The present invention refers to a method to remove organic chemicals and organometallic complexes (organic heavy metal complexes) using zeolite from process water or tailings streams of a mineral processing plant where diethylenetriamine (DETA) or triethylenetetramine (TETA) is used as a flotation reagent and DETA-metal complexes are found in process water or tailings streams. In a preferred embodiment, the process water or slurry tailings streams of a mineral processing plant containing DETA, DETA-metal complexes and residual heavy metals are contacted with natural zeolite. This can be carried out by adding the natural zeolite to the process streams (slurries) while mixing with a mechanical mixer to efficiently adsorb DETA, DETA-metal complexes and heavy metals from the process streams (slurries) on the zeolite. The loaded zeolite is then discarded with the flotation tailings.