$2.$What is the primary purpose of adding chlorine during water treatment?a$)$ To adjust pHb$)$ To remove suspended solidsc$)$ To disinfect waterd$)$ To soften waterWhich of the following is NOT a method of physical water treatment?a$)$ Filtrationb$)$ Coagulationc$)$ Sedimentationd$)$ AerationWhat is the primary purpose of coagulation in water treatment?a$)$ To remove dissolved gasesb$)$ To enhance filtrationc$)$ To remove suspended particlesd$)$ To adjust pHWhat is the function of a flocculant in water treatment?a$)$ To disinfect waterb$)$ To remove turbidityc$)$ To form flocs from suspended particlesd$)$ To adjust pH