Manuela Moreira da Silva

First report of the nutritional profile and antioxidant potential of Holothuria arguinensis, a new resource for aquaculture in Europe

Abstract This work reports for the first time the nutritional profile and antioxidant potential of the edible sea cucumber Holothuria arguinensis from the North-eastern Atlantic. H. arguinensis has high levels of protein, with the amino acids profile dominated by alanine, glycine and proline and low lysine/arginine ratios. Its carbohydrate and energetic contents are also low as well as the total lipid levels, although its lipid profile is rich in polyunsaturated fatty acids (PUFA), especially arachidonic, eicosapentaenoic and docosahexaenoic acids. In addition, H. arguinensis has high levels of calcium. The water and ethanol extracts show ability to scavenge free radicals and to chelate copper and iron ions. Our results indicate that H. arguinensis has a balanced nutritional quality suitable for human consumption. In addition, it contains compounds with antioxidant potential; thus its intake can contribute for a healthy and well-balanced diet. Graphical abstract

A first glance into the nutritional properties of the sea cucumber Parastichopus regalis from the Mediterranean Sea (SE Spain)

Abstract This work reports for the first time the nutritional profile, including proximate chemical composition, amino acids, fatty acids and minerals of Parastichopus regalis from the Mediterranean Sea (SE Spain). The studied species had a high moisture content, moderate protein and low lipid levels. The most abundant amino acids were glutamic acid, arginine and tyrosine. Polyunsaturated fatty acids, especially arachidonic acid, dominated the fatty acid profile. Iron, sodium, calcium and zinc were the most abundant mine rals. In general, P. regalis has a balanced nutritional quality suitable for human consumption.

Treatment Optimization of a Landfill Leachate Testing a Flotation Before the RO

The sustainable urban waste management is one of the biggest challenges that societies have been facing. The deposition of urban waste in landfill is a very common solution, but requires the implementation of leachate treatment systems, that guarantee the protection of natural resources, namely of surface waters and groundwater. This study was performed at Sotavento Landfill and aimed to test a new leachate treatment system, that allow to reduce the ammonia level in the produced permeate. To improve the nitrification/denitrification, was implemented an experimental flotation treatment, between the stabilization lagoon and the reverse osmosis system (RO), which consists of a 100 m3 reactor, where the air is injected through a Venturi system, with the purpose of degrade organic molecules into more simple ones. Between April and July of 2016, were monitored Ammonia, BOD5, COD, Conductivity, pH and Total Nitrogen, in four points throughout the treatment system, storm lagoon, stabilization lagoon, after the flotation system and permeate.

The Best Destination to an Urban Treated Effluent in Algarve: Aquifer Recharge or an Ecohydrological Solution?

The Algarve region is a narrow strip of land located on the south of Portugal, known by the warm Mediterranean climate. Tourism has been the activity that has increased tightly in the last decade, bringing new challenges to the region, with special focuses in the sustainability of the ecosystems. One of these challenges is the sustainable urban water management, with emphasis on the optimization of the sanitation systems and on the waste water treatment plants (WWTP).This study was performed in the WWTP of Paderne village, and the aim was to develop a different cost-effective solution, in order to avoid the discharge of the treated effluent directly in the Algibre stream, classified by Portuguese Environment Agency, as having a poor ecological status. The first option was the use of this effluent for aquifer recharge, thus several laboratory tests were done to assess the soil capacity for that purpose. The second option was to develop an ecohydrological approach, through the construction of an artificial wetland, to improve effluent quality and to allow its reuse for local crops irrigation. To phytoremediation was considered the use of macrophyte species as Phragmites australis or Thypha latifolia. Data about the quality of the treated effluent during the recent years were analysed, provided by the WWTP managing entity, Aguas do Algarve S.A. Results were discussed attending to the viability and the environmental impact of both solutions.

Nickel and Nitrogen Phytoremediation by Cyperus involucratus: Nickel Impairs Biomass Production and Nitrogen Removal

Phytoremediation can be defined as the use of plants to remove, degrade, contain, or immobilize pollutants in water or soils and can improve biodiversity, in combination with other restoration or mitigation goals. This study aimed to assess the interaction between nickel (Ni) and macronutrient levels, on nickel and nitrogen removal by Cyperus involucratus from fresh water. A complete, 3 factor factorial experiment was performed, under laboratory conditions, testing: 3 levels of macronutrients (0, 100 and 200 mg of N/L) × two levels of Ni (0 and 5 mg Ni/L) × presence or absence of plants. The experiment lasted for 34 days. Ni had a negative effect on plant growth: plants kept in solutions without Ni increased their fresh weight in average, by 22% but if kept in solutions with 5 mg Ni/L decreased it by 8.9%. Plants were able to decrease ammonia and nitrate levels in the solutions of the treatments without Ni but Ni in the solutions impaired ammonia and nitrate removal by plants. The Ni Bioconcentration Factors obtained were 243 L/Kg in 2012 for plants washed with water and, 61 L/Kg in 2013 for plants washed with EDTA. The Translocation Factor to above ground parts was 0.3352 (plants washed with EDTA). Whether this is an effect with importance for the real world phytoremediation is still to be ascertained but this work provides evidence for the need of further studies on the interaction between metal toxicity and macronutrient removal for the most important plant species used in constructed wetlands.

Proximate biochemical composition and mineral content of edible species from the genus Cystoseira in Portugal

Abstract Macroalgae are valuable resources for human consumption in many countries. This work reports for the first time a comparative evaluation of the nutritional properties of five edible macroalgae from the genus Cystoseira, namely C. humilis, C. tamariscifolia, C. nodicaulis, C. compressa and C. baccata. For this purpose, their proximate composition was determined in terms of moisture, ash, and total contents of protein, lipids, carbohydrates and mineral profile. Cystoseira tamariscifolia and C. baccata were the species that in general had the higher ash, protein and lipid contents, while the highest levels of moisture and total carbohydrates were detected in C. nodicaulis and C. compressa. Cystoseira species had also high amounts of minerals, especially of potassium, calcium and iron, and a favorable Na/K ratio. The present study shows that Cystoseira has a balanced nutritional composition, suitable for human consumption, and that its intake can contribute to a healthy and well-balanced diet.