Performance of ozone treated rice husk carbon (OTRHC) for continuous adsorption of Cr (VI) ions from synthetic effluent

Abstract

Ozone, a strong oxidizing agent plays a major role in activating the carbon for better adsorption. The present investigation elucidates the ozone treated carbonized rice husk (OTRHC) as adsorbent for the removal of Cr (VI) ions in continuous process. The effects of process parameters such as flow rate, bed height and influent Cr (VI) concentration were studied to determine the break through time. The maximum adsorption capacity of 541mg/g was obtained at 100mg/L of initial concentration, 25mL/min of flow rate, 150mm of bed height and the maximum percentage removal of 86.5% was obtained at 50mg/L of initial concentration, 5mL/min of flow rate, 150mm of bed height. Theoretical models such as Thomas model, Yoon Nelson model, and Bed Depth Service Time model were used to describe the kinetics and interaction behaviour of adsorption in continuous column. It was observed that, the Thomas and Yoon Nelson model were fitted well with experimental data. The BDST model reveals the adsorbate is directly adsorbed on to the surface of the adsorbent. The comparison of experimental break through curve with theoretical break through curve was done using error analysis. Regeneration studies were attempted to check the stability and activity of the adsorbent.