Question

Phosphate ions from fertilizers are sometimes present as contaminants in municipal sewage. These have been removed with some success by:

• A. passing of chlorine
• B. heating at ${70}^{\circ }C$
• C. filtration
• D. passing of steam

Answer 1

Answer: (C)

$\begin{array}{c}\text{Phosphate ions are removed by precipitating it , by adding some}\\ \text{multivalent metal ions like}{Ca}^{+2}\text{or}{Mg}^{+2}\text{.}\\ \text{It then forms solid precipitates that are removed by}\\ \text{filteration.}\end{array}$