The presence of plastic waste in water bodies has led to a growing concern due to the impact on human health. Among the most important plastic additive molecules is bisphenol-A (BPA). On the other hand, micro-pollutant removal processes that make use of agro-industrial waste have aroused the interest of researchers. This is because the accumulation of lignocellulosic materials is also an environmental problem. The objective of this work is to use corncob agro-industrial residue (CC) as an adsorbent in the removal of BPA in aqueous matrix. The adsorption studies were carried out in reaction media containing the ground vegetable fiber and BPA solution in concentrations of 10, 25 and 50 mg L-1, as well as at pHs 3, 5, 7 and 9. Isotherms models and kinetic models were evaluated. The results showed that CC is a potent BPA adsorbent in aqueous solution, leading to about 90% of removal. The adsorption kinetics followed the pseudo-second order model and isotherm that best suited was the Lagmuir model, and the maximum adsorption capacity was 51.25 mgper gram of adsorbent fiber, after 20 min of contact. The thermogravimetric analysis allowed us to conclude that CC is a material resistant to high temperatures, due to the presence of a considerable amount of lignin. Finally, the best results of BPA removal efficiency by CC compared to activated carbon corroborate its high biosorption capacity.

Due to the ability to catalyze the oxidation of several substrates, the enzyme laccase has been used in several applications, among them the bioremediation of emerging pollutants. This work evaluate the capacity of the cocoa agro-industrial residue to induce the production of Pycnoporus sanguineus laccase and to apply the enzymatic extract in the biodegradation of 17-α-ethinylestradiol (EE2). The macro and micronutrient levels of the cocoa residue were previously evaluated to establish correlations with induction of enzymatic production. The fungus was cultured for 7 days at 28 °C and shaking at 150 rpm. For the biodegradation, the enzymatic extract of laccase was added to the solution of EE2 and the percentage of removal was evaluated. The production of enzyme extract was notably increased by the addition of only 1% (m v−1) of agro-industrial cocoa residue. Laccase activity reached 3920 U mL−1 on the 7th day of cultivation, being superior to the positive control (511 U mL−1). The percentage of EE2 removal was 63% after 4 h, and after 8 h of reaction the EE2 concentration was below the limit of detection (LOD, 0.35 µg mL−1). Analysis showed the presence of kojic acid in the enzyme extract, constituting a powerful redox mediator, capable of enhancing the action of laccase.

ABSTRACT One of the most prominent fields of environmental chemistry is the study and the removal of micro-pollutants from aqueous matrices. Analytical techniques for their identification and quantification are becoming more sensitive and comprehensive and, as a result, an increasing number of drugs have been detected in environmental samples. However, the literature shows that conventional treatments for drinking water and wastewater are not sufficient for remove these compounds. This study aims to check whether the process of hydrothermal carbonization (CHT) is effective in removing the synthetic sex hormones: ethinyl estradiol, gestodene and cyproterone acetate from aqueous samples. The system used in CHT basically consists of a pressurized reactor made of stainless steel and solutions of compounds of interest, both individual and mixed, with a concentration of 1.0 μg.L-1 and a pH range of 2.0 to 3.0. The maximum surface temperature in the reactor was about 180 °C, the internal pressure was 20 bar with 90 minutes for the reaction. Four experiments were conducted, one for each hormone and one with the three hormones together. In individual tests removal of the compounds was found to be 99.8% for ethinyl estradiol, 99.3% for gestodene and 100% for cyproterone acetate. For a mixture of the hormones treated under the same conditions, the mean values of CHT-removal of Ethinylestradiol, Gestodene and Cyproterone Acetate were 99.60%, 96.80% and 68.90%, respectively. The impact of the matrix effect may have affected the efficiency of the hormone removal process by CHT.

Enzyme application in biotechnological and environmental processes has had increasing interest due to its efficiency, selectivity and mainly for being environmentally healthful, but these applications require a great volume of enzymes. In this work the effect of different concentrations of ethanol and 2,5 - xylidine on growth and production of laccase by Pycnoporus sanguineus was investigated. In a medium containing 200 mg.L-1 of 2,5 - xylidine or 50 g.L-1 of ethanol, the maximum activity of laccase was 2019 U.L-1 and 1035 U.L-1, respectively. No direct correlation between biomass and activity of laccase was observed for any of the inducers used during the tests. Ethanol concentrations, larger than or equal to 20 g.L-1, inhibited the radial growth of P. sanguineus. This study showed that ethanol, which has less toxicity and cost than the majority of the studied inducers, presents promising perspectives for laccase production by P. sanguineus.