Take the test..... duh.......
Study questions for the class C waste water license.
Info source: TEEX infrastructure training & safety institute waste water treatment resource book Module #1 Introduction to Waste Water Treatment 2023.
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1.Which of the following are important reasons for adequate treatment of a
community's waste water?
Conservation of water
✓
Reduction of fish kills
✓
Protection of public health
✓
All of the above
✓
The following are benefits gained from the complete treatment of wastewater: • Protection of public health from waterborne disease • Protection of the natural environment and the wildlife that depends on it • Elimination of nuisance conditions • Protection of downstream water supplies • Conservation of water for reuse • Removal of toxic and hazardous materials • Protection of water sources for recreational use • Prevention of deposits of solids in lakes, streams, and rivers
2.The extent of treatment required for a waste water discharge depends on ________.
water quality standards set for the receiving stream
✓
the treatment plant disinfection method
✓
what the community can afford
✓
the final use of the sludge
✓
National, state, and local governments set the standards for treatment. These requirements depend on treatment plant location, the water quality standards set for the receiving stream, and the amount and final use of the effluent. Different treatment plants have different requirements. NOTE: the idea is not to make fresh drinking water but to process waste water to the point that it matches or exceeds the quality of the water way it will be discharged into.
3.Which of the following is an important step in waste water treatment?
Waste water collection
✓
Disinfection
✓
Sludge processing and disposal
✓
All of the above
✓
Wastewater treatment involves a series of steps with two goals: (1) a clean effluent discharge, and (2) proper sludge disposal. The steps are as follows: 1. Source pretreatment 2. Wastewater collection 3. Cross-connection control 4. Preliminary treatment 5. Primary treatment 6. Secondary treatment 7. Advanced treatment 8. Disinfection 9. Effluent discharge 10. Sludge treatment and disposal
4.Essential parts of the waste water collection system include ________.
manholes and pipes
✓
infiltration structures
✓
adequate cross connections
✓
flooded lift stations
✓
The collection system may include the following: • Collection lines • Collection system entries (manholes) • Pump stations • Grease and sand traps • Inverted siphons • Diversion structures NOTE: The waste water COLLECTION system is everything required to get waste water to the processing plant of which pipes for liquid transport and manholes for cleaning and access are >essential< to that function. Cross connections are any connection between potable and non-potable water systems which should not mix. Infiltration structures and flooded lift stations are fictitious options to throw you off.
5.The condition of the raw waste water entering the treatment plant could be affected
by which of the following?
Industrial discharges
✓
Excessive rainwater infiltration
✓
Collection system operation and maintenance
✓
All of the above
✓
The following aspects of the collection system can affect wastewater: • Excessive infiltration of groundwater or inflow of storm water into the collection system • Flat grades or low spots in the collection system that cause wastewater to flow more slowly and allow more time for bacterial action • Poorly designed, constructed, or maintained collection systems • High temperatures and unventilated collection lines • High organic loads that quickly deplete available oxygen supply • Poorly maintained and operated lift stations • Industrial waste discharges
6.Grit removal is usually accomplished in ________.
the collection system
✓
disinfection
✓
preliminary treatment
✓
secondary treatment
✓
As the wastewater enters the treatment plant, preliminary treatment removes materials that might interfere with proper treatment, cause damage, or cause excessive wear on system components (Figure 1.4). Important aspects of preliminary treatment include the following: • Coarse or fine screening • Grinding • Grit removal • Grease removal • Pre-aeration • Flow equalization • pH adjustment NOTE: Grit removal is usually accomplished in preliminary treatment because it is necessary to protect equipment further in the process and so that plant employees can maintain the grit removal equipment in a cost effective manner.
7.The purpose of the microorganisms that are present in biological treatment processes is to ________.
remove the bacteria in raw wastewater
✓
add gases to the treatment plant
✓
provide the operator with pets
✓
trap and consume contaminants in wastewater
✓
In secondary treatment, microscopic living creatures called microorganisms remove additional contaminants from the wastewater. Conditions are purposely created that favor the growth and reproduction of treatment microorganisms. These organisms trap and consume waste, using contaminants in wastewater as their food supply. After these organisms are later removed as biological solids, the wastewater will be less contaminated. NOTE: The purpose of the microorganisms.... is to BE the biology in "biological treatment" they eat things and turn them into other things that are more easily removed than the original contaminants.
8.A rotating biological contactor is ________.
a type of biological secondary treatment process
✓
a Ferris wheel for microorganisms
✓
advanced treatment rarely found in Texas
✓
another name for a trickling filter
✓
Biological secondary treatment processes may include any of the following: • Stabilization ponds • Trickling filters • Rotating biological contactors • Activated sludge systems • Sand and rock beds • Hyacinth ponds • Overland flow systems • Mechanically aerated ponds NOTE: An RBC is an alternative to a trickling filter that is also used for biological secondary treatment.
9.The protozoa that cause amoebic dysentery would most likely be destroyed
by _________.
primary treatment
✓
dechlorination
✓
disinfection
✓
sludge processing and disposal
✓
Disinfection destroys or inactivates pathogenic (disease-causing) bacteria, viruses, and protozoa. These infectious agents can cause outbreaks of dysentery, typhoid, hepatitis, cholera, or other diseases if not eliminated during wastewater treatment. NOTE: The purpose of the disinfection process is to eliminate microorganisms in the waste water. this includes both the helpful ones used in the treatment process and pathogens that come in with raw waste water.
10.If a waste water treatment plant does not discharge to a receiving stream, the effluent could be disposed of by which of the following?
Aquifer recharge
✓
Evaporation in a pond
✓
Application to farm land by irrigation
✓
All of the above
✓
Disposal methods for wastewater sludge include: • disposal in landfills; • application on farm land or forest land; • incineration; • disposal in lagoons; and • application for commercial purposes.
11.Using the final effluent from a waste water treatment plant to irrigate pasture land
would ________.
cause an odor nuisance
✓
pollute nearby streams
✓
cause bovine encephalitis
✓
be a beneficial way to reuse waste water
✓
Using reclaimed wastewater for irrigation frees up fresh water to be used for other purposes while also acting as fertilizer.
12.Thickening of waste water sludges, a process that removes excess water, usually
precedes _________.
disinfection of the sludge
✓
phosphorous removal
✓
gravity settling
✓
stabilization
✓
Stabilization is a chemical or biological process that stops the natural fermentation of the sludge.
13.Hauling sludge to a landfill is a common method of ________.
sludge disposal
✓
sludge dewatering
✓
sludge stabilization
✓
sludge incineration
✓
hauling sludge anywhere is not generally used specifically as a method of dewatering, incineration, or stabilization
14.Important factors that determine the type of treatment scheme that will be used
include which of the following?
Land area available
✓
Effluent quality required
✓
Operating costs
✓
All of the above
✓
Each treatment facility while similar must be tailored to the area and population it serves to maximize efficiency.