Post on 09-Apr-2022
Overview of Environmental Chemistry, Career Options
and a Touch of Drinking Water Disinfection Chemistry
Gary L. Emmert
Mobile Analytical Monitoring & Modeling Laboratory
Associate Dean of Natural Sciences
and Professor of Chemistry
Founder and
Chief Executive Officer
The Elements of old…
Air…Water… Earth (Soil)… and add Fire (light) to energize the transformations (reactions) among the elements
Cl2 + 2H2O ⇌ HOCl + H3O+ + Cl―
HOCl + H2O ⇌ OCl― + H3O+
Water Chlorination is the Most Common Form of
Water Disinfection in the United States
Free Available Chlorine :
Total concentration of Cl2 + HOCl + OCl―
Drinking Water Disinfection By-Products (DBPs)
The DBPs produced depend largely on which
chemical disinfectant is used.
Chlorinated water -- (two common classes)
Trihalomethanes (THM4)
Haloacetic acids (HAA5).
“Maximum Contaminant Levels” set by
EPA for finished water.
THM4 MCL for Total-THM4 = 0.080 mg/L (80 g/L)
CHCl3
Chloroform
CHBrCl2
Bromodichloro-
methane
CHBr2Cl
Dibromochloro-
methane
CHBr3
Bromoform
HAA5 MCL for Total-HAA5 = 0.060 mg/L (60 g/L)
CH2ClCO2H
MCAA
CHCl2CO2H
DCAA
CCl3CO2H
TCAA
CH2BrCO2H
MBAA
CHBr2CO2H
DBAA
HAA9 HAA5 plus four unregulated, but important HAAs
CHBrClCO2H
BCAA
CBrCl2CO2H
BDCAA
CBr2ClCO2H
DBCAA
CBr3CO2H
TBAA
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Introduction
Government regulations with regard to DBPs are becoming
stricter
Many utilities struggle each year to meet these regulations –
especially THMs and HAAs
Daily process control strategies - optimize treatment
practices aimed at minimizing THMs and HAAs
But, come on, this is the US of A –
are they really a problem…?
Emmert, G.L., Cao, G., Geme, G., Joshi, N. and
Rahman, M. (2004) Methods for real-time
measurement of THMs and HAAs in distribution
systems. AWWARF and AWWA, Denver, CO.
Water Research Foundation Project 2873
33
Emmert, G.L., Brown, M.A., Simone, P.S.,
Geme, G and Cao, G. (2007) Methods for
real-time measurement of THMs and HAAs in
distribution systems Phase II. AWWARF and
AWWA, Denver, CO.
Capillary Membrane Sampler
Tube within a Tube Sampling
Configuration
Functions as its own calibration
and sampling vessel
Relatively simple alternative on-
line sampling device
37
• Allow rural water utilities access to the same tools used by
large metropolitan water treatment plants
• Mobile laboratory “shared” by three rural water treatment
plants—share in use and share in the cost
• Calibrate model for ~10 days at one water treatment plant,
then use typical parameters to predict THMs for ~20 days.
• Cycle through each member in the Cooperative
approximately once every 30 days
48
Need a “HAAs meter”
• allows for a real-time response
• proactive intervention
• control strategies optimized on the fly
Is water really that important for space missions?
• The cost of putting an object in orbit is estimated
to be ~ $16,000 per pound.
•Water weighs about 8 pounds per gallon.
•1 liter of water in space ~$32,000!!!
•You thought bottled water was expensive…
Is water really that important for space missions?
• The cost of putting an object in orbit is estimated
to be ~ $16,000 per pound.
•Water weighs about 8 pounds per gallon.
•1 liter of water in space ~$32,000!!!
•You thought bottled water was expensive…
The number one factor limiting the number of mission
personnel is the amount of available drinking water.
Silver (I) Ion
Sensor-On-a-Valve
Iodine –
Sensor-On-a-Valve
Lead –
Sensor-On-a-Valve
Three in One – Multipurpose Chemical Analyzer for Space
Externally funded research that is both
“down to earth” and “out of this world”
since 1997
Mobile Analytical Monitoring & Modeling Laboratory
MAMML (current group):Naga Bopanna Drake Williams
Madison Herbert Melissa Alfonso
MAMML Alumni:Dr. Paul Simone, The University of Memphis
Dr. Michael Brown, Foundation Instruments, Inc.
Dr. Gija Geme, Southern Arkansas University
Dr. Lucy Thurston, Marathon Oil, Houston, TX
Ms. Neena Joshi, (MS) Agilent
Dr. Gang Cao, Ph.D., U of Florida
Dr. Md. Rahman,
Dr. Patricia L. Ranaivo,
Dr. Meggan Larson, 3M
Mr. Will Stephens, (MS), SanTan Brewery, St. Louis, MO
Dr. Cynthia Choo, Georgia Pacific, Inc., Memphis, TN
Dr. Jill P. Williamson, NASA-Marshall SFC
Dr. Aaron Brown, Cordant Health Solutions, Flagstaff, AZ
Dr. Christina Henson, Buckman Int. Labs
Dr. Heather Fleming, Buckman Int. Labs
Mr. Dylan Benningfield (MS)
Ms. Noel Harris (MS), Shelby County Schools
Dr. Thomas Watts III
Dr. Robyn A. Snow, Coast Guard Academy Faculty
PittCon 2011, Atlanta, GA
PittCon 2014, Chicago, IL