Environmental Engineering

Question 1

A determination of the concentration, of carbon-based (i.e., organic) compounds aimed at establishing the relative “strength” of wastewater [e.g., biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), and oil and greasé (O&G)].

Answer 1

Organics

Question 2

A measurement of the concentration of particulate solids that can dissolve or suspend in wastewater [e.g., total solids (TS), total suspended solids (TSS), total dissolved solids’ (TDS), total volatile solids (TVS), and total fixed solids (TFS)]

Answer 2

Solids

Question 3

A measurement of the concentration of targeted nutrients (e.g., nitrogen and phosphorus) that can contribute to the acceleration of eutrophication (i.e., the natural aging of water bodies)

Answer 3

Nutrients

Question 4

Analytical tests designed to measure a varied group of constituents directly impact wastewater treatability (e.g., temperature, color, pH, turbidity, odor).

Answer 4

Physical Properties and Other Impact Parameters

Question 5

TKN

Answer 5

Total Kjeldahl Nitrogen

Question 6

test that measures oxygen consumption after 60 days or more is sometimes required in wastewater permits.

Answer 6

UBOD (ultimate biological oxygen demand) test

Question 7

based on the accurate measure of DO (dissolved oxygen) at the beginning and end of a five-day per a five-day period in which the sample is held in dark, incubated conditions

Answer 7

BOD test also known as BOD5

Question 8

The change in DO concentration over five days represents the “__________” for respiration by the aerobic biological microorganisms in the sample.

Answer 8

oxygen demand

Question 9

is an inherent disadvantage of the test because wastewater treatment system personnel cannot use it to make real-time operational adjustments.

Answer 9

five-day completion window

Question 10

is the most popular alternative test to BOD for establishing the concentration of organic matter in wastewater samples.

Answer 10

COD (chemical oxygen demand)

Question 11

The COD test should be considered an ________ of the organic matter in a wastewater sample rather than a ______ for the BOD test.

Answer 11

independent measure; substitute

Question 12

The COD test uses a chemical (__________) that ‘oxidizes” both organic (predominate) and inorganic substances in a wastewater sample

Answer 12

potassium dichromate in a 50% sulfuric acid solution

Question 13

TRUE OR FALSE
COD concentration results higher than BOD concentration for the same wastewater sample since only organic compounds are consumed during BOD testing.

Answer 13

TRUE

Question 14

is gaining popularity because it only takes 5-10 minutes to complete.

Answer 14

TOC (Total Organic Carbon)

Question 15

In the TOC test, organic carbon is converted to carbon dioxide (CO2) and typically measured with __________.

Answer 15

infrared analyzer

Question 16

Like COD, the TOC test can be used to rapidly estimate BOD concentration once a consistent ________ is established on a particular wastewater stream.

Answer 16

TOC to BOD ratio

Question 17

consists of a group of related constituents that are of special concern in wastewater treatment due to their unique physical properties and highly concentrated energy content.

Answer 17

O&G (Oil and Grease)

Question 18

COD is a good estimate of
a 20-day BOD
b. cBOD
c. nBOD
d. Ultimate BOD

Answer 18

D. Ultimate BOD

Question 19

Pick out the wrong statement
a. BOD is a characteristic and not a constituent of water
b. BOD is a measure of the amount of oxygen which will be
demanded & used in 5 days by the biological decomposition of the
organic matter present in water stream present as food for the living
organism
c. BOD is expressed in mg/L
d. None of these

Answer 19

d. None of these

Question 20

Only sample collection containers that can be used to collect O&G samples

Answer 20

glass since O&G adheres to plastic

Question 21

are generally hydrophobic (i.e., “water-hating”) and thus have low solubility in wastewater, resulting in relatively low biodegradability by microorganisms.

Answer 21

O&G (Oil and Grease)

Question 22

Wastewater generated by commercial, industrial and institutional facilities is typically referred to as “_________” compared to typical household wastewater.

Answer 22

high-strength

Question 23

Pick out the wrong statement.
a. The waves used in the long distance radio communication are reflected back to earth by stratosphere,
b. The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone.
c. Mesosphere is characterized by very low atmospheric pressure and low temperature,
d. Troposphere is a dusty zone containing water vapour and clouds.

Answer 23

a. The waves used in the long distance radio communication are reflected back to earth by stratosphere,

Question 24

is characterized by very low atmospheric pressure and low temperature, and is a high-altitude layer with very thin air and very cold temperatures.

Answer 24

Mesosphere

Question 25

is the lowest layer of the atmosphere, where weather phenomena like clouds and dust occur, and it contains water vapor

Answer 25

Troposphere

Question 26

is the layer above the troposphere, and it contains a significant concentration of ozone.

Answer 26

stratosphere

Question 27

radio waves are reflected by the ________

Answer 27

ionosphere

Question 28

The best procedure for determining the DO of a plant effluent is to analyze a. Several grab samples at various flows b. A grab sample of the effluent at high flow c. A grab sample of the effluent at low flow d. A 24-hour composite sample of the effluent

Answer 28

a. Several grab samples at various flows

Question 29

measures the concentration of oxygen dissolved in a water or wastewater sample.

Answer 29

DO test

Question 30

DO measurement most often takes place using _________ with a specialized _______.

Answer 30

an electronic meter fitted; DO probe

Question 31

The concentration of DO in a water sample is significantly influenced by

Answer 31

Temperature, salinity, pressure

Question 32

Relationship of DO with respect to: 1. Temperature 2. Salinity 3. Pressure

Answer 32

1. inversely proportional 2. inversely proportional 3. directly proportional

Question 33

The correct relation between TOD, BOD and COD is given by a. TOD > BOD > COD c.BOD > COD > TOD b. TOD > COD > BOD d.COD > BOD > TOD

Answer 33

b. TOD > COD > BOD

Question 34

measures the total amount of oxygen required to completely oxidize all organic and inorganic compounds in a water sample through high-temperature oxidation.

Answer 34

TOD test (total oxygen demand)

Question 35

Pick out the correct statement a. BOD5 is the ultimate BOD b. BOD5 is greater than BOD4 keeping other conditions same c. BOD5 is less than BOD4 keeping other conditions same d. BOD5 is equal to BOD4 keeping other conditions same

Answer 35

c. BOD5 is less than BOD4

Question 36

The rate of BOD exerted at any time is a. Directly proportional to BOD satisfied b. Directly proportional to BOD remaining c. Inversely proportional to BOD satisfied d. Inversely proportional to BOD remaining

Answer 36

b. Directly proportional to BOD remaining

Question 37

measures the oxygen consumed by microorganisms during the biological breakdown of organic matter

Answer 37

BOD

Question 38

measures the total oxygen required for chemical oxidation of all organic and inorganic matter

Answer 38

COD

Question 39

refers to the amount of biodegradable organic matter that is still present in the water sample after the incubation period, meaning it hasn't been fully oxidized yet.

Answer 39

BOD Remaining

Question 40

represents the amount of oxygen that has been consumed by microorganisms during the incubation period to break down the organic matter.

Answer 40

BOD Exerted

Question 41

BOD remaining can be calculated by?

Answer 41

subtracting the BOD exerted from the initial (or ultimate) BOD.

Question 42

The ratio of BOD5 to ultimate BOD is about a. 1/3 b. 2/3 c. 4 d. 3/4

Answer 42

b. 2/3

Question 43

is a standard measurement and is generally considered to be about 68% of the total (or ultimate) oxygen demand

Answer 43

BOD5

Question 44

What would be the effect on a BOD determination if the dilution water used contained either copper or chloride? a. BOD would be higher c. DO level would increase b. BOD would be lower d. DO level would decrease

Answer 44

b. BOD would be lower

Question 45

is a heavy metal that is toxic to microorganisms, including the bacteria responsible for breaking down organic matter in the BOD test.

Answer 45

Copper

Question 46

While ______ itself is not directly toxic, high concentrations of ________ can interfere with the BOD test by inhibiting the growth of certain microorganisms. Furthermore, _________ (a common disinfectant) can also inhibit bacterial growth and should be neutralized before BOD testing.

Answer 46

Chloride

Question 46

Assertion (A): The determination of pH value of sewage is important. Reason (R): The efficiency of certain treatment methods depends upon availability of pH value. a. Both A and R are true and R is the correct explanation of A b. Both A and R are true but R is not a correct explanation of A c. A is true but R is false d. A is false but R is true

Answer 46

a. Both A and R are true and R

Question 47

The efficiency of many sewage treatment processes, especially biological ones, hinges on maintaining a specific pH range, typically between ___________, for optimal microbial activity and contaminant removal.

Answer 47

6.5 and 8.5

Question 48

Maintaining the appropriate pH can also help prevent ______ of pipes and equipment in the treatment plant.

Answer 48

corrosion

Question 49

pH Dependent Process

Answer 49

Activated Sludge Systems, Heavy Metal Removal, Filtration

Question 50

In sampling waste water for a BOD test, the best results are obtained from a. A grab sample b. A 24-hour composite sample c. A sample made of 2 to 4 portions taken at time of high flow d. A sample taken at time of low flow

Answer 50

b. A 24-hour composite sample

Question 51

Samples should be maintained at a temperature of _______, but not frozen, both during the sampling period and until analysis begins

Answer 51

6°C or lower

Question 52

If chlorine is present, a dechlorination chemical like ___________ should be added before testing.

Answer 52

sodium sulfite

Question 53

is required if the hourly flow varies by more than 10% over the sampling period.

Answer 53

Flow Proportioning

Question 54

If a grab sample is desired for process control purposes, it does not need to be refrigerated if analyzed within _________.

Answer 54

2 hours

Question 55

The three measurements that are essential in calculating the solids and organics on a waste water treatment plant are a. Flow, BOD, DO b. Flow, BOD, SS c. BOD, SS, DO d. BOD, SS, pH

Answer 55

b. Flow, BOD, SS

Question 56

Evaporation of Filter =

Answer 56

TSS (Total Suspended Solid)

Question 57

This disease is caused by poisoning of a certain chronic chemical that impairs kidney function and progressively causes osteomalacia, a calcium deficiency. What is disease and what heavy metal causes it? a. Mercury -Minamata disease b. Cadmium- Itai-ltai disease C. Silver- Argyria d. Chromium - Chromium toxicity

Answer 57

b. Cadmium- Itai-ltai disease

Question 58

Evaporation of Filtrate =

Answer 58

TDS (Total Dissolved Solid)

Question 59

Sum of TSS and TDS

Answer 59

Total Solids

Question 60

Burned TDS or TSS

Answer 60

VDS/VSS (Volatile) or FDS/FSS (Fixed)

Question 61

Sum of FSS and FDS

Answer 61

TFS (Total Fixed Solid)

Question 62

Sum of VSS and VDS

Answer 62

TVS (Total Volatile Solid)

Question 63

Sum of TFS and TVS

Answer 63

TS (Total Solid)

Question 64

meaning "ouch-ouch" in Japanese, is a chronic cadmium poisoning condition characterized by severe bone pain and osteomalacia, primarily affecting the Jinzu River basin in Toyama Prefecture, Japan, due to environmental contamination

Answer 64

Itai-itai disease

Question 65

is a neurological disorder caused by mercury poisoning, specifically methylmercury, stemming from the consumption of contaminated fish and shellfish from Minamata Bay in Japan. Symptoms include sensory disturbances, ataxia, and visual and hearing difficulties.

Answer 65

Minamata disease

Question 66

The source of the mercury pollution was the industrial wastewater discharged from a chemical plant (_________) into Minamata Bay

Answer 66

Chisso Corporation

Question 66

is a global agreement that aims to reduce mercury pollution and protect human health and the environment

Answer 66

Minamata Convention

Question 67

is a rare condition characterized by a bluish-gray discoloration of the skin and other tissues due to the accumulation of silver deposits, often resulting from prolonged or excessive exposure to silver or silver compounds.

Answer 67

Argyria

Question 68

The best procedure for determining the SS of a plant effluent is to analyze a. A series of grab samples taken at different times during the day b. A grab sample of the effluent at high flow c. A grab sample of the effluent at low flow d. A 24-hour composite sample of the effluent

Answer 68

d. A 24-hour composite sample of the effluent