Hygiene Monitoring Results Of Yuyao Drinkng Water From 2006 To 2015

Objective:Through a systematic analysis of the domestic drinking water hygiene monitoring data in the past ten years in Yuyao, this thesis intends to understand the factors that affect the city’s drinking water, health status and water quality on one hand and establish a simple data model to improve water quality, prevent waterborne diseases and provide effective early warning on the other. Besides, it also has the intention of effectively safeguarding the city’s sanitary quality of drinking water and protecting the health of the city people, so as to further call on the government to effectively control the water resources by providing basic data as well as laying a scientific basis for health supervision to establish a long-term management mechanism.Methods:Through the collection of the readings of off-work water and pipe water in the past ten years, more than fourteen thousand-ton water supply units which are centralized and have hygiene licenses have been taken as samples. Besides, excel is also adopted to establish the database, using SPSS 17.0 statistical analysis, comparing various types of water samples by using x2 inspection qualified differences between analysis, using the mann-Whitney U test of different types of water samples from a gap analysis, using H test analysis more groups of water samples of some indicators variance analysis, and finally using Logistic regression to establish a simple model and predicting the water quality factors. As for the analytical statistics above, it is only meaningful when the significance level is within the required limited content. (P< 0.05)Results:The water quality in the past ten years has improved from the total qualified rate from 58.20%in 2006 to the highest of 58.20%, the annual differences have statistical significance x2= 195.696, P< 0.05)。The total qualified rate of water quality in municipal waterworks (97.07%)is much higher than that in rural waterworks (74.71%), there are significant differences between (x2=314.571, P< 0.05).The top three indicators which affect water quality are turbidity, matters visible to the naked eyes and the content of manganese.At different times (raining seasons, level period and dry seasons) the water quality qualified rate have significant differences (%2= 38.741, P< 0.05), and the highest percent of pass is in dry seasons (94.46%), followed by level period (90.72%) and the lowest is in raining seasons (84.68%).There are differences among water quality qualified rate (x2= 376.382, P< 0.05) under the affection of different disinfectants, and the percent of pass is relatively high in the liquid chlorine and sodium hypochlorite group, but is relatively low in chlorine dioxide and bleaching powder groups.Grouped into township waters and municipal waterworks, there are 20 items of indicator differences that are statistically significant.Via H test, results show that the total number of colonies, pH, matters visible to the naked eyes, oxygen consumption, ammonia nitrogen, manganese, zinc, turbidity, nitrate, sulfate, chloride, soluble total solid, chloroform and other 13 indicators have differences in different seasons. the average data arrayed from high to low, the result turns out as follows:total number of bacteria, oxygen consumption, turbidity, sulfate, manganese, visible to the naked eyes, chloride, soluble total solid, chloroform and other indicators are relatively high in raining seasons.H test showed that 22 indexes, namely, the total number of colonies, total coliforms, heat-resistant coliform bacteria, e. coli bacteria, pH, matters visible to the naked eyes, oxygen consumption, ammonia nitrogen, chromaticity, iron, manganese, zinc, turbidity, free residual chlorine, mercury, total hardness, nitrate, sulfate, chloride, soluble total solid, chloroform and carbon tetrachloride exist significant differences in different disinfectants categories. Effect of microbial indicators control:liquid chlorine, sodium hypochlorite group is the best. In the sensory properties and general chemical indicators control:most of the indicators (oxygen consumption, sulfate, total soluble solids, chromaticity, manganese, matters visible to the naked eyes, pH) are the lowest in the sodium hypochlorite group, chlorine dioxide is in the middle group, and the rest of the indicators (total hardness, chloride, iron, zinc) are the lowest in the bleaching powder group; Environmental indicators:chloroform, carbon tetrachloride, mercury—these three indicators are the highest in the liquid chlorine group, nitrate the highest in the bleaching powder group; Carbon tetrachloride, mercury, nitrate having lowest readings in the sodium hypochlorite group and the minimum readings of chloroform in the chlorine dioxide group.According to Logistic regression model, the rate of unqualified water quality in the villages and towns is 2.17 times higher than that in municipal waterworks; the worst of overall qualified rate of water quality is in the raining seasons, level period the second and the dry seasons enjoying relatively the most security; In the use of disinfectants, the qualified rate s of water from high to low arrangement are:liquid chlorine=> chlorine dioxide> sodium hypochlorite bleaching powder Conclusions:The qualified rate of water quality has improved significantly in the past ten years from 2006 to 2015, especially in town waterworks. By contrast, the qualified rate of municipal waterworks is much higher that that in the villages and town waterworks. The primary indicators leading to low qualified rate lie in the top three indicators: turbidity, matters visible to the naked eyes and the content of manganese.10 years’ data analysis shows that the qualified rate of water is the lowest in the raining seasons, the second is in level period, and the highest is in dry seasons.As for all kinds of disinfectants, the water quality qualified rates arrayed from high to low arrangement are:sodium hypochlorite. liquid chlorine chlorine dioxide> of bleaching powder combined with index H test analysis.