1. Using Chlorination and UV treatment for the removal of toxins in Water Treatment
Hernesto Tellez

2. Outline Introduction Chlorine used as a water treatment disinfectant
Waste Water History
Clean Water Act
Widespread use of Chlorination
Chlorine used as a water treatment disinfectant
Chlorine used to kill microbes
Disinfection by-products production
Reactions of DBPs
UV light used as a water Disinfectant
UV used as disinfectant microorganisms
DNA damage

3. Waste Water History Water supply systems during the Roman Empire
Network of Aqua ducts to supply..
Large cities with fresh water
Elaborate Public Baths
Fountains, Latrines
Irrigation and Industry
Waste Water Systems
Waste water collection from numerous sources
Sewer Channels
Cloaca Maxima, Rome’s sewer system
Reconstruction of a sewer channel in the Archaeological Park Xanten in Xanten (Germany)
The famous Cloaca Maxima which drained the Forum was not the only sewer in ancient Rome, see map. The sewers were large enough for men and, in some places, boats to move around underneath the city.

4. Waste Water History

5. Clean Water Act Industrial Revolution, population explosion
Large Cities across US
Waterborne outbreaks in early 1900s
1908 Chlorine used in New Jersey
EPA Clean Water Act 1974
EPA, History of Drinking Water Treatment

6. History of Chlorination
1908 Chlorine used to treat drinking water
By 1995 EPA survey, 64% of community ground water disinfected by use of Chlorine
Widely used because effectiveness and cost
Used to kill Typhoid, Cholera, Dysentery, and…
Bacteria: Salmonella genus (Typhoid) and Escherichia Coli. Outbreak in Walkerton, Ontario in 2000
Viruses: Polio virus, hepatitus-A
Protozoans: Cryptosporidium and Giardia lamblia.

7. Chlorine used to kill Microbes
Most widely used is Hypochlorous Acid (HOCl) made on site
Easily passes through cell membranes to kill bacteria, viruses, and protozoans
Cl2(g) +H2O(aq)  HOCl(aq) + HCl
HCl  H+ and Cl-
Cl gas dangerous to store and handle

8. Disinfection By-products (DBPs)
Chlorine can react with numerous chemicals in water and in micro pollutants
Rxns with Fe, As, pesticides, pharmaceuticals, phenols, …
Cyclohexane, Benzene and Phenols
Chlorine Rxns
Phenol reactions
Chloroform production

9. Phenol Reactions

10. Other DBPs, Steroids

11. UV light as a disinfectant
UV light uses high energy to directly damage the DNA of any microbe involved
Creates the formation of Thymine-Thymine dimers
Also creates Oxygen radicals that react quickly with cellular components

12. Nucleotides

13. DNA Base Pairing

14. DNA Double Helix

15. Thymine Dimers

16. DNA Replication and Mutations

17. DNA Repair

18. References Bougeard, C. M. , Goslan, E. H. , Jefferson, B
References   Bougeard, C. M., Goslan, E. H., Jefferson, B., & Parsons, S. A. (2010). Comparison of the disinfection by-product formation potential of treated waters exposed to chlorine and monochloramine . Water Research , Hader, R. P.-P. (2002). UV-induced DNA damage and repair: a review. Photochemical & Photobiological Sciences , S.J. De Mora, S. D. (2000). environment, The effects of UV radiation in the marine. Cambridge University Press . Tan, Y., Kilduff, J., & Karanfil, T. (2007). Disinfection by-product (DBP) formation and speciation in chlorinated waters after anion exchange treatment. American Chemical Society, (pp ). US EPA. (2000). The History of Drinking Water Treatment. US EPA, Office of Water. V, B. (2006, June). Technical Briefs. Journal of Environmental Health , Zimmer JL, S. R. (2002). Potential Repair of Escherichia coli DNA following exposure to UV radiation from both medium and low-pressure UV sources used in drinking water treatment. Applied and Environmental Microbiology ,