Waste water treatment: Review

Lectures

Introduction

Review

Quality and
treatment

Treatment

Reactors

Physical

Chemical

Biological

Equalization

Precipitation

Activated
sludge

Filtration

Sorption

Trickling

filter

Settling

Ion
exchange

Desalination

Disinfection

Coagulation
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REVIEW

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Units of Measurement
Basic units and conversion factors
Quantity

SI Units

SI Symbol

Length

Meter

m

3.2808

ft

Mass

Kilogram

kg

2.2046

lb

Temperature

Celsius

o

1.8(oC)+32

o

Area

Square meter

m2

10.7639

ft2

Volume

Cubic meter

m3

35.3147

ft3

Energy

Kilojoule

kJ

0.9478

Btu

Power

Watt

W

3.4121

Btu/hr

Velocity

Meter/sec

m/s

2.2369

mi/hr

Flow rate

Meter3/sec

m3/s

35.3147

ft3/s

Density

Kilogram/meter3

kg/m3

0.06243

lb/ft3

C

Conversion
Factor

Gallon is a unit of volume = 3.785 liters
You may download the program convert.exe for future use
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USCS
Units

F


Prefixes

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Quantity

Prefix

Symbol

10-9

nano

n

10-6

micro

10-3

milli

µ
m

10-2

centi

c

10-1

deci

d

10

deka

da

102

hector

h

103

kilo

k

106

mega

M

109

giga

G

Periodic Table

Source: />

Concentration
Solute

+

contaminant

Solvent
pure water

=

Solution

water or wastewater to be treated

Units of Concentration
• mg/L = part per million (ppm) for dilute solution
• ug/L= part per billion (ppb)
• Molarity (mol/L); number of moles= mass/ atomic or molecular weight
• Normality (eq/L); number of equivalents= mass/ equivalent weight
• mg/L as CaCO3
Concentration of X (mg / L) × 50 ( mg CaCO3 / meq)
mg

of X as CaCO3 =
L
Eq. wt. of X ( mg / meq)

• Percent by mass


Example:
Gulf sea water contains about 4% total dissolved solids
(TDS). What is the concentration of TDS in mg/l

Solution:
4% means 4 g TDS/ 100 g water
Since 1000 g water is 1 liter, then 100 g water is 0.1 liter.
4% = 4000 mg TDS/ 0.1 liter water
= 40,000 mg/ liter

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Solids
Solids in water

Suspended
(turbidity)

Dissolved
(mainly salinity)
Filtration

Solids in water

Volatile (organic)

Fixed (inorganic:
salts and metals)

Combustion at 550 oC
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Microorganisms
Microorganism

Size (um)

Viruses

0.02-0.3

Bacteria

0.1-10

Some are pathogenic
Cholera, typhoid

Algae

1-100

Non pathogenic

Fungi

Few umseveral cm

Protozoa

10-300

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Disease
All pathogenic
AIDS, hepatitis, mad cow

Many are nonpathogenic
Some are pathogenic
Amebic dysentery, malaria


Test for Pathogens
Total coliform
coliform
Total

35 oC

Fecal

Fecal

44.5 oC

Nonfecal
Nonfecal


Membrane Filter Technique



Multiple-Tube Fermentation Technique

Note: Pathogenic means disease-causing. Also note that all coliforms are
non pathogenic except E. Coli, but they are good indicator of the presence
of pathogens.
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Water pollution
pollution
Water

Physical
Physical
Radiological
Radiological

•Thermal

•Solids

Chemical
Chemical

Biological
Biological

•Radio-isotopes

•Hardness
•Pathogens
•Heavy metals
•Nutrients
•Pesticides
•Oxygen demanding waste
•Volatile organic compounds (VOCs)

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Treatment Reactors
• Batch Reactors
• Completely Stirred Tank Reactors (CSTR)
• Plug-Flow Reactors
• Dispersed Plug-Flow Reactors
• Packed bed Reactors
• Fluidized Packed bed Reactors

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Reactions

Transform

Chemical

Transfer

Biological
Volatilization

Hydrolysis

Aerobic degradation

Radioactive decay

Anaerobic degradation Sorption

Photodegradation
Combustion
Oxidation-reduction

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Ion exchange
Bio uptake
Sedimentation

Industry

Wells
Pollution Control

Industry
Pretreatment

Wells

Stream
Lake or
Sea

WTP

To
people

Sanitary
sewer
Homes
WWTP
Discharge
or reuse

Examples of WTPs:
Al Fujairah, Al Taweela, and Umm Al Nar

Examples of WWTPs:
Zakher, Al Mafraq, Jebel Ali, and Al Aweer
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CIVL270 Needed Material





Chemistry and microbiology
Mass balance
Water pollution
Pollution control

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