Removal of Pb2+ and Cd2+ From Contaminated Water Using Activated Carbon from Canola Seed Wastes

Abstract

The objective of this work was to produce activated carbon chemically from canola seeds wastes and to apply the activated carbon produced in the sorption of Pb and Cd from contaminated water. The activation of the canola seeds wastes was performed with NaOH (1 mol L) for 6 h under constant stirring. Then the activated material was pyrolyzed for 1 h at 750 °C. The activated carbon was subjected to nitroperchloric digestion for the determination of P, K, Ca, Mg, Mn, Zn, Cu and Pb by flame atomic absorption spectrometry (FAAS). It was also realized the thermogravimetric evaluation (TG), infrared spectra (FT-IR), pHPCZ and scanning electron microscopy (SEM). The metals were evaluated for ideal amounts of adsorbent dose and pH and kinetic, thermodynamic and equilibrium parameters. The mass and pH results demonstrated that four grams of adsorbent is needed to decontaminate one liter of contaminated solution. Linearization were obtained by the mathematical models of Langmuir, Freundlich and D-R, with high capacity of removal of both metals. Thus, using canola waste to produce activated carbon it is possible to add value to the canola seed wastes, also, it contributes directly with the economic, social and environmental sustainability of this productive system.