Iranian Journal of

---

Backgrounds and Objectives: Drinking water quality after treatment and before reaching  the consumer could be affected by distribution pipes, service lines and Home devices. The structure of water coolers, a home device that are widely used in warm months of the year, could potentially affect the quality of drinking water. The aim of this study was to assess the microbial and chemical quality of water from conventional water coolers.
Materials and Methods : Water samples were collected from 29 water cooler systems at the Isfahan  university of medical sciences. 29 control samples also obtained from the nearest drinking water taps. All samples were examined for total heterotrophic bacteria and physicochemical parameters including temperature, ph, turbidity and heavy metals.
Results: All samples from the water cooler systems complied with the EPA guidelines for total heterotrophic bacteria count. There were no significant differences between the levels of heavy metals in water samples from the water cooler systems and taps. There was only a significant difference between the level of Cu in the water samples from cooler systems and taps
Conclusion: The overall results of this study indicated that the use of water cooler systems from hygienic point of view could not cause any problems for consumers

---

Background and Objectives:Antibiotics and hormones are excreted with other wastes following their influences on bodies.These substances can disturbed treatment process by their entery to the wastewater. In this study the inhibitory behavior of antibiotics Ofloxacin and Ciprofloxacin and hormone stradiol 17- valerat have been investigated on Specific Methanogenic Activity (SMA) of anaerobic biomass.
Materials and Methods: Twenty one SMA tests were done using 120-mLvials in batch mode. In each vial, substrate, biomass and biogas were occupied 66, 17, and 17 % (v/v), respectively. Each test longed in range of 15-30 days. Produced methane was measured by gas replacement with 2N KOH solution as CO2 absorbent.
Results: In this study, at the concentrations of 200, 500 and 1000 mg/L of antibiotic Ofloxacin, the methane production reduced to 45, 76 and 88 percent, respectively. Reduced methane production of 68, 81 and 88 percent was observed in Ciprofloxacin concentrations of 100, 200, and 500 mg/L, respectively. Cumulative methane at the concentrations of 0.1, 1, and 5 mg E2 /L was 66, 90, and 121 mL, respectively
Conclusion: Antibiotic Ciprofloxacin at concentrations similar to the antibiotic Ofloxacin have a greater inhibitory effect on specific methanogenic activity of anaerobic biomass. Also, the hormone E2 at lower concentrations showed more inhibitory effect than other two antibiotics Ciprofloxacin and Ofloxacin.

 

 

---

AR-SA MicrosoftInternetExplorer4 Background and Objectives: Aerobic sludge granulation is an advanced phenomenonin which its mechanisms have not been understood. Granulation can be a promising and novel biological wastewater treatment technology to eliminate organic and inorganic materials in future. High salinity is a parameter which leads to plasmolisatian and reduction of the cell activity. This could be a problem for biological treatment of the saline wastewater. Aerobic granule was formed and investigated during this study.
Materials and Methods: This study is an intervention study on the treatment of wastewater with 500-10000 mg/L concentration of NaCl by sequencing batch reactor. Asynthesized wastewater including nutrient required for microorganism's growth was prepared. Input and output pH and EC were measured. Range of pH and DO varied between 7-8, and 2-5 mg/L, respectively. SEM technology was used to identify graduals properties.
Results: In terms of color, granules divided into two groups of light brown and black. Granule ranged in 3-7mm with the sediment velocity of 0.9-1.35 m/s and density of 32-60 g/L.Properties of granules were varied. Filamentous bacteria and fungi were dominant in some granules. However non filamentous bacteria were dominant in others. EDX analysis indicated the presence of Ca and PO₄.
Conclusion: Granules with non filamentous bacterial were compact and settled faster. Presence of different concentrations of salinity leaded to plasmolysis of the bacterial cells and increased concentrations of EPS  in the system as a result  of which granulation accelerated.

---

Background and Objectives: PAHs are main components of urban air pollution and are mutagenic for human being. Seasonal variations have effects on the amount of exposure to PAHs. The objectives of this research were to determine the amount of newsagent’s exposure to PAHs found in the urban atmosphere of Tehran City during warm and cold periods and comparing exposure levels in two periods. Materials and Methods: The assessment of personal exposure was performed based on NIOSH method 5515 and was analyzed by gas chromatography–mass spectrometry (GC/MS). Mann- Whitney test was used to determine the effects of seasonal variation on the amount of newsagent’s exposure to PAHs. Results: The mean levels of newsagent’s exposure to benzo[a]pyrene in the south area of Tehran City were 0.148±0.010 and 0.417±0.041 µg/m³ in summer and autumn seasons respectively. The amount was higher than the mean levels of newsagent’s exposure in other geographic areas of city. The levels of newsagent’s exposure to all PAHs (p<0.001) were significantly higher in autumn compared with summer. Conclusion: The levels of exposure to PAHs during autumn were 2 to 3 fold higher than the levels of exposure during summer. Newsagents in the south area of Tehran City were experiencing higher levels of exposures to PAHs.

---

Background and Objective: The contamination of soils and plants with heavy metals is a serious and growing problem. The present study aimed to determine the concentration of heavy metals in soil and some agricultural products and the probability of risks due to their consumption.

Materials and Methods: This cross-sectional descriptive study was performed using random sampling at harvest time in 2014 on 205 samples of vegetable crops (Leek, chard, parsley, watermelon, melon, tomatoes, cucumber, potatoes, onion, garlic, radish, green peas, and broad bean) and 129 samples of soils under cultivation. Concentrations of Cu, Zn, Cd, and Pb in soil and plant samples were determined by an atomic absorption instrument and the data was analyzed using SPSS software.

Results: There were significant differences between the mean concentrations of Pb, Cu, and Zn for different vegetables (P<0.001), but no significant difference was observed for Cd. The highest mean levels of Pb, Cd, Cu, and Zn were detected in parsley, chard, broad bean, and leek respectively. However, there was no heavy metal pollution in the remainder of the vegetables and soil samples (with the exception of agricultural soils adjacent to the lead mine of Mahneshan area) studied. Hazard probability (HQ) of each element for cancerous diseases was less than unit and the intake of heavy metals was lower than the Provisional Tolerable Daily Intake (PTDI).

Conclusion: The results of this study indicated that major accumulation of heavy metals was obtained in leafy vegetables. Therefore, much attention should be paid to consumption of leafy vegetables, especially vegetables grown in the surrounding industrial areas.