Abstract: Adsorption capacities of acid-modified (MoMB and MoMR) and raw (RaMB and RaMR) mangrove bark and root sorbents on hexavalent chromium ion have been evaluated with respect to pH, adsorbent dosage, particle size, concentration of hexavalent chromium ion and contact time using batch adsorption technique. It was found that acid-modified mangrove sorbents exhibited higher adsorption capacities than raw mangrove sorbents.