Corncob is a kind of side product of corn industry that produced. Corncob predominantly consists of hemicellulose (36%), lignin (6%), and cellulose (41%). The cellulose content in corncob can be used as an adsorbent. In order to utilize corncob as an adsorbent its adsorption ability need to be tested to potassium, sodium, sulfide, and sulfate in leachete at Muara Fajar waste disposal not only i…