REHS Exam Questions and Answers Already Graded A

REHS Exam Questions and Answers Already Graded A 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 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 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 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 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 aluminum Which of the following is not used to disinfect water? a. chlorine b. bromine c. fluorine d. iodine fluorine The presence of which of the following in water would indicate past of possibly intermittent pollution? a. streptococcus fecalis b. escherichia coli c. clostridium perfringens d. enterococci clostridium perfringens Often over 90% of sodium arsenate can be removed by a. filtration b. coagulation c. ion exchange d. all of the above coagulation Reduction of the level of fluorides in drinking water can be accomplished by a. coagulation b. lime softening c. ion exchange d. all of the above all of the above When collecting bacteriological samples that have been chlorinated, what chemical is used to chlorinate the water? a. sodium sulfate b. sodium thiosulfate c. sodium bisulfate d. sodium bisulfite sodium thiosulfate Methylene blue active substance (MBAS) is a test to identify a. hardness of water b. iron in water c. presence of detergents containing phosphates d. presence of coliform in bacteria presence of detergents containing phosphates Which organism is not known as an iron bacterium? a. crenothrix b. giardia lamblia c. ferric chloride d. leptothrix giardia lamblia The final product in biochemical oxidation of ammonia yields; a. nitride b. nitrite c. nitrate d. nitrogen nitrate Which contaminant in water is associated with methemoglobinemia? a. zinc b. lead c. copper d. nitrate nitrate The substance constantly used as a coagulant in water treatment is: a. aluminum sulfate b. calcium sulfate c. potassium chloride d. sodium phosphate aluminum sulfate The disinfecting ability of chlorine is affected most by: a. BOD b. temperature c. hydrogen ion concentration d. dissolved oxygen hydrogen ion concentration Alkalinity exists in three forms, which is not one of these forms? a. bicarbonate b. hydroxide c. carbonate d. hypochlorite hypochlorite Which of the following would not contribute to water hardness? a. calcium sulfate b. magnesium sulfate c. calcium chloride d. sodium chloride sodium chloride Improperly located wells, allowing fecal pollution of the water supply may lead to outbreaks of: a. botulism, leptospirosis, typhus fever, maria b. brucellosis, strep infections, chlorea, yellow fever c. salmonellosis, shigellosis, chlorea, hepatitis d. relapsing fever, histoplasmosis, psittacosis salmonellosis, shigellosis, chlorea, hepatitis Historically in the US, most of the impetus for adequate water