Resumo Há pouca informação disponível sobre a composição química de espécies de peixe de água doce (tilápia-do-nilo, carpa-prateada, carpa-cabeça-grande, carpa-capim e carpa-comum) com grande importância comercial e amplamente cultivadas na região oeste de Santa Catarina, Brasil. Este estudo teve por objetivo determinar a composição de umidade, cinzas, proteínas, lipídeos e ácidos graxos, bem como a qualidade nutricional dessas cinco espécies de peixe de água doce. A umidade foi o componente majoritário nos filés de peixe (74,7%-81,7%), seguida de proteína (15,8%-18,8%) e lipídeos (0,4%-8,2%). O ácido palmítico foi o ácido graxo saturado predominante (90-1.740 mg/100 g) e o ácido oleico foi o principal ácido monoinsaturado (70-2.260 mg/100 g) encontrados nos filés. A carpa-capim, a carpa-comum e a tilápia-do-nilo (cultivada em tanques-rede) apresentaram elevado teor de ácido γ-linolênico (GLA), com valores médios de 536 mg/100 g. A carpa-cabeça-grande é rica em ácidos graxos poli-insaturados ω-3, principalmente eicosapentaenoico (EPA), com 400 mg/100 g, e docosa-hexaenoico (DHA), com 620 mg/100 g, além de possuir a maior relação ω-3/ω-6 (6,11). Em relação à qualidade nutricional lipídica dos filés de peixe, os valores médios foram: índice de aterogenicidade (IA), ~0,59; índice de trombogenicidade (TI), ~0,82; razão hipocolesterolêmica/hipercolesterolêmica (H/H), ~1,98; poli-insaturados/saturados (P/S), ~0,43; e ω-3/ω-6, ~2,18, sugerindo que o consumo dessas espécies de peixe de água doce pode ser considerado benéfico para a saúde humana.

Abstract There is a paucity of information about the chemical composition of commercially important freshwater fish species (Nile tilapia, bighead carp, grass carp, common carp and silver carp) cultivated in the western region of Santa Catarina, Brazil. This study determined the moisture, ash, protein and lipid contents and the fatty acid composition, as well as the nutritional quality of the lipids in fillets of these five freshwater fish species. Moisture was the most prominent fish component (74.7%-81.7%), followed by protein (15.8%-18.8%) and lipids (0.4%-8.2%). Saturated palmitic acid (90-1740 mg/100 g) and monounsaturated oleic acid (70-2260 mg/100 g) were the major fatty acids found in all the fish species. The grass and common carps and Nile tilapia (caged) had high contents of γ-linolenic acid (GLA), with an average of 536 mg/100 g. Bighead carp was the richest source of ω-3 PUFA, mainly eicosapentaenoic (EPA, 400 mg/100 g) and docosahexaenoic (DHA, 620 mg/100 g) acids, and had the highest ω-3/ω-6 ratio of 6.11. The nutritional evaluation of the fatty acid profile indicated that average values were: atherogenicity index (AI) ~0.59, thrombogenicity index (TI) ~0.82, hypocholesterolemic/hypercholesterolemic ratio (H/H ~1.98), polyunsaturated/saturated ratio (P/S) ~0.43 and ω-3/ω-6 ratio ~2.18, values suggesting that the consumption of these freshwater fish species could be of benefit to human health.

One of the outstanding issues of concern by governments and society in general relates to the final destination of solid waste, which can bring severe impacts on social, political, economic and environmental dimensions. The sustainable development of enterprises and industries goes for the care of the planet, thus ensuring the quality of life for future generations and the planet. The disposal of municipal waste in landfills is the technique most commonly employed for the remediation of solid residues. The residues undergo decomposition beneath the soil and in the presence of water this generates leachate, which percolates down to the bottom of the landfill through drainage. This drained liquid is collected from the landfill installations and subjected to treatment, which involves physico-chemical and biological processes. Landfill leachate commonly contains heavy metals due to the incorrect disposal of products such as fluorescent bulbs and batteries. In this context, a method for the treatment of sludge originating from the physicochemical remediation of leachate using thermal plasma is proposed in this paper. The efficiency of the method was verified by monitoring the total organic carbon content, water content and density of the sludge. The quantity of metals present in the samples was determined before and after pyrolysis by thermal plasma using flame atomic absorption spectroscopy (FAAS), scanning electron microscopy (SEM) and X-ray fluorescence (XRF) spectrometry techniques. The results show that the leachate treatment method used was efficient, presenting the best results for the samples of iron and zinc.

The impacts derived from the emission of volatile organic compounds (VOC) into the atmosphere can have harmful consequences for human health and the environment. In this regard, the present paper proposes the construction of a low-cost cold plasma reactor for the treatment of these compounds. Tests with the prototype were performed to confirm the efficiency for BTEX (benzene, toluene and xylene) samples. Degradation efficiency was confirmed by the gas chromatography method.