Adsorption of chrome (VI) and mercury (II) in solution using hyacinth (Eichhornia crassipes)

Abstract

The existence of water hyacinth proliferation in wetlands of the Canal del Dique (BolívarColombia) causes environmental problems because there is no final disposal of these. Therefore, it is necessary to study alternatives for its use. The objective of the study was to evaluate the behavior of the aquatic hyacinth as an adsorbent of Cr (VI) (VI) and Hg (II) (II) in a synthetically prepared solution. The lignocellulosic material was dried at 80°C for 24 h to remove moisture; then crushed and sieved with meshes of different particle sizes; characterized by elemental analysis to check for the presence of cellulose, hemicellulose, and lignin, as well as by Fourier Transform Infrared Spectrometry to verify the existence of functional groups responsible for the adsorption process. It was found that the best particle size was 1 mm, with a removal percentage of 73,4 and 79,3% for Cr (VI) and Hg (II), respectively. When establishing the adsorption kinetics, it was verified that the elimination percentage increases with time up to 5,5 h of contact with the Hg (II) solution and 3,8 h with the Cr (VI) solution.