Cellulose nanocrystal modified with 3‐chloro propyl trimethoxysilane: a new bio‐adsorbent for nitrate removal from water

Abstract

Abstract In this work, preparation, characterization and nitrate removal ability of a chemically modified cellulose nanocrystal (CPTMS/CNC) were investigated for the first time. The FTIR, FESEM, EDX and TG analyses confirmed the successful modification of the cellulose nanocrystal (CNC) by 3‐chloro propyl trimethoxysilane (CPTMS) and the thermal stability of CPTMS/CNC. The optimum removal efficiency (86.5%) occurred at initial pH of 7 and room temperature (~25°C) with an initial nitrate concentration of 20 mg/L, contact time of 10 min and CPTMS/CNC dosage of 3 g/L. The nitrate adsorption dropped noticeably in the presence of sulphate, followed by bicarbonate, chloride and phosphate, respectively. The kinetic adsorption data were fitted well with the pseudo‐second‐order kinetic model and the adsorption process involved two stages. The equilibrium adsorption data obeyed the Freundlich isotherm model. Thermodynamic analysis suggested a spontaneous and exothermic adsorption process with a decrease in random collisions at the solid–solution interface.