In addition to pH adjustment, lime is often used to assist in what process during wastewater treatment?

Lime is frequently utilized in wastewater treatment processes, particularly for heavy metal precipitation. This happens because lime raises the pH of the wastewater, which can lead to the formation of insoluble metal hydroxides. Many heavy metals, such as cadmium, lead, and zinc, will precipitate out of the solution as hydroxides when the pH is sufficiently increased. This process significantly enhances the removal of these harmful substances from the water, making it safer for discharge or further treatment.

While lime can play a role in other processes, such as aiding disinfection or influencing the interaction of nutrients, its primary and most effective application in this context is indeed in facilitating the precipitation of heavy metals. The transformation of these dissolved metals into solid form allows for easier separation from the water, thus improving overall water quality and complying with environmental regulations.