The influence of phosphoric acid activation of carbon from Bintaro fruit (Cerbera odollam Gaertn) on the adsorption of chromium in various conditions of pH

Activated carbon of bintaro fruit (Cerbera odollam Gaertn.) that is planted as a city shade tree comes from a poisonous bintaro mangrove plant. The form of bintaro fruit resembles coconut fibers and contain of lignin and cellulose more than the coconut plant has. Bintaro fruit was chemically activated using H3PO4 (20%, 4%, 60% & 80%) at 650 oC with activation time for 90 minutes. Proximate analyzes include moisture content, ash content, fly ash content, fix carbon content, and iodine absorption. Topography of activated carbon was analyzed by SEM, and functional group analysis was performed with FTIR as well as total chromium used AAS. Adsorption of chromium was carried out under acidic, neutral and alkaline pH conditions. The results showed that the activated carbon of bintaro fruit that was activated with 20% phosphoric acid at an alkaline pH was able to remove the chromium about 66.55%.