Adsorçâo do alaranjado de metila e verde de bromocresol em carvão ativado

Abstract

The contamination of water by synthetic chemical substances represents a serious environmental problems, since many of these substances are toxic and can cause damage to the environment and human health. Thus, the investigation of methods for removing contaminants from wastewater has become necessary. Among these methods, adsorption has stood out due to its applicability and high removal efficiency over a wide range of temperature and pressure. In this sense, the present study describes the adsorption process of methyl orange (AM) and bromocresol green (VB) synthetic dyes in aqueous medium, using activated carbon (CA) as adsorbent material. Different parameters were evaluated, such as contact time, dosage of the adsorbent and initial concentration of the adsorbate. The adsorption kinetics was evaluated using the pseudo-first order and pseudo-second order models, with the kinetic data being better adjusted to the first model for VB and the second model for AM. The adsorption equilibrium time was reached in 1850 and 1440 min for AM and VB, respectively, with their maximum adsorption capacities (Qt) being 3.39 and 2.52 mg g-1 under the conditions studied. The results showed that the removal of AM and VB dyes in aqueous media using CA is favorable, once this material presented maximum adsorption rates of 95% for AM and 75% for VB.