Study On Water Quality Characteristics And Disinfection Technology Of Drinking Water In The Karst Mountain Areas Of Northwest Guizhou Province

With the increasing of both living standards in rural areas and environmental pollution in China,the protection of the quality security of drinking water for rural people has aroused wide concern in recent years.The phenomenon that the microorganism indices exceed the water quality standards?Health Drinking Water Standard GB5749-2006?has became the focused point.In Guizhou karst areas,the low degree of exploitation and utilization of rural water resources is resulted in these aspects:the special geomorphic structure,widespread rocky desertification,the difficulty in preserving of surface water,limited economic conditions and insufficient investment in hydraulic engineering.In addition,rock-ribbed engineering water is growing widely shortage.The water shortage are particularly highlighted in karst mountainous rural area of northwest Guizhou,where ecological environment is fragile,man-land systems are complex,and mining activities are frequent.The daily production and living needs of residents in these mountainous areas mainly rely on dispersed water supply,however,that is not standardized.The main sources of water supply are natural precipitation?rainwater?and epikarst water?mountain spring water?.The disinfection device of dispersed water supply cannot be used in Karst rural mountainous areas in the marke because of high cost and poor universality of equipment and technology at home and abroad,where the economy and civilization are not developed.The health of the residents who drinked directly untreated water was affected.The study investigates the water quality conditions of decentralized water supply in the typical Karst mountainous rural areas in northwestern Guizhou,analyzes the features of the seasonal changes of decentralized water supply,Researches the construction and technology of household automatic disinfection device for drinking water.The study is mainly to provide the theoretical basis and technical support for the dispersed water supply quality and disinfection in karst mountainous rural area.The main research results are as follows:1.Microorganism index exceeds the water quality standards redundantly in northwestern GuizhouIt is found that NO₃-N,COD_Mn,NH₄⁺-N,and microbial indicators are the main pollution factors in the 30 water samples were collected from the study area.The evaluation of single factor index showed that the qualification rates of water quality are 76.67%,73.33%,26.67%,and 3%,respectively;however,the other indicators are qualified.Among them,the microorganism indices exceed the water quality standards,e.g.Colonies number,Coliform number,and Heat-resistant Coliform Bacteria.The analysis of principal components shows that the main factors,include ion concentration,organic matter and microbiological indicator were major factors the comprehensive water quality of decentralized water supply in Guizhou Karst rural areas.2.The construction and application of household automatic disinfection device for drinking waterThe household automatic disinfection device for drinking water is researched and developed to provide safe drinking water in karst mountainous rural area,where the phenomenon of engineering water shortage is prominent,microorganism index exceeds the water quality standards and there is short of technology and equipment for household drinking water disinfection.The study shows that under the salt concentration of 20g/L and electrolysis time of 15-20min,the effluent water of the device satisfies the hygienic standards for drinking water through disinfection of 5-10min.The running cost lows to 0.4 RMB/m³.The household automatic disinfection device for drinking water could satisfies costeffectively the hygienic standards in karst mountainous area.3.The application demonstration research works well in field conditionsThe study shows that under the salt concentration of 20g/L and electrolysis time of 15min,the effluent water of the device satisfies the hygienic standards for drinking water for drinking water through disinfection of 5min except for a water sample.The experiment effect of the disinfection device is affected by the quality of the local water supply.