Environmental Engg‑II (CE-702 (B)) - Important Questions

Explain unit operations and processes and enumerate the various unit operations/processes and treatment systems used for wastewater treatment.

Design a primary settling tank for 150 MLD sewage treatment plant and discuss the process in a sludge digester.

Discuss in brief the various types of settling tanks.

Explain the four types of settling / sedimentation systems in wastewater treatment and criteria for selecting among them.

Write a note on racks and screens and determine head loss through a bar screen.

Explain the importance of micro-organism in biological treatment.

Determine channel dimensions of a rectangular grit chamber for given particle size, settling velocity and flow-through velocity.

Design a primary / rectangular sedimentation tank for sewage flow given detention period and flow velocity.

Calculate daily alum requirement from alum dose and water flow.

Differentiate between attached growth and suspended growth processes and list treatment techniques under each, including preliminary vs primary vs secondary treatment

Design of standard-rate trickling filter: depth/volume/diameter from hydraulic and organic loadings and efficiency by NRC formula

Explain the working of an oxidation ditch with a neat sketch, including its various configurations.

Compare and contrast septic tank with Imhoff tank in scope, function and performance.

Explain activated sludge and treatment of sewage by activated sludge process with sketches

Numerical on SVI, return sludge ratio and return sludge solids concentration from MLSS and settled sludge volume

Explain contact bed and its working operations

Explain working of oxidation pond and symbiotic relationship with kinetic equations for plug flow and complete-mix reactors, and define MCRT, F/M ratio and sludge bulking

Design of two-stage trickling filter using NRC equation with recirculation, including diameters and BOD loadings

Define and explain significance of F/M ratio, MLSS, MLVSS, hydraulic detention time, solids retention time and volumetric organic loading

Explain sludge recycle and derive determination of sludge recycle rate from SVI and MLSS

Explain determination of oxygen requirements in activated sludge process

Explain the need for nitrogen removal from wastewater/effluent and the biological nitrification-denitrification processes/methods for nitrogen removal.

Discuss in brief the biological and chemical methods of removal of phosphorous from waste water.

Explain nitrification and denitrification in biological nitrogen removal and describe methods for phosphorus removal in wastewater treatment.

Explain the mechanisms by which activated carbon removes contaminants from water and the factors affecting its adsorption capacity.

Explain the principle of operation of a diatomaceous earth filter. Why is a precoat necessary and what is the function of body-feed addition during filtration?

Differentiate ultrafiltration, microfiltration and reverse osmosis in terms of pore size, separation mechanism and typical applications.

Describe adsorption treatment of water by activated carbon and the regeneration of granular activated carbon.

What do you understand by Advanced Wastewater Treatment? How it is different from the conventional treatment? Give, in a tabular form, important AWT processes.

Write a detailed short note on ultrafiltration.

List major air pollutants with characteristics, sources and human health effects in tabular form

What is photochemical smog? Explain its formation mechanism, constituents and effects.

A coal fired 800 MW power plant is operating around 38% efficiency. The ash and sulphur content in the coal used respectively are 38% and 4%, and the calorific value of 21 MJ per kg of coal. Find the emission rate of $SO_2$ from the plant.

Define air pollution and explain primary vs secondary sources with examples

Classify air pollutants by origin, physical state and chemical composition and discuss characteristics

Discuss the effects of air pollution on:

What is meant by smog? Discuss its causes and effects.

Write a short note on photochemical smog.

Explain sources and characteristics of sulphur dioxide and hydrogen sulphide

Numerically estimate daily fly ash, bottom ash and particulates from a coal-fired power plant and suggest eco-friendly disposal

Define aerosols and describe their types and characteristics

Write short notes on RSPM vs TSPM, dispersion factors, ELR vs ALR, primary vs secondary pollutants, effects on materials, adsorption by activated carbon

Explain atmospheric dispersion and write the Gaussian plume equation for ground-level / downwind pollutant concentration including location of maximum.

Explain different plume behaviors (looping, coning, fanning, fumigation, lofting, trapping) with neat sketches and the atmospheric stability conditions under which they occur.

Derive the Gaussian Plume Model expression for continuous point source emission, stating assumptions and significance of parameters.

List out meteorological factors influencing air pollution.

Write short notes on (any four):

A municipal wastewater has a $BOD_5$ of $200$ mg/l and $K_1$ (base e) is $0.39$ day$^{-1}$. Determine.