Water Treatment

561 Words2 Pages

The forth step in water treatment is a disinfection. During this stage, disinfectants will be added to kill or inactivate microorganisms that can cause disease in humans. The research on the water sample shows presence of protozoa that cause diseases such as Entamoeba histolytica, Giardia lamblia and Naegleria fowleri (Nemerow, Agardy, Sullivan, & Salvato, 2009). Some protozoa and viruses, which may present in water supplies are extremely harmful. There are two kinds of disinfection which is primary disinfection and secondary disinfection. Primary disinfection functioning in killing or inactivation of microorganism in the desired level while secondary disinfection maintains a disinfectant effectiveness that prevent from the microorganisms grow again. Disinfection treatment methods include chlorination, ozone and ultraviolet light. Chlorination is the most common method of disinfection used to treat water for municipal and individual supplies. It is because chlorination method is easy to conduct and cheapest compare to other method. In municipal supply systems, chlorine is used basically in three forms which are chlorine gas, sodium hypochlorite solution and solid calcium hypochlorite (Cheremisinoff, 1995). Chlorine is very effective for removing almost all microbial pathogens and is appropriate as both a primary and secondary disinfectant. Unfortunately, this method will produce water in which the chlorine can be smelt and tasted by users which most of them find it unpleasant. Binnie and Kimber (2009) stated that the problem can be overcome by dechlorination process after sufficient time for disinfection process. The water will be added with sulfur dioxide or sodium sulfate which reduces the chlorine to chloride (Binnie & Kimber, ...

... middle of paper ...

..., Sullivan, P., & Salvato, J. A. (Eds.). (2009). Environmental engineering: Water, wastewater, soil and groundwater treatment and remediation (6th ed.). Hoboken, New Jersey: John Wiley & Sons.
2. Cheremisinoff, P. N. (1995). Handbook of water and wastewater treatment technology. New York, NY: Marcel Dekker, Inc.
3. Binnie, C. & Kimber, M. (2009). Basic water treatment (4th ed.). London, UK: Thomas Telford Limited.
4. Lajeunesse, A., Blais, M., Benoit, B., Sauve, S., & Gagnon, C. (2013). Ozone oxidation of antidepressants in wastewater – Treatment evaluation and characterization of new by-product by LC-QToFMS. Chemistry Central Journal, 7(15).
Retrieved from http://journal.chemistrycentral.com/content/7/1/15
5. Geldreich, E. E. & LeChevallier, M. (1999). Water quality and treatment: A handbook of community water supplies (5th ed.). New York, NY: McGraw-Hill, Inc.

Open Document