Heavy metals are primarily removed from waste streams through which treatment method?

Heavy metals are primarily removed from waste streams through physical chemical treatment due to the specific mechanisms that this method employs. In physical-chemical treatment, processes such as precipitation, coagulation, and flocculation are utilized to remove contaminants, including heavy metals, from wastewater. These processes enable the heavy metals to form solid particles that can be more easily separated from the liquid waste.

By adjusting the pH or adding chemicals, heavy metals can be converted into insoluble forms that precipitate out of the solution. This effective transformation allows for the removal of metals like lead, cadmium, and mercury, ensuring they do not enter the environment or contaminate water resources.

This method is particularly suitable for heavy metals because it can achieve high removal efficiencies and is adaptable to various types of wastewater containing different concentrations of metals. In contrast, biological filtration, the activated sludge process, and membrane filtration primarily target organic matter and are not specifically designed for metal removal, thus rendering physical chemical treatment the more appropriate choice for addressing heavy metal contamination in wastewater.