Important RGPV Question
CE-702 (B) Environmental Engineering-II
VII Sem, CE
UNIT-I
Q.1 What do you understand by unit operations and processes? Elaborate various types of unit operations used for waste water treatment. (RGPV DEC 2024)
Q.2 Explain the various types of settling for waste water treatment. (RGPV DEC 2024)
Q.3 Explain the importance of micro-organism in biological treatment (RGPV NOV 2023)
Q.4 Describe, for a client, the four types of sedimentation systems and the reasons you would recommend one over another. (RGPV NOV 2023)
Q.5 If the 5 days BOD of a sample is 276 mg/l and ultimate BOD at the same temperature is 380 mg/l, at what rate the waste is oxidized? (RGPV DEC 2020)
UNIT-II
Q.1 Explain with the help of neat sketch, the working of an oxidation ditch. (RGPV DEC 2024)
Q.2 Write a note on racks and screens. How do you determine head loss through bar screen? (RGPV DEC 2024)
Q.3 Compare and contrast septic tank with Imhoff tank in scope, function and performance. (RGPV DEC 2024)
Q.4 What is meant by activated sludge? Describe with sketches the treatment of sewage by activated sludge process. (RGPV DEC 2024)
Q.5 Explain how you determine the oxygen requirements in an activated sludge process. (RGPV DEC 2024)
Q.6 Explain, with the help of neat sketch, the working of an oxidation ditch. Also give various configuration of oxidation ditches. (RGPV NOV 2023)
Q.7 Calculate kg of alum needed per day if alum dose is 28.6 mg/l and the flow is 18 Million litre/day. (RGPV NOV 2023)
Q.8 Compare and contrast septic tank with Imhoff tank in scope, function and performance. (RGPV NOV 2023)
Q.9 What is meant by activated sludge? Describe with sketches the treatment of sewage by activated sludge procner (RGPV NOV 2023)
Q.10 Explain the process of the formation and sloughing of the slime layer in trickling filters. Draw a neat diagram of high-rate trickling filter. (RGPV DEC 2020)
Q.11 Determine the size of a standard rate trickling filter for the following data: (RGPV DEC 2020)
i) Sewage flow = 7 MLD
ii) BOD of raw sewage = 300 mg/l
iii) BOD removed in Primary Clarifier = 40%
iv) Final effluent BOD = 30 mg/l
v) Depth of filter = 1.5 m
UNIT-III
Q.1 Why it is necessary to remove nitrogen from the secondary plant effluents mention different methods used for this. (RGPV DEC 2024)
Q.2 What do you understand by Advanced Wastewater Treatment? How it is different from the conventional treatment? Give, in a tabular form, important AWT processes. (RGPV DEC 2024)
Q.3 Write a detailed note on ultrafiltration. (RGPV NOV 2023)
Q.4 Discuss in brief biological nitrification denitrification for removal of nitrogen from wastewater. (RGPV NOV 2023)
Q.5 Highlight the advantages and disadvantages of ‘Ultra filtration’ and ‘Micro filtration’. (RGPV DEC 2020)
Q.6 Explain the need for removal of nitrogen from waste water. Also, explain the process of Nitrification and Denitrification for nitrogen removal. (RGPV DEC 2020)
Q.7 The sewage flows from a preliminary settling tank to a standard rate trickling filter at a rate of 5 million litres per day having a 5 day BOD of 150 mg/lit. Determine the depth and the volume of the filter, adopting a surface loading of 2500 lit/m²/day and an organic loading of 165 g/m³/day. Also determine the efficiency of the filter unit, using NRC formula. (RGPV DEC 2024)
Q.8 A rectangular grit chamber is designed to remove particles with a diameter of 0.2 mm, specific gravity 2.65. Settling velocity for these particles has been found to range from 0.016 to 0.022 m/sec, depending on their shape factor. A flow through velocity of 0.3 m/sec will be maintained by proportioning weir. Determine the channel dimensions for a maximum wastewater flow of 10,000 m³/day. (RGPV NOV 2023)
Q.9 Design a suitable rectangular sedimentation tank (provided with mechanical cleaning equipment) for treating the sewage from a city, provided with an assured public water supply system, with a max. Daily demand of 12 million litres per day. Assume 80% of water supplied becomes wastewater, detention period is 2 hours and velocity of flow is 0.3 m/minute in the tank. (RGPV NOV 2023)
Q.10 A waste water treatment plant with a design flow of 50,000 m³/d has influent BOD 250 mg/l and effluent BOD of 10 mg/l. The Y (decimal fraction of food converted in kg to biomass kg) is 0.45. Endogenous decay coefficient kd = 0.05d – 1 Assumptions (MLSS=2000 mg/l, under flow concentration from secondary clarifier = 9500 mg/l). Design a completely mixed activated sludge reactor, determine: (RGPV DEC 2020)
i) Volume of reactor
ii) Mass and Volume of solids that must be wasted each day
iii) Recycle ratio.
Q.11 A water treatment plant has two clarifiers treating 0.2 m³/s of water. Each clarifier is 5m wide, 25 m long and 5 m. deep. Determine the percent of particles retained in the clarifier. (RGPV DEC 2020)
Q.12 A city discharges 1.25 m³/s of waste water into a stream whose minimum rate of flow is 8.0 m³/s. The velocity of the stream is about 3.0 km/h. The temperature of the waste water is 20°C and that of the stream is 15°C. The 20°C BOD5 of the waste water is 250 mg/L and that of the stream is 2 mg/L. The waste water contains no dissolved oxygen, but the stream is flowing with saturated DO concentration of 9.2 mg/L. Saturated DO at 15°C is 10.2 mg/L. At 20°C, de-oxygenation constant (Kd) is estimated to be 0.3 per day and re-aeration constant (Ka) is 0.7 per day. Determine the critical oxygen deficit and its location. Also estimate the 20°C BOD5 of a sample taken at the critical point. Use the temperature coefficients of (0) 1.135 for kd and 1.024 for ka. (RGPV DEC 2020)
UNIT-IV
Q.1 What is photochemical smog and how is it formed? (RGPV NOV 2023)
Q.2 Enumerate the different major air pollutants, their characteristics, sources and health effects on human beings in a tabular form. (RGPV NOV 2023)
Q.3 What are the six “criteria” air pollutants? Which one occurs most commonly during summer-time? Why? (RGPV DEC 2020)
Q.4 Write a short note on photo-chemical smog. (350 words) (RGPV DEC 2020)
UNIT-V
Q.1 List out meteorological factors influencing air pollution. (RGPV DEC 2024)
Q.2 Write down the Gaussian distribution equation which is commonly used to predict the concentration of an air pollutant evolving from a source (factory) at any downwind point and the location of the maximum pollution. (RGPV NOV 2023)
Q.3 With a neat sketch Explain the Plume behavior for the different atmospheric conditions. (RGPV DEC 2020)
Q.4 A factory emits 20 g/s of SO2 at height H. The wind speed is 3 m/s. At a distance of 1 km downwind, the values of oy and 62 are 30 m and 20 m, respectively. What are the SO₂ concentrations at the centerline of the plume and at a point 60 m to the side of and 20 m below the centerline? (RGPV DEC 2020)
Q.5 What do you understand by ‘aerosols’? Describe various types of aerosols along with their characteristics. (RGPV DEC 2024)
Q.6 Explain the sources and characteristics of the following air pollutants? (RGPV DEC 2024)
Q.7 A coal fired 1000 MW power plant is operating around 38% efficiency. The ash and sulphur content in the coal used respectively are 35% and 3% and the calorific value of 21 MJ per kg of coal. Find the emission rate of from the plant. (RGPV NOV 2023)
Q.8 Determine the stack gas temperature for the following data: (RGPV DEC 2020)
i) Physical height of stack = 90 m
ii) Wind velocity at the top of stack 2.5 m/s
iii) Pressure 1000 millibars.
iv) Stack gas velocity at the top of stack = 11 m/s
v) Effective height of stack 98.5 m
vi) Ambient temperature 200C
vii) Inside diameter of stack 0.9 m
EXTRA QUESTION
Q.1 A coal fired 800 MW power plant generates daily huge quantum of flyash, bottom slurries, besides particulate matter present in the burnt coal. Estimate the quantum of bottom ash, flyash and particulates generated daily by the plant. Also, suggest eco-friendly method of disposal of the flyash and bottom ash. Following information available: Calorific value of the coal (ash content 38%) burnt 21 MJ/kg; 60% of ash discharged as flyash, and 75% of flyash and 90% of the bottom ash generated may be recovered; overall efficiency of the plant is 40%. (RGPV DEC 2024)
Q.2 Write short notes on (any four) (RGPV DEC 2024)
i) Photochemical smog
ii) Temperature lapse rate
iii) Gaussian Plume Model
iv) Diatomaceous earth filter
v) Ultrafiltration
vi) Ammonia stripping method
Q.3 Compute the diameter of a circular trickling filter for 250 users. Dry weather flow is 120 litres per capita per day. Rate of filtration of trickling filter may be taken as 10 million litres per hectare/metre. (RGPV NOV 2023)
Q.4 Write short notes on: (Any four) (RGPV NOV 2023)
Difference between RSPM and TSPM
ii) Factors affecting the dispersion of air pollutants
iii) Environmental Lapse Rate (ELR) and Adiabatic Lapse Rate (ALR).
iv) Primary and Secondary air pollutants
v) Effect of air pollution on materials
vi) Adsorption by activated carbon
— Best of Luck for Exam —
