What is a common method of lime application used in wastewater treatment?

The correct choice is the slurry feed method of lime application, commonly used in wastewater treatment. This method involves mixing lime with water to create a slurry, which is then introduced into the treatment process. The slurry is beneficial because it allows for a more controlled and uniform application of lime, ensuring that the chemical reacts effectively with the wastewater. This method enhances the dissolution of lime and improves the neutralization of acidity and the precipitation of heavy metals, which are essential processes in wastewater treatment.

In contrast, other methods like granular application may not be suitable for immediate dissolution, potentially leading to uneven distribution and slower reactions. The spray method could introduce issues with efficiency and uniformity as well, while dry powder broadcasting can result in dust generation and potential loss of material effectiveness depending on environmental conditions. Each of these alternatives may have specific applications, but for the purpose of efficient and effective lime application in wastewater treatment, slurry feeding stands out.