ABSTRACT
Objective To understand the sanitary status of drinking water quality in stations along Hexi Corridor Railway from 2018 to 2020. Methods Among of 270 samples of drinking water collected by a railway CDC from 2018 to 2020 were detected and analyzed. Results A total of 270 water samples were detected from 2018 to 2020. Among them, 90 water samples were detected in train water supply stations, and 89 were qualified, with a qualified rate of 98.89%. 180 water samples were detected in non-train water supply stations, and 119 samples were qualified, with a qualified rate of 66.11%. The qualified rate of water quality test items in train water supply stations was significantly higher than that in non-train water supply stations (χ2=36.44, P＜0.05). There was no significant difference in the qualified rate of water quality test items in different years (χ2=2.4,3.01, 0.04, P＞0.05). Conclusion The drinking water source of each station along the Hexi Corridor Railway is supplied by deep groundwater. Without adding disinfectant, the total bacterial count, coliform group, Escherichia coli and other indicators of drinking water in all stations meet GB5749-2006 “sanitary standard for drinking water”. This raises a question on the necessity to add disinfectant when deep groundwater is used as drinking water source. However, the train water supply station, which is used as the source of secondary water supply, provides drinking water for railway train passengers. The free residual chlorine in the water after chlorination can continuously kill microorganisms in the water. Therefore, it is necessary to add disinfectant to the source water of the train water supply station.
ABSTRACT
Objectives To investigate the sanitary condition of the secondary water supply for passenger trains in the administration area, to evaluate the influencing factors of the secondary water supply system for passenger trains, and to put forward suggestions for improving the water quality of the secondary water supply for passenger trains. Methods The water quality of secondary water supply of 48 trains of 24 pairs of CRH type passenger trains and 160 trains of 10 pairs of type 22 passenger trains and 30 pairs of type 25 passenger trains in Lanzhou Railway Bureau in 2019 was analyzed and compared. Results The qualification rate of 208 samples tested was 73.08%. The qualification rate of secondary water supply quality of type 22 and 25 passenger trains was 62.50% and 66.67%, respectively, and the difference was not statistically significant（χ2=0.23 ，P＞0.05）. The qualification rate of secondary water supply of CRH passenger train was 97.92%, which was statistically significantly different compared with that of type 22 and 25 passenger trains（χ2=18.40, 18.15, P2=0.056, 0.054, 0.056, 0.22, 0, and 0.22, P>0.05). The total number of bacterial colonies, total coliform, turbidity and iron in the secondary water supply of type 22 and 25 passenger trains did not meet the standard, while only one water sample for the secondary water supply of CRH passenger trains did not meet the standard. Conclusion The quality of secondary water supply of CRH passenger train is obviously better than that of type 22 and 25 passenger trains. Changing the position of defecation port and water injection pipe of type 22 and 25 passenger trains, selecting non direct train defecation collection system, or adding appropriate amount of chlorine disinfectant into the water supply hose can significantly improve the qualification rate of bacteriological indexes of secondary water supply of passenger trains.