EFFECTIVE REMOVAL OF Cd(II) FROM WASTEWATER USING NITRIC AXIT TREATED RICE HUCK BIOMASS

Abstract

An available source of rice husk biomass (RH) was modified with nitric acid (HN-RH) to enhance its potential use in the adsorption of Cd(II) ions from wastewater. The basic physical-chemical properties of HN-RH were determined, and adsorption experiments for Cd(II) removal were optimized in terms of solution pH, adsorbent dose, and reaction time. The optimum solution pH was found to be 5.0 with an adsorbent dose of 0.1 g. The maximum adsorption capacity of Cd(II) using HN-RH was 125.2 mg/g. In the regeneration process, 1M EDTA was applied for the desorption of Cd(II) ions from Cd-loaded adsorbents. The results showed that HN-RH had a high reuse potential for Cd(II), with a desorption percentage of 68.2% after five cycles. Based on these findings, HN-RH could be utilized as a promising, low-cost adsorbent for the removal of Cd(II) from aqueous solutions.