Deck 29: Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Question 1

The oxygen consuming property of a wastewater sample is designated by the term

A) lagooning.
B) stabilization.
C) biological nitrogen demand.
D) biochemical oxygen demand.
E) lagooning ANF stabilization.

Answer 1

D

Question 2

In sewage treatment, the removal of phosphates and nitrogen compounds is achieved during

A) primary treatment.
B) secondary treatment.
C) advanced treatment.
D) quaternary treatment.
E) All of the choices are correct.

Answer 2

C

Question 3

The problem(s) with using sludge as a fertilizer is/are the

A) presence of heavy metals and similar pollutants AND inhibitory effect it has on plant growth.
B) presence of heavy metals and similar pollutants AND presence of pathogenic organisms and viruses.
C) presence of pathogenic organisms and viruses AND inhibitory effect it has on plant growth.
D) inhibitory effect it has on plant growth AND stimulatory effect it has on methane production.
E) stimulatory effect it has on methane production AND presence of pathogenic organisms and viruses.

Answer 3

B

Question 4

The approximate BOD value for raw sewage is

A) 2000-7000 milligrams per milliliter.
B) 500-800 grams per milliliter.
C) 0-50 kilograms per milliliter.
D) 300-400 milligrams per liter.
E) 300-400 grams per liter.

Question 5

Which of the following is used to cause flocculation?

A) Charcoal
B) Methane
C) Natrium potassium phosphate (nalum)
D) Chlorine
E) Aluminum potassium phosphate (alum)

Question 6

An effective means used early in the 19th century to clear water of the majority of bacteria was the use of

A) chlorine.
B) iodine.
C) alcohol.
D) sand filters.
E) antibiotics.

Question 7

Sludge

A) is a byproduct of sewage treatment.
B) may be a source of pollution.
C) takes up space in a landfill.
D) All of the choices are correct.
E) None of the choices is correct.

Question 8

The anaerobic organisms used in sewage treatment may produce the useful product(s)

A) oxygen.
B) nitrogen.
C) carbon monoxide.
D) methane.
E) nitrogen AND carbon monoxide.

Question 9

The activated sludge process

A) is used during secondary treatment of sewage.
B) is meant to convert inorganic to organic matter.
C) is meant to increase the BOD.
D) removes large objects from the sewage.
E) is meant to convert inorganic to organic matter AND is meant to increase the BOD.

Question 10

The accepted method of testing water supplies for the possible presence of pathogens is to determine the presence of

A) Streptococci.
B) coliforms.
C) Staphylococci.
D) Streptomyces.
E) vibrios.

Question 11

Wastewater treatment decreases the amount of

A) biodegradable carbon.
B) ammonia and nitrate.
C) phosphate.
D) pathogens.
E) All of the choices are correct.

Question 12

Effective treatment of wastewater/sewage is reflected in a(n)

A) lower BOD.
B) higher BOD.
C) unchanging BOD.
D) increase in sulfur.
E) decrease in biomass.

Question 13

In which phase of sewage treatment are trickling filters sometimes used?

A) Primary treatment.
B) Secondary treatment.
C) Tertiary treatment.
D) Quaternary treatment.
E) All of these.

Question 14

Which of the following plays some role in sewage treatment?

A) Activated sludge
B) Trickling filter
C) Septic tank
D) Lagooning
E) All of the choices are correct.

Question 15

Water treatment processes for drinking water

A) are similar to wastewater treatment.
B) have no biological treatment phase.
C) are only necessary when using recycled water.
D) include disinfection but not filtration.
E) include filtration but not disinfection.

Question 16

The term "potable water" refers to water that is

A) safe to swim in but not to drink.
B) only good for irrigation of crops.
C) contaminated with chemicals.
D) safe to drink.
E) in carrying containers.

Question 17

In sewage treatment, the removal of large objects and particulate matter is achieved during

A) primary treatment.
B) secondary treatment.
C) tertiary treatment.
D) quaternary treatment.
E) the night.

Question 18

Vibrio cholerae is most often associated with

A) breathing air.
B) eating food.
C) drinking water.
D) touching animals.
E) having unprotected sex.

Question 19

Advanced treatment of sewage

A) is done to promote nutrient enrichment.
B) is done to prevent possible overproduction of algae and other organisms.
C) involves the removal of phosphates and sulfur compounds.
D) is done to promote growth of photosynthetic organisms.
E) All of the choices are correct.

Question 20

A high BOD value means

A) a large amount of oxygen has been used AND a small amount of degradable organic matter is present.
B) a small amount of oxygen has been used AND a large amount of degradable organic matter is present.
C) a large amount of degradable organic matter is present AND a small number of viruses are present.
D) a small number of viruses are present AND a large amount of oxygen has been used.
E) a large amount of oxygen has been used AND a large amount of degradable organic matter is present.

Question 21

Trickling filters may be used in place of activated sludge in secondary sewage treatment.

Question 22

Other microorganisms besides coliforms that have been used as indicators of fecal contamination may be all of the following EXCEPT

A) Clostridia.
B) Enterococci.
C) bacteriophages.
D) Bacteroides.
E) Clostridia, Enterococci AND bacteriophages.

Question 23

Coliforms are

A) lactose-fermenting.
B) Gram-positive.
C) coccus-shaped.
D) spore-forming.
E) All of the choices are correct.

Question 24

The compost pile temperature at which pathogens, but not thermophiles, are killed is about

A) 20-30ºC.
B) 55-66ºC.
C) 62-75ºC.
D) 90-100ºC.
E) 97ºF.

Question 25

High BOD values reflect small amounts of degradable organic matter in a sample of wastewater or other material.

Question 26

If a compost pile is turned frequently and other conditions are adequate for aerobic digestion, the composting can be completed in

A) six months.
B) six weeks.
C) 1 month.
D) 1 day.
E) three years.

Question 27

Which would be more likely to cause illness: a water sample that tested positive for coliforms or one that tested positive for E. coli O157:H7?

A) Both would be equally capable of causing illness because all coliforms cause illness.
B) The coliform-positive sample would be more likely to cause illness. Coliforms are inherently more pathogenic than the weak O157:H7 lab strain of E. coli.
C) The E. coli O157:H7 sample would be more likely to cause illness. This strain of bacterium is highly pathogenic and capable of causing kidney damage.
D) Neither; there is usually a small amount of coliforms (including E. coli O157:H7) in all water.
E) The coliform-positive sample would be more likely to cause illness. Coliforms indicate the presence of fecal contamination, which always leads to illness.

Question 28

The conversion of organic to inorganic matter is called co-metabolism.

Question 29

Bioaugmentation

A) adds specific microorganisms to a contaminated site.
B) aims at enhancing the growth of the resident population of microbes.
C) usually utilizes genetically engineered bacteria.
D) is typically done offsite.
E) depends on competition between resident and added microbes.

Question 30

Which of the following cannot be used in composting?

A) Grass clippings
B) Nutrient-poor potting soil
C) Meats and fats
D) Vegetable peelings
E) Leaves

Question 31

Why would soil and water be added to a compost pile?

A) The organisms in the soil, along with the moisture from the water, would facilitate the natural decomposition of the material in the compost pile.
B) Without adding soil and water, no decomposition of the material can take place. The material would simply sit there.
C) Water is the medium that photosynthetic organisms use to break down the organic materials in the compost pile.
D) Soil spreads out the material in the pile. If the material is too close together, natural aeration cannot occur and decomposition stops.
E) Water provides the energy that soil organisms need to break down the material in the compost pile.

Question 32

If a compost pile is turned frequently and other conditions are adequate for aerobic digestion, the composting can be completed in 6 weeks.

Question 33

Zero coliforms per 100 ml of water is considered safe for treated potable water.

Question 34

The term "potable water" refers to water that is not necessarily pure, but is safe to drink.

Question 35

As much as 95% of BOD can be removed during secondary treatment.

Question 36

The compost pile temperature at which pathogens, but not thermophiles, are killed is about 20-30ºC.

Question 37

Pollutant degradation may be enhanced by

A) providing dry conditions.
B) providing adequate nutrients.
C) maintaining an acidic pH.
D) lowering the temperature.
E) All of the choices are correct.

Question 38

Bioremediation

A) is the use of biological agents to degrade/detoxify pollutants AND may involve biostimulation or bioaugmentation.
B) is the use of biological agents to degrade/detoxify pollutants AND has as its goal the elimination of pathogens.
C) may involve biostimulation or bioaugmentation AND has as its goal the elimination of pathogens.
D) produces xenobiotics AND is the use of biological agents to degrade/detoxify pollutants.
E) has as its goal the elimination of pathogens AND produces xenobiotics.

Question 39

The activated sludge method can be stopped by the presence of toxic industrial wastes.

Question 40

Which of the following statements about landfills is False?

A) Degradation of wastes is rapid and inexpensive.
B) The excavated site has a plastic liner to prevent wastes from leaching into groundwater.
C) Recycling greatly reduces the amount of wastes sent to landfills.
D) Dangerous levels of methane gas can accumulate.
E) All of the answer choices are True.

Question 41

Which statement does NOT apply to water treatment?

A) The primary treatment of wastewater is a physical process designed to remove materials that settle out. 
B) Advanced treatment of wastewater is often designed to remove ammonia, nitrates, and phosphates.
C) Biosolids that result from anaerobic digestion of sludge can be used to improve soils and promote plant growth.
D) Secondary treatments are designed to convert suspended solids into inorganic compounds and microbial biomass.
E) An important goal of wastewater treatment is the increase of the BOD that stimulates microbial growth.

Question 42

Select the pair that is INCORRECTLY matched.

A) Potable water-lacks pathogenic microbes and harmful chemicals
B) High BOD-low organic content
C) Primary treatment-removal of material that settles
D) High BOD-high organic content
E) Total coliforms-lactose-fermenting members of the family Enterobacteriaceae

Question 43

A site used for disposal of non-hazardous solid wastes in a manner that minimizes damage to human health and the environment is a(n)

A) composter.
B) water treatment facility.
C) sanitary landfill.
D) septic tank.
E) activated sludger.

Question 44

Why is oil not degraded when in a natural habitat underground, yet is susceptible to bioremediation in an oil spill?

A) The high pressure the oil is subjected to underground prevents bacteria from growing and consuming it.
B) The bacteria can't be given the right amounts or types of nutrients to foster an increase in their number deep underground. Nearer the surface, human intervention can increase the factors that will raise the microbe quantity.
C) The bacteria that degrade the oil require a higher than normal salt content, much like what is found in seawater. Underground, they lack this salt level.
D) Oil IS degraded underground, but it happens at a much slower rate because a portion of the cycle is photosynthetic in nature. This process is dramatically increased nearer to the water's surface.
E) There is no oxygen underground, so bacteria are unable to metabolize oil, an aerobic process. When the oil leaks into a water supply, the bacteria present in that oxygen-rich habitat begin to break it own.

Question 45

All of the following are methods used to detect total coliforms in a water sample EXCEPT

A) the ONPG/MUG test.
B) the presence/absence test.
C) the most probable number (MPN) method.
D) membrane filtration.
E) the Gram-stain test.

Question 46

What is the difference between biostimulation and bioaugmentation?

A) Bioaugmentation enhances the growth of local microbes in a contaminated site by providing additional nutrients while biostimulation relies on activities of microorganisms added to the contaminated material, complementing the resident population.
B) Biostimulation generally occurs in situ and is less disruptive while bioaugmentation is performed off site using a bioreactor, a large tank designed to accelerate microbial processes.
C) Biostimulation enhances the growth of local microbes in a contaminated site by providing additional nutrients while bioaugmentation relies on activities of microorganisms added to the contaminated material, complementing the resident population.
D) Biostimulation is a method of degrading environmental pollutants while bioaugmentation is a method of supplementing microbial populations in landfills and composters.
E) Biostimulation is a bioremediation process designed to remove pollutants from an environment. Bioaugmentation is a method used in laboratories to promote the growth of fastidious microbes.

Question 47

Please select the statement that does NOT apply to strategies of bioremediation.

A) Providing optimal bacterial growth conditions is likely to promote pollutant degradation.
B) Biostimulation enhances pollutant degradation by enhancing growth of resident microbes in a contaminated site through providing additional nutrients.
C) Bioaugmentation involves adding microorganisms to contaminated material, complementing the resident population.
D) Low temperature, arid conditions and acidic pH will speed up the rate of pollutant degradation.
E) Co-metabolism occurs when an enzyme produced by a microbe to degrade an added substrate in an environment degrades a pollutant as well.

Question 48

Why do water-testing procedures look for coliforms rather than pathogens?

A) Pathogens are seldom found in water. Testing for coliforms is a way of determining whether there is any human normal microbiota contamination in that water, which should then be treated with chlorine.
B) Pathogens are extremely fastidious in their nutrient requirements and require special growth conditions. Coliforms are easier to culture in a laboratory setting, so it makes sense to test for these rather than for actual pathogens.
C) It is always somewhat dangerous to culture pathogens in a laboratory setting - people in the lab are at risk of contracting serious disease. It is much safer to test for coliforms which simply indicate that humans have been swimming in the water.
D) It is not possible to test for all of the potential pathogens in water, so indicator organisms such as coliforms are used. These microbes are found in feces, so finding them suggests fecal contamination, and indicates a greater likelihood that intestinal pathogens are also present.
E) Pathogens and coliforms are the same thing. Testing for one is also testing for the other. 

Question 49

Why does secondary treatment of wastewater require O₂?

A) Secondary treatment relies on anaerobic microbes to oxidize organic material.
B) Secondary treatment relies on anaerobic microbes to reduce organic material.
C) Secondary treatment relies on aerobic microbes to oxidize organic material.
D) Photosynthetic bacteria are involved in secondary treatment and they require O₂.
E) Flocs require oxygen to facilitate biofilm formation.

Question 50

Please select the statement that applies to pollutants in the environment and bioremediation.

A) Synthetic compounds are more likely to be biodegradable if their chemical composition is different from that of naturally occurring substances.
B) Xenobiotics usually persist in the environment because microorganisms are unlikely to have suitable enzymes to break them down.
C) The biodegradability of a compound can only be changed by significant molecular changes in that compound.
D) Most herbicides and insecticides only are toxic to their target, and do not damage other organisms such as fish, birds, and other animals.
E) Bioremediation generally relies on the addition of specific organisms to the polluted environment.

Question 51

Which statement is False?

A) Artificial wetlands provide a habitat for wildlife.
B) Methane is a by-product of anaerobic digestion.
C) Chlorine, ozone and UV light can be used to disinfect water.
D) Trickling filter systems are used for secondary water treatment.
E) Removal of nitrates by microorganisms requires aerobic conditions.

Question 52

Which definition is INCORRECT?

A) Biochemical oxygen demand (BOD)-the amount of O₂ required for the microbial decomposition of organic matter in a sample.
B) Indicator organisms-microbes whose presence in an environment suggests fecal contamination.
C) Primary treatment-a wastewater treatment process that uses microbes to convert suspended solids to inorganic compounds and removable cell mass.
D) Constructed wetland-method of wastewater treatment in which water is channeled into ponds where aerobic and anaerobic degradation occurs.
E) Anaerobic digestion-process that uses anaerobic microbes to degrade the sludge obtained during wastewater treatment.

Question 53

Which of the following is a disadvantage of landfills?

A) Only a limited number of sites are available for making landfills near urban and suburban areas.
B) Methane gas that is produced in landfills as the organic waste material anaerobically decomposes must be removed.
C) Pollutants such as heavy metals and pesticides frequently leak from landfill sites, reaching underground aquifers and contaminating drinking water.
D) Methane gas that is produced in landfills as the organic waste material anaerobically decomposes must be removed AND only a limited number of sites are available for making landfills near urban and suburban areas.
E) Pollutants such as heavy metals and pesticides frequently leak from landfill sites, reaching underground aquifers and contaminating drinking water, AND only a limited number of sites are available for making landfills near urban and suburban areas.

Question 54

What is the purpose of coagulation in drinking water treatment?

A) Antibodies are used bind bacteria into large masses that can be removed by filtration.
B) Pollutants such as lead are combined into clumps using toxic chemicals, for easy removal.
C) Suspended material is combined using toxic chemicals for easy removal from water.
D) To bind together pollutants, bacteria, and other organisms for removal by chemicals.
E) When suspended material clumps, it sinks and can be easily removed.

Question 55

What is the purpose of grinding yard waste before putting it into composting piles?

A) Bacteria are microscopic organisms and can only break down very small pieces of matter, which grinding produces.
B) Grinding the material breaks down some of the components that microbes cannot digest, such as cellulose.
C) Grinding the matter introduces large amounts of oxygen into the material, which is essential for microbial degradation of matter.
D) Grinding yard waste is a method for introducing degradative microbes into the mix, needed for composting.
E) Grinding the material increases the surface area available for microbial action, so that the material can be degraded more efficiently.

Question 56

In treating an oil spill, why might biostimulation be preferred over bioaugmentation?

A) Adding new microbes (bioaugmentation) poses some risk-when new microbes are added to an environment, the consequences of those additions on resident populations are unknown. Adding nutrients (biostimulation) is safer because once those nutrients are used up, the microbial populations are likely to return to their original levels.
B) Biostimulation involves adding novel microbes to boost the populations of resident microbes. These novel microbes are generally genetically engineered to enhance their abilities to metabolize pollutants such as oil, so are very effective. Bioaugmentation merely involves adding nutrients, so all microbes are favored, even those not performing a useful function.
C) Bioaugmentation involves adding novel microbes to boost the populations of resident microbes. These novel microbes are highly genetically engineered to enhance their abilities to metabolize pollutants such as oil, so are very effective. Biostimulation merely involves adding nutrients, so all microbes are favored, even those not performing a useful function.
D) In fact, biostimulation is not generally favored as an approach. Biostimulation often leads to the generation of antibiotic-resistant microbes, which become a problem for other organisms in the environment. Bioaugmentation is the favored approach because adding nutrients to the area simply enhances the activities of the bacteria already present.
E) Biostimulation and bioaugmentation are always used simultaneously. This is done because neither one of these approaches works well individually. Adding bacteria to an environment will never be successful unless nutrients are also added to that environment.

Question 57

What is the advantage of removing phosphates and nitrates from wastewater?

A) Nitrates and phosphates can support the growth of algae and cyanobacteria, and these photosynthetic organisms will then produce organic compounds, thereby increasing the BOD of the water.
B) Nitrates and phosphates can support the growth of fish, which then produce increased amount of wastes, thereby increasing the BOD of the water.
C) Nitrates and phosphates inhibit the growth of bacteria that normally purify the water; without them, the BOD of the water rapidly increases.
D) Nitrates are usually removed by denitrifying bacteria that use nitrate during anaerobic respiration to form N₂, a gas that is toxic and detrimental to other organisms. Removing nitrates protects these organsisms.
E) Phosphates are an integral part of prokaryote cytoplasmic membranes. If there are too many phosphates in the water, microbial growth is stimulated, leading to the risk of contamination.

Question 58

What are indicator organisms?

A) Microbes that are contaminants in laboratory media.
B) Microbes whose presence in an environment suggests fecal contamination.
C) Microbes whose presence in an environment suggests the presence of animal urine.
D) Microbes that alert a physician to the presence of a gastrointestinal illness.
E) All of the choices are correct.

Question 59

Considering that Cryptosporidium oocysts are resistant to chlorine, which step in water treatment protects us from this pathogen?

A) Settling
B) Coagulation
C) Sedimentation
D) Filtration
E) Disinfection and storage

Question 60

Synthetic compounds are most likely to be biodegradable if they

A) are chemically different form naturally occurring substances.
B) have three chlorine atoms per molecule.
C) are chemically similar to naturally occurring substances.
D) are present in very large amounts.
E) None of these is True.