Bio-adsorbents for the Removal of Heavy Metals from Water

Abstract

The work represents the bio-adsorption of arsenic(III) from standard solutions and real water samples using a powdered avocado seed as a bio-adsorbent. The adsorbent was synthesized, demineralized, and characterized by X-ray diffraction (XRD), scanning elec- tron microscope coupled with energy dispersive spectroscopy (SEM-EDS), Fourier trans- formation infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) theory. Batch adsorption studies were carried out by using avocado seed, and AsIII was analyzed by using inductively coupled plasma optical emission spectroscopy (ICPOES) after optimiz- ing the following parameters: pH 6, analyte concentration 2 mg L?1, bio-adsorbent dosage 0.8 g, contact time 120 min between analyte and adsorbent, and temperature from 22 to 40?C. The adsorption capacity of 93.75 mg/g was obtained, and the Langmuir isotherm was adopted by the adsorbent due to the chemisorption that occurs on the surface between the functional groups of the bio-adsorbent and AsIII.