Wastewater Treatment

Front 1

A common remedy for activated sludge system problems is to increase the waste activated sludge (WAS) flow. When would an increase of WAS rate not be correct?

Back 1

When straggler floc is present in clarifier and or settleometer

Front 2

Problem: The chlorine residual is falling and inspection of the 150 pounds cylinder and chlorine feed equipment shows ice forming on the chlorine regulator and feed lines the best method to fix the falling chlorine residual is?

Back 2

Place a second cylinder online.

Front 3

Caution must be used when adding a caustic chemical to a digester lime can combine with carbon dioxide in the digester to form what problem?

Back 3

A dangerous vacuum

Front 4

Problem: There are high suspended solids in the water applied to the filters due to bulking sludge in the secondary clarifier. Polymer is used as a filter aid chemical but the effluent turbidity is worsening. What is the best method to correct the filter problem?

Back 4

Run jar test to determine best polymer dosage

Front 5

An advantage of a continuous back wash up flow deep bed sand filter is?

Back 5

Filters do not need to be taken out of service for back washing

Front 6

The aeration tank DO has been running normal which is 1.5 to 2.0 mg/l the whole month. Today's DO reading has spiked to nearly 6.0 mg/l in the aeration tank and the clarifier and plant effluent are cloudy. What is the most likely cause of the rise and DO?

Back 6

A toxic shock load of cyanide has entered the plant

Front 7

Problem: Plant fecal coliform counts do not meet state standards. The chlorine supply is not the problem and there is adequate vacuum and chlorine feed. The chlorine contact tank has no solids build-up and the effluent flow is below design. What is the most likely cause of the poor fecal coliform kill?

Back 7

High chlorine demand from excessive nitrite in the effluent

Front 8

The point, location or structure where wastewater discharges from a sewer, drain, or other candu it is called a what?

Back 8

Outfall

Front 9

How many pounds of anionic polymer will be used per day for the belt filter press operation if the polymer is dosed at 4.6 mg/ l and the flow to the press is 50000 gallons per day?

Back 9

1st divide 50000 gallons per day by a million to give you 0.05MGD multiply that by 4.6 mg per liter and then by 8.34 pounds per gallon to give you roughly 1.9 pounds per day

Front 10

The volatile acid to alkalinity ratio of a properly operating anaerobic digester is?

Back 10

0.1 parts acid to one whole part alkalinity

Front 11

What is a disadvantage of running a digester in the thermophilic temperature range?

Back 11

The higher cost of heating the digester with natural gas

Front 12

Which condition of a surface water, river or stream will allow more DO saturation?

Back 12

Cold water temperature

Front 13

Problem: Solids are washing out of the secondary clarifier of the activated sludge plant. Plant personnel increase the return activated sludge flow rate (RAS), which slows the problem temporarily, but then it worsens after 30 minutes. What is the cause of the plant problem?

Back 13

Increasing the RAS flow decreased the detention time in the clarifier

Front 14

When using lime to precipitate phosphorus from treated effluent it is important to maintain the ph at or above?

Back 14

11.0

Front 15

What is the upward force caused by groundwater on a sedimentation tank if the ground water depth is 6' above the tank bottom? The tank is 80' wide and a 157' long.

Back 15

To find the capacity multiply the 6' depth by the 80' width by the 157' length to get 563,693 gallons. Then multiply that capacity times 8.34 pounds per gallon to give you roughly 4,700,000 lbs

Front 16

Problem: The luxury uptake method of phosphorus removal is failing to remove phosphorus to permitted levels. Indicators include the following: influent phosphorus is 8 mg/l. Effluent phosphorus exceeds 1 mg/l. Fermentation basin phosphorus is 10 mg/l. Aeration basin phosphorus is 8 mg/l what is the most likely cause of the poor phosphorus removal?

Back 16

Poor release of phosphorus in the fermentation basin

Front 17

Calculate the SVI for the activated sludge treatment plant given the following information: 30 minute settleability is 675, 60 minutes settleability is 420, MLSS is 3650 mg/l MLVSS in mg/l is 74%

Back 17

Divide your 30 minute settleability which is 675 by the MLSS which is 3650 and then multiply by a 1000 to give you 185

Front 18

It takes 22% less oxygen to process one pound of carbonaceous waste then 1 pound of nitrogenous waste what does this indicate?

Back 18

Low nutrients and the influent waste water

Front 19

Which of the following presents the greatest hazard while working and a wastewater laboratory? Chemical, electrical, inert or hypothermia?

Back 19

Chemical

Front 20

What should the PH in a rapid mix basin for maximum phosphorus removal when using lime?

Back 20

9.5-10.0

Front 21

A sand and gravel filter has been working well then head loss occurred, back washing did not help, what's the best solution?

Back 21

Rake or remove and replace the surface level

Front 22

When bacteria Laden with phosphorus are placed in anaerobic environment what do they do?

Back 22

Phosphorus is released and then regained in the aerobic zone and then almost fully removed when recycled

Front 23

What is used in the recovery of a stuck digester?

Back 23

A caustic material such as soda ash or lime

Front 24

All sulphides will be present in the form of H2S when ph falls below what?

Back 24

5.0

Front 25

When there is foaming anaerobic digester what should be checked?

Back 25

DO levels

Front 26

Sulfur dioxide leaks can be found using what?

Back 26

Potassium permanganate solution

Front 27

At what concentration can chlorine be fatal in just a few breaths?

Back 27

1000 ppm

Front 28

Sludge with less than 1% solids should not be wasted into a digester why?

Back 28

Because it is mostly water

Front 29

Which statement best describes optimal BFP speed?

Back 29

Slow enough to avoid washout while maintaining high levels of efficiency

Front 30

Describe the components of the Florida right to know act

Back 30

Safety data sheet or chemical list reporting, tier two chemical inventory reporting and toxic release and inventory reporting

Front 31

If ph drops below ideal levels for phosphorous removal using lime precipitation what can happen?

Back 31

Increase alkalinity/buffer capacity

Front 32

The difference in shaft alignment between motor and pump can be checked using a?

Back 32

Caliper

Front 33

For ammonium removal and activated sludge what is an absolute necessity?

Back 33

Oxygen

Front 34

By increasing feed rate in an anaerobic digester in addition to decreasing detention time what else happens?

Back 34

There is a change in the microbial community and an increase in gas production

Front 35

Aerobic digestion converts what?

Back 35

Organic material and to carbon dioxide

Front 36

Define a stuck digester

Back 36

Low gas production high volatile acid to alkalinity relationship poor liquid to solid separation also referred to as a sour digester

Front 37

If reuse is being used by industry and quality standards are not met what should you do 1st?

Back 37

1st establish a good monitoring system and then and enforce the pre-treatment of the industrial portion

Front 38

When using polymer in a gravity thickener for sludge when will a larger polymer dosing to be required?

Back 38

When the level of Volatile solids increases

Front 39

What do you call a body of water at the lower end of a river that is subject to title fluctuation?

Back 39

Estuary

Front 40

If a gravity filter experiences rapid build-up of head loss what is the cause?

Back 40

Poor chemical treatment

Front 41

Which material could end up in a digester that bacteria can't effectively utilize?

Back 41

Digestate: hair and petroleum based items such as rubbers and plastics

Front 42

Breakpoint chlorination for ammonia removal what is the chlorine to ammonia ratio?

Back 42

5:1

Front 43

What is the minimum PH at the time of bio solids application on land?

Back 43

62-640. 700 requirements for land application of class AA, A and B biosolids the ph of bio solids soil mixture shall be 5.0 or greater at the time it is applied to land

Front 44

On which crops can reclaimed water be used for irrigation?

Back 44

Basically, any crop that has to be peeled, skinned, cooked or otherwise prepared thermally can be irrigated including tobacco and citrus. Crops that can be consumed without peeling cooking or otherwise prepared thermally are prohibited from using reclaimed water for irrigation

Front 45

How do you go about changing food to micro organism ratios?

Back 45

By either increasing wasting or adding more food such as sugar water

Front 46

What is the purpose of adding methanol in biological reactors during denitrification?

Back 46

It is added as a carbon source to supplement what is already in the process

Front 47

What is indicated by straggler flock and light colored foam on the surface of an aeration tank ?

Back 47

This could indicate the onset of denitrification and grease presence

Front 48

In short from a managerial perspective explain what the X and Y theory is

Back 48

The X theory is assumed all workers are lazy. The y theory assumes all workers are self starters. Z theory is a belief in group decision making

Front 49

Effluent quality turn poor with a decrease of stock ciliates and rotifers and an increase of free swimming ciliates and flagellates indicates what?

Back 49

Sludge is changing from older and more stable to younger and less stable

Front 50

What is the principle of organizational structure in which each working unit has one person in charge?

Back 50

Departmentalization

Front 51

What is a roughing filter?

Back 51

A filter that provides free treatment for turbid water

Front 52

What causes gasification of a gravity thickener?

Back 52

A change and temperature specifically to warmer temperatures

Front 53

At what food to micro organism ratio is best effluent generally produced?

Back 53

0.2 to 0.6 lb/ BOD to lb/MLVSS

Front 54

In time of crisis, what is the most important aspect?

Back 54

Communication with the customer

Front 55

What is the 1st step in solving an odor problem?

Back 55

Identifying the source

Front 56

What is the principle of span of control?

Back 56

The number of subordinates directly controlled by a supervisor

Front 57

If there is scale on the cathode of electrolytically process reactor on an odor scrubbing system what would you flush it with?

Back 57

Dilute nitric acid

Front 58

What 2 factors determine plant staffing requirements?

Back 58

The amount of flow the plant is designed for in MGD and a treatment process used

Front 59

What are the duties of operator's?

Back 59

As per FDEP 62-602.650

Report to the permittee or supplier of water and the department and if applicable the local regulatory agency as soon as possible but within 24 hours following the discovery of any serious plant breakdown or condition causing or likely to cause unsafe treatment plant operation or any discharge of water or wastewater not in accordance with chapters 62-550 62-555 and 62-302 F.A.C., or the facility's permit or any major interruption in service

Front 60

What is basic disinfection according to Fl DEP?

Back 60

A) Meet the following criteria

1) the arithmetic mean of the monthly geometric means, of the fecal coliform values collected during an annual period shall not exceed 200 per 100 ml of reclaimed water or effluent sample;

2) The geometric mean of the fecal coliform values for a minimum of 10 samples of reclaimed water or effluent, each collected on a separate day during a period of 30 consecutive days (monthly), shall not exceed 200 per 100 ml of sample;

3) No more than 10% of the samples collected during a period of 30 consecutive days shall exceed 400 fecal coliform values per 100 ml of sample; and,

4) Any one sample shall not exceed 800 fecal coliform values per 100 ml of sample

B) regardless of the number of samples collected, the monthly geometric means of the fecal coliform values shall be calculated and reported on the discharge monitoring report, and the arithmetic mean shall be calculated using the monthly geometric mean

C) where chlorine is used for disinfection, a total chlorine residual of at least 0.5 mg/l shall be maintained after at least 15 minutes contact time at the peak hourly flow. Higher residuals or longer contact times shall be provided to meet the criteria for basic disinfection as described in paragraph 62-600.440(5)(a), F.A.C. The chlorine residual and contact time selected shall be justified in the preliminary design or engineering report. Rapid and uniform mixing shall be provided.