Vegetation productivity under climate change depends on landscape complexity in tropical drylands

Mitigation and Adaptation Strategies for Global Change - All Clean Development Mechanism (CDM) projects are designed to contribute to the sustainable development of the host country. Livelihood is...     

Photocatalytic degradation of lignin and lignin models, using titanium dioxide: the role of the hydroxyl radical

The role of hydroxyl radicals on the degradation of lignins during a cellulosic pulp bleaching process including a photocatalytic stage, was assessed using peroxyformic acid lignins EL1 and REL1 and two phenolic niphenyl lignin models 1 and 2. The irradiations were performed in the absence of photocatalyst TiO2 and H2O2 (condition a), in the presence of TiO2 (condition b) and in the presence of H2O2 (condition c). The experiments were conducted in alkaline (pH approximately 11) aqueous ethanol solutions with oxygen bubbling. The relative phenolic content of the irradiated solutions, which is indicative of the involvement of hydroxyl radicals, was determined by ionization absorption spectroscopy. The results obtained show that the catalyzed reaction involves both degradation of the phenolate groups by electron transfer and hydroxylation of the lignin aromatic structure. Benzyl alcohol structural elements in sodium borohydride reduced lignin REL1 and compound 2 were also found as good trapping agents for the hydroxyl radicals. The degradation of EL1 was studied by measuring its fluorescence emission by comparison to the fluorescence of compound 2. The emission spectra indicate that some biphenyl phenolate anions in EL1 are reacting under UV/visible irradiation and some others, probably polyphenolic chromophores emitting less fluorescence, are formed.     

Effects of activated sludge and UV disinfection processes on the bacterial community and antibiotic resistance profile in a municipal wastewater treatment plant

Environmental Science and Pollution Research - Wastewater tertiary treatment has been pointed out as an effective alternative for reducing the concentration of antibiotic resistant bacteria and...     

Construction materials as a waste management solution for cellulose sludge

Sustainable waste management system for effluents treatment sludge has been a pressing issue for pulp and paper sector. Recycling is always recommended in terms of environmental sustainability. Following an approach of waste valorisation, this work aims to demonstrate the technical viability of producing fiber-cement roof sheets incorporating cellulose primary sludge generated on paper and pulp mills.From the results obtained with preliminary studies it was possible to verify the possibility of producing fiber-cement sheets by replacing 25% of the conventional used virgin long fiber by primary effluent treatment cellulose sludge. This amount of incorporation was tested on an industrial scale. Environmental parameters related to water and waste, as well as tests for checking the quality of the final product was performed. These control parameters involved total solids in suspension, dissolved salts, chlorides, sulphates, COD, metals content. In the product, parameters like moisture, density and strength were controlled.The results showed that it is possible to replace the virgin long fibers pulp by primary sludge without impacts in final product characteristics and on the environment.This work ensures the elimination of significant waste amounts, which are nowadays sent to landfill, as well as reduces costs associated with the standard raw materials use in the fiber-cement industrial sector.     

Organochlorine concentrations in franciscana dolphins, Pontoporia blainvillei, from Brazilian waters

Blubber samples were collected from ten franciscana dolphins either incidentally captured in fishing operations or stranded on São Paulo (SP) and Paraná (PR) states littoral, Southeastern and Southern Brazilian coast, respectively. Determination of PCB, DDT and HCB concentrations were performed by capillary gas chromatograph coupled to electron capture detector (ECD). ΣDDT, ΣPCB and HCB concentrations ranged from 264 ng g⁻¹ to 5811 ng g⁻¹ lipid, from 909 ng g⁻¹ to 5849 ng g⁻¹ lipid and from 10 ng g⁻¹ to 61 ng g⁻¹ lipid, respectively. Regarding DDTs, the distribution of the mean percentages decreased in the following order: p,p′-DDE > p,p′-DDD > p,p′-DDT. The ΣDDT/ΣPCB ratio varied between 0.27 and 0.42 in Northern and Central SP coast, while in Southern SP and PR coast the values were 1.6 and 1.9, respectively. Dissimilarities in ΣDDT/ΣPCB ratios point to different sources of organochlorine compounds to franciscana dolphins in the study area. Considering the endocrine disruptive action of organochlorine compounds, the concentrations found in franciscana dolphins from Brazilian waters may represent an additional obstacle to the conservation of this endangered cetacean species.     

Two- and three-dimensional ultrasound in malformations of the medullary canal: report of four cases

A comparison between two-dimensional (2D), and three-dimensional (3D) ultrasonography was made in four fetuses diagnosed with neural tube defect (NTD) in the first half of pregnancy. 3D ultrasonography (orthogonal and multiplanar systems) proved to be an excellent complement to 2D, particularly when using orthogonal planes. When using the 3D multiplanar surface imaging system, excellent images of the malformations can be rapidly obtained. Copyright © 2001 John Wiley & Sons, Ltd.     

Predicting bioaccumulation of PAHs in the trophic chain in the estuary region of Paranagua, Brazil

The presence of polycyclic aromatic hydrocarbon (PAH) compounds in sediment and water samples collected in the estuary area of Paranagua, southern Brazil, was investigated. There is a lot of port activity in the region. Recreational fishing is widespread; thus, there is concern about possible contamination by PAHs. The 16 priority PAHs were investigated, and only eight were found. The total concentration of PAHs ranged from 40.8 to 406.8 ng/g. High molecular weight were the most abundant, while PAHs with a low molecular weight were absent. There are suspicions that the main source of PAHs is combustion, but some uncertainties exist, and there may even be the presence of PAHs resulting from accidental spills of crude oil. Although the sediments contain PAHs, the amount is below the maximum concentrations allowed by the Brazilian environmental legislation, as well as the maximum levels at which adverse effects are observed. From the analytical results, a probable bioaccumulation was assessed in the local trophic chain using a mathematical model (Arnot and Gobas, Environ Toxicol Chem 23(10):2343?C2355, 2004). The model showed that there is a possibility of biomagnification along the food chain selected. Three fishes with high local consumption were selected, and the concentration of some PAHs could be found in those fishes.