and industrialized areas of the basin. Some metallic parameters, such as iron and arsenic violations, may be related to mining activities in the rich soil of the Iron Quadrangle area located within the Minas Gerais State. Trend analysis results indicated that most monitoring stations did not have significant modification (elevation or reduction) trends over time, which, together with the high violation percentages, might indicate the maintenance of a scenario of constant pressure upon water resources, in particular in those more urbanized areas.     

Traditional olive orchards on sloping land: Sustainability or abandonment?

Traditional olive orchards account for a large share of the area under olives in the EU, particularly in marginal areas, like those analysed in the OLIVERO project. In general, traditional olive growing can be described as a low-intensity production system, associated with old (sometimes very old) trees, grown at a low density, giving small yields and receiving low inputs of labour and materials. Though such systems are environmentally sustainable, their economic viability has become an issue, since EU policies favour more intensive and competitive systems. Orchards that have not been intensified seem to be threatened by the recent reform of the EU olive and olive oil policy, as income support has been decoupled from production. The main purpose of this paper is to identify the present constraints to traditional olive growing, and to recommend some private and public interventions to prevent its abandonment. During the OLIVERO project, traditional olive production systems were identified and described in five target areas (Trás-os-Montes-Portugal, Cordoba and Granada/Jaen-Spain, Basilicata/Salerno-Italy, and West Crete-Greece). The causes and consequences of abandonment are discussed, based on the analysis of the costs and returns, which revealed that these systems are barely economically sustainable. Their viability is only assured if reduced opportunity costs for family labour are accepted, and the olive growing is part-time. Based on these results, recommendations are made to prevent the abandonment of traditional olive growing and to preserve its environmental benefits.     

A gas chromatography-quartz crystal microbalance for speciation of sulfur compounds in landfill gas

A new method, based on separation with gas chromatography and detection with a quartz crystal microbalance, was used for the quantification of ethane-1-thiol, propane-1-thiol, ethyl methyl sulfide, propane-2-thiol, butane-2-thiol and butane-1-thiol. The analytical error, the analysis time and the general analytical performance are identical for gas chromatography-mass spectrometry (GC-MS) and gas chromatography-quartz crystal microbalance (GC-QCM). However, the GC-QCM method constitutes a low cost alternative to GC-MS for monitoring individual sulfur compounds in landfill gas. It is an easily assembled apparatus made with an injection device, a furnace, a column, a crystal cell and a quartz crystal.