Wastewater
BOD
Indicator
Lab Techniques
Other

100

Waste water treatment has as purpose to eliminate
What is a pathogens, organic compounds, solid in suspension and microbial nutrients?

100

What is BOD and how relates to the efficiency of the wastewater plant?
What is Biochemical or Biological Oxygen Demand. This value correlates to the amount of biological degradable compounds present in water or waste water

100

What kind of microorganisms are used as a sign of possible fecal contamination in water
What is indicator microorganisms

100

What technique used in the lab can be use to determine the total amount of microorganisms present in the samples?
What is heterotrophic count plates (HPC)

100

What is the disadvantage of using HPC technique?
What is can not determine if the microorganisms growing on the HPC plates are actually pathogenic and can't determine the identity

200

This step in wastewater treatment is base in the presence and action of microorganisms.
What secondary treatment

200

When measure the BOD levels in a sample, what parameters would you measure?
What is the amount of oxygen consumed by microorganisms after 5 days of performing biological oxidation (breakdown waste)

200

Why are the indicator microorganisms a better way to detect enteric microorganism (possible pathogens) in water?
What is indicator are enteric microorganisms commonly associated to possible pathogens, so the presence of one indicate the possible presence of the other

200

What technique can be used in the lab to determine the presence or absence of coliforms and E. coli?
What is Colilert technique

200

Why is the detection of pathogens is done by detection of indicators and not directly by detecting the pathogens
What is detecting pathogens is dangerous, expensive, require special training, need identify each possible pathogen so time consuming and require too much time to get all this done.

300

What group of microorganisms is the predominant population in the aeration tank? according to their oxygen requirement
What is aerobic and facultative aerobic

300

Government establish strict regulations on the levels of BOD the final effluent can contain before been released. Why are this regulation in place?
What is to protect the receiving water body of water from reducing the oxygen level and kill fauna living in it

300

What group of indicators are not good indicators and are only used as initial indicator of contamination?
What is total coliforms as this group of microorganisms include environmental coliforms so the can give false positive results

300

What technique is use to detect presence and semi-quantify the total coliform and E. coli in water samples?
What is most probably number technique in the form of Quanti-tray

300

What are the 3 purposes of wastewater treatment
What is eliminate pathogens and toxins, reduce BOD and waste (microorganisms nutrients) from the sewage to minimize the environmental effect.

400

The degradation of solid in suspension in the wastewater treatment depends on the capacity of this microorganisms to consume a variety of compounds? According to their capacity to obtain food by consuming organic matter, this microorganisms are
What is a heterotrophic

400

What stage in the wastewater treatment has the highest effect on the reduction of the BOD and why?
What is the secondary treatment due to the presence and action of microorganisms

400

Why are indicator more convenient to use to detect fecal contamination than pathogens directly
What is indicators are non-pathogenic, cheaper and easier to detect

400

What technique is used to differentiate between E. coli and E. aerogenes?
What is IMVIC

400

What are the 2 purposes of measuring the bacterial load of the incoming sewage and the final effluent?
What is evaluate the efficiency of the wastewater plant and ensuring the final effluent comply with the government regulations

500

The aeration tank receive in a regular base RAS that mix with the incoming primary effluent. What is the reason for this procedure.
What is to increase the number of mature microorganism into the aeration tank and increase the speed of degradation of solids in suspension

500

What is the most common method to evaluate the level of solid in suspension (organic compounds) in waste water?
What is biochemical oxygen demand (BOD)

500

The use of indicator microorganisms has advantages, but also disadvantages. What are disadvantages associated to this microorganisms?
They are are just indicates POSSIBLE presence of pathogens, can not identify or quantify the amount of pathogens present.

500

You know the sample is contaminated but you need to determine the source of the fecal contamination?
What is membrane filtration method

500

Under what condition can cause positive results for all the samples in the Colilert tests?
What is ........ discuss this one with your classmates :)