Browsing by Author "Teixeira, Margarida Ribau"
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- Chronic toxicity of polystyrene nanoparticles in the marine mussel Mytilus galloprovincialisPublication . Gonçalves, Joanna M.; Sousa, Vânia Serrão; Teixeira, Margarida Ribau; Bebianno, MariaNanoplastics (NP) (1–100 nm) are a growing global concern, and their adverse effects in marine organisms are still scarce. This study evaluated the effects of polystyrene nanoplastics (10 μg/L; 50 nm nPS) in the marine mussel Mytilus galloprovincialis after a 21 – day exposure. The hydrodynamic diameter and zeta potential of nPS were analysed, over time, in seawater and ultrapure water. A multibiomarker approach (genotoxicity (the comet assay) was assessed in mussel haemocytes, and the antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)), biotransformation enzyme (glutathione – S – transferase (GST)), and oxidative damage (LPO)) was assessed in gills and digestive glands to evaluate the toxicity of nPS towards mussels. In seawater, aggregation of nPS is favoured and consequently the hydrodynamic diameter increases. Genotoxicity was highly noticeable in mussels exposed to nPS, presenting a higher % tail DNA when compared to controls. Antioxidant enzymes are overwhelmed after nPS exposure, leading to oxidative damage in both tissues. Results showed that mussel tissues are incapable of dealing with the effects that this emerging stressor pursues towards the organism. The Integrated Biomarker Response index, used to summarise the biomarkers analysed into one index, shows that nPS toxicity towards mussels are both tissue and time dependent, being that gills are the tissue most compromised.
- Microalgal systems for wastewater treatment: technological trends and challenges towards waste recoveryPublication . Morais, Etiele; Cristofoli, N.L.; Maia, Inês Beatriz; Magina, Tânia; Cerqueira, Paulo R.; Teixeira, Margarida Ribau; Varela, João; Barreira, Luísa; Gouveia, LuisaWastewater (WW) treatment using microalgae has become a growing trend due the economic and environmental benefits of the process. As microalgae need CO2, nitrogen, and phosphorus to grow, they remove these potential pollutants from wastewaters, making them able to replace energetically expensive treatment steps in conventional WW treatment. Unlike traditional sludge, biomass can be used to produce biofuels, biofertilizers, high value chemicals, and even next-generation growth media for “organically” grown microalgal biomass targeting zero-waste policies and contributing to a more sustainable circular bioeconomy. The main challenge in this technology is the techno-economic feasibility of the system. Alternatives such as the isolation of novel strains, the use of native consortia, and the design of new bioreactors have been studied to overcome this and aid the scale-up of microalgal systems. This review focuses on the treatment of urban, industrial, and agricultural wastewaters by microalgae and their ability to not only remove, but also promote the reuse, of those pollutants. Opportunities and future prospects are discussed, including the upgrading of the produced biomass into valuable compounds, mainly biofuels.
- Pharmaceuticals removal from wastewater with microalgae: a pilot studyPublication . Pereira, André; Morais, Etiele Greque; Silva, Liliana; Pena, Angelina; Freitas, Andreia; Teixeira, Margarida Ribau; Varela, João; Barreira, LuísaUrban wastewaters contain pharmaceuticals that are not appropriately removed in conventional wastewater treatments, limiting treated water reuse. Microalgae have been shown to remove pharmaceuticals from urban wastewater in laboratory trials, but few studies have been conducted under natural conditions. In this work, pharmaceutical removal was assessed in a pilot-scale microalgal tertiary wastewater treatment in real conditions. Even after secondary treatment, the water contained measurable amounts of pharmaceuticals (an average of 218.4 ng/L) that significantly decreased to 39.83 ng/L at the exit of the microalgal system. Pharmaceuticals’ average removal rates were slightly higher in the summer (79.1%) than in autumn (71.1%). Antibiotics and antipsychotics were better removed (88.8 and 86.4%, respectively) than antihypertensives (75.3%) and others (Bezafibrate and Diclofenac; 64.0%). Physicochemical characteristics of the wastewater influenced pharmaceutical removal; significant positive correlations were observed between anti-hypertensive drug removal and ammonium concentration (r = 0.53; p < 0.05), total nitrogen and total pharmaceutical removal (r = 0.46; p < 0.05), and total nitrogen and antipsychotic drug removal (r = 0.47; p < 0.05). The results demonstrate the effectiveness of microalgal tertiary treatment in the removal of pharmaceuticals.
- The use of Moringa oleifera as a natural coagulant in surface water treatmentPublication . Camacho, Franciele Pereira; Sousa, Vania Serrao; Bergamasco, Rosangela; Teixeira, Margarida RibauMoringa oleifera (MO) seed is a natural plant with active bio-coagulate compounds that can be used for water clarification since it reduces the use of chemical-based coagulants. This study aims to evaluate the impact of Moringa oleifera (MO) seeds and MO seeds with a reduced amount of oil as coagulants in conventional water treatment to remove cyanobacteria from different natural surface waters. Tests were performed for waters with low (5-10 NTU) and high (30-60 NTU) initial turbidity with and without Microcystis aeruginosa cells and for MO integral powder, MO oil-extracted with ethanol and with a pressurized technique, and MO extracted with NaCI. The results show that MO oil-extraction is not necessary when using MO seeds as a coagulant in coagulation/flocculation/sedimentation (CF/S). Chlorophyll a and turbidity removals were up to 85% for high-turbidity waters, with 50 mg.L-1 MO obtained, for MO integral powder and for all of the MO extraction methods used. Therefore, for these waters, integral powder (without any extraction) can be used. For low-turbidity waters and using a 1 M saline extraction of the active coagulant compound, chlorophyll a and turbidity removals were approximately 60%. It was also demonstrated that MO is capable of removing some of the organic matter present in water, namely, aromatic organic matter, between 40 and 50% when using MO extracted with NaCI. However, dissolved organic matter results showed an increase independent of the type of MO extraction used. (C) 2016 Elsevier B.V. All rights reserved.
- Vertical flow constructed wetland as a green solution for low biodegradable and high nitrogen wastewater: A case study of explosives industryPublication . Madeira, Luís Miguel; Carvalho, Fatima; Teixeira, Margarida Ribau; Ribeiro, Carlos; Almeida, AdelaideThe removal of nitrogen compounds from a pretreated explosives wastewater in vertical flow constructed wetland planted with Vetiveria zizanioides (0.24 m(2) x 0.70 m), filled with light expanded clay aggregates (Leca (R) NR 10/20), was studied. Experiments under constant hydraulic load, 50 +/- 4 Lm(-2) d(-1) and 83 +/- 5 L m(-2) d(-1) without and with flooding level (25%), respectively, were made at different ammonium (3-48 mg NH4+-N L-1), nitrate (56-160 mg NO3--N L-1) and nitrite (0.3-1.1 mg NO2--N L-1) concentrations. Results indicate that without flooding level (unsaturated) the removal efficiencies obtained were 30 +/- 9, 7 +/- 1 and 96 +/- 2%, respectively to NH4+-N, NO3--N and NO2--N. When using flooding level and an external carbon source (C/N ratio from 1.3 +/- 0.19 to 2.5 +/- 0.20), the organic matter (COD) removal efficiencies were above 90%, 75% for NH4+-N and 55% to NO3--N. Increasing the C/N ratio from 2.9 +/- 0.21 to 4 +/- 0.22 did not contributed to upgrade the efficiencies of COD, NH4+-N and NO3--N removal. The denitrification process was occurred in aerobic conditions and nitrite production have ben occurred, probably due to the presence of aerobic conditions that inhibited partially denitrification. (C) 2021 Elsevier Ltd. All rights reserved.
- Worldwide cases of water pollution by emerging contaminants: a reviewPublication . Morin-Crini, Nadia; Lichtfouse, Eric; Liu, Guorui; Balaram, Vysetti; Ribeiro, Ana Rita Lado; Lu, Zhijiang; Stock, Friederike; Carmona, Eric; Teixeira, Margarida Ribau; Picos-Corrales, Lorenzo A.; Moreno-Piraján, Juan Carlos; Giraldo, Liliana; Li, Cui; Pandey, Abhishek; Hocquet, Didier; Torri, Giangiacomo; Crini, GrégorioWater contamination by emerging contaminants is increasing in the context of rising urbanization, industrialization, and agriculture production. Emerging contaminants refers to contaminants for which there is currently no regulation requiring monitoring or public reporting of their presence in our water supply or wastewaters. There are many emerging contaminants such as pesticides, pharmaceuticals, drugs, cosmetics, personal care products, surfactants, cleaning products, industrial formulations and chemicals, food additives, food packaging, metalloids, rare earth elements, nanomaterials, microplastics, and pathogens. The main sources of emerging contaminants are domestic discharges, hospital effluents, industrial wastewaters, runoff from agriculture, livestock and aquaculture, and landfill leachates. In particular, effluents from municipal wastewater treatment plants are major contributors to the presence of emerging contaminants in waters. Although many chemicals have been recently regulated as priority hazardous substances, conventional plants for wastewater and drinking water treatment were not designed to remove most emerging contaminants. Here, we review key examples of contamination in China, Portugal, Mexico, Colombia, and Brazil. Examples include persistent organic pollutants such as polychlorinated biphenyls, dibenzofurans, and polybrominated diphenyl ethers, in lake and ocean ecosystems in China; emerging contaminants such as alkylphenols, natural and synthetic estrogens, antibiotics, and antidepressants in Portuguese rivers; and pharmaceuticals, hormones, cosmetics, personal care products, and pesticides in Mexican, Brazilian, and Colombian waters. All continents are affected by these contaminants. Wastewater treatment plants should therefore be upgraded, e.g., by addition of tertiary treatment systems, to limit environmental pollution.