8/11/2019 Example MT Exam

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United Arab Emirates UniversityName______________________

College of EngineeringDept. Civil & Env. Eng. Student ID#________________

CIVL375: Water and Wastewater Technolog

!nd Semester "5"$Sect%on &

'%dTerm ()am 'a)* +rade !" T%me &:&5

1. (3.0 pts) This problem isrelated to the schematic below which shows a flow

diagram of a domestic wastewater treatment plant. Select the correct answer

a.The type of particle settling encountered in the grit chamber is (are)

(i) Type I settling (ii) Type II settling(iii) Type III settling (iv) Type III and IV settling

b.The type of particle settling encountered in the primary settling tank is (are)

(i) Type I settling (ii) Type II settling

(iii) Type III settling (iv) Type III and IV settling

c.The type of particle settling encountered in the secondary settling tank is (are)

(i) Type I settling (ii) Type II settling

(iii) Type III settling (iv) Type III and IV settling

d.The objective of aeration in the aeration tank is to(i) increase dissolved oygen (ii) reduce the p!

(iii) remove undesirable gases (iv) increase the p!

e. The activated carbon reactor shown is designed as a

(i) batch reactor (ii) plug flow reactor

(iii) continuous"stirred tank reactor (iv) packed bed reactor

f.If the primary settling tank of this treatment plant is #$"ft deep and the tank receives

a flow rate of $ million gallon per day. The minimum weir length that should be

provided for this tank is%

(i) #&&&& ft (ii) #&& ft (iii) #$ ft (iv) &. ft

'Sbar screen TS traveling screen * grit chamber +Sprimary settling tank

,Taeration tank SS secondary settling tank - filtration ,* activated carbon

*T contact tank

*astewater 'S

*T

*hlorine

TS+S

,TSS

Treated

wastewater

,*-

8/11/2019 Example MT Exam

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2. (1.5 pts.)In the design of a wastewater treatment plant/ the 0uality of the effluent

and the capacity of the plant are basic re0uirements for the design. 1n what basis each

of these two re0uirements is determined2

3. (2.0 pts.) The 3S 4+, states that 5bacterial 0uality criteria for drinking water from

public supplies re0uire not more than # total coliform6#&& ml as the arithmetic mean

of all water samples eamined per month/ with no more than 7 coliforms6#&& ml in

any sample if the number of samples is $&6month or no more than 7 coliforms6#&&

ml in 89 of the samples if the number of samples eceeds $&6month:.The effluent of a water treatment plant that serves #8/&&& people was sampled at

regular intervals over a month period for coliform testing and the results are shown in

the table below%

Sample number # $ ; 7 8 < = > ? #& ## #$ #; #7 #8 #