Water Treatment OIT Test Questions with 100% Correct Answers | Latest Version 2024/2025 |, Exams of Water and Wastewater Engineering

Download Water Treatment OIT Test Questions with 100% Correct Answers | Latest Version 2024/2025 | and more Exams Water and Wastewater Engineering in PDF only on Docsity!

Water Treatment OIT Test Questions with 100% Correct

Answers | Latest Version 2024/2025 | Expert

What units are used to measure water pressure? a) Kilowatts b) Kilopascals c) Horsepower d) Head units - Answer- b) Kilopascals Which of the following is NOT an example of PPE (Personal Protective Equipment)? a) Exhaust fan b) SCBA c) Face shield d) Traffic vest - Answer- a) Exhaust fan Which of the following are operators-in-training NOT allowed to do? a) There are no restrictions on the duties of an operator-in-training b) Any operational duties if not in the presence of another operator c) Anything which could effect the quality of the water/wastewater d) Be the operator with overall operational responsibility of the system - Answer- d) Be the operator with overall operational responsibility of the system Define the term "head" as used in hydraulic systems. a) The block of an internal combustions engine b) The ability of a piston pump to overcome the force of gravity c) The height or energy of water above a specified point

d) The distance between the liquid level and the cover of a well - Answer- c) The height or energy of water above a specified point Which of the following statements accurately describes some of the properties of chlorine? a) I a colourless gas which is toxic to plants and animals; is flammable and explosive b) Is a greenish/yellow gas with a penetrating odour; is heavier than air c) Is a yellowish gas with an irritating odour; insoluble in water d) Is lighter than air; soluble in water and forms a salt which is lethal to microorganisms - Answer- b) Is a greenish/yellow gas with a penetrating odour; is heavier than air What happens when two or more different elements combine? a) chemical compound is formed b) atom is created c) molecule is formed d) concentration is created - Answer- a) chemical compound is formed What is the definition of a confined space? a) Any space which is not actively ventilated by an electrical ventilation system b) Any space from which exit by an injured worker is difficult c) Any space where hazardous gas can accumulate or an oxygen deficient atmosphere can occur d) Any space where the distance from floor to ceiling is less than 3 metres - Answer- a) Any space which is not actively ventilated by an electrical ventilation system The flow of electrical current is measured in a) Amperes

b) water quality analysts c) medical officers of health d) sewage works operators - Answer- d) sewage works operators Which of the following is NOT an isolation valve? a) ball b) check c) butterfly d) globe - Answer- b) check An operator smells hydrogen sulphide at the entrance of a deep confined space. that actions should the operator take? a) hydrogen sulphide is only detected in low concentrations and will only cause headaches at this concentration. Proceed if the task is short b) Vent the confined space while working c) Hydrogen sulphide gas in all concentrations is only an irritant, so proceed with the task d) Do not enter the confined space until there is no hydrogen sulphide detected, and then only when all safety equipment is in place - Answer- d) Do not enter the confined space until there is no hydrogen sulphide detected, and then only when all safety equipment is in place What is the main purpose of the Safe Drinking Water Act? a) Certify operators b) Protect human health c) Supervise drinking water systems d) Sample and test drinking water - Answer- b) Protect human health What does a sample with a high BOD level indicate?

a) Low organic material content b) High organic material content c) High level of inorganic suspended solids d) Low level of pathogenic bacteria - Answer- b) High organic material content Which of the following statements is the most accurate concerning a "Certificate of Approval" (C of A), issued by the Ministry of Environment? a) The terms and conditions stated in a C of A are legally enforceable b) The terms and conditions stated in a C of A are recommendations on how the facilities should be operated c) A C of A is only required for facilities built before 1965 d) Once a facility has been built the C of A is no longer required and can be discarded - Answer- a) The terms and conditions stated in a C of A are legally enforceable Coagulation is the mixing of coagulants with water to: a) disperse colloidal material b) form floc c) inactivate colloids d) suspend floc - Answer- b) form floc Trihalomethanes are produced when chlorine reacts with: a) inorganic materials b) chlorine dioxide c) organic materials d) ultra violet light - Answer- c) organic materials

c) it is the amount of time a coagulant is exposed to water before flocculation occurs d) it is the amount of time it takes for chlorine to sterilize water - Answer- b) it is the amount of time allowed for chlorine to react in water to provide disinfection Backflow siphonage is caused by: a) positive pressure in the water main b) unprotected connections c) unprotected openings d) negative pressure in the water main - Answer- d) negative pressure in the water main When flushing a water main, operators should ensure that the pressure in nearby areas does not drop below _______. a) 60 kPa b) 140 kPa c) 350 kPa d) 550 kPa - Answer- b) 140 kPa Which of the following best describes the largest volume of water a distribution system would normally supply during a day? a) minimum demand (L/hour) b) average demand (L/hour) c) peak demand (L/hour) d) average demand per person (L/hour/person) - Answer- c) peak demand (L/hour) Distribution lines are flushed periodically to:

a) increase water pressure in the system b) reduce the risk of water hammer c) ensure that chlorine does not accumulate in pipes d) remove deposits from the pipeline - Answer- d) remove deposits from the pipeline What is NOT one of the main purposes of distribution storage? a) to help satisfy peak demand b) to allow for a uniform water treatment and pumping rate c) to provide water for firefighting needs d) to store a large volume of water for long periods of time - Answer- d) to store a large volume of water for long periods of time What is the name of the valve which connects the customer's service line to the municipal water line? a) bypass valve b) control flume c) curb stop d) check valve - Answer- c) curb stop In an activated sludge process, some of the sludge collected in the secondary sedimentation tank is returned to the _______ to maintain the mass of the mixed liquor. a) grit channel b) aeration tank c) primary sedimentation tank d) digester - Answer- b) aeration tank

d) grit channel, primary sedimentation, secondary sedimentation, aeration tank - Answer- c) grit channel, primary sedimentation, aeration tank, secondary sedimentation Secondary treatment typically removes ______ of the BOD and suspended solids. a) 20-39% b) 40-59% c) 60-79% d) 80-99% - Answer- d) 80-99% Water entering a wastewater treatment plant will pass through a bar screen. The bar screen is designed to remove which of the following items? a) dissolved solids b) grit and sand c) large objects d) nutrients - Answer- c) large objects Define the term 'supernatant' a) a solution which is supersaturated b) a substance used to reduce odour in polluted waters c) the liquid located above a sediment or precipitate d) an operator who is extremely proficient in fulfilling their duties - Answer- c) the liquid located above a sediment or precipitate A __________ is used to move wastewater from a wastewater lift station to an elevated gravity sewer: a) sewer lateral

b) force main c) sanitary trunk main d) transmission main - Answer- b) force main What happens when a sewer is surcharged? a) infiltration of ground water into sewers b) flushing a sewer with clean water to clean debris away c) hydraulically overloading a sewer d) taxing a customer's water bill to pay for collection devices - Answer- c) hydraulically overloading a sewer Which of the following infectious diseases can be transmitted through domestic wastewater? a) hepatitis b) giardiasis c) cryptosporidiosis d) all of the above - Answer- d) all of the above What is meant by the term "combined sewers"? a) industrial sewage and domestic sewage are collected in the same sewers b) stormwater and sewage are collected in the same sewers c) the main sewer line which takes all of a city's sewage to the treatment plant d) a sewer which contains both gravity sewers and force mains - Answer- b) stormwater and sewage are collected in the same sewers Why is hydrogen sulphide gas a problem in sewers?

When operating a pump, an operator feels a vibration and hears a slight hammering noise. a) water hammer b) cavitation - Answer- b) cavitation