Iron or calcium are used in wastewater treatment to break what?

In wastewater treatment, iron or calcium is often utilized as a coagulant or flocculant to assist in the removal of chelants. Chelants are compounds that can bind to heavy metals, keeping them in solution and making them more difficult to remove through conventional treatment processes. By introducing iron or calcium, these coagulants can help to destabilize these chelant-metal complexes, allowing the metals to be separated from the water through sedimentation or filtration.

This process is crucial because the presence of chelants in wastewater can complicate treatment efforts and can interfere with the efficiency of biological processes. Thus, by targeting chelants specifically, practitioners can improve overall wastewater quality and ensure that heavy metals are effectively removed, leading to safer discharge into the environment or successful reuse.