Degradation of some biorecalcitrant pesticides by homogeneous and heterogeneous photocatalytic ozonation

Photo-Fenton/ozone (PhFO) and TiO2-photocatalysis/ozone (PhCO) coupled systems are used as advanced oxidation processes for the degradation of the following biorecalcitrant pesticides: alachlor, atrazine, chlorfenvinfos, diuron, isoproturon and pentachlorophenol. These organic compounds are considered Priority Hazardous Substances by the Water Framework Directive of the European Commission. The degradation process of the different pesticides, that occurs through oxidation of the organic molecules by means of their reaction with generated OH radical, follows a first and zero-order kinetics, when PhFO and PhCO are applied, respectively. These two Advanced Oxidation Processes, together with the traditional ozone+UV, have been used to investigate TOC reduction of the different pesticide aqueous solutions. The best results of pesticide mineralization are obtained when PhFO is applied; with the use of this advanced oxidation process the aqueous pesticide solutions become detoxyfied except in the case of atrazine and alachlor aqueous solutions for which no detoxification is achieved at the experimental conditions used in the work, at least after 2 and 3 h of treatment, respectively.     

Single and mixture effects of pesticides and a degradation product on fluvial biofilms

The Morcille River located in the Beaujolais vineyard area (Eastern France) is subjected to strong vine-growing pressure leading to the contamination by a range of herbicides and fungicides of the surrounding freshwater environment. Particularly high concentrations of norflurazon, desmethyl norflurazon and tebuconazole were recorded in spring 2010 at the downstream site of the river. Despite their occurrence in rivers, scarce toxicity data are available for these products, in particular in the case of desmethyl norflurazon (main norflurazon degradation product). Furthermore, the toxicity data are generally available only for single compounds and are issued from single species toxicity tests, leading to a lack of ecological relevance. Consequently, this study was undertaken to evaluate the toxic effects of norflurazon, desmethyl norflurazon and tebuconazole singly and in a ternary mixture on fluvial biofilm. Toxicity tests were performed in microplates for 48 h. Photosynthetic endpoints were measured using pulse amplitude-modulated fluorometry; diatom densities and taxonomic composition were determined. After 48 h of exposure, significant effects on optimal quantum yield (F _v/F _m) for desmethyl norflurazon and mixture were observed.     

The importance of scientific literacy in fostering education for sustainability: Theoretical considerations and preliminary findings from a Brazilian experience

Scientific literacy can be considered as a new demand of post-industrial society. It seems necessary in order to foster education for sustainability throughout students' academic careers. Universities striving to teach sustainability are being challenged to integrate a holistic perspective into a traditional undergraduate curriculum, which aims at specialization. This new integrative, inter- and transdisciplinary epistemological approach is necessary to cultivate autonomous citizenship, i.e., that each citizen be prepared to understand and participate in discussions about the complex contemporary issues posed by post-industrial society. This paper presents an epistemological framework to show the role of scientific literacy in fostering education for sustainability. We present a set of 26 collaborative concept maps (CCmaps) in order to illustrate an instance of theory becoming practice. During a required course for first-year undergraduate students (ACH 0011, Natural Sciences), climate change was presented and discussed in broad perspective by using CCmaps. We present students' CCmaps to show how they use concepts from quantitative and literacy disciplines to deal with the challenges posed by the need of achieving a sustainable development.     

Allocation of GHG emissions in combined heat and power systems: a new proposal for considering inefficiencies of the system

The paper industry is responsible for a considerable amount of greenhouse gas (GHG) emissions mainly due to its intensive energy requirements. The production of heat and power streams in a cogeneration system, i.e., a combined heat and power (CHP) plant, releases considerable amounts of GHG emissions into the atmosphere. Such emissions are already subjected to legislation globally. The amount of GHG emissions is usually calculated from the product of the total amount of energy activity multiplied by an emission factor. However, each energy output stream should get a share of emissions responsibility. This fact could assist in assigning weights to the emissions generated for power and thermal purposes in a combined heat and power plant. However, developing a suitable method of allocating emissions in a cogeneration system is still a concern and a subject research for scientists, companies and policy makers. This paper exposes and evaluates different published allocation methods and applies them to a real case of a combined heat and power plant integrated in a paper mill and proposes a new allocation method.     

Seasonal changes in the diet and feeding behaviour of a top predator indicate a flexible response to deteriorating oceanographic conditions

Shifts in the diet of top predators can be linked to changes in environmental conditions. In this study, we tested relationships between environmental variation and seasonal changes in diet of a top predator, the grey-headed albatross Thalassarche chrysostoma, breeding at Bird Island, South Georgia in an austral summer of 1999/2000. Oceanographic conditions in that year around South Georgia were abnormal (i.e. anomalously high sea surface temperature to a relative 19-year long-term mean). The diet of grey-headed albatrosses showed high seasonal variation, shifting from cephalopods (42.9 % by mass) in late February to Antarctic krill Euphausia superba (58.3 %) in late April, and grey-headed albatrosses breeding performance was low (16.8 %). This study shows these albatrosses did not manage to find sufficient alternative prey and highlight the risk to top predators if there is an increase in the frequency or severity of food shortages in Antarctic waters.     

First fossil evidence of an “interglacial refugium” in the Pyrenean region

A refugium is generally understood as an area where temperate species survive cold periods, such as the Iberian, Italian, or Balkan Peninsulas in Europe. Strictly speaking, this definition refers to what is known as a glacial refugium. However, there are various types of lesser-known refugia such as the interglacial refugium, which denotes a mountainous region at low latitudes, such as the Pyrenees, where species adapted to the cold survive during interstadial periods. The small-vertebrate association from the sequence of Cova Colomera, which is located on the southern face of the Pyrenees and contains the final cold spell of the Late Pleistocene and the beginnings of the temperate period in which we currently find ourselves (the Holocene), could constitute the first fossil evidence of such an interglacial refugium, thus providing new paleoecological data on the phenomenon.     

Gaudeamus lavocati sp. nov. (Rodentia, Hystricognathi) from the early Oligocene of Zallah, Libya: first African caviomorph?

A new African species of hystricognathous rodent, Gaudeamus lavocati sp. nov., is described herein from the early Oligocene deposits of Zallah locality (Sirt basin, Central Libya). The dental morphology of this species is very close to that of some earliest South American caviomorphs. It allows a reinterpretation of molar crest homologies among earliest caviomorphs, pentalophodonty being confirmed as the plesiomorphic molar condition in Caviomorpha. This morphological resemblance argues for close affinities between Gaudeamus and earliest South American hystricognaths. Cladistic analysis supports Gaudeamus lavocati sp. nov. as the first known African representative of Caviomorpha, implying that its ancestors were part of the African phiomyid group that crossed the South Atlantic by a direct immigration route. Alternatively, the series of derived dental features of Gaudeamus could also be interpreted as evolutionary synchronous convergences of an African hystricognath lineage towards the specialized pattern of some caviomorphs. However, the high level of similarities concerning teeth morphology and enamel microstructure and the similar age of fossiliferous strata on both continents make this interpretation less probable. The phylogenetic position of this taxon is of considerable importance because it represents an enigmatic component of the phiomorph–caviomorph radiation in Africa and appears as a new clue toward the understanding of caviomorph origins.     

Life cycle assessment of solar photo-Fenton and solar photoelectro-Fenton processes used for the degradation of aqueous α-methylphenylglycine

A comparative Life Cycle Assessment (LCA) of solar photo-Fenton and solar photoelectro-Fenton, two solar-driven advanced oxidation processes (AOPs) devoted to the removal of non-biodegradable pollutants in water, is performed. The study is based on the removal, at laboratory scale, of the amino acid α-methylphenylglycine, a good example of soluble and non-biodegradable target pollutant. The system under study includes chemicals, electricity, transport of all raw materials to the plant site, and the generation of emissions, but it does not take into account the impact of the infrastructure needed to build a hypothetical solar plant. Nine environmental impact categories are included in the LCA: global warming potential, ozone depletion potential, aquatic eutrophication potential, acidification potential, human toxicity potential, photochemical ozone formation potential, fresh water aquatic ecotoxicity potential, marine aquatic ecotoxicity potential, and terrestrial ecotoxicity potential and abiotic resource depletion potential. Although previous experimental results show that both AOPs are able to efficiently degrade the pollutant, the LCA indicates that solar-driven photo-Fenton is the most environmentally friendly alternative, mainly because the use of electricity in solar photoelectro-Fenton experiments involves high environmental impacts.