There are many processes capable of decontamination of polychlorinated biphenyls in several matrixes. The set of inputs, materials, operation conditions and efficiencies are wide. The base catalyzed dechlorination process shows application potential in great scale, mainly due mild chemical reaction conditions and low cost raw materials. The KPEG is a familiar process of base catalyzed dechlorination. This decontamination treatment was developed mainly on mineral insulating oil. Few information is found related to process residues, usually in reaction sludge means, limited to inform that its destination must fulfill specific territorial laws. In these work KPEG treatment process was performed on decontamination of mineral insulating oils containing between 200 and 330 ppm of polychlorinated biphenyls to evaluation of reaction residues and of the decontamination percentage. Chemical characterization of these residual material allows achievement of important information to explore procedures for recovery, regeneration and/or right disposal. The analysis performed on the residues showed the presence of reaction products containing unsaturation, absents on neat polyethylene glycol, possible organic complexes products with alkali metal as also the presence of chloride ions. In oil was verified the presence of less chlorinated biphenyls, probably formed by partial dechlorination of highly chlorinated biphenyls.

Hexagonal boron nitride (h-BN), graphite analogous structure, has many interesting applications due to its excellent thermal, electrical and mechanical properties. In this study, different routes of liquid exfoliation using solvent and ultrasound were used to obtain two-dimensional (2D) nanosheets of h-BN. The efficiency of the exfoliative routes was evaluated by Transmission electron microscopy (TEM) and UV-Vis spectroscopy. Results demonstrated that the technique was effective in the exfoliation of h-BN bulk and that the solvent's choice, considering an optimum surface tension of the solvent-solute system, and the rotation of the centrifugation in the selection of the exfoliated nanosheets, are crucial for the performance of the technique. The most promising exfoliation route has been found to be the dispersion of h-BN in solvent mixture (20% IPA in water) for 3 h on ultrasound, followed by centrifugation at 1500 or 3000 rpm.

Polychlorinated biphenyls (PCBs) were widely used between 1940 and 1970 as an insulating fluid for transformers and capacitors. However, they are bioaccumulative and potentially carcinogenic and, according to the 2001 Stockholm Convention, must be eliminated by 2025. In Brazil, they have been gradually eliminated but contaminated equipment remains. The Brazilian official standard for PCBs content in oil analysis is the ABNT NBR 13882 and there is also the IEC 61619 International Standard, both based on GC-ECD quantification. This work identified the inefficiency of these analytical methods and highlights potential failures which generated discrepancies on quantification of these contaminants. It was observed that the IEC 61619 is superior to ABNT NBR 13882 in analytical criteria, but has problems with the inefficiency of the adsorbent material used in pretreatments for removal of oxidation products from oil where these adsorbents adsorbed some PCBs molecules, causing errors in quantification.