4th sem SE CO4 part 3

SEMESTER:4^TH

SUBJECT: SANITARY ENGINEERING

UNIT/CO-4

TITLE OF THE UNIT: SEWAGE TREATMENT AND DISPOSAL

TOPIC: TREATMENT UNITS

SCREENS

•    Screening is the first unit operation used at wastewater treatment plants (WWTPs). Screening removes objects such as rags, paper, plastics, and metals to prevent damage and clogging of downstream equipment, piping, and appurtenances. Some modern wastewater treatment plants use both coarse screens and fine screens.

GRIT CHAMBER

Grit chambers are long narrow tanks that are designed to slow down the flow so that solids such as sand, coffee grounds, and eggshells will settle out of the water. Grit causes excessive wear and tear on pumps and other plant equipment.