Acoustic cavitation induced synthesis of zirconium impregnated activated carbon for effective fluoride scavenging from water by adsorption

Abstract

Environmental concern associated with the side effects of high fluoride content in ground water and surface water has prompted the researchers to look for an efficient, convenient and easy method. Considering the potential of a good adsorbent, present study reports the synthesis of a composite by impregnating zirconium on powdered activated carbon (AC) using ultrasound as the tool for synthesis and applying it for fluoride adsorption from water. The nature of the composite was determined through characterization by scanning electron microscopy (SEM), energy dispersive Xray (EDX), Xray diffraction (XRD), N adsorption analysis (BET) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The pH (point of zero charge) of the adsorbent was found to be 5.03; with the optimum pH obtained at 4 for adsorption of strong electronegative fluoride ions. The initial fluoride concentration was varied from 2.5 up to 20 mg.L and the maximum adsorption capacity of 5 mg.g was obtained. A maximum fluoride removal of 94.4% was obtained for an initial concentration of 2.5 mg.L within an equilibrium time of 180 min. The adsorption isotherm followed the Langmuir isotherm model indicating a monolayer adsorption process and the adsorption kinetics followed pseudo second order model. The effects of various coexisting ions (HCO, NO, SO, Cl) commonly present in the water were found to have negligible impact on the process performance. Conducting the adsorption-desorption studies for five consecutive cycles for an initial fluoride concentration of 10 mg.L, the removal efficiency reduced from 86.2 to 32.6%. The ultrasonic method provided an easy route to synthesize the composite in less time and significantly reduced energy consumption by more than 96% compared to the conventional method.

Synergy of the flow behaviour and disperse phase of cellulose nanoparticles in enhancing oil recovery at reservoir condition

“…This is consistent with a previous study of Nitayavardhana et al [61], who reported that the cost of energy consumption for ultrasonic pre-treatment of cassava chips to produce ethanol was 11 kJ compared to 22 kJ for heat treatment. The finding here also agrees with those in previous studies of Bubalo et al [62] and Mullick and Neogi [63], who reported that ultrasonic provides an easy route to synthesize composite in less time and reduce energy consumption by more than 45–65% and 96%, respectively, compared to using conventional methods. Considering the capital and operating cost, a model plant would save approximately $1,114, 447 each year on pre-treatment cost if it invests in ultrasonic [64].…”

Adsorptive Removal of Methylene Blue and Crystal Violet onto Micro-Mesoporous Zr3O/Activated Carbon Composite: A Joint Experimental and Statistical Modeling Considerations

“…While in recent works, zirconium and zirconia was used with activated carbon (AC) as composites for the removal of pollutants in water. For instance, Mullick and Neogi [19] have impregnated zirconium on powdered activated carbon (AC) using ultrasound as the tool for synthesis and applying it for fluoride adsorption from water. However, Xiong et al [20] have used iron-zirconiummodified activated carbon nanofiber for the adsorption of phosphates.…”

Amino Acid Complexes of Zirconium in a Carbon Composite for the Efficient Removal of Fluoride Ions from Water

“…When recording FTIR spectra of the compounds after adsorption, the same characteristic signals were observed as for the non-adsorbed compounds, except for the symmetric and asymmetric signals of C=O and C-O. The overlapping signals present in the bulk, pure compound disappeared and became simple, well-resolved signals, and there was a decrease in the signal assigned to the Zr-O vibrational mode, which may be attributed to the ligand exchange between the hydroxyl ion and the fluoride ion [ 30 , 31 , 53 ].…”