NGHIÊN CỨU ĐẶC TÍNH HẤP PHỤ ION NITRAT TRÊN VẬT LIỆU THAN HOẠT TÍNH ĐƯỢC AMIN HÓA BẰNG (3 - AMINOPROPYL) TRIETHOXYSILAN

ADSORPTION CHARACTERISTICS OF NO3- ON AMINE GRAFTED ACTIVATED CARBON USING APTESIn this study, activated carbon was amine-grafted with (3-Amineopropyl) triethoxysilane (APTES) for nitrate adsorption enhancement. Material characterizations by SEM, F-TIR, EDS, Zeta potential measurement, etc. demonstrated the successful amine graft on the activated carbon surface, leading to a charge reversal of the material surface from negative to positive and a superior increase in the NO3- adsorption capacity in comparison with that of bare activated carbon. At the optimal conditions: pH 7, adsorption time of 60 minutes, and adsorbent material of 0.05g, the maximum adsorption capacity of the modified material is relatively high, qmax = 55.21 mg/g. The adsorption of NO3- on the material followed the Langmuir isotherm model and pseudo-second-order kinetics, suggesting that the adsorption included both physical and chemical adsorption processes. When desorbed with 0.5M HCl as the eluting solution, the material could be reused at least 5 times with an adsorption efficiency of ~ 80%. The synthesized material was applied to remove NO3- in some lake water samples in Hanoi with a removal efficiency of ~ 95%.