Evaluation of Banana peel flour in natura and modified with Thiosemicarbazide in the Adsorption of As(III) in different aqueous matrices

Abstract

Arsenic is a toxic element that brings recurring concerns to both human health and the environment. This metalloid is found in minerals and is present in the composition of pesticides and mining wastes that can cause various environmental impacts. In view of this, studies aimed at developing new sustainable methodologies, such as the use of bioadsorbers for the removal of this and other pollutants, have attracted the attention of the scientific community. In the present work, the capacity of banana peel without any modification (in natura, FBN) and modified with thiosemicarbazide (FBM) were investigated for the removal of As(III) in samples of deionized water and synthetic seawater. The optimization of variables that influence adsorption of As(III) indicated: 250 mg of the adsorbent; pH 4.0 and 60 min of contact. Under these conditions, adsorption efficiency of 85% for FBM and 35% FBN in deionized water was obtained. In the synthetic seawater matrix, the adsorption was 70% for FBM. Kinetics studies indicated adjustment to the intra-particle diffusion model and the adsorption isotherm model was that of Freundlich. The FBM proved to be efficient and low cost, considered an alternative to conventional treatment.