Leila rezaei; Vali Alipour; Sakine shokooheyan; Amin Ghanbarnejad
Volume 2, Issue 1 , January 2014, , Pages 36-41
Abstract
Background: Pre-chlorination of raw water containing natural organic matters may lead to forming harmful disinfection by-products such as trihalomethanes (THMs), the measurement of which needs expensive advanced analytical instruments. This study was conducted to anticipate THMs formation potential in ...
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Background: Pre-chlorination of raw water containing natural organic matters may lead to forming harmful disinfection by-products such as trihalomethanes (THMs), the measurement of which needs expensive advanced analytical instruments. This study was conducted to anticipate THMs formation potential in Bandar Abbas drinking water system using cheap and simple experiments and a mathematical model. Methods: In a 24 week sampling program, 96 samples were collected weekly from raw water (RW), clarification (CE), filtration (FE), and disinfection effluent (DE). After measuring the Dissolved Organic Carbon (DOC), residual chlorine, contact time, temperature and pH of water, THMs concentration was calculated using a mathematical model. Results: The means of DOC concentration in RW, CE, FE and DE were 5.56, 4.21, 3.50, and 3.01 (mg/l), respectively. The mean of temperature values varied from 22.28 in RW to 21.25 in DE and the mean of pH variations was measured from 6.75 in DE to 8.37 in CE. Also, the mean of residual chlorine concentration was 0.0 to 1.72 in RW and DE, respectively. Conclusion: The means of calculated THMs were 37.92±4.82μg/l, 51.15±9.44μg/l, and 52.71±8.37μg/l for CE, FE, and DE respectively; this did not meet the related EPA standard (30- 40μg/l); therefore, further detailed studies should be conducted to resolve the consumers’ concerns in this regard.
Mohammadreza Heydari; Nader Parsa; Rahim Davani
Volume 1, Issue 2 , October 2013, , Pages 67-76
Abstract
Background: Trihalomethanes are toxic and dangerous substances that are formed in the presence of organic materials when water is chlorinated for disinfection. The Iranian National Standard, World Health Organization, European Union, U.S. Environmental Protection Agency and International Agency for Research ...
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Background: Trihalomethanes are toxic and dangerous substances that are formed in the presence of organic materials when water is chlorinated for disinfection. The Iranian National Standard, World Health Organization, European Union, U.S. Environmental Protection Agency and International Agency for Research in Cancer standards have established a Maximum Contaminant Level for Trihalomethanes for the quality of consumable water. The aim of this study was to determine if the trihalomethanes level in the water of Fars province swimming pools comply with these recommendations.Methods: The laboratory study design was conducted by utilizing spectrophotometer Hack DR5000 VIS-UV equipment for evaluating trihalomethanes concentrations, digital photometer Palin-test for measuring chlorine and pH to process different samples collected from 43 indoor and outdoor swimming pools in Fars Province, Iran. The dependent variable was trihalomethanes and chlorine compounds were independent variables. Precise laboratory experimental methods and appropriate statistical analysis were conducted using SPSS.Results: Mean concentration of trihalomethanes was found to be 242.1μg/l, ranging from 0 to 990μg/l for 43 public swimming pools in Fars province. Association of trihalomethanes and chlorine components with analysis of variance (ANOVA) model was highly significant (P<0.0001).Conclusion: Study results showed that there were strong associations between chlorine compounds and trihalomethanes concentrations. The mean trihalomethanes was 1.2-times (241.2μg/l VS. 200.0μg/l) higher than the national and 3-folds (241.2μg/l VS. 80.0μg/l) higher than the worldwide standards. Therefore, based upon standard recommendations, this conclusion could pose a hazard to public health.
