Adsorption of Nitrate onto ZnCl₂‐Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics

Abstract

Coconut granular activated carbon (CGAC) was modified by impregnating with ZnCl 2 solution to remove nitrate from aqueous solutions. Sorption isotherm and kinetic studies were carried out in a series of batch experiments. Nitrate adsorption of both ZnCl 2 -modified CGAC and CGAC fitted the Langmuir and Freundlich models. Batch adsorption isotherms indicated that the maximum adsorption capacities of ZnCl 2 -modified CGAC and CGAC were calculated as 14.01 mgN·g −1 and 0.28 mgN·g −1 , respectively. e kinetic data obtained from batch experiments were well described by pseudo-second-order model. e column study was used to analyze the dynamic adsorption process. e highest bed adsorption capacity of 1.76 mgN·g −1 was obtained by 50 mgN·L −1 inlet nitrate concentration, 20 g adsorbents, and 10 ml·min −1 flow rate. e dynamic adsorption data were fitted well to the omas and Yoon-Nelson models with coefficients of correlation R 2 > 0.834 at different conditions. Surface characteristics and pore structures of CGAC and ZnCl 2 -modified CGAC were performed by SEM and EDAX and BET and indicated that ZnCl 2 had adhered to the surface of GAC after modified. Zeta potential, Raman spectra, and FTIR suggested the electrostatic attraction between the nitrate ions and positive charge. e results revealed that the mechanism of adsorption nitrate mainly depended on electrostatic attraction almost without any chemical interactions.

Adsorption Equilibrium, Thermodynamic, and Kinetic Study of O2/N2/CO2 on Functionalized Granular Activated Carbon

“…The broad peak at 1500 cm –1 corresponds to the C–O stretching vibration. 52 − 56 Furthermore, the peaks between 1438 and 1500 cm –1 are correlated to the vibration of C=C bonds. The structure of the aromatic C–H out-of-plane bending vibration is related to a peak at 800 cm –1 .…”

Nutritive Solutions Formulated from Organic Fertilizers

“…There are various chemical causes or reasons by which materials are related to ions or cations, among them attraction forces or electrostatic repulsions (mainly present in inorganic compounds), dispersive forces, or π-π interactions (organic compounds such as organic matter) stand out [9]. Among the materials used for the retention of inorganic compounds such as metals, metalloids, and heavy metals include activated carbons, zeolites, clays, lignocellulosic materials, carbon nanotubes, composites from green materials such as mixed cellulose with iron oxides and also can be used an ion exchange resins and membranes [10,11]. In the case of organic compounds, the material traditionally used in Mexico and other countries is activated carbon.…”

Bioremediation of dyes using coconut parts via adsorption: a review

“…Various coconut parts were modified to treat heavy metals in the waste water [29][30][31], organic compounds in the water stream (i.e. butylparaben, benzene, toluene, carbofuran) [32][33][34], carbon dioxide gaseous from the flue gas [35] and inorganic pollutants from the drinking water [36][37][38].…”