Environmental Protection and Pollution Control
34 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary purpose of the 'Minimal National Standards' (MINAS) for industries?

  • To ensure that industries take anti-pollution measures within their techno-economic capability (correct)
  • To provide a relaxation in pollution standards for industries
  • To impose stricter pollution standards on industries without considering their capabilities
  • To set unattainable standards for industries

Under what circumstances can MINAS be relaxed?

  • When the industry is willing to pay a fine
  • When the recipient environment demands stricter quality of the effluent
  • When the industry is unable to meet the standards
  • Under no circumstances (correct)

Who is empowered to prescribe standards stricter than MINAS?

  • The Central Pollution Control Board (CPCB)
  • The Ministry of Environment
  • The State Pollution Control Boards (correct)
  • The Industry Regulatory Body

What is the concept developed by the Central Pollution Control Board (CPCB) to designate water bodies?

<p>Designated best use (D)</p> Signup and view all the answers

How many 'designated best uses' has the CPCB identified?

<p>5 (A)</p> Signup and view all the answers

What is the primary purpose of the 'designated best use' concept?

<p>To determine the quality of water required for a specific use (D)</p> Signup and view all the answers

What is the importance of environmental education in the context of pollution?

<p>It plays a crucial role in negating the adverse impacts of pollution (D)</p> Signup and view all the answers

What is the main challenge in addressing environmental degradation?

<p>Complexity of environmental problems (B)</p> Signup and view all the answers

What is the recommended maximum particle size of suspended solids for inland surface water?

<p>850 microns (A)</p> Signup and view all the answers

What is the purpose of implementing environmental laws?

<p>To take proactive steps to prevent environmental degradation (C)</p> Signup and view all the answers

What is the maximum permitted suspended solids in marine/coastal areas for process wastewater?

<p>100 mg/L (D)</p> Signup and view all the answers

What is the significance of having a firm hand in implementing environmental protection laws?

<p>To ensure effective implementation of laws (C)</p> Signup and view all the answers

What is the hindered settling velocity represented by?

<p>uH (C), us (D)</p> Signup and view all the answers

What is the value of n in Stoke's law region?

<p>4.6 (D)</p> Signup and view all the answers

What is the formula for bulk density?

<p>ρb = ρs(1 - ε) + ρfε (C)</p> Signup and view all the answers

What is the assumption in the ideal sedimentation basin about the distribution of flow?

<p>Uniform horizontal velocity entering the settling zone (D)</p> Signup and view all the answers

What happens to particles that enter the sludge zone?

<p>They remain in the sludge zone (C)</p> Signup and view all the answers

What is the characteristic of the upflow clarifier?

<p>The velocity of the rising water is greater than the settling velocity of the particle (A)</p> Signup and view all the answers

What happens to the area through which the water passes as it rises in the upflow clarifier?

<p>It increases (C)</p> Signup and view all the answers

What is the purpose of the settling zone in the sedimentation basin?

<p>To remove particles from the water (D)</p> Signup and view all the answers

What is the condition for particles to be completely removed from a horizontal flow sedimentation tank?

<p>ut ≥ vo (A)</p> Signup and view all the answers

What is the typical flow velocity range used when piping flocculated water to the settling tank?

<p>0.15 to 0.6 m/s (C)</p> 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?

<p>$\frac{vt}{vo} * 100$ (A)</p> Signup and view all the answers

What is the maximum horizontal velocity through the tank that does not allow resuspension of settled particles?

<p>Scour velocity (VH) (C)</p> Signup and view all the answers

What is the purpose of the diffuser wall in the settling tank?

<p>To reduce the flow velocity and spread the flow evenly (B)</p> Signup and view all the answers

What is the recommended head loss through the holes in the diffuser wall?

<p>4 to 5 times the velocity head (D)</p> Signup and view all the answers

What is the value of the cohesion constant (k) for sticky interlocking matter?

<p>0.6 (D)</p> Signup and view all the answers

What is the typical diameter of the holes in the diffuser wall?

<p>0.10 to 0.20 m (A)</p> Signup and view all the answers

What is the expression for the scour velocity (VH) in a horizontal flow sedimentation tank?

<p>$\frac{8k \rho_p - \rho_f}{gD_p}f$ (B)</p> Signup and view all the answers

What is the purpose of controlling horizontal flow velocities in the settling zone?

<p>To reduce turbulence and scour particles (A)</p> Signup and view all the answers

What is the condition for the ratio of length to width in a rectangular classifier?

<p>At least 6 (A)</p> Signup and view all the answers

What is the condition for the overflow rate in a horizontal flow sedimentation tank?

<p>At least four times the settling velocity (D)</p> Signup and view all the answers

What can be used to check on turbulence and back-mixing in the settling zone?

<p>Reynolds and Froude numbers (A)</p> Signup and view all the answers

What is the condition for the horizontal velocity in a horizontal flow sedimentation tank?

<p>At most one-third of the scour velocity (C)</p> 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.

Quiz Team

Description

Learn about environmental degradation, education, and pollution control measures, including standards for discharge of environmental pollutants.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser