Podcast
Questions and Answers
What is the primary purpose of the 'Minimal National Standards' (MINAS) for industries?
What is the primary purpose of the 'Minimal National Standards' (MINAS) for industries?
Under what circumstances can MINAS be relaxed?
Under what circumstances can MINAS be relaxed?
Who is empowered to prescribe standards stricter than MINAS?
Who is empowered to prescribe standards stricter than MINAS?
What is the concept developed by the Central Pollution Control Board (CPCB) to designate water bodies?
What is the concept developed by the Central Pollution Control Board (CPCB) to designate water bodies?
Signup and view all the answers
How many 'designated best uses' has the CPCB identified?
How many 'designated best uses' has the CPCB identified?
Signup and view all the answers
What is the primary purpose of the 'designated best use' concept?
What is the primary purpose of the 'designated best use' concept?
Signup and view all the answers
What is the importance of environmental education in the context of pollution?
What is the importance of environmental education in the context of pollution?
Signup and view all the answers
What is the main challenge in addressing environmental degradation?
What is the main challenge in addressing environmental degradation?
Signup and view all the answers
What is the recommended maximum particle size of suspended solids for inland surface water?
What is the recommended maximum particle size of suspended solids for inland surface water?
Signup and view all the answers
What is the purpose of implementing environmental laws?
What is the purpose of implementing environmental laws?
Signup and view all the answers
What is the maximum permitted suspended solids in marine/coastal areas for process wastewater?
What is the maximum permitted suspended solids in marine/coastal areas for process wastewater?
Signup and view all the answers
What is the significance of having a firm hand in implementing environmental protection laws?
What is the significance of having a firm hand in implementing environmental protection laws?
Signup and view all the answers
What is the hindered settling velocity represented by?
What is the hindered settling velocity represented by?
Signup and view all the answers
What is the value of n in Stoke's law region?
What is the value of n in Stoke's law region?
Signup and view all the answers
What is the formula for bulk density?
What is the formula for bulk density?
Signup and view all the answers
What is the assumption in the ideal sedimentation basin about the distribution of flow?
What is the assumption in the ideal sedimentation basin about the distribution of flow?
Signup and view all the answers
What happens to particles that enter the sludge zone?
What happens to particles that enter the sludge zone?
Signup and view all the answers
What is the characteristic of the upflow clarifier?
What is the characteristic of the upflow clarifier?
Signup and view all the answers
What happens to the area through which the water passes as it rises in the upflow clarifier?
What happens to the area through which the water passes as it rises in the upflow clarifier?
Signup and view all the answers
What is the purpose of the settling zone in the sedimentation basin?
What is the purpose of the settling zone in the sedimentation basin?
Signup and view all the answers
What is the condition for particles to be completely removed from a horizontal flow sedimentation tank?
What is the condition for particles to be completely removed from a horizontal flow sedimentation tank?
Signup and view all the answers
What is the typical flow velocity range used when piping flocculated water to the settling tank?
What is the typical flow velocity range used when piping flocculated water to the settling tank?
Signup and view all the answers
What is the percentage of particles removed (P) with a settling velocity of vt in a horizontal flow sedimentation tank designed with an overflow rate of v0?
What is the percentage of particles removed (P) with a settling velocity of vt in a horizontal flow sedimentation tank designed with an overflow rate of v0?
Signup and view all the answers
What is the maximum horizontal velocity through the tank that does not allow resuspension of settled particles?
What is the maximum horizontal velocity through the tank that does not allow resuspension of settled particles?
Signup and view all the answers
What is the purpose of the diffuser wall in the settling tank?
What is the purpose of the diffuser wall in the settling tank?
Signup and view all the answers
What is the recommended head loss through the holes in the diffuser wall?
What is the recommended head loss through the holes in the diffuser wall?
Signup and view all the answers
What is the value of the cohesion constant (k) for sticky interlocking matter?
What is the value of the cohesion constant (k) for sticky interlocking matter?
Signup and view all the answers
What is the typical diameter of the holes in the diffuser wall?
What is the typical diameter of the holes in the diffuser wall?
Signup and view all the answers
What is the expression for the scour velocity (VH) in a horizontal flow sedimentation tank?
What is the expression for the scour velocity (VH) in a horizontal flow sedimentation tank?
Signup and view all the answers
What is the purpose of controlling horizontal flow velocities in the settling zone?
What is the purpose of controlling horizontal flow velocities in the settling zone?
Signup and view all the answers
What is the condition for the ratio of length to width in a rectangular classifier?
What is the condition for the ratio of length to width in a rectangular classifier?
Signup and view all the answers
What is the condition for the overflow rate in a horizontal flow sedimentation tank?
What is the condition for the overflow rate in a horizontal flow sedimentation tank?
Signup and view all the answers
What can be used to check on turbulence and back-mixing in the settling zone?
What can be used to check on turbulence and back-mixing in the settling zone?
Signup and view all the answers
What is the condition for the horizontal velocity in a horizontal flow sedimentation tank?
What is the condition for the horizontal velocity in a horizontal flow sedimentation tank?
Signup and view all the answers
Study Notes
Environmental Protection and Pollution Control
- Environmental degradation is a complex issue that requires a multi-dimensional approach.
- Environmental education can play a crucial role in negating the adverse impacts of pollution.
General Standards for Discharge of Environmental Pollutants
- Part-A: Effluents
- Suspended solids: maximum 100 mg/L (inland surface water), 600 mg/L (public sewers), 200 mg/L (land for irrigation)
- Particle size: shall pass 850 micron IS Sieve
Minimal National Standards (MINAS) for Industries
- CPCB lays down specific standards for effluents discharged from industries
- Standards are based on techno-economic capability of the industry to take anti-pollution measures
- MINAS cannot be relaxed, but State Pollution Control Boards can prescribe stricter standards if necessary
Primary Water Quality Criteria
- CPCB has developed a concept of "designated best use" for water bodies
- 5 designated best uses have been identified
Hindered Settling
- Hindered settling velocity (uH) = us
- Methods to calculate uH: Stoke's law region (very small particles), Newton's law region (large particles)
Ideal Sedimentation Basin
- Assumptions: discrete particle settling, four zones in the basin (inlet, outlet, sludge, and settling), even distribution of flow and particles
- Particles that enter the sludge zone are captured and remain in the sludge zone
Sedimentation Zones
- Horizontal flow clarifier
- Upflow clarifier
- Settling in an upflow clarifier: particles having settling velocity ut ≥ vo will be completely removed
Scour Velocity
- Maximum horizontal velocity through the tank that does not allow resuspension (scouring) of settled particles
- Formula: VH = (8k ρp - ρf) gDp / (f ρf)
Design of a Municipal Wastewater Plant
- Flow rate: 60000 m3/d
- Target particle characteristics: DP = 200×10-6 m, k = 0.05, f = 0.025, ρP = 1.25×103 kg/m3
- Design considerations: rectangular classifier, overflow rate, horizontal velocity, scour velocity, diffuser wall
Inlet Zone
- Velocity must be reduced and flow spread evenly over the cross section of the settling tank
- Diffuser wall is used to accomplish this
- Port velocities: 0.20 to 0.30 m/s, hole diameter: 0.10 to 0.20 m, spacing: 0.25 to 0.60 m apart
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Learn about environmental degradation, education, and pollution control measures, including standards for discharge of environmental pollutants.