Intake and Digestibility of Nutrients of Corn and \u3cem\u3eStylosanthes\u3c/em\u3e Silages in Diets for Sheep

The low concentration of water soluble carbohydrates, the high buffering capacity and the low autochthonous population of lactic acid bacteria are limiting factors to legume ensiling. However, recent research with tropical legumes has shown that the silages presented an adequate fermentation profile (Liu et al. 2012; Silva et al. 2012; Pereira et al. 2012). Nevertheless, there are few studies on the use of stylosanthes silages cv. Campo Grande (Stylosanthes capitata + Stylosantes macrocephala) for sheep feeding. The objective of this study was to evaluate the intake and digestibility of nutrients of stylosanthes and corn silages in sheep diets

Citrus fruit residues as alternative precursors to developing H2O and CO2 activated carbons and its application for Cu(II) adsorption

Due to its toxicity, the presence of Cu(II) ions released in aquatic environments presents a serious threat to the environment and human health. In search of sustainable and low-cost alternatives, there are citrus fruit residues, which are generated in large quantities by the juice industries and can be used to produce activated carbons. Therefore, the physical route was investigated for producing activated carbons to reuse citrus wastes. In this work, eight activated carbons were developed, varying the precursor (orange peel-OP, mandarine peel-MP, rangpur lime peel-RLP, and sweet lime peel-SLP) and the activating agent (CO2 and H2O) to remove Cu(II) ions of the aqueous medium. Results revealed promising activated carbons with a micro-mesoporous structure, a specific surface area of around 400 m2 g–1, and a pore volume of around 0.25 cm3 g–1. In addition, Cu (II) adsorption was favored at pH 5.5. The kinetic study showed that the equilibrium was reached within 60 min removing about 80% of Cu(II) ions. The Sips model was the most suitable for the equilibrium data, providing maximum adsorption capacities (qmS) values of 69.69, 70.27, 88.04, 67.83 mg g–1 for activated carbons (AC-CO2) from OP, MP, RLP, and SLP, respectively. The thermodynamic behavior showed that the adsorption process of Cu(II) ions was spontaneous, favorable, and endothermic. It was suggested that the mechanism was controlled by surface complexation and Cu2+-π interaction. Desorption was possible with an HCl solution (0.5 mol L–1). From the results obtained in this work, it is possible to infer that citrus residues could be successfully converted into efficient adsorbents to remove Cu(II) ions from aqueous solutions