Chitosan /Zeolite Y/Nano ZrO2 nanocomposite as an adsorbent for the removal of nitrate from the aqueous solution

In the present study, a series of chitosan/Zeolite Y/Nano Zirconium oxide (CTS/ZY/Nano ZrO2) nanocomposites were made by controlling the molar ratio of chitosan (CTS) to Zeolite Y/Nano Zirconium oxide in order to remove nitrate (NO3−) ions in the aqueous solution. The nanocomposite adsorbents were characterized by XRD, FTIR, BET, SEM and TEM. The influence of different molar ratios of CTS to ZY/Nano ZrO2, the initial pH value of the nitrate solution, contact time, temperature, the initial concentration of nitrate and adsorbent dose was studied. The adsorption isotherms and kinetics were also analyzed. It was attempted to describe the sorption processes by the Langmuir equation and the theoretical adsorption capacity (Q0) was found to be 23.58 mg nitrate per g of the adsorbent. The optimal conditions for nitrate removal were found to be: molar ratio of CTS/ZY/Nano ZrO2: 5:1; pH: 3; 0.02 g of adsorbent and temperature: 35 °C, for 60 min. The adsorption capacities of CTS, ZY, Nano ZrO2, CTS/Nano ZrO2, CTS/ZY and CTS/ZY/Nano ZrO2 nanocomposites for nitrate removal were compared, showing that the adsorption ability of CTS/ZY/Nano ZrO2 nanocomposite was higher than the average values of those of CTS (1.95 mg/g for nitrate removal), ZY, Nano ZrO2, CTS/Nano ZrO2, and CTS/ZY.