Adsorptive removal of dyes by utilizing activated carbon-supported copper derived from natural bitumen

Abstract

This study explored the efficacy of a cost-efficient activated carbon (AC) derived from natural bitumen through chemical activation with phosphoric acid. The objective was to evaluate bitumen-based activated carbon (AC) potential as a novel adsorbent by integrating Cu (NO3)2.3H2O onto AC for the removal of harmful dyes from water-based solutions. Assessments of the adsorption capabilities of Cu@AC were conducted using representative samples of cationic and anionic dyes, namely methylene blue (MB) and methyl orange (MO). The incorporation of Cu onto the AC, leading to the formation of Cu@AC, resulted in a significant enhancement of the adsorption capacity of AC. The adsorption capacity of Cu@AC was measured using Brunauer–Emmett–Teller (BET) and iodine number measurements, with the most optimal Cu@AC sample exhibiting a BET surface area of 611 m2/g. Surface chemical properties were analyzed through FT-IR spectroscopy, while the microstructure of the produced Cu@AC was examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The efficiency of the adsorption process was influenced by factors such as pH, initial dye concentration, adsorbent dosage, and contact time. The most effective processing conditions for dye removal were determined as pH 11 for MB and pH 5 for MO, with an initial concentration of 25 mg/L, a 0.5 g/L adsorbent dosage, and a temperature of 333 K for a duration of 90 min. Under these optimized conditions, removal efficiencies exceeded 90% for MO and 80% for MB. The results demonstrated that Cu@AC has the potential to function as a cost-effective alternative to commercially available activated carbons for efficiently eliminating dyes from contaminated water.

Keywords

• activated carbon adsorbent
• methyl orange
• methylene blue
• adsorption