To measure the mutagenic activity of micro-organic pollutants in drinking water, mutagenic test was conducted using Salmnella typhimurium TA 98 strain on the water sample taken from three water supply station and six tap water in Seoul in July and November 1987. The results were as follows : 1. The average amounts of organic matters in raw, treated, and tap water sampled in July were 0.38mg/l, 0.28mg/l, and 0.45mg/l, respectively, and sampled in November were 0.34mg/l, 0.24mg/l, and 0.22mg/l, respectively. The amount of organic matters of tap water sampled in November did not increase while that of tap water sampled in July increased compare to those of raw or treated water. 2. The amount of organic matters is the highest in neutral fraction compare to acidic and basic fractions. 3. In the five out of six tap water and raw water of Paldang and Kuui station sampled in July, the mutagenic ratios were greater than two (both direct and indirect mutagenicity). 4. In the three out six tap water and raw and treated water of Kuui station sampled in November, the mutagenic ratios were greater than two. 5. While mutagenic were low in acidic and basic fraction, they were high in neutral fraction. The samples which had high mutagenic activity in the total amount also showed high mutagenic activity in neutral fraction. 6. While mutagenic activity was decreased after the treatment of water, it was increased in tap water as the distance from the water supply station increases.
Drinking Water* ; Drinking* ; Seoul* ; Water ; Water Supply

In 2000, there were about 755 millions people lack fresh water, of which 51% lived in the municipal regions of developing countries. In 2020, it will cover the fresh water for people who live in the municipal regions of latrine America and Caribe. 86% of rural people in Africa has not fresh water. There were about 3.3 billions people have been using the unhygienic toilet of which 74% live in the countryside
Water Supply ; Environment ; Hygiene

A cross-sectional study of the supply and use of water was carried out on 8180 households in 3 districts of Quang Binh province and Thua Thien Hue province. The results showed that: two water sources with high rate of usage were deep well (59.3%) and drilled well (19.2%). The rate of households with adequate water supply was 81.5%, among which deep wells were at highest rate of 48.4%, and tap water were at lowest rate of 1.8%. 58.3% of households were found with water containers including: built tanks (49.3%), buckets (24.7%), earthenware vessels (25.3%). 84.6% of water containers were built far from breeding facilities. 95.4% of wells had high wall, 84.8% with surrounding yards but only 8.8% with covers. It is necessary to improve the quality of living water in public by supplying better water sources
Water Supply Family Characteristics

Worldwide, several regions suffer from water scarcity and contamination. The infiltration and subsurface storage of rain and river water can reduce water stress. Artificial groundwater recharge, possibly combined with bank filtration, plant purification and/or the use of subsurface dams and artificial aquifers, is especially advantageous in areas where layers of gravel and sand exist below the earth's surface. Artificial infiltration of surface water into the uppermost aquifer has qualitative and quantitative advantages. The contamination of infiltrated river water will be reduced by natural attenuation. Clay minerals, iron hydroxide and humic matter as well as microorganisms located in the subsurface have high decontamination capacities. By this, a final water treatment, if necessary, becomes much easier and cheaper. The quantitative effect concerns the seasonally changing river discharge that influences the possibility of water extraction for drinking water purposes. Such changes can be equalised by seasonally adapted infiltration/extraction of water in/out of the aquifer according to the river discharge and the water need. This method enables a continuous water supply over the whole year. Generally, artificially recharged groundwater is better protected against pollution than surface water, and the delimitation of water protection zones makes it even more save.
Filtration ; Fresh Water ; analysis ; Water Purification ; instrumentation ; methods ; Water Supply

PURPOSE: The purpose of this study was to develop nursing practice guidelines for water treatment system used in hemodialysis and to evaluate the guidelines by applying them in practice. METHOD: The first draft for the guidelines was developed based on advice and recommendations obtained from procedure review of critical literature. The draft was modified through evaluation by an expert group and pilot application to practice. The final draft was evaluated by the expert group using the AGREE instrument (Appraisal of Guidelines for Research and Evaluation). RESULTS: For the pilot test using the draft guidelines, 144 samples were collected from the water treatment system and hemodialysis machines. Results showed no bacteria. Endotoxin tests and chemical tests passed the criteria. After revision of the draft guidelines and additions to the draft guidelines, the final draft was confirmed. The quality of the final draft was evaluated by 4 experts using the AGREE instrument. The mean standard score was 76.9% for the 19 items. CONCLUSION: The clinical guidelines developed in this research can be utilized as systematic and scientific guidelines for water treatment systems used in hemodialysis. In addition, the results of the research can contribute to improving care services.
Bacteria ; Hemodiafiltration ; Renal Dialysis ; Water ; Water Purification ; Water Supply

The present drinking water purification system in Egypt uses surface water as a raw water supply without a preliminary filtration process. On the other hand, chlorine gas is added as a disinfectant agent in two steps, pre- and post-chlorination. Due to these reasons most of water treatment plants suffer low filtering effectiveness and produce the trihalomethane (THM) species as a chlorination by-product. The Ismailia Canal represents the most distal downstream of the main Nile River. Thus its water contains all the proceeded pollutants discharged into the Nile. In addition, the downstream reaches of the canal act as an agricultural drain during the closing period of the High Dam gates in January and February every year. Moreover, the wide industrial zone along the upstream course of the canal enriches the canal water with high concentrations of heavy metals. The obtained results indicate that the canal gains up to 24.06x10(6) m3 of water from the surrounding shallow aquifer during the closing period of the High Dam gates, while during the rest of the year, the canal acts as an influent stream losing about 99.6x10(6) m3 of its water budget. The reduction of total organic carbon (TOC) and suspended particulate matters (SPMs) should be one of the central goals of any treatment plan to avoid the disinfectants by-products. The combination of sedimentation basins, gravel pre-filtration and slow sand filtration, and underground passage with microbiological oxidation-reduction and adsorption criteria showed good removal of parasites and bacteria and complete elimination of TOC, SPM and heavy metals. Moreover, it reduces the use of disinfectants chemicals and lowers the treatment costs. However, this purification system under the arid climate prevailing in Egypt should be tested and modified prior to application.
Egypt ; Industry ; Seasons ; Water Microbiology ; Water Movements ; Water Pollutants ; Water Purification ; methods ; Water Supply ; analysis

OBJECTIVETo investigate the sanitary status of urban secondary water supply facilities in Haidian district of Beijing.

METHODSAdopting the quantitative classification table drafted by the Bureau for Sanitation Inspection and Supervision of Haidian district, we carried quantitative classification (A, B, C grade) on all 1725 secondary water supply facilities in Haidian district for two times. At the same time, we collected 20 residential areas with stratified random sampling method. As the public points in the first quantitative classification, the effect of level publicity on changing the sanitary grade of the secondary water supply facilities were observed.

RESULTSIn the first two times of quantitative classification, A-level and B-level secondary water supply facilities took up 81.04% (1398/1725) and 89.04% (1536/1725) of all secondary water supply facilities respectively; the ratio of effective sanitary permits achieved 86.14% (1486/1725) and 92.35% (1593/1725) respectively; and the ratio of effective water quality test reports achieved 86.60% (1494/1725) and 97.10% (1675/1725) respectively. There were 52 secondary water supply facilities in 20 collected areas, including 8 A-level, 27 B-level and 17 C-level secondary water supply facilities before level publicity, and 19, 29 and 4 after level publicity. The impact of level publicity on changing the sanitary grade of the secondary water supply facilities was statistically significant (χ(2) = 12.60, P = 0.002).

CONCLUSIONThe city secondary water supply facilities in Haidian district are overall in good sanitary conditions. Quantitative classification and level publicity can effectively improve the sanitary status of secondary water supply facilities.

Objective: To analyze the pollution status and influencing factors of Legionella pneumophila in a secondary water supply facility in a city. Methods: From June to August 2020, a survey on the level of Legionella pneumophila in secondary water supply unit was carried out in a city in northern China, and 304 sets of secondary water supply facilities were included in the study. A total of 760 water samples were collected from the inlet and outlet water of the secondary water supply facilities and some water samples in the water tank were collected for the detection of Legionella pneumophila, standard plate-count bacteria and related physical and chemical indicators. Through questionnaire survey, the basic information of secondary water supply facilities and daily management of water quality were collected. Multivariate logistic regression model was used to analyze the influencing factors of Legionella pneumophila contamination. Results: Among 304 sets of secondary water supply facilities, most of them were located in residential buildings [57.24% (174/304)]. High and low water tank water supply, low water tank variable frequency conversion water supply and non-negative pressure water supply accounted for 26.6% (81/304), 36.8% (112/304) and 36.5% (111/304), respectively. About 25.7% of facilities (78/304) were positive for Legionella pneumophila. Among them, the positive rates of Legionella pneumophila in high and low water tank water supply, low water tank variable frequency conversion water supply and non-negative pressure water supply facilities were 38.3% (31/81), 29.5% (33/112) and 12.6% (14/111), respectively. The results of multivariate logistic regression model analysis showed that the disinfectant residue could reduce the risk of Legionella pneumophila contamination in water samples, and the OR (95%CI) value was 0.083 (0.022-0.317). The increase of the standard plate-count bacteria and conductivity might increase the risk of Legionella pneumophila contamination in water samples. The OR (95%CI) values were 3.160 (1.667-5.99) and 1.004 (1.001-1.006), respectively. Compared with the non-negative pressure water supply, the risk of Legionella pneumophila contamination of secondary water supply facilities was increased by water supply from high and low water tanks and variable frequency conversion water supply from low water tanks, with OR (95%CI) values of 4.296 (2.096-8.803) and 2.894 (1.449-5.782), respectively. Conclusion: The positive rate of Legionella pneumophila in secondary water supply in the study city is high. Disinfectant residue, conductivity and method of water supply are associated with the positive rate of Legionella pneumophila.
Humans ; Legionella ; Water Microbiology ; Water Supply ; Legionella pneumophila ; Reproduction ; Disinfectants

The radioactive safety of drinking water has attracted increasing public concern. The newly issued Standards for Drinking Water Quality (GB5749-2022) in China has revised the radiological parameters. This article provides an overview of the main sources, levels of radionuclides in drinking water, and summarized the individual doses criterion and adverse health effects associated with exposure of the public to radionuclides from drinking-water. It analyzes and discusses the relevant revision content of radiological parameters, including the guidance values for screening gross α and gross β, subtracting the contribution of potassium-40 from gross β activity when the gross β activity concentration exceeds the screening level, and the basis for establishing the limit values of reference indices uranium and radium-226. Specific implementation and evaluation suggestions are also proposed.
Humans ; China ; Drinking Water ; Radioisotopes/analysis* ; Uranium/analysis* ; Water Supply

For drinking water security the German waterworks proceed on a comprehensive concept, i.e., the protection of all the regions from the recharge area to the client. It includes the protection of the recharge area by a precautionary management, a safe water treatment, a strict maintenance of the water distribution network, continuous control and an intensive training of staff. Groundwater protection zones together with effective regulations and control play a very important role. Three protection zones with different restrictions in land-use are distinguished. Water in reservoirs and lakes is also protected by Surface Water Protection Zones. Within the surrounding area the land-use is controlled, too. Special treatment is necessary if acidification happens caused by acid rain, or eutrophication caused by the inflow of sewage. Very important is the collaboration between waterworks and the farmers cultivating land in the recharge area in order to execute water-protecting ecological farming with the aim to reduce the application of fertilizers and plant protection agents. Probable financial losses have to be compensated by the waterworks.
Ecology ; Germany ; Water Pollutants ; isolation & purification ; Water Pollution ; prevention & control ; Water Purification ; methods ; Water Supply ; analysis