The lighter impurities such as oil and grease that float on the surface of waste water in large sedimentation tanks is called:

The solid waste that settles down at the bottom of sedimentation tanks during the primary treatment of sewage is called:

The process of passing waste water through a sand or grit chamber to allow the setting of sand, grit, stones and broken glass is called:

The suspended impurities dissolved in waste water

The process by which weeds and microorganisms grow excessively in nutrient rich water is called:

Disease which spread through stagnant water of a blocked drainage

A scraper in waste water treatment plant

Which of these acts on clarified water in an aeration tank

Name the disposal method in which solid organic wastes are subjected to combustion so as to convert them into residue and gaseous products:

A skimmer in waste water treatment plant