Sintesis Karbon Aktif Berbahan Dasar Mikroalga Chlorella vulgaris Menggunakan Aktivator KOH dan Iradiasi Gelombang Mikro

Abstract

Microalgae Chlorella vulgaris has been used as a raw material in the synthesis of powdered activated carbon. Dry microalgae was pyrolyzed at a temperature of 500^oC for 30 minutes to obtain microalgae charcoal. The combination of chemical activation treatment using KOH with concentrations of 10, 30, and 50% assisted by microwave irradiation have been used to prepare activated carbon. The properties of activated carbon were analyzed included yield, ash content, volatile substance content, pure activated carbon content, iodine solution absorbency, BET surface area and activated carbon imaging using SEM EDX. The results showed that Chlorella vulgaris microalgae has a carbon element content of 16.09% which has the potential to be used as an activated carbon feedstock. The microalgae activated carbon produced has a range of yield of 27.60-48.64%, ash content 27.98-44.23%, volatile substance content 23.08-30.92%, pure activated carbon content 32.69-41.10%, absorption of iodine solution 189.46 - 260.23 mg/g, surface area BET was obtained at 34,933 m² / g, with a pore average of 46.59 nm in the sample with the highest iodine absorption. Activation using microwave irradiation and higher KOH concentration, i.e. 50%, can reduce the yield and an ash content of activated carbon, on the other hand, increase the level of volatile substances and iodine absorption. SEM EDX imaging results show the formation of micropores on the surface of microalgae activated carbon, however the impurities promotes the deterioration of surface area and lowering the absorption performance of microalgae activated carbon.