Water Treatment OIT: test Questions with 100% Correct Answers | Latest Update | Verified

What does the term 'contact time' mean? a) it is the amount of time a person is exposed to chlorine b) it is the amount of time allowed for chlorine to react in water to provide disinfection 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 - ️️b) it is the amount of time allowed for chlorine to react in water to provide disinfection 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 - ️️c) hydraulically overloading a sewer Trihalomethanes are produced when chlorine reacts with: a) inorganic materials b) chlorine dioxide c) organic materials d) ultra violet light - ️️c) organic materials Which of the following is NOT an isolation valve? a) ball b) check c) butterfly d) globe - ️️b) check What units are used to measure water pressure? a) Kilowatts b) Kilopascals c) Horsepower d) Head units - ️️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 - ️️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 - ️️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 - ️️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 - ️️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 - ️️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 - ️️a) Any space which is not actively ventilated by an electrical ventilation systemThe flow of electrical current is measured in a) Amperes b) Ohms c) Volts d) Watts - ️️a) Amperes What is meant by the term 'organic compounds'? Chemical compounds that are: a) not made from carbon b) contain carbon, hydrogen and oxygen c) can easily oxidize d) can dissolve in water - ️️b) contain carbon, hydrogen and oxygen The volume of chlorine increases ______ times when it is depressurized into gas a) 100 b) 200 c) 350 d) 450 - ️️d) 450 What causes hardness in water? a) high pH b) low turbidity c) dissolved mineral salts d) alkalinity - ️️c) dissolved mineral salts O. Reg. 129/04 addresses the licensing of: a) drinking water operators b) water quality analysts c) medical officers of health d) sewage works operators - ️️d) sewage works operators 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 - ️️d) Do not enter the confinedspace 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 - ️️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 - ️️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 - ️️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 - ️️b) form floc What is the chlorine residual in water? a) the amount of chlorine applied to the water daily b) low concentrations of chlorine gas c) chlorine salt which is left after water evaporates d) amount of chlorine that remains in water after disinfection - ️️d) amount of chlorine that remains in water after disinfection The chlorine dosage of a town's water source is 4.0 mg/L. The chlorine demand for the water is 3.7 mg/L. What is the chlorine residual?a) 0 mg/L b) 0.3 mg/L c) 3.7 mg/L d) 4.3 mg/L - ️️b) 0.3 mg/L