Abstract:
Objectives To analyze the examination results of pH, turbidity and residual chlorine in finished water from water-supplies as well as in tap water of Changzhou from 2006 to 2016 in order to provide scientific basis for on-line monitoring and warning the quality of drinking water.
Methods Descriptive epidemiological method was used to analyze the examination results of pH, turbidity and residual chlorine in finished water from 3 municipal water supplies as well as in tape water from 21 monitoring sites by the Changzhou Center for Disease Control and Prevention once a month from 2006 to 2016.
Results The mean value of pH, turbidity and residual chlorine in finished water from 3 municipal water supplies were 7.57±0.22, 0.28±0.18 (NTU) and 0.59±0.14(mg/L), respectively; the qualification rates were all 100%. There were no significant difference on the mean of pH in finished water among 3 municipal water supplies (P=0.108), while there were significant difference on the mean value of turbidity and residual chlorine in finished water among 3 municipal water supplies (P < 0.05). The mean value of pH, turbidity and residual chlorine in tape water from 21 monitoring sites were 7.59±0.23, 0.35±0.18 (NTU) and 0.32±0.21 (mg/L), respectively; the qualification rates were all 100%. There were significant differences on the mean value of pH, turbidity and residual chlorine in tap water among 21 monitoring sites (P < 0.05). Moreover, there were no significant difference on the mean of pH between finished water and tape water (P=0.096). The turbidity in finished water was significantly lower than that in tape water (P < 0.05), and the residual chlorine in finished water was significantly higher than that in tap water (P < 0.05). There were significant differences on the mean value of pH, turbidity and residual chlorine in finished water and in tap water among 12 months (P < 0.05).
Conclusions To know the mornitoring results of pH, turbidity and residual chlorine and the rule of changing for finished water and tap water could provide scientific basis for on-line monitoring and warning the quality of drinking water.