Background & Aims of the Study: Saveh city-located in the semi-arid area in Iran-has brackish water and it was forced to use reverse osmosis desalting systems. Water is not distributed through the distribution network to homes so, people have to buy water from certain places and transfer water through household storage vessel. They have to buy more water and keep it at home for more than 1 week. Therefore, the probability of microbial contamination or the regrowth of microorganisms rise. The aim of this study was to evaluate the changes in the free RESIDUAL CHLORINE (FRC) and the number of bacteria in desalinated water samples that collected from water kiosk system that provide desalinated water for the public. Material & Methods: Samples collected at the beginning and the end of the water network and stay for 9 days at room temperature and similar condition as public stored at home. The samples analyzed for FRC, total coliform (TC), fecal coliform (FC), heterotrophic plate count (HPC) and organic matter for 9 days. Results: The results indicated that FRC concentration at the beginning of water network was 1 mg/L and after 9 days it was reached to 0. 5 mg/L at the end of the water network. The amount of UV254 at the end of water network was 0. 0134 cm-1 and after 9 days it was reached to 0. 0125 cm-1. There aren’ t detected any TC and FC in samples even at beginning of the examination and also, after 9 days storage of water. The number of HPC colony for samples at the end of the network it reached 22 CFU/ml, after 9 days. Conclusion: It was concluded that desalinated water that stored at household storage vessel in Saveh has good quality and meets standard limit value until 9 days. It should be noted that this conclusion depends on various conditions, including various environmental factors. However, Water treatment officials need to pay more attention to the amount of CHLORINE remaining in drinking water in Saveh because after 9 days, there was still 0. 5 mg/L of RESIDUAL free CHLORINE in the water.

One of the parameters responsible for decreased water quality in a distribution system is temperature changes. This study was conducted to examine the effect of temperature on pH, turbidity, and RESIDUAL CHLORINE in Sanandaj, Iran, Water Distribution System. The required water samples were taken from 85 stations during April to October 2014. Sampling was carried out over 6 months and twice per month. The average amount of RESIDUAL CHLORINE measured at these stations was 0.58 and 0.52 mg/l, and turbidity was 0.86 and 0.98 nephelometric turbidity unit (NTU) in winter and spring, respectively. The temperature did not have any effect on pH, the amount of pH in winter and spring were 7.56 and 7.57, respectively. The results showed significant differences in the concentration of RESIDUAL CHLORINE and turbidity of Sanandaj Water Distribution Network between winter and spring (P£0.01). Thus, the concentration of RESIDUAL CHLORINE and turbidity varies in warm and cold seasons. However, no significant difference was observed in pH (P³0.01). The research results indicated that temperature does not have any effect on the qualitative parameters measured in the study area.

Background: Outbreaks of legionellosis may be a side effect of institution-water treatment. However, the long-term outcomes and the predictive factors of Legionella prevalence in such systems have still not been fully studied. This study was therefore conducted to investigate the prevalence of Legionella spp. and to evaluate the role of bacteriological water quality parameters on its prevalence and removal in hospital water systems.Methods: A total of 45 samples were collected from distinct sites at seven hospitals in Tehran, Iran. The prevalence of this bacterium was assayed through a sensitive and specific technique for DNA detection using PCR. Multivariable stepwise regression analysis was used to explore the independent effects of the baseline factors on the incidence of Legionella. Two positive samples were also identified for species by DNA sequencing.Results: Legionella were detected in 31.1% of samples. Showerheads and cold-water taps were the most and the least contaminated sources with 55.3 and 9 percent positive samples, respectively. Total mean of RESIDUAL CHLORINE was 0.38 mg/L, with the peak value of 1.7 mg/L. Legionella detection was proportional to the RESIDUAL CHLORINE content of water and the results indicated that RESIDUAL CHLORINE content is a critical factor in the incidence and proliferation of Legionella (r=-0.33). The prevalence of Legionella also coincided with the prevalence of HPC and amoeba cysts.Conclusion: The high positive rate of Legionella colonization shows that hospital-acquired legionellosis might be under diagnosed in studied hospitals. Further, Legionella colonization is independent of the type of water, system characteristics and of preventive maintenance measures.

Disinfected water at the water treatment plant may be polluted again when the water is being transported. Hence, the water should be protected against the possible pollutions by keeping the dis-infectant residues in the transportation line. If CHLORINE is selected as the disinfectant, it will be added to the water in a way that its residue re-mains in the line so as to prevent any unpredicted pollution. The term free RESIDUAL CHLORINE (FRC) is given to each one of the (HClO), (OCl-), Cl- (g) compounds. Due to the following reasons it is better to diminish or removal the concentration of RESIDUAL CHLORINE at the point of use.

Background: Natural Organic Matters (NOMs) react in the presence of RESIDUAL CHLORINE in distribution network pipes, producing such byproducts as Trihalomethanes which are carcinogenic and mutagenic. The present study was conducted to investigate the quality of drinking water in Shiraz. Methods: In this cross-sectional study, 54 samples were taken from 27 locations in both summer and winter. For each sample, temperature, RESIDUAL CHLORINE, pH, and NOM were measured during the two seasons. RESIDUAL CHLORINE and temperature measurement were performed at the sampling sites, but pH and NOM were measured in the laboratory. Results: According to the results, the mean concentrations of Total NOM (TNOM), RESIDUAL CHLORINE, pH, and temperature varied from 0. 9 to 5 m-1, 0 to 1. 2 mg/L, 7. 4 to 8 and 18 to 23. 5 ᵒ C in summer and from 0. 3 to 1. 5 m-1, 0 to 0. 8 mg/L, 7. 6 to 8. 2 and 9. 7 to 10. 8 ᵒ C in winter, respectively. In addition, the concentrations of all measured parameters, except for pH, were reported to be higher in summer than in winter. Conclusion: As a result, since the amount of NOM in the drinking water distribution network of Shiraz was not zero, regular monitoring of these compounds in the distribution networks is recommended to be done by engineers.

To possibly help in understanding the chemistry of the D process using E. urophylla × E. grandis LH 107 as the pulping material, RESIDUAL lignin in kraft-oxygen pulp bleached by CHLORINE dioxide was extracted by the dioxane/water acidolysis method. The content of functional groups in the extracted lignin was determined by 13C and 31P NMR spectroscopy. A relatively significant difference could be seen in the chemical properties of RESIDUAL lignin between oxygen delignified (O) and CHLORINE dioxide treated (OD) pulp. The results suggest a decreased function group content in the RESIDUAL lignin of CHLORINE dioxide treated kraft-oxygen pulps. It is quite interesting that the depletion of phenolic hydroxyl and methoxyl group present in RESIDUAL lignin is due to the quinone formation during the oxidation of CHLORINE dioxide, based on the data obtained in HSQC and 13C NMR spectra of non-cyclic and cyclic MATS, and the content in condensed and unsubstituted phenolics is reduced to the same degree, which is contrary to what we generally perceive