Removal of Congo Red Dye Using Green Kyllinga Weed Extract and Silver Nanoparticles as Catalysts

This study describes the ability of green kyllinga weed extract (GKWE) with silver nanoparticles (AgNPs) as catalysts for the removal of congo red (CR) dye from synthetic coloring wastewater. AgNPs were synthesized using GKWE as a reducing agent, resulting in the formation of AgNPs with an average size of 17.64 nm. For the catalytic study, the experiment was carried out in batch mode. Different parameters such as the effect of pH, amount of AgNPs as a catalyst, initial CR dye concentration, and amount of GKWE were evaluated for the removal of CR dye for 30 mins reaction times. The CR removal was achieved between 91.2% and 96.7% at the optimum condition which is at pH 2, 0.5 mL of 2 mM AgNPs as a catalyst, 60-100 mg/L of initial CR dye concentration, and 1 mL amount of GKWE were used. The result showed that the combination between GKWE and AgNPs had a synergy interaction in enhancing the removal of CR dye from coloring wastewater via the coagulation-flocculation and sedimentation process.