Adsorptive removal of 2,4-dichlorophenol from aqueous solution by using used black tea leaves

Abstract

Bioadsorbents are drawing the attention of the environmental scientists in removing organic pollutants from aqueous solution because of their availability and low cost. In this research, adsorptive removal of 2,4-dichlorophenol (2,4-DCP) onto used black tea leaves (UBTLs) as well as on sodium chlorite modified used black tea leaves (SCM-UBTLs) was investigated at different conditions. The value of pH was optimized at 2. Smaller particle size (50-100 µm) of both the adsorbents showed maximum removal of 2,4-DCP. However, SCM-UBTLs exhibited comparatively higher (54%) removal of DCP than unmodified used black tea leaves (UM-UBTLs) (40%) at similar conditions (pH, particle size and dose). Equilibrium attained within three hours for both the adsorbents of smaller particle size at pH 2. Adsorption follows the Ho’s pseudo-second-order kinetics rather than Lagergren pseudo-first- order for both the adsorbents. The experimental data was justified with the FTIR spectra of adsorbed and unadsorbed surfaces.