Iranian Journal of

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Background and Objectives: New studies indicate that nitrate concentration in groundwater is increasing in most cities. High concentrations of nitrate in water increase the potential health risk in the community and the environment. In infants, No₃ _ is reduced to No₂ _, which combines with hemoglobin in the blood to form met hemoglobin leading to blue-tinged blood for babies under six months old in particular ,Namely, so-called ‘‘blue baby syndrome&apos&apos and  it  also produce carcinogenic compounds . Therefore high nitrate concentration is important. The aim of the present study is removing nitrate from water using zero_valent iron.
Materials and Methods: Analyses were conducted on synthetic samples. These samples were analyzed considering reaction times, pH, initial nitrate and sulfate concentration.
Results: Results showed that at Nitrate with an initial concentration of 200mg L1^-  after 60 min of reaction at pH(s) 7, 6 and 5 about 67.8%, 72.5 % and 88% was reduced, respectively in concentration of 100 and 300 mgL^- (pH=6) the removal efficiency is 60 and 83 percent, respectively. In sodium sulfate and nitrate with concentration of 300, the removal efficiency reached from 72 to 70 percent.
Conclusion: Results show that the initial pH is important to achieve maximum efficiency of nitrate removal. So the lower pH levels increases removal efficiency of nitrate. All of the experiments indicated that removal is the highest in the first 5 min. Generally with an increasing initial nitrate concentration the removal efficiency of nitrate increases.

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MicrosoftInternetExplorer4 Background and Objectives: Heavy metals including antimony and cobalt as two contaminant factors leach from polyethylene terephthalate packages into water under some conditions. Therefore, their detection was concerned at different storage conditions.
Materials and Methods: Five time-temperature treatments were carried out for 5 water samples. Storage conditions were defined as following: at outdoor and sunlight ambient temperature, room temperature, and at 40˚C at different intervals for 8 weeks, at 65˚C for 6 weeks and 80˚C for 7 days. Detection was performed by ICP-AES method and the data analysis was processed by SPSS software.
Results: Antimony concentration increased by storage time at all temperatures and for all samples, however enhancing proportion was different in samples. At outdoor, 40˚C and room temperature, concentration increase was below the MCL by the end of storage period. But at 65˚C and 85˚C, antimony concentration exceeded MCL by study time and the difference between samples 4 and 5, for example, was significant (p≤0.05). Cobalt concentration at the beginning and during the study was also too less and lower than the detection limit.
Conclusion: By increasing temperature and time, leaching of antimony into water increases. Moreover, sunlight has effect but not noticeable at the temperature of present study. In this study, blue or clear packaging had no significant effect on antimony leakage (P>0.05).