Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 6th Sem 2161304 Biological Processes For Wastewater Treatment Previous Question Paper
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?VI (NEW) EXAMINATION ? WINTER 2020
Subject Code:2161304 Date:22/01/2021
Subject Name:Biological Processes for Wastewater Treatment
Time:02:00 PM TO 04:00 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Marks
Q.1 (a) Differentiate between Biological and Physicochemical analysis
03
(b) Explain clearly the difference between BOD, COD and TOC.
04
(c) Derive the relationship to find the amount of methane per gram of
07
COD.
Q.2 (a) Define the terms: (i) SVI (ii) organic loading (iii) yield coefficient
03
(b) A sample of wastewater was incubated for 7 days at 20 ?C and BOD
04
result is 208 mg/l, BOD rate constant K = 0.15 day-1. Calculate (i)
5 ? day BOD (ii) 10 ? Day BOD (iii) Ultimate BOD
(c) Explain mass balance for substrate for CFSTR with recycle.
07
Q.3 (a) Explain about stuck rector.
03
(b) With reference to attached growth processes explain mass transfer
04
limitations.
(c) Explain the Thomas method for determination of reaction rate
07
constant and ultimate BOD.
Q.4 (a) Explain the role of microorganism in wastewater treatment?
03
(b) Give classification of biological treatment processes.
04
(c) Compute the mean cell residence time, recirculation ratio, and
07
volume of a reactor from the following data to design a
conventional activated sludge process. Compare the recirculation
ratio if the effluent biomass concentration of 15 mg/L is considered
in the mass balance analysis. Given data: ? Daily average
wastewater flow, Qavg = 20 MLD ? Sludge wasting flow, Qw =
140 m3/d ? Biomass concentration in reactor, X = 4000 mg/L ?
1
Returned sludge concentration, Xr = 10000 mg/L ? Hydraulic
retention time, = 4 hours
Q.5 (a) Differentiate between Anoxic and Anaerobic process.
03
(b) Write the Difference Between Aerobic & Anaerobic Treatment
04
Process.
(c) Enlist the modifications of Activated sludge Process and explain
07
any two with sketch.
Q.6 (a) Discuss the problems of bulking in ASP
03
(b) Enlist the parameters affecting anaerobic digestion and explain
04
alkalinity requirement.
(c) Explain anaerobic treatment process as a four stage process.
07
Q.7 (a) Discuss about multistage anoxic digester.
03
(b) Explain single stage and two stage trickling filter.
04
(c) Write a short note on systems with packaged (pre-engineered)
07
treatment plants.
Q.8 (a) Write a brief note on slow sand filter.
03
(b) Discuss the mechanism of working of RBC with neat sketch.
04
(c) Explain the major problems faced by small communities to treat the
07
domestic wastewater
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This post was last modified on 04 March 2021