SUMMARY Corncob (Zea Mays L.) have chemical composition of cellulose, hemicellulose and lignin which potentially to be used as an adsorbent. This research aims to convert corncorb into charcoal through a carbonization process with klin drum and activated with CaCl2, then applied to improve the quality of peat water. Carbonization was carried out with klin drum method and activated with CaCl2 1…