Project

1
Availability of Safe Drinking Water

• Project 2
• Faculty Mentor Dr George A Sorial,
• Graduate Student Mentor Hafiz Salih
• 2008 NSF RET Site
• Water Quality Group
• Environmental Engineering Division
• Department of Civil and Environmental Engineering

2
Introduction

• Odorous compounds - Single greatest public
  relations issue faced by water utilities
• Cost of controlling taste and odor problems is
  substantial
• Two main compounds Geosmin and MIB II
• Source Cyanobacteria

Nutrients
Cyanobacteria Bloom
Geosmin MIB II
Warm Temperatures
Biodegradation
Cyanobacteria
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Geosmin

• Geosmin (C12H22O)
• Source Blue green algae (cyanobacteria) and
  actinomycete bacteria
• Earthy taste and odor
• OTC 4 ng/L

4
MIB II

• MIB II - 2-Methylisoborneol (C11H20O)
• Source Oscillatoria (cyanobacteria)
• Musty odor and taste
• OTC 9 ng/L

5
Challenges in Treatment

• Extremely low OTC
• Cannot be removed by conventional treatment
  processes
• Presence of NOM in all water sources
• GAC capacity reduces due to NOM
• Activated carbon fibers (ACF) have better surface
  properties, high adsorption capacity

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Activated carbon (AC)

• Made of organic materials such as wood, nuts
  shells, lignite, and bituminous
• Carbonization (changes raw material to char),
  followed by activation (creation of pores by
  oxidation)
• Granular activated carbon (GAC), powder activated
  carbon (PAC), and activated carbon fibers (ACF)

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GAC ACF
Introduction Adsorbent
inch
inch
8
Pore Structure
GAC
ACF
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Pores Size Distribution
Source Mochida et al Carbon 38 (2000) 227239
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Adsorption

• The ability of solid substances to attract
  molecules of solutions and separate them form the
  bulk solution
• Physical adsorption (physisorption) motorized by
  Van der Waals forces
• Chemical adsorption (chemisorption) where
  chemical bonds are formed

11
Source http//www.airpurifiers.com
12
Why AC adsorption

• Relatively low
• cost
• Simple
• Tap filters

Source http//www.freedrinkingwater.com
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Adsorbent Properties
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Materials Methods

• Adsorbates Geosmin, MIB Humic acid
• Adsorbents ACC-15, ACC-20 ACC-25 GAC F-400
• Organic-free water autoclaved DI water,
  buffered with 0.01M KH2PO4, pH adjusted to 7 with
  10M solution of NaOH

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Materials Methods

• Calibration curve 1, 5, 10, 15 20 µg/L
• R-squared gt 0.95
• Response Factor (RF)
• Coefficient of Variance (CV)
• CVlt10

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Materials Methods

• Adsorption isotherms
• Myers Isotherm
• IAST Binary Adsorption

Where qe the amount adsorbed µg/g of
adsorbent Co initial concentration of the
adsorbate (geosmin or MIB), µg/L Ce
equilibrium concentration of adsorbate (geosmin
or MIB), µg/L V volume of solution in the
isotherm bottle, 125 mL m mass of ACFs in the
isotherm bottle, g

• Hi, Ki and pi are regression parameters

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Analytical Procedure
GC - FID
SPME
UV - Vis
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Project Time line
19
Water Treatment Plant Layout