Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Summer 6th Sem 2160604 Water And Waste Water Engineering Previous Question Paper

Enrolment No.___________

**GUJARAT TECHNOLOGICAL UNIVERSITY**

**BE - SEMESTER? VI EXAMINATION ? SUMMER 2020**

**Subject Code: 2160604**

**Date:29/10/2020**

**Subject Name: WATER & WASTE WATER ENGINEERING**

**Time: 10:30 AM TO 01:00 PM**

**Total Marks: 70**

**Instructions:**

**1. Attempt all questions.**

**2. Make suitable assumptions wherever necessary.**

**3. Figures to the right indicate full marks.**

**MARKS**

**Q.1 (a)**How will you estimate Waste water discharge of your city?

**03**

**(b)**How will you select treatment train for a waste water treatment

**04**

plant giving you desired BOD and SS removal?

**(c)**Design flash mixer for flow of 270m3/hr

**07**

**Q.2 (a)**List out sewer appurtenances. Draw neat sketch of storm water relief

**03**

works.

**(b)**What are the objectives of aeration ? List out aerators.

**04**

**(c)**Derive equation of settling velocity

**07**

**OR**

**(c)**Derive shield's formula for self cleansing velocity.

**07**

**Q.3 (a)**Write design criteria for flocculator

**03**

**(b)**How will you determine optimum coagulant dose ?

**04**

**(c)**Explain procedure of determining storage capacity of reservoir.

**07**

**OR**

**Q.3 (a)**Give brief note on flexible joint

**03**

**(b)**Forecast population by means of geometrical increase method for

**04**

following data for year 2000 and 2010.

Year

1960

1970

1980

1990

Population 7000

11000

16000

22500

**(c)**A city with 1.5 lakh population is to be supplied water at 100lpcd

**07**

from a river 1 km away. The difference in water level of sump and

reservoir is 30 m. If the demand has to be supplied in 8 hours.

Determine the size of main and B.H.P. of pumps. Assume suitable

data

**Q.4 (a)**What is F/M ratio ?

**03**

**(b)**Define septic tank. Give the design criteria for a septic tank.

**04**

**(c)**What is HRTF? Determine the size of HRTF for flow of 4.50 MLD.

**07**

If recirculation ratio = 1.5, BOD of wastewater =250 mg/l and final

effluent desired = 30 mg/l. Assume suitable data if required.

**OR**

**Q.4 (a)**Discuss about sludge drying beds

**03**

**(b)**Describe steps of designing trickling filter

**04**

**(c)**Design a septic tank for a hostel building of 100 students Also design

**07**

the soil absorption system for the disposal of the septic tank effluent,

assuming the percolation rate as 20 minutes per cm. Also assume peak

discharge is 240 lpm

1

**Q.5 (a)**Why sludge recirculation is done in activated sludge process?

**03**

**(b)**How phosphorus removed by chemical precipitation ?

**04**

**(c)**Design a rectangular grit chamber for treating 5 MLD of sewage.

**07**

**OR**

**Q.5 (a)**Write note on pressure filter.

**03**

**(b)**List out different types of pipe with suitability of each.

**04**

**(c)**Design bell mouth canal intake for 11 MLD discharge.

**07**

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2

This post was last modified on 04 March 2021