Photodegradation of metoprolol in the presence of aquatic fulvic acids. Kinetic studies, degradation pathways and role of singlet oxygen, OH radicals and fulvic acids triplet states.

Metoprolol is a pharmaceutical used for the treatment of cardiovascular diseases and disorders, whose frequent detection in surface waters raises concern. Indirect photodegradation is an important degradation pathway in waters and dissolved organic matter has a major role as photosensitizer. In this study, metoprolol photodegradation, in the absence and in the presence of fulvic acids extracted from the Vouga River (Portugal) (VRFA), was assessed under simulated sunlight.

Photodegradation of metoprolol using a porphyrin as photosensitizer under homogeneous and heterogeneous conditions.

Porphyrins are known as effective photosensitizers and can be an interesting key in phototreatment of water contaminated with micropollutants such as pharmaceuticals. They already showed to be efficient photocatalysts for the degradation of dyes, chlorophenols and other pollutants. This work demonstrates the applicability of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (HTFPP) as photosensitizer for treatment of water contaminated with metoprolol, a highly prescribed β-blocker, which is not completely removed in sewage treatment plants.

First study on oyster-shell-based phosphorous removal in saltwater - A proxy to effluent bioremediation of marine aquaculture.

The efficiency of oyster-shell waste for the removal of phosphorous (P) in saltwater was herein evaluated. For that, different factors were tested, being attained >56% and >98% P removal by natural oyster shell (NOS)-fraction <0.125mm and COS (calcined oyster shell)-fraction 0.

Identification and characterization of photodegradation products of metoprolol in the presence of natural fulvic acid by HPLC-UV-MS.

Metoprolol is a β-blocker highly prescribed for the treatment of heart diseases. It is not efficiently removed in wastewater treatment plants and it has been detected not only in the treated effluents, but also in natural waters. Thus, the knowledge of its fate in the environment is an important issue, and photodegradation is an important degradation pathway.

Insights on the Optical Properties of Estuarine DOM - Hydrological and Biological Influences.

Dissolved organic matter (DOM) in estuaries derives from a diverse array of both allochthonous and autochthonous sources. In the estuarine system Ria de Aveiro (Portugal), the seasonality and the sources of the fraction of DOM that absorbs light (CDOM) were inferred using its optical and fluorescence properties. CDOM parameters known to be affected by aromaticity and molecular weight were correlated with physical, chemical and meteorological parameters.

Effect of copper ions on the degradation of thiram in aqueous solution: identification of degradation products by HPLC-MS/MS.

The aim of this work was to examine the effect of Cu(II) on the degradation of thiram (Thi) in aqueous solutions, since the literature focused on this effect is scarce and copper based fungicides can be applied together with thiram or during the same season to agricultural crops. The effect of Cu(II) on the degradation of thiram was followed by both UV-vis and HPLC-MS/MS. When thiram is dissolved in pure water its degradation occurs very slowly, being negligible during the first 7 days.

Dissolved organic and inorganic matter in bulk deposition of a coastal urban area: an integrated approach.

Bulk deposition can remove atmospheric organic and inorganic pollutants that may be associated with gaseous, liquid or particulate phases. To the best of our knowledge, few studies have been carried out, which simultaneously analyse the presence of organic and inorganic fractions in rainwater. In the present work, the complementarity of organic and inorganic data was assessed, through crossing data of some organic [DOC (dissolved organic carbon), absorbance at 250 nm (UV250nm), integrated fluorescence] and inorganic [H(+), NH4(+), NO3(-), non sea salt sulphate (NSS-SO4(2-))] parameters measured in bulk deposition in the coastal urban area of Aveiro.

Photobleaching of lignin derived compounds from pulp mill effluents upon irradiation: the key role of receiving waters.

Lignin derived macromolecular compounds are the main constituents responsible for the hazardous effects of discharged effluents from the pulp and paper industry in receiving waters. It was shown by ultraviolet-visible (UV-vis) and fluorescence spectroscopies that a selective photodegradation of these structures occurred upon irradiation of fulvic acids (FA) from a kraft pulp mill effluent. Though photodegradation was not remarkably affected by the presence of the natural photosensitizer nitrate, it was inhibited under the presence of chloride.

The inner filter effects and their correction in fluorescence spectra of salt marsh humic matter.

The inner filter effects in synchronous fluorescence spectra (Δλ=60 nm) of sedimentary humic substances from a salt marsh were studied. Accordingly to their type and the influence of plant colonization, these humic substances have different spectral features and the inner filter effects act in a different manner. The fluorescence spectra of the humic substances from sediments with colonizing plants have a protein like band (λexc=280 nm) which is strongly affected by primary and secondary inner filter effects.

Influence of soil copper content on the kinetics of thiram adsorption and on thiram leachability from soils.

This work aimed to assess the influence of soil copper content on the sorption processes of thiram, a fungicide widely used in agriculture, most of the times together with copper. Two different types of studies were performed: (1) desorption studies of thiram with acetonitrile after batch adsorption equilibration, and ageing of the wet soil for a variable period of time; (2) kinetic studies of thiram adsorption performed using the soil in its original form and after fortification with copper ions. In the desorption studies, with the increase of the ageing time, a decrease of the thiram peak and a simultaneous increase of a new peak, assigned to a copper complex, were observed in the chromatograms.

Seasonal and air mass trajectory effects on dissolved organic matter of bulk deposition at a coastal town in south-western Europe.

Rainwater contains a complex mixture of organic compounds which may influence climate, terrestrial and maritime ecosystems and thus human health. In this work, the characteristics of DOM of bulk deposition at a coastal town on the southwest of Europe were assessed by UV-visible and three-dimensional excitation-emission matrix fluorescence spectroscopies and by dissolved organic carbon (DOC) content. The seasonal and air mass trajectory effects on dissolved organic matter (DOM) of bulk deposition were evaluated.

First spectroscopic study on the structural features of dissolved organic matter isolated from rainwater in different seasons.

The complexity of rainwater dissolved organic matter (DOM) and the large percentage considered uncharacterized has made it difficult to determine the role of rainwater DOM in regional and global carbon budgets. Recent studies have concentrated on determining the structural characteristics of the bulk DOM in rainwater, but a comparison between the structural characteristics of rainwater DOM from different seasons is lacking. In this work, DOM was extracted from rainwater collected in different seasons by a procedure based on adsorption onto DAX-8 resin and a comparison between the spectroscopic characteristics of extracted DOM was performed using UV-visible, excitation-emission matrix (EEM) fluorescence and (1)H NMR spectroscopies.

Chemical composition of rainwater at a coastal town on the southwest of Europe: what changes in 20 years?

Rainwater was collected at the Portuguese west coast between September 2008 and September 2009, and analysed for pH, conductivity, and Cl⁻, NO₃⁻, SO₄²⁻, and NH₄⁺ concentrations. Results of rainwater chemical composition were compared with those obtained at the same site between 1986 and 1989. In both collection periods rainwater was predominantly (≈ 80%) associated to oceanic air masses.

Molecular fluorescence analysis of rainwater: effects of sample preservation.

Very different filtration and preservation procedures may be found in the literature on the study of the rainwater dissolved organic fraction. Thus, the influence of sample filtration and preservation procedures on the fluorescence of rainwater dissolved organic matter (DOM) was studied in this work. Rainwater was filtered through different filters (quartz 0.

Sorption-desorption behavior of atrazine on soils subjected to different organic long-term amendments.

Sorption of atrazine on soils subjected to three different organic amendments was measured using a batch equilibrium technique. A higher K(F) value (2.20 kg(-1)(mg L(-1))(-N)) was obtained for soil fertilized with compost, which had a higher organic matter (OM) content.

Influence of different organic amendments on the potential availability of metals from soil: a study on metal fractionation and extraction kinetics by EDTA.

The effects of long-term application of different organic amendments, as compared to mineral fertilizer, on Zn, Cu and Pb content and leachability in a luvisol derived from loess were assessed. The organic fertilizers, applied since 1962, were compost (COM) - from green organic household waste, sewage sludge (SLU) - from municipal water treatment facilities, farmyard manure (FYM) and the doses applied since 1997 were 90tha(-1), 10tha(-1) and 9tha(-1), once in 3years, respectively. The kinetics of metals extraction with 0.

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.

Effects of solar radiation on the fluorescence properties and molecular weight of fulvic acids from pulp mill effluents.

The pulp and paper industry generates large volume of wastewater that adversely affects water resources. Lignin derived macromolecular compounds, similar to natural humic substances, are the main waste products in the pulp mill effluents. The UV-Vis and fluorescence spectroscopies were used to assess the effect of solar exposition on fulvic acids from a kraft pulp mill effluent.

Spectroscopic characteristics of ultrafiltration fractions of fulvic and humic acids isolated from an eucalyptus bleached Kraft pulp mill effluent.

In order to investigate the chemical heterogeneity of fulvic and humic acids previously isolated from a bleached Kraft pulp mill effluent, a sequential ultrafiltration (UF) scheme through four polyethersulphone membranes was applied. The unfractionated fulvic and humic acids and their fractions were characterized by UV-VIS, synchronous fluorescence (with Deltalambda=60 nm) and FTIR spectroscopies. The FTIR spectra were compared with those of lignin isolated from Eucalyptus globulus wood and from the black liquor of a Kraft pulping process.