Which one of the following impurities is easiest to remove from wastewater?
Which one of the following impurities is easiest to remove from wastewater?

a. Bacteria

b. Colloids

c. Dissolved solids

d. Suspended solids

Answer: d. Suspended solids

Explanation: The suspended solids in water refers to the various contaminants such as sand, small stones, etc. These are heavy ads that are placed underwater. They do not mix easily or dissolve easily. Therefore, they can be separated from water by various means such as sedimentation, water filter, etc. Bacteria are very small objects that cannot be seen with the naked eye, so they are very difficult to remove. Proper disinfection is necessary for removal. Colloids and other suspended contaminants also require special filtration and cleaning methods to separate them from water.