An eco-friendly composite adsorbent for efficient removal of Cu2+ from aqueous solution

Abstract Citric acid (CA) has been widely investigated as a modifier for biomass adsorbents in wastewater treatment, but utilization of the filtrate from this process has never been scrutinized by now. The present study provided an effective method to utilize the filtrate collected from the process of CA modified bamboo shoot shell (BSS). The dissolved fibers of BSS (CA-BSSF) in the filtrate were blended with chitosan (CS) to prepare the composite adsorbent (CA-BSSF/CS) for Cu 2+ adsorption. FTIR and SEM were used to characterize this new adsorbent. The adsorption performances of Cu 2+ on CA-BSSF/CS were evaluated by batch process. The results showed that a better Cu 2+ adsorption capacity of CA-BSSF/CS than CS. The adsorption process could be well described by the Freundlich isotherm and the kinetic of adsorption followed a pseudo-second-order rate equation. The adsorption reaction was a spontaneous process and would happen at low temperature. Reuse studies revealed that the adsorption capacity of CA-BSSF/CS did not change significantly after repeated use 5 times compared with the fresh one. This suggests that the CA-BSSF/CS is a suitable sorbent for the removal of Cu 2+ from aqueous solution.