L iquid waste containing heavy metals is very dangerous, so it must be removed before being disposed of in a container. One way to treat liquid waste containing heavy metals is by ion exchange using natural zeolite media.Zeolite is a silicate alumina mineral with a hollow skeleton structure. Therefore the metal ions and water molecules between these cavities are free to move so that they can be used as ion exchangers and are reversibly dehydrated.The ability of zeolite as an ion exchange medium is expressed in terms of the ion exchange capacity (meq / 100 grams). If the influent containing heavy metals Cr (III) and Cr (VI) is flowed continuously through the zeolite, then we will know the volume and concentration of the cumulative breakthrough effluent of Cr (III) and Cr (VI) by the zeolite.In the study, various influent concentrations and influent pH were varied to see their influence on the cumulative breakthrough e0uent volume and concentration. At the time of operation, a discharge of 130 ml / minute, an operating time of 240 minutes, an influent volume of 31.2 liters, the amount of zeolite 80 grams, regenerant AI, (S 4) 1 at a dose of 50 grams / liter, regeneration rate of 30 ml / minute, is used. regeneration time 100 minutes. To determine the volume and concentration of cumulative breakthrough effluent, effluent samples were taken from Cr (III) and Cr (VI) during operation.Based on the calculation of the cumulative breakthrough effluent volume and concentration, it was found that the best operating conditions for Cr (III) were at an influent concentration of 12 mg / l, while the best operating conditions for Cr (VI) were at a concentration of 20 mg / l.