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Plastic films used to make market bags are based on polymers such as polyethylene, polystyrene and polypropylene. These materials require a long time to degrade in the environment. Alternative technologies have been developed to reduce the degradation time and the impact on the environment caused by the conventional polymer materials, using pro-degrading additives or by the development of biodegradable polymers. In Brazil, some city's laws require the use of biodegradable material in the production of market bags, but the absence of specific surveillance policies makes their chemical composition unknown. The plastic bags didn't show the expected environmental behavior by the manufactures, so it is important to understand the reasons why they are not biodegradable in Brazilian landfills. In this paper, 7 samples that were obtained from a trading company and commercial market of Belo Horizonte were analyzed. The samples were characterized by biodegradable analysis, XRF, FTIR, SEM and TGA/DTA, which allowed the identification and evaluation of the thermal behavior of the material in an inert and oxidizing atmosphere. The results showed that plastic bags were composed by a mixture of PLA and PBAT, with possible presence of TPS and titanium and calcium fillers. All samples presented low biodegradability in compostable environment.

There are few studies about Moringa oleifera derivates in polymer developments where vegetable oil was used as a plasticizer and a biodegrading agent. The polymerization of moringa oil (MO) was carried out assisted by microwaves without catalysts presence. There aren't studies about the polymerization of MO using microwaves technology. Moringa's oil and its polymer (PMO) were used as a biodegrading agent for mixtures of low density polyethylene (LDPE) with poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA). The mixtures producted films that were characterized and submitted to biodegradation analysis in order to discuss the influence of moringa components. Results showed that both moringa components improved thermal properties and reduced the crystalline phase of the mixture. The addition of PMO had improved the biodegradation capacity up to five times while MO had improved it up to three times. The results showed the greatest influence of moringa components on biodegradation of mixtures with cited polymers.

Indigo carmine is a blue synthetic dye widely used in textile industry, as a food additive, in pharmaceutical industries, and as pH indicator. The use of this dye can leave to contamination of waste water and environment, damaging aquatic fauna and flora. An alternative for the treatment of water contaminated by dyes would be the degradation through oxidative processes. In this work, the indigo carmine degradation through a heterogeneous Fenton process using fly ash, an industrial waste, as Fe(II) source, was evaluated.. The dye final concentration was quantified by ultraviolet/visible light absorption spectroscopy. The optimal reaction conditions were determined using factorial design. The results showed that fly ash is able to remove approximately 42 % of the indigo carmine dye from solution without any pre-treatment.

Vegetable oils are used as a base for the synthesis of polymers and monomers with structures similar to that of petroleum, as plasticizers for conventional polymers and biodegrading additives. The Moringa oleifera oil was extracted from seeds and polymerized after being submitted to 16 h of microwave irradiation without catalysers. This polymer was characterized and the efficiency of the oil polymerization was verified by the reduction of double bonds and the increase of molecular weight up to 50,000 g mol. Films produced by a mixture of low-density polyethylene (LDPE) with poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA) present low tensile resistance and low biodegradation behaviour. In order to improve those properties, the Moringa polymer (PMO) was mixed with LDPE and PBAT/PLA in specific mass concentrations. The films produced with this mixture were characterized and submitted to biodegradation analysis. The PMO behaves as a compatibilizer by improving thermal properties, reducing the crystalline phase and improving the biodegradation behaviour. The biodegradation improved up to five times in comparison to conventional polymers and it restores the mechanical properties.

Abstract:The present work evaluated the efficiency of the adsorption process using sawdust biochar associated to Advanced Oxidative Processes in the removal of the drug propranolol in simulated aqueous effluents. The biochar was activated chemically (washed with HCl) and physically (heating at 800 ° C) to favor adsorption. The results suggested that the adsorption equilibrium followed the model of Lagmuir monolayers. The combination of the adsorption and degradation processes resulted in almost complete removal of the contaminant in aqueous medium. Ecotoxicity test with Artemia salina showed that the degradation products are not toxic to this microcrustacean.Keywords: Sawdust biochar; adsorption; propranolol; advanced oxidative processes; emerging pollutant. ResumoO presente trabalho avaliou a eficiência do processo de adsorção usando biocarvão de serragem associado a Processos Oxidativos Avançados na remoção do fármaco propranolol em efluentes aquosos simulados. O biocarvão foi ativado quimicamente (lavado com HCl) e fisicamente (aquecimento à 800 °C) para favorecer a adsorção. Os resultados sugeriram que o equilíbrio de adsorção seguiu o modelo de monocamadas de Lagmuir. A combinação dos processos de adsorção e degradação resultou na remoção quase completa do contaminante em meio aquoso. Teste de ecotoxicidade com Artemia salina mostrou que os produtos de degradação não são tóxicos a este microcrustáceo.Palavras-chave: Biocarvão de serragem; adsorção; propranolol; processos oxidativos avançados; contaminante emergente.