Biosorption of copper ion by natural and modified wheat straw in fixed-bed column

摘要

Adsorption of copper ions from aqueous solution was studied by natural wheat straw (NWS) and modified wheat straw (MWS) with citric acid in fixed-bed column. The experiments were conducted to investigate the effects of the bed depth, the flow rate, and the influent concentration of copper ions. The column data were fitted by the Thomas model using nonlinear regressive analysis while bed depth/service time analysis (BDST) model was applied at different bed depth. The Thomas model was found suitable for the description of breakthrough curve. The bed depth service time (BDST) model was applied to predict the service times with other flow rate and initial concentration. The theoretical breakthrough curve was compared with experimental breakthrough curve profile in the dynamic process. The copper-loaded adsorbent was regenerated using hydrogen chloride solution. The results showed that the adsorption capacity of MWS for copper ion was higher than NWS and both NWS and MWS can be reused.