Comparison of the Adsorption Performance of Biodegradable Chitosan-Cadmium Sulfide Composite Microspheres for Cationic Malachite Green and Anionic Congo Red Dyes
International Journal of Environmental Research, cilt.21, sa.1, 2027 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 21 Sayı: 1
- Basım Tarihi: 2027
- Doi Numarası: 10.1007/s41742-026-01286-z
- Dergi Adı: International Journal of Environmental Research
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Environment Index, Geobase, Zoological Record, Natural Science Collection (ProQuest), Biomedical Reference Collection: Corporate Edition (EBSCO)
- Anahtar Kelimeler: Adsorption, Cadmium Sulfide, Chitosan, Congo Red, Malachite Green
- Yıldız Teknik Üniversitesi Adresli: Evet
Özet
This study investigates the adsorption performance of cadmium sulfide (CdS)-filled chitosan (CS) biocomposite microspheres. Two different types of dyes were used as model dyes, such as cationic (Malachite green (MG)) and anionic (Congo red (CR)). The characterization was conducted using FTIR-ATR, SEM, XRD, zeta potential, and pHpzc analyzes. To identify the ideal conditions for the adsorption process, several experimental variables including pH, concentration, contact time, and temperature were examined. The ideal parameters were found to be pH 6 for CR dye and pH 7 for MG dye, 90 min of contact time for both dyes, 120 rpm stirring speed, and 0.045 g for CR dye and 0.125 g for MG dye. The non-linear Langmuir, Freundlich, D-R, and Temkin isotherm models were all fitted with adsorption data. The best fit of the adsorption process to the non-linear Langmuir isotherm model was demonstrated by the high correlation coefficient and low error functions. From the non-linear Langmuir model, the value of CS-CdS-30 composite microspheres was calculated as 74.80 mg/g for CR dye and 30.85 mg/g for MG dye at 298 K. Furthermore, the CR and MG kinetics were characterized by the non-linear pseudo-second-order process. By conducting the adsorption process at various temperatures, thermodynamic characteristics were examined, and it was discovered that the adsorption process was spontaneous (= -29.66 kJ/mol for CR dye and = -24.51 kJ/mol for MG dye at 298 K) and endothermic (= +17.36 kJ/mol for CR dye and = +29.79 kJ/mol for MG dye). The prepared composite microspheres can be effectively used for up to five cycles.