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Polypropylene (PP) is one of the most widely used polymers in the world, mainly due to its versatility, good properties and low cost. However, as it does not easily degrade in the natural environment, several research projects have been developed in order to increase its biodegradability. The use of pro-degrading additives has been explored, as they promote the polymer degradation process. However, few studies have evaluated the degradation of these materials in natural aqueous environments such as rivers and lakes, which contain large amounts of PP residues. Thus, the present work aims to evaluate the influence of different additives on the degradation process of PP in natural freshwater. Samples from degradation tests were evaluated for 6 months, and their structural, morphological and thermal properties (crystallinity, etc.) were monitored. From the obtained results, it was observed that the additives influenced the degradation of PP. In addition, the enzymatic additive had more promising results since it caused more significant changes in the properties analysed, especially in relation to the morphology and structural characteristics analyses (and consequently the carbonyl index), indicating a greater influence on the degradation process. Thus, the materials studied in this work are an alternative in the field of plastic packaging, reducing the effects caused by plastic waste on the environment. [ABSTRACT FROM AUTHOR]

Preservatives such as chromated copper arsenate (CCA) are used to increase the resistance of wood to deterioration. The components of CCA are highly toxic, resulting in growing concern over the disposal of the waste generated. The aim of this study was to investigate the removal of Cu, Cr and As present in CCA-treated eucalyptus wood from utility poles removed from service in southern Brazil, in order to render them non-hazardous waste. The removal was carried out by acid leaching in bench-scale and applying optimal extractor concentration, total solid content, reactor volume, temperature and reaction time obtained by factorial experiments. The best working conditions were achieved using three extraction steps with 0.1 mol L −1 H 2 SO 4 at 75 °C for 2 h each (total solid content of 15%), and 3 additional 1 h-long washing steps using water at ambient temperature. Under these conditions, removal of 97%, 85% and 98% were obtained for Cu, Cr and As, respectively, rendering the decontaminated wood non-hazardous waste. The wastewater produced by extraction showed acid pH, high organic loading as well as high concentrations of the elements, needing prior treatment to be discarded. However, rinsing water can be recycled in the extraction process without compromising its efficiency. The acid extraction is a promising alternative for CCA removal from eucalyptus wood waste in industrial scale. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes are an emerging option to treatment of the painting industry effluents. The aim of this study was to compare the effectiveness of the Fenton and photo-Fenton processes in chemical oxygen demand (COD), total organic carbon (TOC) and phenolic compounds removal from wastewaters generated during alkydic resins manufacture. The optimized treatment conditions are the following: pH 3.0, 15.15×10−3 molL−1 FeSO4 and 0.30molL−1 H2O2 for a reaction time of 6h. photo-Fenton experiments were carried out in the presence of sunlight or artificial radiation and complementary additions of H2O2 were made for all experiments. The best results were obtained with photo-Fenton process assisted with solar radiation, with reductions of 99.5 and 99.1% of COD and TOC levels, respectively. Fenton and photo-Fenton (with artificial irradiation) processes presented lower but not insignificant removals, within 60–80% reduction for both COD and TOC. In addition, an excellent removal (95%) of total phenols was obtained using photo-Fenton process assisted with artificial irradiation. This study demonstrated that the use of photo-Fenton process on alkydic resins wastewater treatment is very promising especially when solar light is used. [Copyright &y& Elsevier]