CE-602 Environmental Engineering - I - May 2023 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aList and Explain about the various equations used to determine fire demand?
   How to answer

   • List fire demand formulae: Kuichling's, Freeman's, National Board of Fire Underwriters, Ministry of Urban Development
   • Write each equation with terms defined
   • Explain applicability / population range
   • Comparison of results
2. 7 Marks
   bA water supply scheme has to be designed for a city having a population of 1,20,000. Estimate the total draft (in MLD) which is required for an average water consumption of 220 lpcd. Use Kuichling's method to calculate fire demand?
   How to answer

   • Calculate average daily demand = population x per capita
   • Calculate fire demand by Kuichling's method $Q = 3182\sqrt{P}$
   • Add fire demand to average/max daily to get total draft
   • Convert to MLD
3. 7 Marks
   aExplain various methods to determine turbidity in given water sample?
   How to answer

   • Define turbidity and its units (NTU/JTU)
   • Explain Jackson turbidity meter
   • Explain Baylis turbidimeter / Nephelometer
   • Explain Secchi disc and laboratory procedure
4. 7 Marks
   bA water supply scheme has to be designed for a city having population of 1,00,000. For an average water consumption of 250 LPCD. Estimate:

   1. i)Average daily demand
   2. ii)Maximum daily demand
   3. iii)Maximum hourly demand
   4. iv)Fire Demand as Per National Board of Fire under Writer's Formula
   How to answer

   • Average daily demand = P x q
   • Maximum daily = 1.8 x average
   • Maximum hourly = 1.5 x max daily / 2.7 x average
   • Fire demand by National Board of Fire Underwriters / Writer's formula
5. 7 Marks
   aWhat are intake structures? Explain about the working of canal intake?
   How to answer

   • Define intake structures and their functions
   • Types of intakes
   • Working of canal intake with components
   • Neat sketch description
6. 7 Marks
   bA city has a population of 1,50,000. Water is to be supplied at a rate of 160 litres per head per day. If the static lift of the pump is 40 metres, calculate the B.H.P of motor. The rising main is 300 m long and its diameter is 50 cm. Assume that motor efficiency is 85%, pump efficiency is 60%, f = 0.01 and peak hour demand is 1.5 times the average demand.
   How to answer

   • Compute average and peak discharge
   • Compute total head = static lift + friction loss using Darcy-Weisbach
   • Compute power $P = \rho g Q H / \eta$
   • Divide by motor and pump efficiencies to get B.H.P.
7. 7 Marks
   aDerive Stoke's law for settlement of discrete particles in water. How do you modify the law, taking into account of the temperature effect?
   How to answer

   • State assumptions for discrete settling
   • Force balance: gravity, buoyancy, drag
   • Derive terminal velocity $v_s = g(\rho_s-\rho)d^2/18\mu$
   • Explain temperature effect via viscosity correction
8. 7 Marks
   bDefine Coagulation. Write down the chemical reactions of aluminium sulphate and chlorinated copper as when used as coagulants.
   How to answer

   • Define coagulation and its purpose
   • Write reaction of aluminium sulphate with alkalinity
   • Write reaction of chlorinated copperas as coagulant
   • Conditions for effective coagulation
9. 7 Marks
   aWith the help of neat sketches, explain Manholes and Lamp holes.
   How to answer

   • Define manholes and lamp holes with purpose
   • Provide neat sketches with components labelled
   • Explain construction and spacing
   • Differentiate uses
10. 7 Marks
    bDetermine the surface overflow area for settling tank of $0.5\text{ m}^3/\text{sec}$ flow using design overflow rate as $32.5\text{ m}^3/\text{m}^2/\text{day}$. Also find the depth of the tank if detention time is 95 min. Assume L/B from 2/1 to 5/1 and length should not exceed 100 m.
    How to answer

    • Surface area = Discharge / overflow rate
    • Volume = Q x detention time, depth = Volume / Area
    • Check L/B ratio 2 to 5 and length <100 m, adjust dimensions
    • Final L, B, depth
11. 7 Marks
    aExplain in detail about the construction and laying of sewers?
    How to answer

    • Alignment, excavation and bedding
    • Laying, jointing and testing of sewer pipes
    • Backfilling, safety and ventilation
12. 7 Marks
    bCalculate the velocity of flow and corresponding discharge in a sewer of circular section having diameter equal to 1 m laid at a gradient of 1 in 500. The sewer runs at a depth of 0.6 m. Use Manning's formula taking n = 0.012?
    How to answer

    • Compute hydraulic mean depth for partial flow at 0.6 m depth
    • Apply Manning's formula $V = (1/n)R^{2/3}S^{1/2}$
    • Compute wetted area for partial depth
    • Discharge $Q = A V$
13. 7 Marks
    aWhat is Population equivalent? Calculate the population equivalent if the average standard $BOD_5$ of industrial sewage comes out to be 300 kg/day?
    How to answer

    • Define population equivalent
    • Standard per capita BOD ~80 g/day
    • Formula PE = total BOD / per capita BOD
    • Compute for 300 kg/day
14. 7 Marks
    bFollowing observations were made on a 3% dilution of waste water. DO of aerated water = 3mg/lit DO of diluted water sample after 5 days of incubation = 0.8 mg/lit DO of waste water sample = 0.6 mg/lit. Calculate 5 day BOD. Given $K_D$ = 0.1 per day.
    How to answer

    • BOD = [(DO_initial - DO_final) - blank correction] / dilution fraction
    • Apply 3% dilution and given DO values
    • Account for $K_D = 0.1$ per day if ultimate BOD needed
    • Compute 5-day BOD in mg/l
15. 14 Marks
    Write a short notes on any two:

    1. i)Sources of surface water
    2. ii)Disposal of sewage
    3. iii)Chemical parameters of sewage
    4. iv)Water borne diseases
    How to answer

    • For each chosen topic give definition and classification
    • Explain key points with examples
    • Mention significance in environmental engineering
    • Conclude briefly