Desenvolvimento de filtros cerâmicos impregnados com nanopartículas de prata para desinfecção de água potável

Brazil has vast amounts of hydric resources, whose quality has been deteriorating due to pollutant dumping. Household waste disposal is one of the main sources of water pollution, stimulating bacteria proliferation and introducing microorganisms, including those from fecal matter. Conventional water disinfection methods are a solution, but on the downside, they lead to the formation byproducts hazardous to human health. In this study, aiming to develop bactericidal filters for the disinfection of drinking water; silver nanoparticles were deposited on alumina foams through three routes: sputtering DC, dip coating and in situ chemical reduction of silver nitrate. The depositions were characterized through X-ray diffraction, scanning electron microscopy and EDS element mapping. The influence of the depositions on permeability and mechanical properties of the ceramic foams was assessed and, in sequence, a preliminary antibacterial efficiency analysis was carried out. Characterization results indicate that the chemical reduction routes were efficient in depositing homogeneously distributed silver particles and that the concentration of the metallic precursor salt affects size and morphology of the particles. The antibacterial efficiency analysis indicates that the chemical reduction filters have potential for water disinfection

A Produção mais Limpa como ferramenta em busca da sustentabilidade empresarial: um estudo de múltiplos casos em empresas do Estado do Rio Grande do Norte

This study aimed to assess the Cleaner Production CP as corporate sustainable tool, through the multiple case studies within companies from Rio Grande do Norte State. In order to achieve this goal a research methodology approach was set. The initial stage of the research methodology was based on a literature review on which it was observed that the CP can be linked with corporate sustainable once it prevents pollution and reduces the operational risks among employees, community and environment. In addition, CP can useful for companies position within competitive position as well as being applied to process, products and services. In order to observe these factors, CP was used within food industry (Company 1), textile industry (Company 2) and in a car dealer (Company 3). Regarding the results, Company 1 changed its raw material as well as implementing housekeeping (control use of water, energy and condensed milk). In Company 2, it was observed the three levels of CP. In other words, housekeeping (e.g. cutting process and manipulation of chemical products), changing technology (high pressure washing machine) and internal and external recycling. In addition, Company 3 considered only level 3 external recycling. As consequence, it was observed that can be applied either within industry as well as service sector. Unfortunately, it was not possible to observe any social gains on a monetary basis. This is due to limitations of the CP methodology and study complexity. Therefore, it was observed improvements regarding to social, environmental and economic areas. Nevertheless, it is necessary more commitment from top level management in order to consider CP like effective sustainable tool

Ergonomia, sustentabilidade sócio-ambiental e atividade de pesca artesanal com jangadas: estudo de caso na Praia de Ponta Negra, Natal-RN

The fishing is made possible by the handiwork of a fisherman, not using appliances that achieve the same levels of industrial fishing productivity and not causing environmental impacts on fish stocks with the same intensity. The adoption of sustainability practices in this type of fishing has been requested for the achievement of environmental and socioeconomic improvements, since its production has been decreasing over the years and overfishing has led to reduced stocks also stand out environmental aggressions such as pollution. Thus, this research aims to analyze the interference of environmental aspects/impacts that permeate the activity performed by fisherman on the beach of Ponta Negra, Natal-RN, in order to propose recommendations for environmental sustainability. We used a methodology based on the ergonomic work analysis (WISNER, 1987; GUERIN, 2001; VIDAL, 2008) using techniques such as observational and interactional observation protocols, photographs, videos, conversational action, and listening to verbalizations. To understand the vulnerability of the environment in which the activity is carried fisherman and the interferences that it suffers, we used the study of environmental aspects/impacts (SÁNCHEZ 2008). As a result, it appears that from the observations located and reports raftsmen, changes in the sea, the search for new fishing grounds farther from the coast, reducing fishery production, waste generation and pollution of the workplace, and the difficulty in docking rafts, factors arising from the pressures both for society as Seen by fisherman, denoting the necessity of drawing up recommendations and actions proposed by management activity by promoting discussion among raftsmen and accountable institutions, and training through workshops on environmental education, aiming to positive changes in the activity fisherman from Ponta Negra and the environment in which raftsmen are inserted in order to seek a sustainable activity, preserving its characteristics

Reciclagem química de Polietileno utilizando Sílica Mesoporosa tipo SBA-15 avalizada por Termogravimetriae Espectrometria de Massas

The chemical recycling of polyolefins has been the focus of increasing attention owing potential application as a fuel and as source chemicals. The use of plastic waste contributes to the solution of pollution problems.The use of catalysts can enhance the thermal degradation of synthetic polymers, which may be avaliated by Themogravimetry (TG) and mass spectrometry (MS) combined techniques. This work aims to propose alternatives to the chemistry recycling of low-density polyethylene (LDPE) on mesoporous silica type SBA-15 and AlSBA-15.The mesoporous materials type SBA-15 and AlSBA-15 were synthesized through the hydrothermal method starting from TEOS, pseudobohemite, cloridric acid HCl and water. As structure template was used Pluronic P123. The syntheses were accomplished during the period of three days. The best calcination conditions for removal of the organic template (P123) were optimized by thermal analysis (TG/DTG) and through analyses of Xray diffraction (XRD), infrared spectroscopy (FT-IR), nitrogen adsorption and scanning electron microscopy (SEM) was verified that as much the hydrothermal synthesis method as the calcination by TG were promising for the production of mesoporous materials with high degree of hexagonal ordination. The general analysis of the method of Analog Scan was performed at 10oC/min to 500 oC to avoid deterioration of capillary with very high temperatures. Thus, with the results, we observed signs mass/charge more evident and, using the MID method, was obtained curve of evolution of these signals. The addition of catalysis produced a decrease in temperature of polymer degradation proportional to the acidity of the catalyst. The results showed that the mesoporous materials contributed to the formation of compounds of lower molecular weight and higher value in the process of catalytic degradation of LDPE, representing an alternative to chemical recycling of solid waste

Hidrocarbonetos policíclicos aromáticos no meio ambiente: diferenciação de fontes em sedimentos e metabólitos em bile de peixes

Many studies on environmental ecosystems quality related to polycyclic aromatic hydrocarbons (PAH) have been carried out routinely due to their ubiquotus presence worldwide and to their potential toxicity after its biotransformation. PAH may be introduced into the environmet by natural and anthropogenic processes from direct runoff and discharges and indirect atmospheric deposition. Sources of naturally occurring PAHs include natural fires, natural oil seepage and recent biological or diagenetic processes. Anthropogenic sources of PAHs, acute or chronic, are combustion of organic matter (petroleum, coal, wood), waste and releases/spills of petroleum and derivatives (river runoff, sewage outfalls, maritime transport, pipelines). Besides the co-existence of multiples sources of PAH in the environmental samples, these compounds are subject to many processes that lead to geochemical fates (physical-chemical transformation, biodegradation and photo-oxidation), which leads to an alteration of their composition. All these facts make the identification of the hydrocarbons sources, if petrogenic, pyrolytic or natural, a challenge. One of the objectives of this study is to establish tools to identify the origin of hydrocarbons in environmental samples. PAH diagnostic ratios and PAH principal component analysis were tested on a critical area: Guanabara Bay sediments. Guanabara Bay is located in a complex urban area of Rio de Janeiro with a high anthropogenic influence, being an endpoint of chronic pollution from the Greater Rio and it was the scenario of an acute event of oil release in January 2000. It were quantified 38 compounds, parental and alkylated PAH, in 21 sediment samples collected in two surveys: 2000 and 2003. The PAH levels varied from 400 to 58439 ng g-1. Both tested techniques for origin identification of hydrocarbons have shown their applicability, being able to discriminate the PAH sources for the majority of the samples analysed. The bay sediments were separated into two big clusters: sediments with a clear pattern of petrogenic introduction of hydrocarbons (from intertidal area) and sediments with combustion characteristics (from subtidal region). Only a minority of the samples could not display a clear contribution of petrogenic or pyrolytic input. The diagnostic ratios that have exhibited high ability to distinguish combustion- and petroleum-derived PAH inputs for Guanabara Bay sediments were Phenanthrene+Anthracene/(Phenanthrene+Anthracene+C1Phenanthrene); Fluorantene/(Fluorantene+Pyrene); Σ (other 3-6 ring PAHs)/ Σ (5 alkylated PAH series). The PCA results prooved to be a useful tool for PAH source identification in the environment, corroborating the diagnostic indexes. In relation to the temporal evaluation carried out in this study, it was not verified significant changes on the class of predominant source of the samples. This result indicates that the hydrocarbons present in the Guanabara Bay sediments are mainly related to the long-term anthropogenic input and not directly related to acute events such as the oil spill of January 2000. This findings were similar to various international estuarine sites. Finally, this work had a complementary objective of evaluating the level of hydrocarbons exposure of the aquatic organisms of Guanabara Bay. It was a preliminary study in which a quantification of 12 individual biliar metabolites of PAH was performed in four demersal fish representing three different families. The analysed metabolites were 1-hydroxynaphtalene, 2-hidroxinaphtalene, 1hydroxyphenanthrene, 9-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1hydroxypyrene, 3-hidroxibiphenil, 3- hydroxyphenanthrene, 1-hydroxychrysene, 9hydroxyfluorene, 4-hydroxyphenanthrene, 3-hydroxybenz(a)pyrene. The metabolites concentrations were found to be high, ranging from 13 to 177 µg g-1, however they were similar to worldwide regions under high anthropogenic input. Besides the metabolites established by the used protocol, it was possible to verified high concentrations of three other compounds not yet reported in the literature. They were related to pyrolytic PAH contribution to Guanabara Bay aquatic biota: 1-hydroxypyrine and 3-hydroxybenz(a)pyrine isomers