Adsorption Study of Congo Red Dye from Synthetic Wastewater at Different Concentrations Using Zinc Sulfide Nanoparticles

Abstract

Zinc sulfide (ZnS) nanoparticles were fabricated using the chemical precipitation method. The X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM) techniques were used to investigate the structural parameters of the formed ZnS. The hexagonal crystal structure of the Zn and ZnS phases was formed. The average crystallite size of the ZnS phase is 10.3 nm, which is much smaller than that of the Zn phase (54.5 nm). Several frequencies and phonon modes were detected in the Raman scattering spectrum belonging to the ZnS nanoparticles. The synthesized ZnS nanoparticles were used as catalysts to eliminate the Congo red (CR) dye, with different concentrations, from synthetic wastewater. The impact of the CR dye concentration and shaking period on the adsorption of CR was thoroughly investigated, and various adsorption kinetic models were tested. After 3 h of shaking, the adsorption efficiency reached 26.01% for 40 mg/L CR dye and 27.84% for 20 mg/L CR dye. The adsorption capacities of the CR dye in the presence of ZnS are 16% and 9% for 40 and 20 mg/L, respectively. Based on the correlation factor, the intraparticle diffusion kinetic model was considered the best of the tested models.

Dual Studies of Photo Degradation and Adsorptions of Congo Red in Wastewater on Graphene–Copper Oxide Heterostructures

“…The absorbance spectrum of CR was measured and exhibited a mean peak at 490 nm. Additionally, there was a small peak at 970 nm [ 28 ], as mentioned in the insert of Figure 1 . Then the calibration curve between the absorbance and the CR dye concentration was drawn using various dye concentrations, ranging from 0.0 to 30 mg/L [ 28 , 29 ].…”

“…Additionally, there was a small peak at 970 nm [ 28 ], as mentioned in the insert of Figure 1 . Then the calibration curve between the absorbance and the CR dye concentration was drawn using various dye concentrations, ranging from 0.0 to 30 mg/L [ 28 , 29 ]. The concentration and absorbance were determined to have a straight-line relationship with a correlation coefficient of R 2 of 0.99, as shown [ 28 ].…”

“…Then the calibration curve between the absorbance and the CR dye concentration was drawn using various dye concentrations, ranging from 0.0 to 30 mg/L [ 28 , 29 ]. The concentration and absorbance were determined to have a straight-line relationship with a correlation coefficient of R 2 of 0.99, as shown [ 28 ]. The dye concentration was directly provided during the UV–Vis spectrum measurement, based on the calibration curve and the spectral absorbance of CR dye as inserted in Figure 1 [ 30 ].…”

Adsorption of Congo red dye from aqueous solution by using siderite waste accompanying phosphate mines: Performance and mechanism

“…The kinetics of adsorption is a fundamental aspect that must be considered when analyzing the time required for the removal of dye and the mechanisms involved in the sorption process [64]. Generally, the adsorption rate of the dye is usually governed by the initial transfer of CR from the solution to the surface of the adsorbent.…”

“…Ultimately, the Elovich equation is commonly used in the investigation of dye sorption in aqueous solutions, particularly in the analysis of adsorption kinetics. One common approach for analyzing data based on the Elovich equation involves using a linear representation, which involves plotting qt as a function of ln(t) [64]. Equation (10), which represents the linear fitting of the Elovich model [70].…”