The release of dissolved air in saturated cold water due to a decrease in pressure
causes which of the following?

Air Binding

The color in filtered water is called?

True Color

What is the final step for removal of suspended solids?

Filtration

Which FAC Chapter addresses drinking water standards, monitoring, and reporting?

FAC 62-550

Inaccurate test results are generally due to?

Poor sampling techniques

What is the highest possible turbidity reduction expected when operating a filtration process under optimum conditions?

99.5%

How is pin point floc removed?

Filtration

Direct filtration omits which process?

Sedimentation

What are the main removal mechanisms in a filter?

Adsorption and sedimentation

Sand drying beds are similar to what type of filters?

Gravity Sand Filters

Which of the following coagulants is generally used as a filter aid?

Nonionic Polymer

What parameters are used to determine when to backwash a filter?

Head Loss, Turbidity, and Time

Where is the application point for a filter aid?

Filter Influent

Before starting the backwash process, what must you check first?

Water supply

Mudballs are caused by which of the following?

Improper backwash

How is the problem in question 15 corrected?

Properly backwash the filter

During a plant walk through, an operator discovers a filter is air bound. What action should she take?

Backwash the filter immediately

Media boils are caused by?

High backwash rates

What is the main goal of filtration?

Removal of turbidity

What is the 4 step in the backwash process?

Start the surface scours

How should an air bound filter be backwashed?

How should an air bound filter be backwashed?

The color in unfiltered water is called?

Apparent Color

After backwashing a filter, there is a high initial head loss. What is most likely cause?

Insufficient Backwash

What causes air binding?

Ans. Operating the filter at high head loss too long
Ans. The release of O2 in saturated cold water due to a decrease in pressure

During a plant tour, an operator noticed that Filter 16 has a sudden increase in head loss. What action should she take?

Do a jar test

What do you call the process of reversing the flow of water through filter media to remove trapped particles?

Filter Backwash

The common boundary layer between two substyances such as water and a solid is called?

Interface

The difference between the water surface and the media surface is called?

Submergence (Head)

What is the filter rate in GPM/sq ft of slow sand filters?

0.015-0.15 GPM/sq ft

High water temperatures require what type of backwash rates?

Higher Backwash rates

The Filter Backwash Rule requires the backwash water to be sent where after dewatering the sludge?

Upstream of all conventional or direct filtration systems (includes
coagulation, filtration, and sedimentation)

What is the ripening period of a filter?

This occurs at startup of a new filter or after backwash of a filter

A filter 12" long and 8" wide drops 3" in 90 seconds. What is the filtration rate in GPM/sq ft?

What is the backwash rise rate in inches/minute if the backwash flow rate is 35 GPM/sq ft?

What is the backwash pumping rate in GPM for a filter 20' long x 30' wide with a desired backwash rate of 25 GPM/sq ft?

How much water is needed to back wash the filter in question 35 for 8 minutes?

Question 35:

What is the backwash pumping rate in GPM for a filter 20' long x 30' wide with a desired backwash rate of 25 GPM/sq ft?

120,000 Gallons (15,000 GPM x 8 min)

During a filter run, flow through the filter was 12.8 MG. It took 120,000 gallons to backwash the filter. What percent of the filter's water production was used for backwashing?

1%

What is the minimum treatment required for drinking water by the Surface Water Treatment Rule (SWTR)?

Filtration and Disinfection

Where should you install a particle counter at a WTP?

As close as possible to the point of measurement

The length of a sample line of a particle counter should be how long?

As short as possible

Pumping sample water to the particle counter may cause what problem?

Air bubbles, which may be erroneously counted as particles

What material is recommended for the sample line of a particle counter?

Black Nylon with Hytril Liner

What is the final step for removal of suspended solids?

Filtration