Investigation On The Status Of Bacteria And Enteroviruses In Drinking Water Of Dezhou City

Objective:To investigate the contamination status of bacteria and intestinal virus in the integration of urban and rural water supply of Dezhou,and to provide basic data for the establishment of virus indexes in drinking water and policy improvement measures in rural areas,to establish a method for virus concentration in water contamination and to provide a basic research for its determination in our country.Methods:The status of water plants in Dezhou was investigated using questionnaires including basic conditions of water plant units,types of water sources and protection,water supply units,water treatment processes and disinfection.Simulated water samples were prepared by MS2 phage.The first concentrated was taken by NanoCream filter to determine the conditions of concentration,compared with filter elution effect of 0.05mol/L glycine 3%beef extract eluent(pH9.0～9.5)and 3%beef extract eluent(pH9.0～9.5)and elution effect of shaking and peristaltic pump.The second one was taken in 13%(w/v)PEG8000 and 1.2%(w/v)NaCl to determine the rate of recovery.In 2016,during wet season(July-Auguster)and dry season(November-December),source water and drinking water(tap water and tap water samples)were collected.Bacteriological indicators,pH,turbidity and disinfectant amount were detected according to the "standard examination methods for drinking water"(GB/T 5750-2006).Source water and drinking water(tap water and tap water)were concentrated by NanoCream and PEG8000-NaCl precipitation.Intestinal virus in source water and drinking water(tap water and tap water)were detected by RT-qPCR.Results:The total of 16 Dezhou urban and rural integrated water supply plants,covering the city’s 5 million 742 thousand and 300 population was chose as study site.Health permit holding rate was 100%(16/16).The type of water is the reservoir water,accounting for 87.5%(14/16).16 water source protection zones have scope,identification and protection fence,all having personnel management,implementation and 24 hours real-time monitoring of main conveyance section.Water treatment technology with conventional treatment process,accounting for 62.5%(10/16)while disinfection mainly chlorine dioxide disinfection,accounts for 81.25%(13/16).16 plants have laboratory as well as water quality monitoring the implementation of four level monitoring systems.After different eluent and elution conditions of concentration by comparison,the initial concentration of NanoCream filter is experimented under the condition of 0.05mol/L glycine and 3%beef extract as eluent(pH 9.0～9.5).Peristaltic pump elution elution with 3%(w/v)and 1.2%PEG8000(w/v)NaCl were used to have a second concentration in water Determination of virus;at the same time,virus recovery the rate of MS2 phage virusand double agar method are also reused,bringing the conclusion of virus recovery rate 50.56%in the first concentrated,concentrated virus recovery rate 88.89%in the second stage and the total recovery rate 45.67%in two concentrated methods.A total of 182 water samples were collected for bacteriological detection,26 sources of water,156 drinking water,64 samples of which were for enterovirus detection,26 of which were for water sources and 38 of which were for drinking water.The total number of colonies of the maxium water value is 1600CFU/mL with 424 CFU/mL in wet period and 279 CFU/mL in dry season.Among them,there were 3 detected total coliforms accounting for 11.54%(3/26),thermotolerant coliform bacteria and Escherichia coli were not detected.The enterovirus were detected in 1 of the 26 samples(3.85%)with a mean copy number of 228 copies/L water.The standard rate of bacteriological indexes of drinking water was 98.1%(153/156),the standard rate of the total number of colonies was 98.1%(153/156),total coliform,thermotolerant coliform bacteria and Escherichia coli compliance rate was 100%(156/156),the standard rate of disinfectant was 92.3%(144/156)and intestinal virus was not detected.Conclusion:The integration of urban and rural water supply in Dezhou is easier to manage.The investigation for hardware facilities are sufficient,the water source quality protections are efficient,and water treatment processes are reasonable,and the water quality monitoring mechanisms are improved.It has also improved the resources,engineering and water quality problems.The two approaches of NanoCream filter and PEG8000-NaCl can be used for drinking water virus concentration.The integration of urban and rural water supply in Dezhou has higher standardized rate in drinking water bacteriological indicators and lower rate in enterovirus contamination risk.Further study should be made to analyze the contamination of drinking water viruses in China and introduction of the standard of the virus index in drinking water.A new method as well as basic data for developing strategies in China’s rural areas will be established,and the standard of the virus index in drinking water will be introduced into the national standard.