REHS Exam 2023 360 Answered Questions

Which of the following organisms are most resistant to unfavorable environmental conditions and indicate past of possibly intermittent pollution? a. fecal streptococci b. eschericha coli c. aerobacter aerogenes d. clostridium sporulates - ANSWER-clostridium sporulates The presence of which of the following is most easily identified by laboratory analysis in water contaminated by feces? a. shigella dysenteriae b. coliform c. entamoeba histolytica d. salmonella typhosa - ANSWER-coliform Which of the following disinfecting compounds can be used in full strength for disinfecting? a. perchloron b. calcium hypochlorite c. chlorinated lime d. sodium hypochlorite - ANSWER-sodium hypochlorite This substance is the first product of the decomposition of organic matter. its presence in water usually indicates "fresh pollution" of sanitary significance. what is it? a. ammonia b. sugar c. carbon dioxide d. hydrogen sulfide - ANSWER-ammonia The presence of which of the following elements in water treatment plant effluent is used as a measure of filtration efficiency? a. copper b. aluminum c. zinc d. lead - ANSWER-aluminum Which of the following is not used to disinfect water? a. chlorine b. bromine