| Abstrakt: |
This study synthesized zinc borate (Zn2 BO3 (OH), ZB) through one-step precipitation from nano zinc oxide and boric acid. FTIR, XRD, SEM, EDX, and Zeta potential characterized the product. Due to the photocatalyst properties Congo Red Day (CRD) was removed from the aqueous solution. Effective factors on the adsorption efficiency are studied (time, amount of adsorbent, concentration, pH, and temperature). Results of the study indicated that the best amount of adsorbent was obtained at 0.1 g which was used against dye when adsorption capacities equal 6.034 mg g-1. Also, the adsorption capacities [q(mg/g)] were obtained at 35.556 mg g-1 in the CRD concentration of 50 mg L-1, and [q(mg/g)] was equal to 20.154 mg g-1 in 100 mL sample at pH 5.5. All adsorption processes using distilled water (DW) were analyzed using UV-Vis spectroscopy. The adsorption capacity was calculated by using Langmuir and Freundlich isotherm models, and results showed that the maximum adsorption capacity (qmax) in the Langmuir model was achieved at 212.7 mg g-1 for Zn2 BO3 (OH). The R-squared (R²) or the low coefficient of determination for Langmuir and Freundlich isotherms adsorption were obtained at 0.98 and 0.89, respectively. The kinetic adsorption based on the first-order and second-order pseudo coefficients were achieved at R² =0.89 and R² =0.99, respectively. The thermodynamics values (ΔS, ΔG, ΔH) are measured and the results indicate that the adsorption process is spontaneous and endothermic. [ABSTRACT FROM AUTHOR] |
