R5320102 Environmental Engineering I

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Code No: R5320102 III B.Tech II Semester(R05) Regular/Supplementary Examinations, April/May 2009 ENVIRONMENTAL ENGINEERING-I (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Name any four important waterborne diseases. What are the sources, symptoms, significance and methods of prevention and (or) control of these diseases. (b) Give the Process flow diagram of a typical Protected Water Supply Scheme for a Town of population 1 lakh using River Water as its source. [8+8] 2. (a) Distinguish between a ‘Reservoir Intake’ and a ‘Portable Intake’. (b) Discuss the Criteria for ‘Location of Intakes’.

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3. Discuss in detail, with the help of sketches, the role of following design considerations while designing a Settling/Sedimentation system like a clarifier. (a) (b) (c) (d) (e)

Surface loading Detention Time Shape of the Reactor Depth Types of Sedimentation.

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4. (a) Describe the working of a Pressure Filter with the help of a sketch. (b) A private estate uses a Pressure filter to treat 500 cu.m./day of turbid water. If filter operates from 04.00 pm to 08.00 am every day, find the size of pressure filter. Also find the approximate HP of the pump that supplies water to pressure filter under pressure. [16] 5. (a) Explain the general methods of distribution of water employed in municipal water supply schemes. (b) Illustrate with sketch the Grid iron type of layout of pipe system in distributing water, and compare its merits and demerits. [6+10] 6. (a) Name the two factors used as criteria for selection of pipe diameter and slope in design of sewer. (b) Calculate the ratio of discharge of a sewer when flowing at full depth to that when flowing at 3/4 depth. [8+8] 7. Write short notes on the following” (a) (b) (c) (d)

Humus tank Contact bed Dunbar filter Bio-filter.

[4+4+4+4]

8. (a) Design a septic tank for 100 users in a hostel. Assume per capita water demand as 150 litres. (b) Write a note on soak pit. [8+8] ?????

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Code No: R5320102 III B.Tech II Semester(R05) Regular/Supplementary Examinations, April/May 2009 ENVIRONMENTAL ENGINEERING-I (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) If 500 litre of a water sample of pH 4.5 and Fluoride concentration 0.5 ppm is mixed with 1.5 cu.m of water of pH 9.2 and Fluoride 1.2 ppm, find the pH and Fluoride in the mixture. (b) Give the Desirable and Maximum permissible standards as per IS 10500 for any 16 parameters in Drinking water. [16] 2. Write a detailed note, with the help of a sketch, on: (a) Infiltration Galleries and the Distribution Systems. (b) River Intake.

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3. Discuss in detail, with the help of sketches, the role of following design considerations while designing a Settling/Sedimentation system like a clarifier. (a) (b) (c) (d) (e)

Surface loading Detention Time Shape of the Reactor Depth Types of Sedimentation.

[16]

4. (a) Describe the working of a Pressure Filter with the help of a sketch. (b) A private estate uses a Pressure filter to treat 500 cu.m./day of turbid water. If filter operates from 04.00 pm to 08.00 am every day, find the size of pressure filter. Also find the approximate HP of the pump that supplies water to pressure filter under pressure. [16] 5. (a) Explain the Hardy Cross method used for pipe network analysis in water distribution system. (b) A pipe net work consists of the following pipes: Pipe AB BC AD DC

Lenth (metre) 400 600 500 500

Diameter (cm) 30 30 40 25

Friction factor 0.014 0.010 0.012 0.011

If flow at A is 1.0 m3 /sec, while outflows at B,C and D are 0.3, 0.5 and 0.2 m3 /sec, respectively, find the flow in each pipe taking only one trail. The pressure at A is 100 m of water. [8+8] 6. (a) What are the different hydraulic elements and the relation that exists between them, which govern the discharge through a sewer. (b) Find the diameter of a circular sanitary sewer for the following data: i. population = 1,50,000 ii. average sewage flow = 190 litres/head/day iii. slope of sewer = 1 in 1000 [8+8] iv. value of n in Mannings formula = 0.013. 7. (a) What do you understand by the efficiency of a trickling filter? How do you determine the efficiency, using i. NRC formulae and ii. Velz equation? (b) State advantages and disadvantages of a conventional trickling filter. [8+8] 8. (a) Explain the construction and working of sludge lagooing. (b) Explain in brief various methods of final disposal of sludge. ?????

[8+8]

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Code No: R5320102 III B.Tech. II Semester(R05) Regular/Supplementary Examinations, April/May 2009 ENVIRONMENTAL ENGINEERING-I (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. Write short notes on: (a) (b) (c) (d)

Water Quality Testing Industrial Water Demand Fluctuations in water demand Design Period.

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2. (a) If a city of design population 400,000 with a demand of 150 lpcd wants to obtain water by gravity from a reservoir 13 km away, design the pipe diameter. The maximum and minimum water levels in the reservoir are 106.55m and 102.250m. The elevation of water level in storage tank of the city is 96.5000m. Take friction factor as 0.036. (b) Find the Pump-Motor assembly if water is to be supplied to a 50m high overhead tank to serve a population of 1 lakh continuously. The maximum per capita demand is 25 litre/day. Efficiency of pump is 66% and efficiency of motor is 85%. Length of rising main is 1200m and diameter is 0.6m. Neglect losses. Also find the per capita monthly power costs, if each unit of power costs Rs. 2.50. Assume suitable data, if necessary. [16] 3. Write a detailed note on any FOUR of the following: (a) (b) (c) (d) (e) (f)

Significance of Settling Velocity in Sedimentation Significance of Jar Test in water treatment Natural coagulants and Coagulant aids. Stages of treatment in Chemical Precipitation Clariflocculator Feeding arrangements in Coagulation-Flocculation Systems.

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4. (a) If a chlorine dosage of 0.6 ppm is necessary to leave a residue of 0.2 ppm, find the chlorine demand for a flow of 5 MLD. (b) Find the quantity of bleaching powder required to be added into the polluted well of a small residential building. Assume data. (c) A City of population 2 lakhs with a per capita demand of 135 lpcd is to be supplied water after disinfection with a chlorine dosage of 0.8 ppm If Bleaching Powder with 45% available chlorine is used, find the monthly requirement of Bleaching powder. (d) Write a note on ‘Factors affecting efficiency of disinfection’. [16] 5. (a) Calculate the storage required to supply the Demand shown in the following table if the inflow of water to the reservoir is maintained at a uniform rate throughout 24 hours: Time in hrs 0-4 4-8 8-12 12-16 16-20 20-24 Demand in million litres 0.48 0.87 1.33 1.0 0.82 0.54 (b) Differentiate between air relief valve and pressure relief valve.

[8+8]

6. (a) State and describe four important tests that may be carried out to know the characteristics of sanitary sewage. (b) Distinguish between aerobic, anaerobic and facultative micro-organisms and their role in the decomposition of sewage. [8+8] 7. (a) The effluent from a primary settling tank is applied to a standard rate filter at the rate of 3 million liters per day, having a BODs of 175 mg/l. Determine the depth and volume of filter, adopting a surface loading of 2000 l/m2 /day and an organic loading of 150 g/m3 /day. Also, determine the efficiency of such filter unit, using NRC formula. (b) Give a list of methods available for treatment of sewage for both rural and urban conditions. [8+8] 8. (a) Discuss advantages and disadvantages of a septic tank (b) Discuss advantages and disadvantages of an Imhoff tank. ?????

[8+8]

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Code No: R5320102 III B.Tech II Semester(R05) Regular/Supplementary Examinations, April/May 2009 ENVIRONMENTAL ENGINEERING-I (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) If 50 cu.m./day of canal water of pH 3.5 and Chloride concentration 50 ppm is mixed with 1500 cu.m./day of a stream water of pH 9.75 and Chloride 125 ppm, find the pH and Chloride in the mixture. (b) Give the Desirable and Maximum permissible standards as per IS 10500 for any EIGHT parameters in Drinking water. [16] 2. Write a detailed note on any FOUR of the following: (a) (b) (c) (d) (e) (f)

Artificial Rains Rain Water Harvesting Water wars Economical Diameter of a Pumping Main. Location of an intake Towing of Icebergs.

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3. Write a detailed note on: (a) (b) (c) (d)

Stages of Chemical Precipitation Tube Settlers Clariflocculator Factors affecting Efficiency of Coagulation.

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4. Describe a ‘Slow Sand Filter’ with the help of a sketch. Explain in detail how it works and the Operation and maintenance problems associated with it. Also explain its design principles. [16] 5. (a) Determine the storage capacity of a distribution reservoir for a daily requirement of 200000 litres, The pumping rate is limited to 8 hrs( from 8AM to 4 PM). . The pattern of draw off is as under. Time 7 A.M to 8 A.M to 5 P.M to 7 P.M to 8 A.M 5 P.M 7 P.M 8 A.M 30% of days supply 35% of days supply 30% of days supply 5% of days supply (b) Explain the hardy cross method and derive the equation for corrected discharge using the method of balancing heads by correcting assumed flows. [8+8] 6. (a) Name the two factors used as criteria for selection of pipe diameter and slope in design of sewer. (b) Calculate the ratio of discharge of a sewer when flowing at full depth to that when flowing at 3/4 depth. [8+8] 7. (a) Describe in brief various unit operations for chemical clarification along with the design recommendations. (b) What do you understand by secondary treatment (or biological treatment) of wastewater? Enumerate various treatment techniques used for biological treatment. [8+8] 8. (a) Design and sketch a septic tank and soak pit for 100 people. (b) What is the mechanism of waste treatment in an oxidation pond. ?????

[8+8]