At what pH level is chromium typically removed from wastewater?

The removal of chromium from wastewater is typically optimized at a pH level of around 8.0. At this pH, chromium primarily exists in its trivalent form (Cr(III)), which is less soluble and more likely to precipitate out of solution compared to its hexavalent form (Cr(VI)). Precipitation aids in removing chromium from water, making it easier to separate it from the wastewater.

When the pH is increased to 8.0, the conditions are favorable for the formation of chromium hydroxide, enhancing its removal during treatment processes such as coagulation and sedimentation. Maintaining the pH within this range is critical for effective chromium removal and ensuring compliance with environmental standards for discharge. Adjusting the pH is a common practice in wastewater treatment facilities to promote the precipitation of various contaminants, including heavy metals like chromium.