ESTiG - Artigos em Revistas Não Indexados à WoS/Scopus
URI permanente para esta coleção:
Navegar
Percorrer ESTiG - Artigos em Revistas Não Indexados à WoS/Scopus por Domínios Científicos e Tecnológicos (FOS) "Engenharia e Tecnologia"
A mostrar 1 - 6 de 6
Resultados por página
Opções de ordenação
- Advanced treatment of pomace olive oil wastewater through peroxy-electrocoagulationPublication . Martins, Ramiro; Grabowski, TaisThe extraction of olive pomace oil is a significant aspect of the Mediterranean edible oil industry; however, the wastewater generated contains pollutants that can harm the environment and public health. In this study, peroxi-electrocoagulation (PEC) with aluminum electrodes was used to treat wastewater and reduce pollutant concentrations. A Box-Behnken Design study was conducted to investigate the relationship between hydrogen peroxide dosage, electric current density, and initial pH in the PEC process, and the removal of chemical oxygen demand (COD) and total phenolic compounds (TPh). The study found that the PEC process could remove an average of 22% of COD and 82% of TPh, with the highest removal obtained with hydrogen peroxide dosages of 30 g L -1 and 20 mA cm -2. However, pre-treatment with other processes is necessary to reduce harmful elements in the effluent before undergoing biological treatment.
- Assessing surface water contamination by toxic metals via bioindicators: public health implicationsPublication . Martins, RamiroThis study presents the results of heavy metal concentrations in aquatic mosses collected from the Ave River Basin during two field surveys (campaigns II and III) and a comparison with data from a field survey carried out 15 years earlier (campaign I). The findings indicated high levels of chromium in the samples from the two previous campaigns, along with aggravated contamination of cadmium, lead, and zinc compared to campaign I. The order of metal accumulation in the moss samples, from highest to lowest, was Fe > Zn > Cu > Cr > Ni > Pb > Cd > Hg. The Metal Pollution Index (MPI) revealed changes in contamination levels between campaigns. Most stations experienced a decrease in classification due to increased water flow and reduced accumulation during Campaign II. The contamination patterns suggest the influence of industrial activities, particularly metal coating facilities. Monitoring and mitigation efforts are necessary to address persistent heavy metal pollution in the Ave River Basin.
- Bioindicators for assessing heavy metal contamination in surface waters and public healthPublication . Martins, RamiroThis study presents the results of heavy metal concentrations in aquatic mosses collected from the Ave River Basin during two field surveys (campaigns II and III) and a comparison with data from a field survey carried out 15 years earlier (campaign I). The findings indicated high levels of chromium in the samples from the two previous campaigns, along with aggravated contamination of cadmium, lead, and zinc compared to campaign I. The order of metal accumulation in the moss samples, from highest to lowest, was Fe > Zn > Cu > Cr > Ni > Pb > Cd > Hg. The Metal Pollution Index (MPI) revealed changes in contamination levels between campaigns. Most stations experienced a decrease in classification due to increased water flow and reduced accumulation during Campaign II. The contamination patterns suggest the influence of industrial activities, particularly metal coating facilities. Overall, ongoing monitoring and mitigation efforts are necessary to address persistent heavy metal pollution in the Ave River Basin.
- Enhancing energy recovery from raw glycerol via ultrasound-assisted anaerobic digestionPublication . Martins, RamiroAnaerobic digestion of crude glycerol derived from biodiesel production is being studied as an alternative to valorization through methane production. The high organic load (1800 g COD L -1) of crude glycerol can cause kinetic stress, leading to inhibition of methanogenic microorganisms. To overcome this issue, an alternative approach is the use of ultrasound energy, which promotes cell wall and membrane disruption and releases intracellular material that enhances biodigestion. Considering this alternative, the main objective of this study was to test ultrasound pretreatment to facilitate the subsequent anaerobic digestion of crude glycerol
- Green solutions for industrial effluent treatment: he role of aquatic mossesPublication . Martins, RamiroIn the present study, the performance of the aquatic moss Fontinalis antipyretica for removing cadmium and lead from simulated wastewaters has been evaluated. Five kinetic models were fitted to the experimental data and compared. Previously, the effect of parameters such as the initial solution pH, contact time, and initial metal ion concentration on biosorption was investigated using a sorbent dose of 2 g l-1. The initial pH of the solution was found to have an optimum value in the range of 4.0-6.0. The equilibrium sorption capacity of cadmium and lead by Fontinalis antipyretica increased with the initial metal concentration. For an initial metal concentration of 10 mg l -1, the uptake capacity of the moss, at equilibrium, is the same for both metals (4.8 mg g -1). Nevertheless, when the initial concentration increases up to 100 mg l-1, the uptake of Pb(II) is higher than 78%. The pseudo-second order biosorption kinetics provided the better correlation with the experimental data (R 2 0.999).
- Using bioindicators to assess heavy metal contamination in surface waters and public health impactsPublication . Martins, RamiroThis study aims to explore the use of bioindicators for assessing metal contamination in surface waters and its effects on public health. Theoretical Framework: The persistence and variation of heavy metal contamination in the Ave River Basin over 15 years underscore the need for ongoing monitoring and intervention. The detection of elevated levels of chromium, cadmium, lead, and zinc in aquatic mosses highlights the continuing impact of industrial activities, particularly metal coating facilities, on the river's ecosystem. Method: In the study area, the Ave River and some of its tributaries, a monitoring programme of twelve sampling points was defined in two campaigns and eight metallic ions were determined in the laboratory by atomic absorption spectrophotometry (Cd, Pb, Cu, Cr, Fe, Hg, Ni and Zn). Results and Discussion: The highest metal accumulation in mosses was observed for iron (Fe), whereas the lowest accumulation was found for mercury (Hg) during Campaign II. The order of metal accumulation in the moss samples, from highest to lowest, was Fe > Zn > Cu > Cr > Ni > Pb > Cd > Hg. The Metal Pollution Index (MPI) revealed changes in contamination levels between campaigns. Research Implications: The contamination patterns suggest the influence of industrial activities, particularly metal coating facilities. Monitoring and mitigation efforts are necessary to address persistent heavy metal pollution in the Ave River Basin. Originality/Value: The results of this research will contribute to a better understanding of the sources and loads of pollutants discharged and responsible for the contaminants. This can be used to discourage potential polluters and better manage the basin's water resources and possible risks to human health.