Vermicompost for Indigo Blue and Congo Red Removal

Abstract

The data obtained through this work revealed that the vermicompost is a natural adsorbent able to removal two textile dyes from an aqueous medium. The values of maximum adsorption capacity for congo red (23.25 mg/g) and indigo blue (40.39 mg/g) obtained from the Mathematical Langmuir Model reveal it. The conditions of adsorbent mass, stirring time between adsorbent and dyes were optimized. Additionally, the values of Gibbs free energy demonstrate the predominance of physical interaction between both dyes and vermicompost. Through Langmuir constant values, it was possible to identify similar affinities between both dyes and vermicompost. The value of dimensionless constant indicates favorable adsorptions process. Finally, through physicochemical analysis from scanning electron microscopy and Fourier Transform Infra-Red Spectroscopy, the characteristics of vermicompost were verified revealing essential aspects to efficient adsorbent.