(SEM VI) THEORY EXAMINATION 2024-25 ENVIRONMENTAL ENGINEERING

BCE603 – ENVIRONMENTAL ENGINEERING

Time: 3 Hours | Max Marks: 70

SECTION A – Short Answer Questions

(2 × 7 = 14 marks | Attempt ALL)

Write definition + 1–2 key points

1. Freshwater Resource & Factors Affecting Domestic Water Demand

Freshwater resource: Water available in rivers, lakes, groundwater suitable for human use.
Factors: Climate, standard of living, water tariff, habits of people.

2. SCADA

SCADA (Supervisory Control and Data Acquisition) is used to monitor and control water distribution systems in real time by collecting data like flow, pressure, and leakage.

3. Turbidity

Turbidity is the measure of cloudiness in water due to suspended particles.
Significance: High turbidity reduces disinfection efficiency and indicates pollution.

4. Coagulation

Coagulation is the process of destabilizing colloidal particles to form flocs for removal.
Common coagulant: Alum (Al₂(SO₄)₃).

5. Aerobic Decomposition

It is the breakdown of organic matter in the presence of oxygen, producing CO₂, water, and energy.

6. Theoretical Oxygen Demand (ThOD)

ThOD is the amount of oxygen required to completely oxidize organic matter chemically.

7. Coincident Draft

Coincident draft is the maximum water demand occurring at the same time from different users.

SECTION B – Medium Answer

(7 × 3 = 21 marks | Attempt ANY THREE)

Write concept → explanation → example/diagram

1. Population Forecasting Methods                   Arithmetic increase method: Assumes constant growth

Geometric increase method: Assumes percentage growth
Used for estimating future water demand.

2. Service Reservoirs – Design Considerations              Storage capacity

Location and elevation                                                  Inlet, outlet, and overflow arrangement

Structural safety and accessibility

3. Environmental Impact of Wastewater Disposal         Water pollution (eutrophication)

Soil contamination                                                        Groundwater pollution
Indicators: BOD, COD, pathogens, nutrients, heavy metals.

4. Sedimentation & Filtration

Sedimentation: Settling of suspended solids under gravity

Filtration: Removal of fine particles through sand media     (Neat sketches fetch extra marks)

5. Activated Sludge Process (ASP)                                  Aeration tank

Secondary clarifier                                                          Sludge recirculation
Challenges: Sludge bulking, high energy use, operational control.

SECTION C – Attempt ANY ONE

(7 marks)

1. Leakage Detection & Control in Old Pipelines          Acoustic methods: Accurate but costly

Pressure management: Preventive approach             District metered areas: Effective for large networks
Compare on cost, efficiency, and difficulty.

2. Population Forecasting Numerical                      Given data → apply Arithmetic & Geometric methods
Comment which method suits rapid urbanization (Geometric).