Characterization and Adsorption Performance of Teak Sawn Derived Activated Carbon for Cr(VI) Removal from Batik Industry Effluents

Sawn timber waste requires proper disposal management owing to its potential to pollute water. Teak (Tectona grandis L.) sawn timber residue can be converted to activated carbon for heavy metal adsorption. This study aimed to characterize T. grandis activated carbon, determine its maximum adsorption capacity for Cr(VI) in batik wastewater, and evaluate the adsorption isotherm models. The sawn teak was carbonized, chemically activated with 1 M HCl for 24 h. Characterization was performed using SEM and FTIR. Adsorption experiments were conducted with 0.5 L of wastewater from the batik hand-drawn industry in Giriloyo. Cr(VI) was adsorbed using 0.5-3.0 g of activated carbon and with the contact time of 30-240 min. SEM revealed pores filled with adsorbate, whereas FTIR showed new bands at 600-500 cm −1 corresponding to the Cr-O spectral bond. The adsorption followed the Freundlich isotherm model, with a maximum capacity of 0.027 mg/g using 0.5 g at contact time of 30 min. The highest removal efficiency of (91%) was achieved with 3.0 g at 120 minutes contact time. These findings demonstrate that T. grandis activated carbon is an effective adsorbent for Cr(VI) removal, offering potential applications in sustainable batik wastewater treatment.