Iranian Journal of

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Background and Objectives: Measurement of light intensity is a recommended practice for insuring the delivery of required germicidal dose in disinfection operations by UV lamps. Use of sensitive to light chemicals which is the base of actionometeric methods could be considered as a suitable manner for estimating the intensity of UV lamp in circumstances that special radiometers are not available.
Materials and Methods: lodide-iodate mixture was used as an actinometer for this study. The light intensities of a UV lamp (LP 25W) were first determined by a special UVC ‌radiometer at certain distances from the lamp. Then the test of determining the suitable period of time for irradiation of actinometer was accomplished.  Finally، the color changes of iodide - iodate solutions at the predetermined distances were evaluated at the wavelength of 352 nm. The latter analysis can be done by a common (visible) spectrophotometer.
Results:‌ Results indicated that use of this actinometer is more suitable at the distances of 35 to 60 cm from the center of the lamp bulb، since iodode-iodate solution has a detectable color change at this range of distance in one minute irradiation which may be considered as a reasonable time for actionmeteric operations.
Conclusion:  Although all kinds of actinometers should not be regarded as precise as special radiometers and there would be need to use pure chemicals for actinometeric determination of light intensity، it can be claimed that the recommended procedure in this study which is the newest actinometeric method can be used in acceptable evaluation of UV intensity with least difficulty in providing necessary instruments.

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Background and Objectives: Conducted studies about arsenic have shown that consumption of water contaminated with arsenic can causes different adverse health effects in consumers. World Health Organization (WHO) has enacted 10µg/L arsenic in drinking water as a guideline value. Regarding some reports about arsenic presence in a village of Hashtrood county and related health effects and also considering this fact that determination of arsenic as a poisoning chemical is not included in routine monitoring of water by responsible organizations, in present study all of drinking water sources in Hashtrood county in East Azerbaijan province were studied for arsenic presence.
Materials and Methods: Water supply and its sanitation situation were studied in all of cities and residential villages (200 villages) by field visiting. Arsenic content of water samples were determined using Ez arsenic test kit, a product of Hach Company. For assurance of the kit results, 20 water samples with different concentration of arsenic were analyzed using Inductively Coupled Plasma (ICP) method and then achieved results was compared together.
Results: Arsenic was present in drinking water of 50 villages that in 9 villages its level was higher than Iranian standard (50µg/L). During the study totally 11087 persons (21.96% of rural areas population) in Hashtrood county were exposed to different levels of arsenic via drinking water. Correlation between kit and ICP results was significant (R² = 0.9715)
Conclusion: Studied region in present study is a polluted area to arsenic by geogenic sources. It is necessary to replace water source of villages with higher level than national standard with safe drinking water. Annually measurement of arsenic in drinking water of all villages spatially polluted villages should be considered by responsible organization e.g. Health Network and Rural Water and Wastewater Company. Used kit in our study is recommendable for this purpose.

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Background and Objectives:

In many countries, there is a popular belief that the simultaneous

handling of food and money contributes to the incidence of food-related public health incidents.

The objective of this study was to determine the total bacterial count and the presence of food borne

bacterial pathogens on Iranian currency notes, collected from food-related shops.

Materials and Methods: A total of 120 Iranian currency notes, comprising notes in four  denomination (2000, 5000, 10000 and 20000 R) were collected from various food-related shops including, butchery, bakery, confectionary, fast food, ice cream and poultry meat shop. The currency notes were categorized into three groups according to their physical conditions. All currency notes were examined for total bacterial count, Escherichia coli, Staphylococcus aureus, Bacillus cereus, Salmonella and Listeria according to the standard techniques.
Results: The average number of total bacterial count in four denomination of currency notes (2000,  5000, 10000 and 20000 R) were 118.49, 106.32, 69.44 and 220.81 CFU/cm2, respectively. The association between total bacterial count and denomination of the currency was not statistically significant. Of the 120 currency notes on which bacteriological analysis was conducted 13.3 %, 32.5% and 10.8 % were contaminated with E. coli, S. aureus and B. cereus, respectively. Salmonella and Listeria were not isolated from samples. Currency notes collected from butchery, bakery, confectionary, fast food, ice cream and poultry meat shop were contaminated with E. coli at the rate of 60, 0, 5, 5, 0 and 10 % with S. aureus at the rate of 55, 30, 10, 25, 40 and 35 % with B. cereus at the rate of 0, 10, 20, 5, 20 and 10 %, respectively. There was not a statistically significant association between physical condition and bacterial contamination of the currency notes. The effect of presence or absence of cashier in food-related shops on bacterial contamination of the currency notes was also evaluated.
Conclusion: Money has got the potential to change through many different hands and could be  exposed to many different environments at a relatively high frequency. Since there is very little information regarding the hygienic history of any forms of currency, great care should be taken when the same person facilitates the handling of money and the preparation and handling of food to avoid cross contamination.

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Backgrounds and Objectives: Noise in large cities is considered by the World Health Organization to be the third most hazardous type of pollution. Buses are an interesting object of study in the theme of noise pollution. They are at the same time a source of urban environmental (traffic) noise and occupational noise exposure source for drivers. The object of this study is Occupational noise exposure evaluation in drivers of bus transportation of Tehran city.
Materials and Methods: Noise levels in 90 buses were sampled in three separate sub-sample including (1)30 Ikaroos buses (2)30 Man buses (3)30 Shahab buses, which were selected by simple random sampling. Noise exposure level was normalized to a nominal 8-h working day (LEX, 8h). Simultaneous Octave Frequency Analysis were measured and sound intensity level (SIL) for bus drivers were calculated. Results, which are obtained from separate buses were compared together and too with standard levels.
Results: the normalized noise exposure levels (LEX, 8h) in Ikaroos bus drivers(82dB A) were higher than that of in in Man bus drivers (77/6dB A) and this Values were higher than that of in Shahab bus drivers(75dB A).SIL values for Ikaroos bus drivers were higher than other that of other bus drivers. Results obtained of Frequency Analysis showed that age of buses in mid frequencies ws a meaningful on noise increase.
Conclusion: Results showed that type and age of buses were effective factors in drivers. noise exposure levels (LEX, 8h), which was consistent with previous studies in this field.

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Backgrounds and Objectives : Heavy metals in dust can enter to the human body through ingestion andinhalation. They can pollute the water and soil resources via atmospheric precipitation and accumulate in the plants tissue and enter human body by water and food. The aim of this study was measurement of the heavy metals in wet and dry atmospheric precipitation and effects of pollution sources at the ground surface on the concentration of heavy metals in the atmospheric precipitations.
Materials and Methods: In this study the zanjan city was divided into 5 zones and wet and dry precipitations were collected in autumn, winter and spring (2008- 2009) from zones. The concentrations of Pb, Cd, Cr and Zn the collected precipitations were determined by Atomic Absorption spectroscopy method.
Results: The averages of concentrations of Pb, Cd, Cr and Zn were 0.082, 0.286, 0.018, and 0.009 (mg/m 2.d)respectively. The correlation coefficients between Pb-Zn was 0.8 (P<0.01) and for Cr-Cd, Cd-Pb, and Cr-Pb were 0.89, 0.58 and 0.61 respectively.
Conclusion: The results showed that the industrial sources of heavy metals play the main role in concentration of heavy metals in wet and dry atmospheric precipitation in Zanjan.The correlation coefficients showed that the lead and zinc result from a common source. This source can be the lead and zinc factories locating around the city. The measurement of heavy metals in atmospheric precipitation shows the effects of anthropogenic sources in air quality. The heavy metals concentration in atmospheric precipitation can be use as air pollution index.

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Backgrounds and Objectives: The dispersion of particulate matter has been known as the most serious environmental pollution of cement plants. In the present work, dispersion of the particulate matter from stack of Kerman Cement Plant was investigated using Computational Fluid Dynamics (CFD) modeling.
Materials and Methods: In order to study the dispersion of particulate matter from the stack, a calculation domain with dimensions of 8000m × 800m × 400m was considered. The domain was divided to 936781 tetrahedral control volumes. The mixture two-phase model was employed to model the interaction of the particulate matter (dispersed phase) and air (continuous phase). The Large Eddy Simulation (LES) method was used for turbulence modeling.
Results: The concentration of particulate matter in the whole calculation domain was computed. The predicted concentrations were compared to the measured values from the literature and a good agreement was observed. The predicted concentration profiles at different cross sections were analyzed.
Conclusion:The results of the present work showed that CFD is a useful tool for understanding the dispersion of particulate matter in air. Although the obtained results were promising, more investigations on the properties of the dispersed phase, turbulent parameters and the boundary layer effect is needed to obtain more accurate results.

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Backgrounds and Objectives:Total and Fecal coliforms (TC and FC), heterotrophic plate count (HPC), were counted by microbiological method and E.coli O157:H7 were detected through immunological and Real time PCRmethods inwater intake and all of units of Isfahanwater treatment plant (IWTP).
Materials and Methods: The microbial profile including TC, FC, and HPC, were monitored and turbidity and total organic carbon were analyzed in 8 locations of water intake, and unit operation and processes of IWTP, including, inlet, sedimentation, ozonation, and filtration and finished water. Immunological method through anti-serum kits and molecular method of RT-PCR were used to detect E.coli O157:H7 in the 8 locations and also the sludge of the sedimentation basin and filters backwash water of IWTP.
Results: Survival of E.coli O157:H7 in sludge sample of sedimentation basin was indicated by formation of agglutination particles in immunological method and through indicator probes in the RT-PCR method. However, E.coli O157:H7 was not detected in water samples of other units of IWTP. The removal percent of TC, FC, and HPC were: 59.5, 49, and 54.8 % in sedimentation basin 66, 45.8, and 57 % in ozonation: 98.8, 98, and 78.8 in the filtration and 96, 100, 91% in disinfection, respectively.
Conclusion: This study approved the existence of the pathogenic coliform, E.coli O157:H7 in the
sludge of sedimentation basin. Absent of E.coli O157:H7 in the finished water indicates that the existing units of IWTP could eliminate these pathogenic bacteria, before reaching the final units of the plant, including the filters and disinfection.

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Background and Objectives:Dual media filters have two different layer beds consist of sand and Anthracite. Advantage of dual media filters is longer run duration and more filtration rate. The purpose of this study was to achieve a performable model to improve single media Filters in water treatment plants.
Materials and Methods: in this cross-sectional study, two pilots mono and dual media were made and in a 5 month period samples taking were done. Total samples taken from input and output of each pilot, was 40. The samples then introduced for the measurment of turbidity and total organic carbon. Meanwhile the filters head loss also quantified in 40 times head loss measurement was done.
Results: Average turbidity removal in mono and two layer pilots were 63 and 65 percent respectively. Average removal of Total Organic Carbon in mono and two media pilots were 40 and 66 percent respectively. Head loss in dual and single media pilots were 0 .68 and 1.15 m respectively.
Conclusion: Although average torbidity removal disparity between two pilots was not significant the amount of total organic carbon removed was considerable. Average head loss in single media pilot was more than dual media type. Ratio of UFRV in dual media to mono media filter was 51:30 it shows that filtration rate capacity will be improved up to70 percent by changing media type.

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Background and Objectives: Fresh fruit juice is one of the best drinks which have minerals and vitamins and is a good source for water compensation, but if microbial quality of the fruit juice does not meet the standard level, it can be play as a source for food disease infections.
Material and method:In his cross-sectional study, all of 58 fruit juice shops in Bandar Abbas were selected as study population, correspondence rate was 84 percent. The samples were tested for total Coliform, Escherichia coli, Staphylococcus aureus, yeasts and molds.
Results:Testing the samples showed among 146 samples, 142 of them were contaminated by microorganisms. All of Carrot and mango juices were contaminated. The mean contamination rate of juices to Coliform bacteria, Mesophilic bacteria, Escherichia coli and yeasts were 86.2, 53.2, 57 and 56.6 percents respectively.
Conclusion:97.3 percents of samples did not have a good microbial quality for human consumption. If consumption of fresh fruit juices will cause the consumer at risk of food borne diseases, all the natural benefits of them in terms of richness in minerals and vitamins will waste.

 

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Background and Objectives: This study was conducted to investigate the toxicity of Titanium Oxide (TiO2) and Zinc Oxide (ZnO) nanoparticles as two of most widely used nanoparticles. The result of this study can help to designing environmental standard and legislations for nanoparticles.
Materials and Methods: Different concentrations of nano ZnO and TiO2 nanoparticles were added to nutrient Agar culture media. Then, definite numbers of Escherichia coli and Staphylococcus aureus bacteria were added to culture media and inhibition of these bacteria growth was measured in comparison to controls. Obtained data were analyzed to determine nanoparticles' EC50 and NOEC (No Observed Effect Concentration) using SPSS ver.16 and Probit standard test.
Results: 24-hours EC50 of nano ZnO using E. coli and S. aureus determined to be 5.47 mg/L and 2.38 mg/L respectively. In addition, 24-hours EC50 of nano TiO2 using E. coli and S. aureus determined to be 5366 mg/L and 3471 mg/L respectively. In the case of ZnO nanoparticles, no observed effect concentration determined to be 1.15 and 3.28 mg/L for E. coli and S. aureus respectively and in the case of TiO2 nanoparticles no observed effect level determined to be 1937 and 1184 mg/L for E. coli and S. aureus respectively.
Conclusion: This study showed that acute toxicity of nano ZnO is by far more than that of nano TiO2. Regarding the EPA acute toxicity criteria, nano ZnO is categorized as moderately toxic and nano TiO2 is categorized as practically non toxic. Hence, regarding the acute toxicity, in recommending exposure criteria and environmental disposal standards, compared to nano TiO2, nano ZnO requires more attention.

 

 

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Background and Objectives:Yazd province is located in the central desert part of Iran in which water scarcity was one of the most important problems. This has been recently solved to some extent, due to the approved channel project of water transferring from Isfahan to Yazd. Chlorination is usually used in the last stage of water treatment for disinfection in the networks, treatment plants, storages and channel stations. The possibility of carcinogen lateral composites formation is expected by tri-halo-methanes (THMs) due to the reactions occurs between the natural organic materials and free chlorine available in water. Based on the established standard by the country, the permissible limit of THMs in water is 200 mg/L. In this research, in addition to the amount of THMs and their distribution in Yazd water transferring channel and the city water network system, the important parameters and their correlations with THMs formation were discussed.
Materials and Methods: In a year of sampling period, the concentrations of THMs including the four major components of chloroform, bromoform, bromo di-chloro methane and di-bromo chloro methane during all seasons were measured using gas chromatograph and analyzed. This was done for 11 stations including Zayande-rood Basin River and Isfahan water treatment plant up to Yazd Shehneh storage, stations and inline equalization tanks and also five regions of Yazd city network.
Results: According to the results, the maximum rate of THMs (51.14 mg/L) during the sampling period in summer for Yazd city network and in ancient context of Jamea Mosque district was found. In addition, the minimum concentration of THMs was 1.60 mg/L in winter for the domestic network of the city which was related to Azad Shahr district. The Average total amount of THMs during sampling periods in all stations was 12.26 mg/L.
Conclusion: SPSS and Excel softwares were used to analyze the research data in the descriptive and inferential manner. Both statistical methods (Simple correlation coefficient, Pearson and Spearman correlation test)) with 5% significant level were considered for data analysis. The results indicated that no significant difference existed between these parameters and national and international standard scales. These rates were generally desirable and lower than standard limit which indicates acceptable operation in the treatment system and storages in the channel line of Isfahan to Yazd. Furthermore, it was obtained that there is a correlation between THMs rates and effective parameters in producing confidential values such as 95%and 99%for the residue chlorine and heat respectively. Finally the distribution and diffusion plan of THMs in transferring line and civic network of Yazd were drawn.

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Background and Objectives: This study presents an evaluation between IAQX 1.0f and Fluent 6.3.26 in modeling of NOx dispersion in an indoor residential environment. Modeling predictions are compared with sampling results.
Materials and Methods: Aresidential building with about 84 m2 area is modeled. In IAQX 1.0f the building is divided into five zones. Emission factors and absorption rate of sinks is estimated with US.EPA suggested factors. On the other hand, In the Fluent 6.3.26 model, the building was divided into 1777 cells, and the openings are defined by the boundary conditions of the inflow. In this model, pollution sources were simulated by boundary conditions of the mass inflow.
Results:Compared to IAQX 1.0f, Fluent 6.3.26 showed higher estimation of the concentrations in the zones of 1, 2 and 3. In comparison with the measurements, both models had underestimated results.
Conclusion: The results of Fluent 6.3.26 were closer to the sampling results in the zones.

 

 

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Background and Objectives: Nowadays, most countries of the world have shortage of water due to many reasons such as population growth, rising of living standards, indiscriminate water use, and so on. Besides, in absence of adequate water resources, desalination of brackish and saline waters have been used to supply potable water. Freezing process is one of the methods which can be used to desalinate saline waters.The aim of this study was to survey freezing process to produce potable water from saline water of Persian Gulf shores.
Materials and Methods: This study was conducted in lab-scale by using indirect contact freezing. Three samples of 50 liter were provided from Bushehr shores. The implemented process steps were freezing (crystallization), separation of crystals, surface washing, and thawing. Freezing of the samples (each in 0.5 liter containers) were performed by a refrigerator at -20°C and 0.1KW/h energy consumption.
Results: The removal efficiencies of TDS in the first, second, and third samples by first freezing process were 56, 56, and 51 percent, respectively. Moreover, the removal efficiencies by EC were 42, 44, and 40 percent, respectively. Meanwhile, the removal efficiencies of TDS in first, second, and third samples by second freezing process observed 69, 69, and 68 percent, respectively. Moreover, the removal efficiencies by EC were 61, 60, and 63 percent, respectively. Also, the removal efficiencies of TDS in first, second, and third samples by third freezing process were 72, 73, and 72 percent, respectively. Moreover, the removal efficiencies by EC were 77, 78, and 77 percent, respectively. The production of the potable water by this method was 15-20 percent of the entry water.
Conclusions: According to the obtained results, potable water was obtained after third freezing of the saline water. Meanwhile, TDS of the produced water was less than maximum allowed concentration of Iranian standards.

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Background and Objectives: Gamma rays, the most energetic photons within the any other wave in the electromagnetic spectrum, pose enough energy to form charged particles and adversely affect human health. Provided that the external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined, environmental gamma dose rate and corresponding annual effective dose were determined in the cities of Ardabil and Sar Ein.
Materials and Methods: Outdoor environmental gamma dose rates were measured using an Ion Chamber Survey Meter in 48 selected locations (one in city center and the remaining in cardinal and ordinal directions) in Ardabil and Sar Ein. Ten more locations were monitored along the hot springs effluent in Sar Ein. Measurements of gamma radiation dose rate were performed at 20 and 100 cm above the ground for a period of one hour.
Results: Average outdoor environmental gamma dose rate were determined as 265, 219, and 208  for Ardabil, Sar Ein, and along the hot spring effluent, respectively. The annual affective dose for Ardabil and Sar Ein residents were estimated to be 1.45 and 1.39 mSv, respectively.
Conclusion: Calculated annual effective dose of 1.49 and 1.35 are appreciably higher than the population weighted average exposure to environmental gamma radiation worldwide and that analysis of soil content to different radionuclide is suggested.

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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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Background and Objectives: One of the complete treatment processes for industrial and municipal wastewater treatment is membrane bioreactor process which has dominant potential in process and operation sections. This study was conducted to compare the performance of extended aeration activated sludge (EAAS) with submerged membrane bioreactor (SMBR) systems in the treatment of strength wastewater, in the same condition.
Materials and Methods: The initial activated sludge was brought from the Plascokar Saipa wastewater plant. The Plexiglas reactor with effective volume of 758 L was separated by a baffle into the aeration and secondary sedimentation parts with effective volumes of 433 L and 325 L, respectively. The chemical oxygen demand (COD) concentration of the influent wastewater of the EAAS and SMBR systems were between 500-2700 and 500-5000 mg/L, respectively.
Results: Results showed that the SMBR system produced a much better quality effluent than EAAS system in terms of COD, biochemical oxygen demand (BOD5), total suspended solids (TSS) and ammonium. By increasing the COD concentration, the concentration of mixed liquor suspended solids (MLSS) and the removal efficiency of organic matter in the SMBR system, were increased regularly, however the removal efficiency of COD in the EAAS system was irregular. 
Conclusion: The average BOD5/COD ratio of effluent in the EAAS and SMBR systems were 0.708±0.18 and 0.537±0.106, respectively. These show that the organic matters in the effluent of the SMBR system was less degradable and thereupon more biological treatment was achieved. Nitrification process was completely done in the SMBR system while the EAAS system could not achieve to complete nitrification.

 

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Background and Objectives: Aydughmush dam was built on Aydughmush River at 19km in southwest of Mianeh City. The dam is multipurpose and its main aims are the spring floods control, supplying potable water for villages and providing irrigation water. Different pollutants which probably discharge to the river finally enter to the dam reservoir so this study focuses on evaluating the quality of the dam reservoir.
Materials and Methods: In this cross sectional study standard field parameters including dissolved oxygen, temperature, Biochemical and chemical oxygen Demand, Most Probable Number of Coliforms, Fecal Coliform, Turbidity, Total Dissolved Solids, Total Solids, pH, conductivity and others were measured at eight different stations during the spring and summer in 2010. Sampling points were selected on the basis of their importance. Water quality index was calculated using water quality index calculator given by National Sanitation Foundation (NSF) information system.
Results: The highest value of WQI of the samples was 84.89 in A3 station in July while the lowest value was 67.96 in A2 station in May. The lower value of WQI has been found mainly due to the slightly lower value of DO in the dam reservoir water. Most of the water samples were found within Good category of National Sanitation Foundation Water Quality Index (NSF-WQI). Comparison of the measured parameters based on the sampling stations and  various months by variance and t-student analysis showed a significant relationship for some parameters(P<0.05). Nutrient budget determination indicates that the concentration of phosphate, nitrite, nitrate and ammonia at inlet are higher than outlet of the dam reservoir.
Conclusion: The calculated (WQI) showed good water quality. Based on the results of NSFQWI calculations, the dam reservoir water quality is suitable for various purposes.

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MicrosoftInternetExplorer4 Background and Objectives: Nanotechnology defined as understanding and controlling of materials at dimension between 1-100 nm, which show unusual physical and chemical properties. With Increasing development of nanotechnology, concerns associated with release of materials containing nanoparticles into the environment is rising. The purpose of this study is investigation of salinity effect on the acute toxicity of silver nanoparticles in rainbow trout fry (Oncorhynchusmykiss).
Materials and Methods: In order to conduct the toxicity tests, the Caspian Seawater(12±0.2 ppt) and (0.4 ppt) as sources of brackish water and freshwater were used, respectively. Toxicity of silvernano particles were evaluated in brackish water and freshwater at concentrations of1, 2, 4, 8, 16, 32and64ppm and  0.12, 0.25, 0.5, 1, 2, 4 and8 ppm, respectively. In addition, in order to investigate the quality of the used silver nanoparticles the Zetasizer, ICP, and TEM method were applied.
Results: Results of 96-hour median lethal concentration(LC50 96h), showed that toxicity of silver nanoparticles for rain bow trout fry in brackish water is 12 times less than its toxicity in freshwater.
Conclusion: According to the toxicity categories, analysis of the results showed that, for rainbow trout fry (1g), silver nanoparticles are classified as highly toxic agent substances in fresh water, and little toxic in brackish water, respectively.

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MicrosoftInternetExplorer4 Background and Objectives: Phenols in trace quantities are usually present in the treated effluent of many wastewater-treatment plants. Phenol compounds even at low concentration can cause toxicity, health and significant taste and odor problem in drinking waters. This research focuses on understanding the sorption process and developing a cost-effective technology for the treatment of water contaminated with phenolic compounds, which are discharged into the aquatic environment from a variety of sources. In order to remove phenolic compounds from water, a new natural sorbent, rice husk ash, was developed.
Materials and Methods: Removal of phenol, 2-chlorophenol and 4-chlorophenol were characterized by spectrophotometric technique at wavelengths of 269.5, 274 and 280 nm, respectively, under batch equilibrium conditions and via changing the parameters of contact time, initial pH, and initial concentration of adsorbates and dosages of sorbent. Finally, the results were analyzed by the kinetic and isotherm models.
Results: in this study, the equilibrium time was found to be 240 min for full equilibration of adsorbates. Removal percent of 2-chlorophenol was lower than two others. The maximum removal of phenol, 2-CP and 4-CP was observed at an initial pH of 5. The percentage removal of these phenolic compounds increased with increasing adsorbent dose and decreasing initial concentration. In kinetics studies, correlation coefficient and ARE factor showed that the sorption of phenol (R2=0.9999), 2-chlorophenol (R₂=0.9992) and 4-chlorophenol (R₂=1) fitted by pseudo second order model. Isotherm studies also revealed that, Langmuirmodel for phenol (R₂=0.9499), Freundlich model for 2-chlorophenol (R₂=0.9659) and 4-chlorophenol (R₂=0.9542) were the best choices to describe the sorption behaviors.
Conclusion: Sorption process is highly dependent on the pH and it affects adsorbent surface characteristics, the degree of ionization and removal efficiency. At high pH hydroxide ions (OH-) compete for adsorption sites with phenol molecules. The sorption was done rapidly and a plateau  was reached indicating the sorption sites occuupied till  they were saturated. Since the increasing sorbent dose would improve sorption site, its increasing enhances phenolic compounds removal.

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MicrosoftInternetExplorer4 Background and Objectives: since there is not any information about the quality and quantity of carpet cleaning wastewater, this study was done for the evaluation of carpet cleaning wastewater   characterization in Tehran.
Materials and Methods: There are 122 carpet-cleaning units in Tehran. Compound samplings were taken from 10 randomly selected carpet-cleaning units. Each unit was sampled 5 times and analyzed based on the Standard Methods. Quality parameters measured included chemical oxygen demand (COD), detergent, color and suspended solids (SS), and data was analyzed using statistical software spss16.
Results: Results showed that the amount of water usage for carpet cleaning was 30.84 liters per square meter of carpet washed. The average level of COD, color, detergent and SS in the effluent of carpet cleaning unit was 367.4   mg/l, 171.85 ADMI, 55.51 mg/l and 359.62 mg/l, respectively.
Conclusion: The effluent characteristics of carpet cleaning units are almost with in the domestic wastewater range. However, since these wastes are disposed untreated into the environment which are then enter surface and groundwater, all measured parameter were higher than proposed standards regulated by EPA, So treating process must be done before disposal.

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