Questions and Answers
What is preliminary treatment?
The 1st stage of sewage treatment where large debris, such as sticks, grit, and rags pass through a screen followed by a grit chamber, where the flow of water is slowed enough to allow for sedimentation.
What stage of treatment is grit removal usually accomplished in?
Preliminary treatment.
What is a Rotating Biological Contactor?
A type of biological secondary treatment process.
How are protozoa (cause of amoebic dysentery) destroyed?
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What are other ways to dispose of effluent wastewater besides stream discharge?
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What does the Clean Water Act do?
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What is the Texas Water Code?
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Who reviews plans and specifications for new construction projects before construction begins?
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Water quality fees may be as high as how much per permit?
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What are administrative penalties that may be assessed against any violator?
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Every city with more than how many in population needs to establish a water pollution control program?
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State law requires that reports are to be submitted no later than which day of the following month?
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What are major surface waters classified as for the purposes of water quality management?
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What is inflow in wastewater management?
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How many gallons per day will each person contribute to the wastewater treatment plant?
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How much BOD will each person contribute to the wastewater treatment plant each day?
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What is the cause of septic wastewater?
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What are classifications of solids in wastewater?
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What do organic compounds in wastewater include?
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What type of organic matter is present in wastewater?
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What does BOD measure?
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What are ways that oxygen can be depleted in streams?
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What is a gas found in treatment systems that is NOT dangerous?
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What are cycles of decay?
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A flow totalizer is required when the plant design flow is more than how much?
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What includes non-hazardous wastes?
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What includes hazardous wastes?
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What is the synergistic effect?
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How many cubic feet of screenings per million gallons of wastewater will coarse screens remove?
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What are the benefits of preaeration?
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What is the main purpose of a sedimentation tank?
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How much settleable solids is removed in primary settling?
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How much suspended solids is removed in primary settling?
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How much BOD is removed in primary settling?
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How much total organic matter is removed in primary settling?
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What percentage of suspended solids will settle out within 2 hours?
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Study Notes
Wastewater Treatment Processes
- Preliminary Treatment: First stage of sewage treatment; involves screening out large debris and sedimentation in a grit chamber.
- Grit Removal: Typically accomplished during the preliminary treatment stage.
- Rotating Biological Contactor: Utilized in biological secondary treatment processes.
Disinfection and Wastewater Disposal
- Protozoa Destruction: Achieved through disinfection to eliminate sources of diseases like amoebic dysentery.
- Effluent Disposal Methods: Include aquifer recharge, evaporation in ponds, and irrigation on farmland.
Regulatory Framework
- Clean Water Act: Establishes fundamental regulations for pollutant discharges into U.S. waters.
- Texas Water Code: Grants TCEQ authority over waste discharges into water bodies in Texas.
- TCEQ Responsibilities: Reviews construction project plans and specifications prior to construction.
Fees and Penalties
- Water Quality Fees: Can reach up to $115,000 per permit.
- Administrative Penalties: May be assessed at up to $25,000 daily for each violation.
Population and Reporting Requirements
- Pollution Control Program Requirement: Cities with populations exceeding 10,000 must implement programs and hire qualified personnel.
- Report Submission Deadline: Required by the 20th day of the following month.
Surface Water Management
- Surface Water Classifications: Major surface waters are classified as segments for water quality management.
Wastewater Contributions and Characteristics
- Individual Contribution to Wastewater: Each person contributes approximately 100 gallons per day.
- Daily BOD Contribution per Person: Amounts to 0.17 pounds.
Wastewater Composition and Effects
- Septic Wastewater Cause: Due to bacterial action.
- Types of Solids in Wastewater: Include fixed/ash, suspended/dissolved, and organic/inorganic solids.
- Organic Compounds: Comprised of carbon, hydrogen, and oxygen, primarily of animal and vegetable origin.
Biological Oxygen Demand (BOD)
- BOD Definition: Measure of oxygen used up in decomposition processes.
- Oxygen Depletion Sources: Include untreated waste discharges, nighttime algae blooms, and high BOD in effluents.
Treatment System Gas
- Dissolved Oxygen: Found in treatment systems and is non-dangerous.
Decay Cycles
- Includes: Carbon, nitrogen, and sulfur cycles.
Flow Measurement
- Flow Totalizer Requirement: Necessary when plant design flow exceeds 0.5 million gallons per day (MGD).
Waste Classification
- Non-Hazardous Wastes: Include chlorides, alkalinity, color, phosphorus, and iron.
- Hazardous Wastes: Include cyanides, sulfides, organics, and gasoline.
Interactions and Screening
- Synergistic Effect: Refers to reactions between different waste streams.
- Screening Efficiency: Coarse screens can remove 0.5 to 6.0 cubic feet of screenings per million gallons of wastewater.
Additional Treatment Benefits
- Preaeration Benefits: Freshens wastewater, removes grease, and scours gases.
- Sedimentation Tank Purpose: Facilitates the settling of solids and the rise of scum under low velocity conditions.
Settling Efficiency
-
Settling Performance in Primary Treatment:
- Settled Solids Removal: 90-95% of settleable solids.
- Suspended Solids Removal: 50-70%.
- BOD Removal: 35%.
- Total Organic Matter Removal: 20-30%.
- Settlement Rate: Approximately 70% of suspended solids settle within 2 hours.
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Description
Test your knowledge on wastewater treatment processes with this quiz designed for the TX Class C Wastewater Treatment License. Each flashcard covers key terms and definitions, including stages of sewage treatment like preliminary treatment and technologies such as Rotating Biological Contactors.