ABSTRACT
Objective To investigate the scope and distribution of water iodine in centralized water supply projects,and provide a basis for taking appropriate control measures in Gansu Province.Methods Collected 2 copies of water samples of all the different water supply of centralized water supply project water in the province's 87 counties (cities,districts),the source water iodine of all centralized water supply projects was tested by the method of cerium sulfate catalytic spectrophotometry.The relationship between different water types and different iodine levels in deep well water were analyzed.Results Of the total 1 563 centralized water supply projects,the median of water iodine was 6.38 μg/L,the range was 0.00-182.10 μg/L,the rates were 62.0％ (969/1 563),30.1％ (471/1 563),6.9％ (108/1 563),0.5％ (7/1 563) and 0.5％ (8/1 563) in water iodine level of ＜ 10,10-＜ 50,50-＜ 100,100-＜ 150 and ≥ 150 μg/L.The surface water was 26.7％ (418/1 563),the median of water iodine was 4.42 μg/L,the groundwater was 73.3％(1 145/1 563),the median of water iodine was 8.10 μg/L,the iodine content of surface water was lower than that of the groundwater (Z =-10.089,P ＜ 0.01);in surface water,the rate of river,lake,reservoir and other water source was 55.7％ (233/418),7.7％ (32/418),21.5％ (90/418) and 15.1％ (63/418),and the median was 2.52,31.10,6.65 and 5.40 μg/L,the iodine content between surface water and water sources of different water sources was significant different (x2 =179.976,P ＜ 0.01);in the groundwater,the rate of deep well,shallow well and spring was 55.5％ (635/1 145),41.3％ (473/1 145) and 3.2％ (37/1 145),and the median was 17.90,3.66 and 4.18 μg/L,the iodine content in groundwater from different sources was significant different (x2 =357.346,P ＜ 0.01).Iodine content of different well depth was significantly different (x2 =288.959,P ＜ 0.01),there was a positive correlation between iodine content and well depth (r =0.364,P ＜ 0.01).Conclusions Iodine content of the surface water is generally lower in many water types in Gansu,iodine content is higher in deep well,and there is high iodine deep well water in local areas.It is recommended that water iodine be included in the population iodine nutrition assessment index.
ABSTRACT
Objective To evaluate sanitary quality of drinking water of small centralized water supply in rural areas using fuzzy comprehensive evaluation method.Methods Fifteen rural small centralized water supply facilities in Jinhua City were randomly selected.The health -related indicators were detected,and fuzzy comprehensive evaluation was used to evaluate the test results.Results The qualification rate of fifteen rural small centralized water supply facilities detected was 6. 67%.The qualified rate of the heat-resistant coliform bacteria in all items was 26. 67%,and the qualified rate of total coliforms was 6. 67%.The qualified rate of total numbers of colony,fluorid,chloride,sulfate,total dissolved solids, iron,oxygen consumption,total hardness and nitrate was all 1 00%.Sanitary quality of the water supply facilities was judged by the fuzzy membership evaluation.There were 4 water supply facilities evaluated as level Ⅰ(good),level Ⅱ(qualified ) and level Ⅳ (bad ) respectivley,and 3 water supply facilities evaluated as level Ⅲ (poor ).Fuzzy comprehensive index of sanitary quality was less than 0. 5 .Conclusion There is a risk of security in rural small centralized water supply water of Jinhua City.The low qualified rate of rural small centralized water supply water was due to heat-resistant coliform bacteria and total coliforms.The relevant departments should strengthen the hygiene management. Disinfection equipment should be installed,and standardized disinfection should be promoted to improve water quality.
ABSTRACT
Objective To know the sanitary status of waterworks for centralized water supply in Anhui province,and try to enhance the implementation Standards for Drinking Water Quality (GB 5749-2006).Methods From April to November in 2008,the hygienic status and water quality self-test capacity of the waterworks at city,county,enterprise and town levels were investigated.Results As for the source water,over 70% of waterworks were up to the Grade Ⅲ standard.In the hygienic management and water treatment process,the city level water workswere better.The rates of complete water treatment were 80.63%,73.78%,58.12% and 60.46%,respectively for different level water works.The rates of the water quality test equipments fulfilled were 77.77%,42.99%,38.18% and 13.77% respectively.For water quality test,the 119 waterworks only focused on the aesthetic,general chemical and microbiological indexes.The performance rates of toxicological indicators,disinfectants indicators,radioactive indicators and other indicators were 17.65%,26.68%,15.97% and 3.49%,respectively.Conclusion Hygienic management of waterworks of levels for centralized water supply in Anhui province needs to be strengthened,and the water treatment process needs to be improved,the capacity building for self-test of water quality in the waterworks needs to be enhanced.
ABSTRACT
Objective To investigate the water quality of finished water of the centralized water supply system in Shenzhen according to 106 indexes of water quality standards of China.Methods The collection and preservation of water samples was according to the standard examination methods for drinking water-collection and preservation of water samples (GB/T 5750.2-2006).The sanitary quality of the finished water samples collected from 35 centralized water supply systems in cities were determined and evaluated according to the Standards for Drinking Water Quality (GB 5749-2006) in May of 2008.Results The average qualified rate of drinking water was 82.9% (29/35) in Shenzhen.Among 106 indexes,4 indexes (such as turbidity,aluminum,manganese and free chlorine residue) exceeded the standard limits in degrees in some centralized water supply system.Conclusion According to the results of the present paper,it is considered that the water quality of the product water from the centralized water supply system in Shenzhen is good.
ABSTRACT
Objective To know the drinking water safety of water plants in Zhejiang and to provide the scientific data for government decision-making.Methods By the nonrandom sampling,the water plants were selected,103 in 2002,102 in 2003, 138 in 2004,419 in 2005,and 555 in 2006.The quality of tap water,product water and source water was determined according to the related standards.Results The eligible rate of product water and tap water in 2002 was 85.4%and 81.7%respectively,in 2003 it was 83.3%and 90.2%respectively,in 2004 it was 70.9%and 69.9%respectively,in 2005 it was 62.5%and 73.5% respectively,in 2006 it was 36.8%and 48.4%respectively.The eligible rate of source water was 68.1%.Conclusion The main problem in drinking water safety in Zhejiang is that the water supply systems in the rural areas are not good enough,no water treatment and disinfection is still common.
ABSTRACT
Objective To understand the water quality of centralized water supply in Shanghai and provide the scientific data for further improvement of the health inspection and management of centralized water supply. Methods The management situation of centralized water supply, the water quality of water source, product water and tap water were investigated by using the methods in Analytical Methods for Water and Sanitary Standard for Drinking Water Quality (2001) in Shanghai in 2006. Results The current situation of management of 165 units of centralized water supply including 19 self-supply water plants in Shanghai was satisfactory. The analysis of drinking water showed that COD and total coliform in source water exceeded the standard limit remarkably(the eligible rates were 63.93% and 22.95% respectively), the eligible rates of COD, turbidity and manganese in product water and tap water were 25.45%, 18.18%, 27.88% and 18.06%, 13.89%, 11.81% respectively. Conclusion The results of the present investigation show that in Shanghai the main problems about the water quality are water source contamination by organic pollutants and the undeveloped water treatment.
ABSTRACT
Objective To know the hygienic condition of different kinds of drinking water plants in Shanxi Province.Methods In 2007,422 water plants and 2 083 secondary water supply units were selected and the information and data that provided by all Sanitation Institute for Health Inspection and Supervision in Shanxi Province were analyzed.Results The hygienic conditions of city's municipal administration water supply systems were the best.Total qualified rate of water quality was 97.67%.The hygienic conditions of rural school's homemade water supply systems were the worst,the qualified rates of all items in the program were the lowest.Most of them had no any analyst and laboratory for water quality test.Only 10.2% of them had water disinfection facilities.Total qualified rate of water quality was 75.32%.In most of water plants,the lack of water quality test facilities and disinfection facilities was one important problem in drinking water safety.In addition,the lack of clean and disinfection in secondary water supply systems was another problem.Conclusion The hygienic conditions of drinking water plans are unsatisfactory and should be improved in Shanxi Province.
ABSTRACT
Objective To explore the water quality of the product water from the centralized water supply system in Hunan, 2006. Methods The sanitary quality of the product water samples collected from 28 centralized water supply system in cities and 39 centralized water supply system in counties in Hunan, 2006, which distributed among the area of Xiangjiang River, Zishui River, Yuanjiang River and Lishui River, were determined and evaluated according to the Standards for Drinking Water Quality (GB5749—2006). Results The eligible rate of the water sample was 70.1%. Among 74 water quality indexes, 12 indexes (such as antimony,aluminum,pH value,manganese and so on) exceeded the standard limits in degrees in some centralized water supply systems. Most of the routine indices of water quality were unqualified and the reference indices were qualified. The quality of some water samples presented statistical difference in some indices (such as aluminum, sulphate, arsenic, et al) among 4 different river areas in Hunan province (P