Question Answer
High dosages, long contact times, high temperatures, and low pH combine to ____ the effectiveness of disinfection? Increase
There are concerns about possible chlorate formation with this disinfection method? Chlorine dioxide
What are the common causes of taste and odour sources (list five)? Dissolved gases, biological growths, decaying organic matter, wastewater effluent/storm runoff contaminants, distribution system problems
This dissolved gas that causes taste and odour problems is common with groundwater? Hydrogen sulfide
These sources (and list group) of taste and odour problems often develop in the water or sediments of lakes, reservoirs, and rivers? Biological growths group (algae, protozoa, and slimes)
What are two ways in which microorganisms produce taste and odour problems? Metabolic byproducts (as microorganisms grow and multiply) and cellular material of microorganisms (ruptured cells)
Taste and odour treatment methods can be divided into two broad categories? Removal and destruction
Taste and odour removal techniques include (list three methods)? Conventional treatment; de-gasification; adsorption
This treatment process has been shown to reduce the organic content of water, which provides the added benefit of taste and odour control? Coagulation (inorganic salt – alum)
This taste and odour treatment method is often useful in removing volatile odour producing compounds from water? Aeration
This taste and odour treatment method is more successful in treating odour problems than taste problems? Aeration
This method to remove volatile odour producing compounds is also known as degasification? Aeration
Aeration as a taste and odour control is considered as a ____ rather than a ___ removal method? Physical/chemical
This aeration method is designed to pass the water through the air? Cascade and spray aerators
This aeration method is designed to introduce air into the water? Blower system
This aeration method combines cascade and spray systems with blower systems, but is not common in water treatment plants? Air stripping
This aeration method works by increasing the surface area of water? Cascade method
This aeration method works by creating small water droplets to increase the surface area of water? Spray method
This taste and odour control method destroys the responsible compounds by breaking them down into less objectionable substances? Chemical oxidation
What are the four commonly used chemicals for chemical oxidation (taste and odour control)? Chlorine, potassium permanganate, chlorine dioxide, and ozone
Many easily detectable odours in raw water are readily treated by the use of ___? Chlorine
This chemical oxidation method for taste and odour control is commonly used in conjunction with aeration? Potassium permanganate
When using potassium permanganate, the final product is _____, which is an _____brown precipitate that can be removed by sedimentation and filtration? Manganese dioxide/insoluble
All of the potassium permanganate must be converted to ___ before ____? manganese dioxide/filtration
What test can be used to determine the maximum permanganate dose that can safely be applied to the treatment process and react completely before reaching the filters? Jar test
Permanganate should be added to the water ____ in the treatment process so that the contact time is ___? Early/maximized
If a permanganate overdose does occur, what can be used to control the problem until the permanganate dosage rate has been adjusted to the correct level? Powdered activated carbon
Typical permanganate dosage rates for various water treatment plants range between? 1 to 3 mg/L
Never store permanganate in the same area as _____, because these two chemicals can spontaneously combust when mixed? Activated carbon
What is the most common and most effective method of taste and odour control currently available? Activated carbon
This taste and odour control method is capable of removing virtually all gases and dissolved substances from water when it is used in sufficient quantities? Activated carbon
What is considered as the most important property of activated carbon? Particle size
This property of activated carbon determines the types of equipment, processes, and procedures used? Particle size
This type of activated carbon is used in equipment quite similar to rapid gravity or pressure filters, with the carbon taking the place of sand or sand/coal media? Granular activated carbon
This type of activated carbon is typically used in fairly large plants? Granular activated carbon
This type of activated carbon is by far the more common type used? Powdered activated carbon
This type of activated carbon is simply added to the water at some point in the treatment process prior to filtration? Powdered activated carbon
Which two chemicals should not be mixed with activated carbon because these compounds will neutralize each other? Chlorine and potassium permanganate
What are common dosages of powdered activated carbon used to control taste and odour problems? 5 to 15 mg/L
This type of feeder for powdered activated carbon is typically used when it is a regular procedure? Slurry feeder
This type of feeder for powdered activated carbon is typically used when it is required for short-term periods? Dry feeder
This taste and odour chemical is considered as hydrophobic? Powdered activated carbon
A powdered activated carbon slurry tank must be _____ to prevent ____? continuously mixed/settling
How is powdered activated carbon separated from the water? Clarification and filtration
This chemical is considered an electrical conductor, the accumulation of which on live electrical equipment increases the possibility of short-circuits? Powdered activated carbon
It is the preferred chemical form (state) used in water treatment because of easier handling, simpler feeding equipment, and a reduced exposure nuisance? Liquid form
Small steel cylinders, up to about a hundred kilograms net weight, are usually moved in a _____ by hand or with a hand truck? In a vertical position
These should be isolated from operating areas; restrained in position; and stored in rooms separate from ammonia storage? Chlorine gas cylinders
List three things that liquid chemical storage tanks should have? Level indicator; overflow; spill containment
This treatment chemical may require explosion-proof electrical handling equipment? Activated carbon
This type of chemical should be stored in tanks that are vented to the outside atmosphere, but not through vents in common with day tanks? Acids
This substance is used to detect ammonia? HCl
This must be used in cases where the discharge point of a chemical feed system is below the level of the metering pump? Antisiphon valve
If the pressure on the discharge side of the chemical metering pump is lower than the pressure on the suction side, the check valves will both _____ all of the time allowing the chemical to freely flow into the water uncontrolled? Stay open
This device is simply a spring-loaded valve with an “artificial head” that requires some pressure from the metering pump before there can be any flow through it? Antisiphon valve
This device is required, by law, on fluoride feed systems in certain jurisdictions? Antisiphon valve
The main drawback to this type of dry feeder is the fact that the actual weight of chemical delivered will vary according to changes in the bulk density or feeding characteristics of the chemical? Volumetric feeder
This type of volumetric feeder has a motor driven plate located underneath a feed hopper which provides a ribbon of chemical that is discharged at varying depth which is controlled by a gate? Oscillating plate
This type of volumetric feeder uses a plow blade to remove material from the feeding system, and the feed rate is adjusted by changing the depth of the ribbon, the speed of the delivery system, or the position of the plow blade? Rotating disk
This chemical should be stored so that any bag can be easily removed if it catches fire? Activated carbon
This chemical is also known as aqua ammonia? Ammonium hydroxide
This chemical is highly corrosive to copper, copper alloys, and aluminum? Ammonium hydroxide
This treatment chemical gives off very pungent fumes at room temperature; must be kept as cool as possible; is extremely dangerous; and has suffocating fumes? Ammonium hydroxide
This ammonium based treatment chemical poses no real hazards other than skin irritation? Ammonium sulphate
This chemical in its dry form is not corrosive to ferrous alloys, but in liquid form it is corrosive and requires delivery using PVC or polyethylene materials? Chlorine
This treatment chemical is considered as very hazardous; and highly corrosive to many materials including concrete and most metals? Ferric chloride
This treatment chemical has irritating fumes; is highly corrosive to many materials including glass; and protective clothing is essential? Hydrofluorosilic acid (fluoride)
A chemical that absorbs or attracts moisture from the air is? Hygroscopic
The dust from this treatment chemical is considered as poisonous? Potassium permanganate
This treatment chemical must be “activated” before use, and when it is “activated” it may release activating agents such as sulphuric acid? Sodium silicate (activated silica)
What are two main types of corrosion? Galvanic and microbial (metabolic)
This main type of corrosion occurs when a chemical reaction between the metal and the water causes a small electrical currents to flow? Galvanic corrosion
This main type of corrosion occurs because of a mechanism which requires iron, which consequently decays iron piping? Metabolic (microbial)
It is a method to quantify (express in numbers) the aggressiveness of water so that its composition can be adjusted to result in the formation of the desired thin film of calcium carbonate? Langlier Index
If the LI is a positive number, the water will probably be? Scale forming
If the LI is a negative number, the water will probably be? Corrosive
When making dilutions or solutions of chemicals in water, always add the _____ to the______ to prevent being injured? chemical to the water
This chemical is the most commonly used chemical to cause contact burns? Sulphuric acid
List three factors that will ensure meaningful laboratory results when collecting samples? Representative sample; sampling techniques; sample preservation
This type of sample is often used where the water sample does not flow on a continuous basis? Grab sample
This type of sample is often used where the water characteristics are relatively constant? Grab sample
This type of sample is used to measure specific characteristics that are likely to change rapidly, such as temperature, dissolved gases, chlorine residual? Grab sample
This type of sample tends to level off peaks to show average conditions, and to provide the most meaningful basis on which to calculate loadings and mass balances? Composite
What are the two types of composite samples? Proportional and non-proportional
With this type of composite sample, the quantity of each individual sample that is added to the composite sample is proportional to the flow at the time of sampling? Proportional composite sample
With this type of composite sample, equal volumes of individual samples are used over a given time period? Non-proportional composite sample
This type of composite sampling provides the most representative sample and the most accurate estimate of quantities of parameters being measured? Proportional composite sample
This type of composite sample is the more commonly used method that provides results which are accurate enough for most operating purposes? Non-proportional composite sample
When collecting a drinking water sample, a convenient flow that allows enough time for the line between the main in the faucet to be flushed is? 2 L a minute
Lab procedures to measure this chemical parameter of water requires a pH metre and reagents, and these reagents are sodium carbonate solution 0.05N; sulphuric acid stock solution 0.1N; and standard sulphuric acid 0.02N. Instead of a pH meter, titration endpoint can be determined using methyl Orange and phenolphthalein indicator solutions? Alkalinity
This lab procedure to measure this chemical parameter of water requires “standard phenylarsine oxide” (PAO) solution; an acetate buffer solution; a phosphate buffer solution; and potassium iodide solution (5% Kl)? Amperometric titration/chlorine residual
This lab procedure is used to test this water quality parameter and uses a nessler tube method, and can only be used when the turbidity is below 1.0 NTU? Colour
When titrating for this parameter, the indicator solution changes from red to blue. List the indicator solution and parameter? Hardness/EDTA
The nephelometric method of testing for turbidity determines the amount of light reflected at a _____ angle to a source beam? 90° angle

Leave a Reply

Your email address will not be published. Required fields are marked *