Modification of natural bentonite by exchanging Ca2+ cations to NH4+ has been studied. The modified material then used as a coagulation agent in way to reduce POME waste pollution. The material was characterized with FTIR and SEM instruments. The results of the FTIR analysis showed the modified bentonite undergo wavenumber shift at 3380 cm-1 to 3396 cm-1 which has sharper band shape, and the be…