The revision of the national standards for drinking water quality is an important, rigorous and delicate endeavor. The paper introduced the revision of this standard, emphasizing the revision principle, overall technical considerations, and revision contents. Recommendations were also proposed for the implementation of this standard.
Humans ; Drinking Water ; Water Quality ; Reference Standards ; China ; Water Pollutants, Chemical/analysis* ; Water Supply

The establishment of limit values for standards of drinking water quality is an important and complex process. This study systematically introduced the methodology of the establishment of standard limit values for drinking water quality and elaborated on the workflow of setting limit values of water quality indicators, principles and methods of selecting water quality indicators, derivation of safety reference values, and establishment of limit values. It also aimed to provide reference and support for the future revision of relevant standards.
Humans ; Water Supply ; Drinking Water ; Reference Standards ; Water Quality ; Water Pollutants, Chemical/analysis*

BACKGROUND: Diarrheal disease attributable to water and sanitation can be prevented using point-of-use water treatment. In Ethiopia, a small number of households treat water at point-of-use with appropriate methods. However, evidence on factors associated with household use of these treatment methods is scarce. Therefore, this study is intended to explore the household use of appropriate point-of-use water treatment and associated factors in Ethiopia. METHODS: The data of 2005, 2011, and 2016 Ethiopian demographic and health surveys were used for analysis. Households reportedly treating water with bleach, boiling, filtration, and solar disinfection in each survey are considered as treating with appropriate treatment methods. Household water treatment with these treatment methods and factors associated was assessed using bivariate and multivariable regression. In addition, a region level difference in the treatment use was assessed by using multilevel modeling. RESULTS: The number of households that reported treating water with appropriate water treatment methods was 3.0%, 8.2%, and 6.5% respectively in 2005, 2011, and 2016. Household heads with higher education had 5.99 (95% CI = 3.48, 10.33), 3.61 (95% CI = 2.56, 5.07), and 3.43 (95% CI = 2.19, 6.37) times higher odds of using the treatment methods respectively in 2005, 2011, and 2016 compared to household heads who had no education. There was a significantly high number of households that used appropriate water treatment methods in 2011 (AOR = 2.78, 95% CI = 2.16, 3.57) and 2016 (AOR = 2.18, 95% CI = 1.64, 3.89) compared to 2005 data. In pooled data analysis, the reported use of the treatment methods is associated with household head education, residency, drinking water sources, and owning radio and television. From a multilevel modeling, within-region variation is higher than between-region variations in the use of treatment methods in each survey. CONCLUSIONS Below 10% of households reportedly treating water at point-of-use in each survey attributable to different factors. Designing intervention strategies for wide-scale use of treatment methods at the country level is fundamental.
Adolescent ; Adult ; Ethiopia ; Female ; Humans ; Male ; Middle Aged ; Multivariate Analysis ; Socioeconomic Factors ; Surveys and Questionnaires ; Water Purification ; methods ; standards ; statistics & numerical data ; Water Supply ; statistics & numerical data ; Young Adult

Consumer Product Safety ; Drinking Water ; standards ; Equipment Safety ; Food Safety ; Public Health ; instrumentation ; methods ; Safety Management ; Water Supply

OBJECTIVEIt aims to investigate the changes in composition and structure of bacterial communities developing on biological activated carbon (BAC) particles, and the bacterial functions.

METHODA pilot plant had been in service for 180 days, aiming to develop bacterial communities on activated carbon naturally. After 180 days of operation, the bacterial communities were determined by denaturing gradient gel electrophoresis (DGGE) analyses of PCR-amplified 16S rRNA genes. The study on community composition and the phylogenetic relationships of the organisms was complemented by a sequence analysis of cloned PCR products from 16S rRNA genes. Gas chromatography-mass (GC-MS) measurement was used to determine organic chemical composition of inflow and outflow water on the 300th day. TOC and NH(4)(+)-N were also tested in this experiment.

RESULTSIt showed that the stable bacterial structure did not develop on BAC particles until the 9th month during running time of the BAC filter. The communities were finally dominated by Pseudomonas sp., Ba-cillus sp., Nitrospira sp., and an uncultured bacterium. Stable bacterial communities played an important role in removal of NH(4)(+)-N and total organic carbon (TOC). Results from gas chromatography-mass (GC-MS) showed that 36 kinds of chemicals in feed water were eliminated, and concentrations of 5 kinds of chemicals decreased. These chemicals served as nutrients for the dominant bacteria.

CONCLUSIONThe findings from the study suggested that the stability of microbial structure was beneficial for improving NH(4)(+)-N and TOC removal efficiencies. The dominant bacteria had the advantage of biode-grading a wide range of organic chemicals and NH(4)(+)-N.

Ammonia ; chemistry ; Bacteria ; classification ; genetics ; Biofilms ; Carbon ; chemistry ; Filtration ; instrumentation ; methods ; Microscopy, Electron, Scanning ; Pilot Projects ; Waste Disposal, Fluid ; instrumentation ; methods ; Water Microbiology ; Water Purification ; instrumentation ; methods ; Water Supply ; standards

Through the hemodialysis machine and water treatment systems maintenance, the result of complications caused by dialysis can be eliminated. It also of extended the life of hemodialysis machines and improve the quality of dialysis.
Equipment Failure ; Equipment and Supplies ; standards ; Humans ; Maintenance ; Renal Dialysis ; adverse effects ; instrumentation ; Water Supply ; standards

OBJECTIVETo investigate the prevalence of kanamycin (kan) and ampicillin (amp) resistant bacteria in public drinking water.

METHODSBacteria containing kan and amp resistant genes were amplified by PCR and further characterized by colony hybridization and transformation studies. The genus of kan and amp resistant bacteria was determined with standard methods.

RESULTSAmong the 625 drinking water samples, 400 contained kan and amp resistant bacteria and the percentage was 42.5% and 57.5%, respectively, which was further confirmed by the amplification of a 810 bp kan resistant gene and a 850 bp amp resistant gene. Of the 170 kan resistant bacteria, 90 were Gram negative and 80 were Gram positive. Of the 230 amp resistant bacteria, 160 were Gram negative while 70 were Gram positive. Salmonella, Shigella, Staphylococcus, Streptococcus, and E.coli were detected as 13%, 11%, 17%, 30%, and 29%, respectively. Bacterial strain DH5alpha transformed with plasmids isolated from kan and amp resistant bacteria confirmed that the antibiotic resistant genes were mediated by plasmids.

CONCLUSIONDrinking water is contaminated with kan and amp resistant bacteria due to poor sanitary conditions.

Anti-Bacterial Agents ; pharmacology ; Bacteria ; drug effects ; isolation & purification ; Drug Resistance, Bacterial ; Pakistan ; Polymerase Chain Reaction ; Water Microbiology ; standards ; Water Supply ; standards

OBJECTIVETo study environment-friendly determination of azobenzene in trace amounts using beta-cyclodextrin (beta-CD)-modified Au electrode.

METHODSbeta-CD-modified Au electrode was fabricated with a two-step approach, and then a gold electrode modified with beta-CD was used to detect azobenzene by employing Osteryoung square wave voltammetry.

RESULTSThe modified electrode could detect azobenzene, showing a good linearity between the electrochemical current and concentration.

CONCLUSIONAlthough the electrochemical current is related with concentration, the detection limit is around 1.0 x 10(-10) mol/L. This study may provide a new environment-friendly approach for monitoring water quality.

Azo Compounds ; analysis ; chemistry ; Electrochemistry ; Electrodes ; Environmental Monitoring ; instrumentation ; methods ; Gold ; chemistry ; Reproducibility of Results ; Sensitivity and Specificity ; Water Supply ; analysis ; standards ; beta-Cyclodextrins ; chemistry

OBJECTIVETo investigate the feasibility of reducing THM precursors and controlling bromate taste and odor in drinking water taken from the Yellow River by an ozonation combined system.

METHODSThe appropriate ozone dosage was determined, and then the changes of TOC, UV254 and THM formation potential (THMFP) in the combined system were evaluated.

RESULTSOne mg/L ozone could effectively remove taste and odor and meet the maximum allowable bromate level in drinking water. The pre-ozonation increased THMFP, but the conventional treatment system could effectively reduce the odor. The bio-ceramic filter could partly reduce CHCl3FP, but sometimes might increase CHCl2BrFP and CHClBr2FP. The biological activated carbon (BAC) filter could effectively reduce CHCl3FP and CHCl2BrFP, but increase CHClBr2FP. Compared with other filters, the fresh activated carbon (FAC) filter performed better in reducing THMFP and even reduced CHClBr2FP.

CONCLUSIONThe combined system can effectively reduce taste, odor, CHCl3FP, and CHCl2BrFP and also bring bromate under control.

Bromates ; chemistry ; isolation & purification ; China ; Chlorine ; Humans ; Odorants ; analysis ; prevention & control ; Ozone ; chemistry ; pharmacology ; Rivers ; chemistry ; Taste ; Trihalomethanes ; chemistry ; isolation & purification ; Water Supply ; analysis ; standards

OBJECTIVETo assess the health safety of copper, steel and plastic water pipes by field water quality investigations.

METHODSFour consumers were randomly selected for each type of water pipes. Two consumers of every type of the water pipes had used the water pipes for more than 1 year and the other 2 consumers had used the water pipes for less than 3 months. The terminal volume of tap water in copper and steel water pipes should be not less than 0.1 liter, whereas that in plastic water pipes should be not less than 1 liter.

RESULTSThe mean values of the experimental results in the second field water quality investigation of the copper and steel water pipes met the Sanitary Standards for Drinking Water Quality. The items of water sample of the plastic water pipes met the requirements of the Sanitary Standards for Drinking Water Quality.

CONCLUSIONCopper, steel, and plastic pipes can be used as drinking water pipes.

China ; Copper ; analysis ; Humans ; Manufactured Materials ; standards ; Materials Testing ; Plastics ; analysis ; Public Health ; Quality Control ; Steel ; analysis ; Water ; chemistry ; Water Pollutants ; analysis ; Water Supply ; standards