Methylene blue adsorption using soybean dregs-mesopore activated carbon

Water waste generated by dyeing activities to color clothes in the textile industry is one of the pollution events that occur in the aquatic environment. Methylene blue is a type of clothing dye that is commonly used in the textile industry. The purpose of this research is to investigate the adsorption of methylene blue using activated carbon (AC) made from soybean dregs. Activated carbon is produced by carbonization at a temperature of 650 oC with holding times of 40, 80, and 120 minutes, then cooled for 12 hours. The carbonized sample was activated by heating it to 650 oC and doping it with nitrogen at a rate of 200 mL/min. The TGA, Ultimate, SEM, and adsorption isotherm tests were used to determine the properties of activated carbon, while the methylene blue adsorption test was used to determine the adsorption capacity of activated carbon on methylene blue. The results showed that increasing the carbonization holding time increased the fixed carbon and carbon content, pore surface area, and absorption capacity. Optimal conditions were achieved on activated carbon with a carbonization holding time of 120 minutes because it produced the highest fixed carbon (67.16%), carbon (71.56%), pore surface area (16.169 cm2/g), methylene blue adsorption capacity (2.128 mg/g), and adsorption efficiency (90.28%). This activated carbon has a mostly mesopore pore structure with an average pore diameter of 9.26 nm