Author : Nusrat Sharmin 1
Date of Publication :19th December 2017
Abstract: Role of Total organic carbon in trihalomethane formation in the treated water of Saidabad Water Treatment Plant (SWTP) was investigated during the months of November 2014 to June 2015. Total organic carbon (TOC) concentration of the incoming raw water varied seasonally with amount ranging from 20.52mg/L –40.69mg/L in drier months (November-February) which later decreased to 8.30mg/L –15.02mg/L in wet season (April-June). A significant increase was also observed in trihalomethane concentrations in dry months at the SWTP outlet, with the highest concentration level of 145.80 μg/L being recorded in January. Based on this trend, a site-specific positive correlation (r = 0.526) was found between raw water TOC and treated water THM using Pearson Method of Correlation. THM in the distribution system also followed this seasonal pattern and the concentration levels of trihalomethanes increased with increasing distance from the treatment plant. A low but definite correlation was found between distance and formation of THM (r = 0.257). In the six locations selected in Dhaka city, total trihalomethane concentration in the tap water ranged from 28.52 μg/L to 191.17 μg/L. In most cases, the concentration levels obtained in drier months were higher than the maximum permissible limits of 80μg/L set by United States Environmental Protection Agency (USEPA).
Reference :
-
- U. Guyo, M. Moyo, B. Nayamunda, M. Shumba and F. Chigondo, “Determination of trihalomehtan formation in raw and treated water supply to a local city in Zimbabwe,” International Journal of Engineering Research & Technology (IJERT) Vol. 2 Issue 2, February – 2013.
- Fraas, T. B., “Multiple linear regression models for predicting trihalomethane formation from chlorinated natural waters”, M.Sc Thesis, Department of Civil engineering, The University of Arizona.
- Abdullah, M. P., Yew, C. H. and Ramil, M. S. B., “Formation, modeling and validation of trihalomethanes (THM) in Malaysian drinking water: a case study in the districts of Tampin, Negeri Sembilan and Sabak Bernam, Selangor, Malaysia,” Water Research, vol. 37, pp. 4637-4644, 2003.
- Arisa, I. R., “Assessment of water quality and THM formation at Saidabad Water Treatment Plant,” B.Sc. Engg. Thesis, Civil Engineering Department, BUET, Dhaka, 2008.
- Trehy, M. L., and Beiber, T. I., “Effects of Commonly Used Water Treatment Processes on the Formation of THM's and DHAN's,” Proc. Annual American Water Works Assoc. Conference, Atlanta, Georgia, 1980.
- Amy, G. L., Chadik, P. A. and King, P. H., “A Statistical Analysis of Surrogate Parameters for Predicting Trihalomethane Formation Potential (THMFP),” Journal of American Water Works Association, vol. 79(7), pp. 89-97, 1984.
- Singer, T. and Reckhow, G., “Disinfection byproductChlorination of Drinking Water, Journal of American Water Works Association,” vol. 73, pp. 392-399, 1999.
- Badawy MI., “Trihalomethane in drinking water supplies and reused water,” Bull Environ Contam Toxicol vol. 48, pp. 157–62, 1992.