Search

In order to obtain a sufficient removal of heavy metal ions from water, new resources should be exploited to design more efficient and eco-friendly adsorbents. In this work, we have demonstrated an efficient, simple, and reusable adsorbent, which can be operated at the water treatment site. The simultaneous adsorption behavior and competitive interactions between As(III) and As(V) from aqueous solution onto chitosan/diatomaceous earth composite (CSD) were investigated at different solution-pH and adsorbent dosages. The adsorption mechanism was interpreted depending on the data of X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FTIR) spectroscopy. Results of batch equilibrium experiments indicated that the pH and adsorbent dosages have significantly influenced the adsorption process, and the adsorption of heavy metals was better fitted with Langmuir isotherm and pseudo-second-order models. The binary maximal adsorption capacities of As(III) and As(V), as determined from the Langmuir adsorption isotherms, were 87.81 mg/g and 44.07 mg/g at a pH of 6, respectively. The presence of phosphate (PO43−) as co-existing anions has an obvious impact on the adsorption of arsenic species. Based on the obtained results, the prepared adsorbent showed a great promise to be used in arsenic species adsorption from aqueous solution.