Biosorpsi Ion Logam Kadmium (Cd2+) Pada Biosorben Rumput Laut Coklat (Padina australis) Asal Pantai Liti Pulau Kisar

The research about biosorption of Cadmium (Cd2+) metal ion in brown seaweed biosorben (Paladina australis) from Liti beach, Kisar island has been done. Analysis of decreasing Cd2+ content using Atomic Absorption Spectrophotometer (SSA) and also use FTIR to know functional groups contained in alginate compounds. A total of 0.5 g of brown seaweed powder was introduced into 25 mL of Cd2+ 50 ppm solution with variations of pH 1-7 and shaker for five hours. After the  optimum  pH  was  obtained,  the  adsorption  process  was  applied  on  pH  5 solution with variation of contact time 1, 3, and 5 hours, after which it was filtered. The result of analysis and calculation showed that Cd2+ ion was optimum at pH 5 of 99.64% and 3 hours contact time was 74.54%.