The present research used cocoa mesocarp (chocolate production residue) as a precursor material of charcoal. This residue was subjected to temperatures of 500°C, 600°C and 700°C for times of 30, 60 and 90 minutes. Charcoals obtained were ground and classified according to their particle diameter in fine and coarse. Subsequently, the adsorption capacity of each treatment with oxalic acid (C2 H2 O4 ) was evaluated to determine the optimum charcoal to be used as a blank. According to results, 600°C60'F treatment showed the best adsorption capacity. This one was subjected to ultrasound at 20kHz at different wave amplitudes (20 % and 40 %) as well as exposure times of 5, 10 and 20 minutes. Evaluation was compared to blank through physicochemical parameters such as chemical kinetics and equilibrium, isotherms of adsorption of C2 H2 O4 , and estimation of the adsorption surface. Finally, re...

El objetivo de la investigación fue cuantificar la deposición de hollín en el follaje de la vegetación arbustiva, formada principalmente por ficus (Ficus macrophylla), en el ecosistema urbano de Florida Baja–Chimbote durante el periodo de máxima producción (mayo, junio y julio) en las fábricas productoras de harina y aceite de pescado. El aire de esta zona está cada vez más distante de ser aire limpio por contener altas concentraciones (187.6 µg/m3 en 24 h) de partículas suspendidas totales (PST), provenientes de la actividad industrial, comercial, urbana, del parque automotor y de los procesos naturales. Las partículas de hollín generadas por pirólisis en las calderas de las fábricas productoras de harina y aceite de pescado (a partir del diesel) forman parte de una gama de partículas aglomeradas comúnmente de forma esférica, con diámetros aerodinámicos deÂ...

Selenium-yeast is obtained by the culture of Saccharomyces cerevisiae LALVIN Bourgovin RC 212 in the medium YEPD, with sodium selenite addition (concentrations of 2 to 10 mg Se(IV)/L) during exponential growth phase, after 48 hours at 30°C and 200 rpm. Total intracellular selenium quantification in the selenium-yeast is feasible with the starch-iodine spectrophotometric method at 590 nm and the addition of 8 mg Se(IV)/L yields the most biomass, a >90% cellular viability, pink coloration and a total intracellular selenium of 738±30 mg/kg in dry basis Finally, the used methodology to find the cellular viability and the analytical method proposed to determine the total intracellular selenium are accessible for monitoring the bioprocess.