Browsing by Author "Silva, Manuela"
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- Effect of calcium chloride and 1-MCP (Smartfresh (TM)) postharvest treatment on 'Golden Delicious' apple cold storage physiological disordersPublication . Gago, Custódia; Guerreiro, Adriana; Miguel, Maria; Panagopoulos, Thomas; Silva, Manuela; Antunes, Maria DulceCalcium (Ca2+) and 1-methylcyclopropene (1-MCP) appear to have opposite effects on the development of bitter pit. However, both post-harvest treatments seem capable of influencing fruit ripening, reducing superficial scald and improving post-storage quality. The objective of this work was to investigate the effect of calcium chloride and 1-MCP alone or combined on the incidence and development of physiological disorders and the delay of ripening of apples during storage (at 0.5 degrees C in air) and subsequent shelf-life at room temperature approximate to 22 degrees C. 'Golden Delicious' apples were harvested in 10 orchards and treated with calcium chloride (1.5%, w/v), 1-MCP (625 nL L-1), calcium chloride plus 1-MCP, and without any treatment (control). Physiological disorders and quality parameters were evaluated at harvest and after 6 months storage as well as after 7 d shelf-life. The 1-MCP treatment was effective to prevent superficial scald, slow softening, increase soluble solids content and reduce electrolyte leakage and color changes associated with ripening, during storage and shelf-life. However, this treatment also enhanced the development of bitter pit, especially the moderate and severe symptoms in some orchards, which may be attributable to orchard cultivation techniques. CaCl2 alone and CaCl2 plus 1-MCP reduced bitter pit intensity by reducing moderate and severe incidence, maintained higher lightness and had firmer fruit than control.Postharvest dips of 'Golden Delicious' apples in CaCl2 before 1-MCP application (CA + MCP), may be a good solution to prevent scald, and reducing the bitter pit which is enhanced by 1-MCP alone. (C) 2016 Elsevier B.V. All rights reserved.
- Hydrochemistry of mediterranean temporary ponds and associated groundwater in SW PortugalPublication . Salvador, Nuria; Monteiro, José Paulo; Silva, Manuela; Carvalho, Maria do Rosario; Marques, J. M.; Chambel, A.Under the project LIFE Charcos we aim to understand the influence of groundwater in the water balance and hydrochemistry of Mediterranean Temporary Ponds, located in Costa Sudoeste in Portugal, to explain the variations observed in biodiversity between ponds. This paper represents a first step for establishing a relationship between the chemical composition of the ponds waters and the chemical composition of its associated groundwater. Most of the sampled waters are circum-neutral with very low mineralization (TDS < 1000 mg/L) and show varied composition. In the north of the Costa Sudoeste the ponds waters are mostly of sodium-chloride type and have mixed composition at south. During the ongoing project surface water and groundwater samples will continue to be collected and results will be updated. (C) 2017 Published by Elsevier B.V.This is an open access article under the CC BY-NC-ND license.
- Importância das plantas do sapal para reter os metais que chegam à Ria Formosa devido às atividades humanasPublication . Silva, Manuela; Duarte, D. N.; Chicharo, LuisOs sapais são ecossistemas costeiros, na transição entre a terra e o mar, que se caracterizam por ser colonizados por plantas vasculares superiores, herbáceas e arbustivas, que apresentam grande resistência à salinidade, e que por isso se designam de halófitas. Estas plantas desenvolveram ao longo do tempo estratégias de adaptação, que lhes permitem resistir a períodos de submersão, mais ou menos longos, consoante se localizam em baixo, médio ou alto sapal.
- Latent dimensions between water use and socio-economic development: a global exploratory statistical analysisPublication . Balata, Edson Elídio; Pinto, Hugo; Silva, ManuelaWater use and socio-economic development are interconnected in complex ways. Causalities are not easy to identify but it is evident that a nexus between water use and socio-economic development does exist. Considering the diversity of national situations relating to these interrelated phenomena, its study should be considered from a global perspective. This article critically reviews the literature and information from official sources on the relevance of water use and circular economy in order to create a global picture, linking water with socio-economic development. Data from 195 countries was analyzed statistically. A factor analysis defined five essential latent dimensions on the nexus between water use and socio-economic development: development and basic services, population and resource, economic volume, health and well-being, and population density. Based on the identified factors, countries were classified into six groups: Global South in difficulty, global semi-periphery, advanced economy, Middle East and other Global South developing economy, global weight, and small highly developed economy. The clustering results clarify connections between water use conditions and socio-economic development. Understanding the variety of national profiles is helpful to reveal the magnitude and urgency of dealing with the nexus between water use and socio-economic development for many countries.
- Metal contamination in Ria Formosa saltmarsh sediments and halophyte vegetationPublication . Silva, Manuela; Duarte, Duarte; Chicharo, LuisSaltmarsh vegetation may retain certain substances from anthropogenic activities in surrounding areas, providing a control of contaminants such as heavy metals, coming from industry, agriculture and urbanization. In the last decades there are been na increase in urbanization and industrialization of the area surrounding Marim – Ria Formosa, where this study was performed.
- Metals from human activities in a coastal Lagoon Saltmarsh - Sediment toxicity and phytoremediation by Sarcocornia fruticosaPublication . Silva, Manuela; Aníbal, Jaime; Duarte, D. N.; Veloso, N.; Patrício, F.; Chicharo, LuisAnthropogenic pressure on coastal areas has been increasing in the last decades, threating the saltmarshes and the ecosystem services they provide. Sarcocornia fruticosa can have an important role in sequestration of metals from human activities. This study evaluated the effect of metal toxicity in saltmarsh sediment (measured by Ecological Risk Index-ERI) on S. fruticosa ability to metal (Cd, Cr, Ni, Pb and Zn) remediation (Enrichment Factor and metal translocation). The impact of urbanization was studied through the metal loads on stormwaters during two main rainfall events, and the industrial impact was assessed through data analyses in a saltmarsh area influenced by a stream that receives industrial runoffs. The S. fruticosa response on metal remediation was affected by ERI. In more polluted locations, retained metals on roots and prevented the most toxic (Cd and Pb) from reaching the aerial organs, avoiding tissues death and metal remobilisation to the saltmarsh. Meanwhile, in rhizosediments with conditions to high metal bioavailability, S. fruticosa transported Cd and Pb to aerial organs, but used the Zn translocation to decrease their toxicity. This halophyte resilience is important to saltmarsh metal sequestration in high toxicity conditions, and allows the maintenance of other ecosystem services, contributing to the environmental protection and public health.
- A new insight into the influence of habitat on the biochemical properties of three commercial sea cucumber speciesPublication . González-Wangüemert, Mercedes; Roggatz, Christina C.; Rodrigues, Maria Joao; Barreira, Luísa; Silva, Manuela; Custódio, LuísaThis work makes a comparative evaluation of the biochemical profile of three sea commercial cucumber species (Holothuria mammata, H. polii and H. tubulosa) caught from different locations of the Mediterranean Sea (SE Spain). All species had high levels of moisture (from 73.6% in H. mammata to 81.2% in H. tubulosa), crude ash (from 9.61% in H. mammata to 14.7% in H. tubulosa) and protein (3.01% in H. tubulosa to 11.1% in H. mammata). They also had a low fat content, from 0.21% in H. tubulosa to 0.55% in H. mammata. Holothuria polii had intermediate values between the other two species, for all considered variables. All species had adequate protein/lipid ratios (H. mammata, 20:1; H. polii, 23:1; H. tubulosa, 14:1) and low lipid levels, enriched in omega-3 polyunsaturated fatty acids, especially arachidonic acid. The fatty acid profile suggests that H. polii is feeding on sediments more influenced by terrestrial inputs than the remaining species. Holothuria mammata and H. tubulosa are feeding on marine food sources mainly, but also with some terrestrial influence. The most abundant amino acids detected were alanine, arginine, glutamic acid, and glycine. All species had similar contents of essential amino acids (EAA) and ratios of EAA/non-essential amino acids. Holothuria tubulosa had a high content of toxic metals including Cr, Pb and Ni. This work highlights differences in compositional characteristics between different species of the same genus (Holothuria) from different locations.
- Reduction of carbon emissions in a mediterranean urban wastewater treatment plantPublication . Silva, Manuela; Cristovão, Luís; Marinho, Duarte; Esteves, Eduardo; Fraqueza, Gil; Martins, AntónioIn the last few decades, with the rapid growth of population, and more than half of them living in cities, the urban wastewater treatment has become a big challenge that consumes many resources, namely energy. In a climate change scenario, the Mediterranean region is facing more frequent water scarcity periods, and urban water reuse can be a solution, at least for supplying some non-potable water uses. In this context, the performance of urban wastewater treatment plants (WWTP) is of utter importance, to produce environmentally safe treated water while reducing energy consumption and carbon emissions (CE). Activated sludge is the biological process most widely used in wastewater treatment and requires aeration systems in order to promote the oxidation of organic matter and ammonia. It is known that the energy consumed in the aeration processes is of major importance for the global WWTP CE. This study was carried out in a WWTP in southern Portugal, wherein an aeration control system that responds in real time to ammonia and nitrate concentrations was tested. The system is set to optimize the duration of the aerated and non-aerated periods, for nitrification and denitrification. During the experimental period, BOD, COD, Escherichia coli, TN and TP were monitored in the treated effluent, in order to verify the quality standards that allow its reuse. The aeration control system contributed to a decrease of about 13% of the specific energy consumption, when compared with the corresponding period in previous years, representing a CE reduction of about 1.2 t CO2 eq, during the experimental period. The treated effluent maintained its high quality standards and can be used, for example, in agricultural irrigation of local crops. Aeration control systems reacting in real time can have an important role to decrease CE of urban WWTPs; however, further research is needed, including more WWTPs and analyzing seasonal variations in energy consumption over the year.
- Urban wastewater reuse for citrus irrigation in Algarve, Portugal—Environmental benefits and carbon fluxesPublication . Silva, Manuela; Resende, Flávia C.; Freitas, Bárbara; Aníbal, Jaime; Martins, António; Duarte, AmilcarWater scarcity is increasing in the Mediterranean and alternative sources of water are needed to meet food production needs, protect the environment and reduce the effects of climate change. Currently, many urban wastewater treatment plants (WWTP) produce high volumes of treated effluents which can be an alternative source of water for agriculture irrigation, since they fulfill the quality requirements for crops and the environment. This work analyzed the quantity and quality of a treated effluent produced by an urban WWTP in Algarve, and the environmental benefits of its use on the irrigation of a citrus orchard, as an alternative to groundwater. Carbon dioxide emissions related to orange production were quantified and the orchard’s potential to sequester CO2 was estimated. The reuse of this urban wastewater is revealed to be technologically feasible and environmentally advantageous, avoiding the overexploitation of the local aquifer and preventing the eutrophication of aquatic ecosystems, contributing to the improvement of soil characteristics and decreasing the carbon emissions in orange production. Furthermore, it was found that during the five-month experimental period, the citrus orchard sequestered 87.5% of the CO2e emitted by WWTP in the effluent treatment, converting 72,623 kg of sequestered CO2 into orange biomass