Biosorption of methylene blue by natural and chemical modified wheat straw in fixed-bed column

摘要

Adsorption of methylene blue (MB) 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 MB. The column data were fitted by the Thomas model and Yan model using nonlinear regressive analysis, while bed depth/service time analysis (BDST) model was applied at different bed depths. The Yan and BDST were found suitable for describing the adsorption process. The exhausted adsorbent was regenerated using hydrogen chloride solution and the adsorbent was reused. The results showed that the adsorption capacity of MWS was higher than NWS and both NWS and MWS can be reused.