New silica based adsorbent material from rice straw and its in-flow application to nitrate reduction in waters: Process sustainability and scale-up possibilities.

This paper shows a particular example to move to a sustainable circular economical process from valorization of rice straw ashes by developing a green synthesis for obtaining a useful sub-product. This strategy can palliate negative effects of the agriculture waste practices on the environment and also the obtained silica reduced nitrate content in waters. It is demonstrated that the silica synthesis developed at lab was scalable more than a hundred times with good results. Adsorption studies of nitrate in standards and real well waters at lab scale and scaling-up provided similar results. Adsorption values near to 15 mg/g for nitrate standards and 8.5 mg/g for well water were obtained until achieving the initial nitrate concentration. Experimental breakthrough curves fitted to Thomas model, which gave similar results for adsorption capacities. The adsorption capacity was checked with that obtained by a commercial resin, providing improved results. The method at large scale was compared with industrial traditional methods and green adsorbents.

Evaluation of sugar cane bagasse subjected to haying and ensiling / Avaliação do bagaço de cana-de-açúcar submetido à fenação e à ensilagem

This work aimed to evaluate sugar cane bagasse from cachaça production, subjected to hay-making and ensiling. The experiment was conduced at Universidade Federal de Lavras, MG, using the completely random delineation (CRD), with seven treatment and three repetitions. The treatments were constituted of in natura sugar cane bagasse (INB), manually hayed and baled sugar cane bagasse, mechanically hayed and baled, manually baled INB and mechanically baled INB, whole ensiled INB and chopped ensiled INB. Bromatological composition, tampon capacity (TC), pH values and total sugar rate of the INB were evaluated. For the ensilage, there were used cistern silos and for the baling, manual and mechanical balers. The bagasse was baled in natura, or after reaching 89 percent rate of DM, according to the treatments. The evaluated characteristics were dry matter rate (DM), crude protein (CP), fiber in neutral detergent (FND), fiber in acid detergent (FAD). The results went through variance analyses and the averages were compared by the Scott - Knott test (P<0.05). The INB presented rates of 51.70 percent of DM; 2 percent of CP; 79.43 percent of FND; 48.78 percent of FAD and 16.4 percent of total sugar in the MS. The sugar cane bagasse presented low TC and the silage presented satisfactory pH for good conservation. The dehydration followed by the manual baling provided a decrease in the cell wall components, revealing itself as the best bagasse conservation method.

Neste trabalho, objetivou-se avaliar o bagaço de cana-de-açúcar proveniente da produção de cachaça, submetido à fenação e à ensilagem. O experimento foi conduzido na Universidade Federal de Lavras, MG, utilizando-se o delineamento inteiramente casualizado (DIC), com sete tratamentos e três repetições. Os tratamentos foram constituídos por bagaço de cana in natura (BIN), bagaço de cana fenado e enfardado manualmente, bagaço de cana fenado e enfardado mecanicamente, BIN enfardado manualmente, BIN enfardado mecanicamente, BIN ensilado inteiro e BIN ensilado picado. Foram avaliadas a composição bromatológica, capacidade tampão (CT), valores de pH e os teores de açúcares totais do BIN. Para a ensilagem foram utilizados silos cisternas e para o enfardamento, enfardadoras manual e mecânica. O bagaço foi enfardado in natura, ou após atingir teor de 89 por cento de MS, conforme os tratamentos. As características avaliadas foram os teores de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA). Os resultados foram submetidos à análise de variância e as médias foram comparadas pelo teste de Scott-Knott (P<0,05). O BIN apresentou teores de 51,70 por cento de MS; 2 por cento de PB; 79,43 por cento de FDN; 48,78 por cento de FDA e 16,4 por cento de açúcares totais na MS. O bagaço de cana apresentou baixa CT e as silagens apresentaram pH satisfatório para boa conservação. A desidratação seguida do enfardamento manual proporcionou diminuição nos componentes da parede celular, revelando-se o melhor método de conservação do bagaço.