1. Drinking water, Disinfection by-products and Developing countries Junjie Zhu Advisor: Paul Anderson Illinois Institute of Technology,Chicago,IL
BACKGROUND
Disinfection By-Products (DBPs): Organic matter reacts with disinfectants during water treatment
① Important: Deeply related with people’s daily life all over the world, especially in developing
countries because drinking water may contain DBPs!
② Threaten: Widely use Chlorine as infectant in developing countries and produce Chlorination By-
Products (CBPs) which threatem people’s drinking water quality.
③ Inadequate: Understanding of DBP composition and treatment methods are inadequate
④ Trend: 600 DBPs[1] have been identified, but more and more new DBPs being detected
⑤ Alternative: Understand Natural Organic Matter (NOM) and remove it
TECHNOLOGY & METHODS
ONGOING WORK
UV254nm
What is UV254nm?
Water quality test parameter using ultraviolet (UV) light at the UV 254nm wavelength
Why is UV254nm?
Serve as an indication of organics in water and wastewater since most organics are absorbed at the UV 254nm wavelength
Relationship between UV254nm and [NOM]
UV254nm = ε∙b∙[NOM]
ε:Molar absorbtivity of organic matter in water
b:Path length of the water sample (Constant)
[NOM]:Concentration of NOM in the water
Inadequate
Only detect ring structure. For example, UV254 wouldn’t detect methanol
Ongoing work
① River flowrate and UV254nm
Flowrate and UV254nm
( Fox river at Elgin,IL)
a.Similar pattern between flowrate and UV254nm from Oct,2007 to Sep,2008 (Missing May,08 data)
b.UV254nm increases when flowrate increases
c.Why same flowrate, different UV254nm?
Flowrate vs UV254nm
( Fox River at Elgin,IL)
c.Why same flowrate, different UV254nm?
Might be temperature difference. For example:
2007,Oct.1, 2, 24 are 64, 68, 47 ℉ respectively
Dec.10, 11, 28 are 28, 31, 31 ℉ respectively
② Air Temperature and UV254nm
(Monthly average data used)
Air Temperature and UV254nm
( Fox river at Elgin,IL)
a.Air temperature higher, UV254nm larger
b.UV254nm ranges from about 0.1 to 0.3
c.Same air temperature, different UV254nm?
May be caused by different flowrate and other factors.
Thanks to City of Elgin,IL for water data
FUTURE WORK
1.Water Temperature and UV254nm
2.Compostion of NOM and
River flowrate, Water Temperature, Air Temperature
3.Different water sources and NOM
THOUGHTS
NOM dominates the organic matter in drinking water treatment systems. Compared to these DBPs removal short-term solutions, removal of NOM is one of the most effective, low cost and long-term way to decrease DBPs production.
Assessment and characterization of NOMs should be further investigated and methods developed to remove NOMs based on their chemical and physical characteristics. Research figures that different NOM sources should be emphasized[2], the concentration and formation of DBPs potential varied with season[3]. Analysis of NOM based on sources and seasonal change can improve NOM removal’s efficiency, reduce the DBPs and provide safe drinking water in developing countries.
Investigation on relationship between
Concentration of NOM and
River flowrate, Air Temperature, Water Temperature
Compostion of NOM and
NOM and Different water sources
REFERENCES
[1].
[2].M.Fabbricino, G.V.Korshin, Modelling disinfection by-products formation in bromide-containing waters. Journal of Hazardous Materials 168 (2009)
[3].Chao Chen, Xiao-jiao Zhang,etc. Disinfection by-products and their precursors in a water treatment plant in North China Seasonal changes and fraction analysis. Science of the Total Environment 397 (2008)