Waste Water Engineering 2022 Question Paper — Government College of E…
The 2022 Waste Water Engineering previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.
- University: Government College of Engineering and Technology, Jammu
- Subject: Waste Water Engineering
- Course: Waste Water Engineering
- Branch: Civil Engineering
- Year: 2022
- Paper: end-term
- Duration: 180 minutes
- Total marks: 100
Instructions
- Attempt five questions in all, selecting atleast two questions from each section.
- Assume missing data, if any, suitably.
Questions
Section-A
- Q1. (a) Elaborate various types of water carriage system with advantages and disadvantages of each. (b) The drainage area of a town is 20 hectare. The classification of the surface of its area is as follows: Percentage of total surface area | Type of surface | Runoff coefficient 25 | Hard pavement | 0.85 25 | Roof surface | 0.80 15 | Unpaved street | 0.30 25 | Garden and lawns | 0.15 10 | Wooden area | 0.10 If the time concentration for the area is 30 minutes, find the maximum runoff. Use the following formula for intensity of rainfall: $R_i = 900 / (t + 60)$ [20 marks]
- Q2. (a) What do you understand by 'sewer appurtenances'? Why are they necessary? Enumerate various appurtenances commonly used. (b) Calculate the velocity of flow and corresponding discharge in a sewer of circular section having diameter 1m, laid at a gradient of 1 in 500. The sewer runs at 0.6 depth, take N = 0.0012. [20 marks]
- Q3. (a) Draw a neat sketch of sewage ventilation. What is the necessity of ventilation of sewers. (b) Explain with the help of neat sketches, various types of joints used in sewer line. [20 marks]
- Q4. (a) Elaborate the various chemical characteristics of sewage with its significances. (b) The BOD of a sewage incubated for one day at 30°C has been found to be 100 mg/l. what will be the 5-day 20°C BOD. Assume K = 0.12 at 20°C. [20 marks]
Section-B
- Q5. (a) Design a grit chamber for a maximum wastewater flow of $8000\text{ m}^3/\text{day}$, to remove particles upto of 0.2 mm dia. having specific gravity of 2.65. The settling velocities of these particles is found to range from 0.018 to 0.022 m/sec. Maintain a constant flow through velocity of $0.3\text{ m/sec}$ through the provision of a proportional flow weir. (b) Write a note on racks and screens. How do you determine head loss through bar screens? [20 marks]
- Q6. (a) Explain with sketches the treatment of sewage by activated sludge process. Mention the advantage and disadvantages of this system. (b) A single stage trickling filter is designed for an organic loading of $10000\text{ kg}$ of BOD in raw sewage per hectare metre per day with a recirculation ratio of 1.2. This filter treats a flow of $4\text{ mld}$ of raw sewage with a BOD of $220\text{ mg/l}$. Using NRC formula, determine the strength of the effluent. [20 marks]
- Q7. (a) Elaborate the mechanism of purification in facultative ponds. (b) Explain in brief the working principles of aerobic, anaerobic and facultative type stabilization ponds. [20 marks]
- Q8. (a) Design a septic tank for 125 persons, estimated peak discharge is $300\text{ lpm}$. Also design design the soil absorption system for the disposal of the septic tank effluent, assuming the percolation rate as 20 min. per cm. (b) Enumerate the advantages and disadvantages of Imhoff tanks. [20 marks]