Spatio-temporal prediction of atmospheric benzene (Part I)

Benzene is a carcinogenic and genotoxic pollutant which mainly affects the people health through the inhalation. Nevertheless, this pollutant is not frequently measured by air-quality networks. To solve this problem, some models have been published to estimate benzene concentrations in the atmosphere. However, the lack of measures makes difficult the application of complex models in order to get a detailed spatio-temporal analysis, namely in urban areas. In this work was developed a simple semi-empirical model to predict benzene concentrations based on the ratio of benzene and carbon monoxide concentrations in order to predict the concentrations of this pollutant in large areas and periods with lack of benzene measurements but with higher impact in the human health. The model was applied to an urban area, the Metropolitan Area of Oporto, for a period of 12 years (1995–2006). Monthly correlations between benzene and carbon monoxide concentrations at Custóias air-quality station are significant (p = 0.01) and higher in winter (r _s > 0.7) than in summer (0.3 > r _s > 0.7). Estimate of the monthly ratio of the concentration of these two pollutants range between 199 and 305. The methodology validation shows good results (r _s = 0.81) which allow, assuming the availability of carbon monoxide data, the use of this tool for areas with low benzene recorded data. The application of this methodology in the study area shows an annual average trend decrease of benzene concentrations during the study period, which may be linked to a general trend decrease of benzene emissions in European urban areas, including the study domain.     

Water quality of the Ribeirão Preto Stream, a watercourse under anthropogenic influence in the southeast of Brazil

It is known that Brazil still has a privileged position of water quantity and quality, but water use has not proceeded in a responsible manner and often results in impairment of quality. This study aims to evaluate limnological parameters, parasites and bacteria, and concentrations of heavy metals (Cd, Pb, Cu, Cr, Mn, Hg, and Zn) in surface water of Ribeirão Preto Stream. The Ribeirão Preto Stream is located in urban areas under anthropogenic influence. The results showed that the levels of dissolved oxygen values were lower than those established by the National Environmental Council (CONAMA Resolution No 357/2005). The reading of electrical conductivity showed values typical of impacted environments. The parasitological analysis revealed the presence of nematode larvae. The bacteriological analysis showed higher values for total coliform and Escherichia coli than those set by the Brazilian National Environment Council (CONAMA). The heavy metals Cd, Pb, Cu, Cr, Mn, Hg, and Zn showed concentrations in accordance with the guidelines established by CONAMA. The results provide data on the quality of these waters and showed the necessity to protect the watercourse from point sources of contamination, recommending their continued monitoring.     

Assessing dam implementation impact on threatened carnivores: the case of Alqueva in SE Portugal

Large dam construction in water deficient areas is a management decision often controversial. Besides providing water storage, economical benefits, and a source of renewable energy, the construction and flooding caused by large dams cause disruptions in natural systems. We monitored the pre- and post-Alqueva dam impacts on the threatened carnivore species (polecat, otter, wildcat and Iberian lynx) populations in SE Portugal, and assessed which factors mostly contribute to post-dam distribution. Major short term impacts of large dams are: (1) increase in accessibility and human presence; (2) movement of heavy machinery and dam-workers; (3) deforestation with habitat loss and fragmentation; (4) change from lotic to lentic system; (5) lower prey availability and harsher capture; and (6) changes in land use adjacent to the reservoir. Thus, the response to those impacts can be predicted as a decline of polecat, wildcat and lynx distribution ranges, and a recovery of the otter from the severe short term impacts. Our results corroborate this hypothesis for all the species, especially during deforestation/early flooding. Otter's distribution range increased in the phase of greater impact, with a subsequent decrease with flooding. Our results suggest carnivores used "escape" areas with favourable habitat and prey conditions, however, the areas with higher probability of species presence decreased by two fold showing a drastic range reduction. To ensure populations' survival of these charismatic threatened carnivore populations of Mediterranean landscapes of south-east Portugal, we propose continuing the monitoring program and the development of a conservation program for the subsisting areas of optimal and suboptimal habitats.     

Source and distribution of organic matter in surface sediments from mangroves on the island of Itaparica, Bahia/Brazil

Elemental analysis and isotopic composition evaluated the impact of human activity at the surface sediments in the largest island of Todos os Santos Bay, northeastern Brazil. Saturated hydrocarbons (n-alkanes and isoprenoids) by gas chromatography coupled with a flame ionization detector and ¹³C by mass spectrometer were determined from 30 surface sediment samples in mangroves at the Itaparica Island (Bahia-Brazil) in the rainy and dry season. These data, distribution, and ratio of carbon/nitrogen showed a mixture of sources: continental, marine, and anthropogenic ones. From the chromatographic profiles, light oil contamination was observed in the dry regions of Baiacu, Campinas, and Ponta Grossa, while in Jiribatuba it was observed during the rainy season. However, δ¹³C results during dry and rainy season in the presence of oil also showed in Misericordia and Cacha Prego districts for both periods and Ponta Grossa during the rainy season. Principal component analysis, using a correlation matrix, revealed the latent relationships among all the surface sediment stations investigated and confirmed our analytical results.     

Biological activities of the essential oil from the leaves of Lantana montevidensis (Spreng) Briq. in mice

Environment, Development and Sustainability - This work aimed to analyze the chemical composition and evaluate the anti-inflammatory and antinociceptive properties of the essential oil obtained...     

Removal of polyvinylamine sulfonate anthrapyridone dye by application of heterogeneous electro-Fenton process

Diversity and rapidly multiplication of the pollutants incite as to improve the conventional treatments wastewater methods. One of the bottlenecks often faced is the presence into wastewater of organic pollutants with complex structures that requests the design of efficient processes. Thus, this work investigates the removal of polyvinylamine sulfonate anthrapyridone (PSA) dye which complex structure makes difficult its degradation by conventional technologies. For that, a heterogeneous oxidative process using pyrite as sustainable catalyst was designed. Initially, the performance of the system BBD-carbon felt as anode and cathode, respectively for the production of H₂O₂ was determined in comparison with system boron-doped diamond nickel foam. The carbon felt electrode provided the highest oxidant production, and it was selected for the treatment of the polymeric dye. Several oxidative processes were evaluated, and the best degradation levels were obtained by application of electro-Fenton-pyrite process. In addition, it was determined that dye removal followed a kinetic model of pseudo-first-order achieving the highest efficiency by operation at optimum dosage of pyrite 2 g/L and 200 mA of current intensity. Depending on the optimal experimental conditions, these values lead to a nearly complete mineralization (total organic carbon removal of 95%) after 6 h. Furthermore, the reusability of pyrite was evaluated, by removal of PSA in four cycles.

     

Insights into real cotton-textile dyeing wastewater treatment using solar advanced oxidation processes

Different advanced oxidation processes (AOPs) were applied to the treatment of a real cotton-textile dyeing wastewater as a pre-oxidation step to enhance the biodegradability of the recalcitrant compounds, which can be further oxidized using a biological process. Tests were conducted on a lab-scale prototype using artificial solar radiation and at pilot scale with compound parabolic collectors using natural solar radiation. The cotton-textile dyeing wastewater presents a lilac color, with a maximum absorbance peak at 641 nm, alkaline pH (pH?=?8.2), moderate organic content (DOC?=?152 mg C L^?1, COD?=?684 mg O₂ L^?1) and low-moderate biodegradability (40 % after 28 days in Zahn–Wellens test). All the tested processes contributed to an effective decolorization and mineralization, but the most efficient process was the solar-photo-Fenton with an optimum catalyst concentration of 60 mg Fe²⁺ L^?1, leading to 98.5 % decolorization and 85.5 % mineralization after less than 0.1 and 5.8 kJ_UV L^?1, respectively. In order to achieve a final wastewater with a COD below 250 mg O₂ L^?1 (discharge limit into water bodies imposed by the Portuguese Legislation-Portaria no. 423/97 of 25 June 1997), considering the combination of a solar-photo-Fenton reaction with a biological process, the phototreatment energy required is 0.5 kJ_UV L^?1, consuming 7.5 mM hydrogen peroxide, resulting in 58.4 % of mineralization $ \left({t}_{30\mathrm{W}}=3.2\ \min; \overline{T}=30.7\ {}^{\circ}\mathrm{C};\overline{\mathrm{pH}}=2.80;{\overline{\mathrm{UV}}}_{G,n}={13\ \mathrm{W}\ \mathrm{m}}^{-2}\right). $      

Removal of non-steroidal anti-inflammatory drugs ibuprofen and ketoprofen from water by emulsion liquid membrane

In this work, the removal of the worldwide non-steroidal anti-inflammatory drugs ibuprofen (IBP) and ketoprofen (KTP) by emulsion liquid membrane (ELM) was carried out. An ELM system is made up of hexane as diluent, Span 80 as the surfactant and sodium carbonate as the inner aqueous solution. Effect of experimental conditions that affect the extraction of IBP such as surfactant concentration, emulsification time, sulfuric acid concentration in external phase, acid type in external phase, internal phase concentration, type of internal phase, stirring speed, volume ratio of internal phase to membrane phase, treatment ratio, IBP initial concentration, diluent type and salt was investigated. The obtained results showed that by appropriate selection of the operational parameters, it was possible to extract nearly all of IBP molecules from the feed solution even in the presence of high concentration of salt. Under optimum operating conditions, the efficiencies of IBP removal from distilled water (99.3 %), natural mineral water (97.3 %) and sea water (94.0 %) were comparable, which shows that the ELM treatment process represents a very interesting advanced separation process for the removal of IBP from complex matrices such as natural and sea waters. Under the optimized experimental conditions, approximately 97.4 % KTP was removed in less than 20 min of contact time.     

A step forward using QuEChERS (Quick,Easy, Cheap,Effective, Rugged,and Safe) based extraction and gas chromatography-tandem mass spectrometry—levels of priority polycyclic aromatic hydrocarbons in wild and commercial mussels

A new and fully validated QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction and gas chromatography–tandem mass spectrometry methodology was developed and subsequently implemented for the quantification of 16 polycyclic aromatic hydrocarbons (PAHs) in wild (from Matosinhos Beach, Portugal) and commercial (from Ria de Arousa, Spain) mussels. The method proved to be robust, precise, and accurate, with recoveries ranging from 89.2 to 111.8 %. Total sums of 16 PAHs were 52.91 and 37.58 ng/g of wet weight for wild and commercial specimens, respectively. The three- to four-ring PAHs were the most abundant, and a mixture of petrogenic and pyrolytic sources were suspected to occur in both origin areas. Although the contamination levels were below the European regulated limits, specifically for commercial mussels (this despite wild specimens are also consumed), care should be taken in terms of human health, since we are still not aware of the low-dose versus long-term effects, even more in high-risk population groups.