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The influence of ethanol on the degradation kinetics of linear alkyl benzene sulfonate (LAS) and organic matter was investigated using batch experiments with different initial LAS concentrations (8.3 mg L-1 to 66.9 mg L-1) and biomass immobilized on sand. Data were fitted with a substrate inhibition model. Concentrations of 2.4 mg LAS L-1 and 18.9 mg LAS L-1 (without and with ethanol) provided the maximum LAS utilization rate by the biomass (Sbm). For LAS degradation, ethanol addition favored a lower decrease in the specific substrate utilization rate (robs), even at the LAS concentration usually reported as inhibitory (> 14.4 mg L-1). For organic matter degradation, robs was higher with ethanol. Higher biomass differentiation was observed at higher LAS concentrations. With ethanol, microbial selection occurred at LAS concentrations near Sbm. At higher LAS concentrations, the dominance and diversity values did not change significantly with ethanol, whereas without ethanol, their behaviors were irregular.

This paper reports the real-time behavior of the leakage current flowing on glass-type insulator strings of a 230-kV substation tower during washing. Monitoring of two insulator strings in the tower is achieved by use of a pair of optical-fiber sensors that detect samples of the leakage current waveforms and transmit those samples to a processing module via an optical link. It is observed that leakage current during washing may reach high peak levels, and the effectiveness of the washing can be inferred by the degree of leakage current after drying of the insulator strings. Direct monitoring of the leakage current can thus be used as an important guideline for proper washing procedures during this type of intervention as well as for determining the effectiveness of the procedure.

Motor gasoline must present characteristics that guarantee its quality and the good performance of internal combustion engines without harming the environment. The contamination of gasoline by solvents can seriously adulterate its physical-chemical properties and affect its volatility and detonation capacity. To investigate organic solvent adulteration in gasoline samples, thermal analysis technique (TG/DTG) can be used as an auxiliary tool in the study of the thermal behavior of liquid fuels, as demonstrated by the present work involving a comparative analysis of kerosene-free and doped gasoline.

Abstract This paper aims to investigate sustainable waste management solutions for the city of Rio de Janeiro in Brazil, based on a life cycle approach. The Life Cycle Assessment (LCA) was performed by using the LCA-IWM methodology. The model was adapted to the Brazilian solid waste context and to the local characteristics, including waste composition, electricity mix and regulations. The annual amount of waste generated was the functional unit adopted. Eight municipal solid waste management strategies were evaluated. Scenarios including mixed waste collection and source separated collection as well as materials recovery and energy from waste were investigated. Scenarios were ranked based on the LCA results. Sensitivity analysis was carried out by varying the electricity mix. The results indicate that the current situation of municipal solid waste (MSW) in Rio de Janeiro presents the worst performance in terms of aggregated environmental burdens, indicating the urgency for implement new strategies toward a more environmentally friendly and sustainable MSW management system. It is noted that the better LCA performances were obtained in scenarios with high separately collection rates. Among them, the scenario based on recyclables recovery and anaerobic digestion shows to be a promising strategy to improve environmental sustainability. Sensitivity analysis demonstrates that the ranking of scenarios was not affected by changes in the electricity mix. From the results, the investment in source separated waste collection and materials recovery is the most environmentally friendly MSW strategy for Rio de Janeiro. In addition, scenarios with an emphasis in materials recovery presented higher environmental benefits than the alternatives focused on energy generation.

This work evaluates, for the first time, the possibility of producing multifunctional alkali-activated composites combining ultra-low density, low thermal conductivity, high acoustic absorption, and good moisture buffering capacity. The composites were prepared using cork as a lightweight aggregate. This novel material might promote energy savings and tackle the CO2 emissions of the building sector, while simultaneously improve the comfort for inhabitants (e.g. humidity levels regulation and sound pollution reduction). The composites apparent density (as low as 168 kg/m3) and thermal conductivity (as low as 68 mW/m K) are amongst the lowest ever reported for alkali-activated materials (AAM) composites and foams, while their sound absorption ability is comparable to the best performing AAM foams reported to date, but in addition these eco-friendly composites also show good ability to passively adjust the humidity levels inside buildings. The multifunctional properties shown by the cork – AAM composites set them apart from other conventional building materials and might contribute to the global sustainability of the construction sector. Peer Reviewed

Propôs-se, neste trabalho, estudar os efeitos da salinidade da água de irrigação sobre a produção do pinhão-manso (Jatropha curcas L.) após poda realizada aos 396 dias após a semeadura - DAS, em ambiente protegido. A pesquisa foi desenvolvida entre maio de 2008 e janeiro de 2009. A cultura foi conduzida em lisímetros de drenagem (200 L) contendo 230 kg de material de solo, Argissolo Acinzentado, devidamente adubado e corrigido. Testaram-se cinco níveis de condutividade elétrica da água de irrigação - CEa (0,6; 1,2; 1,8; 2,4 e 3,0 dS m-1, a 25 ºC). Empregou-se o delineamento experimental em blocos inteiramente casualizados, com quatro repetições. As plantas foram podadas a 80 cm, ao final do primeiro ciclo de produção. Aos 240 dias após a poda (DAPd), plantas irrigadas com água de 3,0 dS m-1 tiveram o número de cachos reduzido em 93%, o peso médio das cascas, das sementes e dos frutos e número de frutos por planta reduzidos em 97%. Os pesos médios do fruto e da semente foram reduzidos em 67 e 49%, respectivamente. Plantas irrigadas com água de 0,6 dS m-1 e 3,0 dS m-1 produziram 32,03 e 22,5% de óleo, respectivamente.

Abstract The photoelectrocatalysis (PEC) technique was applied in CO2 reduction using different proportions of Cu, Pd, and Pt supported on graphene nanoribbons (GNR) and deposited on the surfaces of TiO2 nanotubes. Altogether, nine combinations of TiO2-NT/GNR-metal were assembled, although only three of them efficiently promoted the generation of methanol and ethanol in high quantities. Comparison with the photocatalysis, photolysis, and electrocatalysis techniques showed the extremely high efficiency of PEC, which enabled production of methanol and ethanol at levels around 19.2-fold and 44.4-fold higher, respectively, than photocatalysis, the second most efficient technique. The presence of metallic nanoparticles in the system facilitated CO2 reduction due to the trapping of the photogenerated electrons, prolonging their lifetime, lowering the reaction energy barrier for CO2 reduction, and provided active intermediates. Therefore, the assembly of these materials containing low amounts of metals is highly promising, since it can assist in alleviating environmental problems caused by CO2 emissions, while at the same time enabling the energetically efficient generation of compounds of commercial value.

Abstract In this study, the compatibility and corrosion behavior of carbon steel, stainless steel, aluminum and copper in contact with blends composed of biodiesel (consisting of soybean oil, beef tallow and swine lard) and petrodiesel were evaluated. Static immersion tests (total, partial and crevice) and exposure in vapor phase were carried out for 2160 h at 50 °C. Our main findings indicate that fuel blends influence the corrosion behavior, being observed a less corrosive attack on the materials, except for copper that presented an anomalous corrosion behavior, with a clear trend towards lower corrosion rates. Carbon steel and stainless steel in total, partial and crevice tests presented surface morphology with slightly changes, while carbon steel exposed in vapor phase showed corrosive attack. Copper presented the highest corrosion rates in partial (9.5273 μm/y), total (9.1484 μm/y) and crevice (6.6178 μm/y) tests in the B7 blend, respectively; and the lowest corrosion rates in total (0.0547 μm/y) for the B15 blend; in partial (0.4926 μm/y) and crevice (0.0182 μm/y) tests for the B30 blend. Among the materials evaluated, copper showed higher influence on biodiesel oxidative stability. Aluminum exhibited good compatibility and did not show any compound formed on its surface without presenting any corrosion.