IRANIAN JOURNAL OF HEALTH AND ENVIRONMENT
Year:2011 | Volume:4 | Issue:2 (12)|Papers Count:12

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: A residential 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.

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 soft wares 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.

Backgrounds and Objectives: Wet air oxidation (WAO) is one of the advanced oxidation process which is mostly used to reduce organic matter concentration from industrial wastewater, toxic and non-biodegradable substance and solid waste leachate. The objective of this paper is comparisons of three advance oxidation in organic matter removal in different conditions from Esfahan composing factory leachateMaterial and Methods: The experiment was carried out by adding 1.5 Lit pretreated leachate sample to 3Lit autoclave reactor and adding 10 bar pressure at temperature of 100, 200 and 300 °C and pressure (10 bars) with retention time of 30, 60 and 90 min. leachate sample in 18 stages from composting factory in Isfahan in the volume of 20 lit was taken and the three methods WAO, WPO, and a combination of WAO/GAC were used for pre-treatments. Pure oxygen and 30% hydrogen peroxide was used as oxidation agent.Results: The result shows significant improvement on the removal rate of COD (7.8-33.3%), BOD5 (14.7-50.6%) by WAO process. The removal efficiency of 4.6-34% COD, 24-50% BOD, was observed in the reactor. Adding the GAC to the reactor improved removal efficiency of all parameters. Combination Process (WAO/GAC) removed 48% of COD, 31-43.6% of BOD. Combination process demonstrated higher efficiency than two other previous methods as BOD5/COD ratio of 90% achieved.Conclusion: The WAO process presented in this paper is efficient for pretreatment of leachate, And the modified WPO process remove organic materials and ammonia moreover WAO/GAC can be considered as an excellent alternative treatment for removing reluctant organic matter (COD, BOD5) and organic nitrogen compounds, which found in leachate.

Backgrounds and Objectives: The Atrak River is an important water supply resource in the Razavi Khorasan, Northern Khorasan and Golestan provinces. This river is the line border of Iran and Turkistan countries. Unfortunately, lack of water quality and quantity data due to nonexistence of a proper surface water quality monitoring station network is one of the main problems for water quality evaluation in the Atrak River. The main objective of the research is to offer a proper framework for surface water quality evaluation regarding to the mentioned limitations.Materials and Method: In the first step, proper surface water quality monitoring stations along Atrak River are selected and water quality conditions are indicated using water quality index (WQI) model. The second step is allocated for determining trophic states of the river. Finally, the river water quality modeling is carried out for one of the most important index of water quality in the Atrak River i.e. total dissolved solids (TDS) based on proposed method by Oconnor (1976).Result: Results of WQI model showed that most of the stations were in the moderate class. The result also showed that most parts of this river had trophic condition. Finally, based on findings of  O’Connor model it is demonstrated that the salinity status observed in these four stations originated from the base flow and therefore, salinity is affected by the natural sources.Conclusion: This methodology in the research can be used in rivers which don’t have the proper surface water quality monitoring stations and therefore encountered with lack of water quality data. It can provide the proper strategy and management tasks to reach the good water quality conditions.

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.

Background and Objectives: Microbial quality, particularly parasitic characteristics in terms of effluent reuse in agriculture is one of the most important indices. The aim of this study is determination of removal efficiency of Kermanshah wastewater treatment (conventional activated sludge) and Gilangharb wastewater treatment plants (stabilization ponds) for cyst and parasitic eggs.Material and Methods: In this study research samples were taken once in five days from both inlet and outlet of wastewater Plants within a period of five months. The identification and counting of cyst and parasitic eggs were carried out by Mac master slide according to Bailenger method.Results: The findings shows that mean of parasitic eggs and protozoan cysts in effluent of Kermanshah wastewater treatment plant were 0.99±0.42 and 0.90±0.25 per liter respectively, indeed removal efficiency for parasitic eggs and cysts are %98.42±3 and %97.5±4.5 respectively, but, any parasitic eggs and protozoan cysts in Gilangharb wastewater treatment plant was not observed and removal efficiency of these tow parameters was %100. Ascaris lumbricoides eggs had most number in influent and effluent of both plants.Conclusion: As results show, removal efficiency for cysts and parasitic eggs in both abovementioned are desirable, and the quality of effluent treatment plant of both the rate of nematode eggs Anglbrg index (number of nematode eggs: 1³ number per liter) is consistent.

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, respectivelyConclusion: 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.

Background and objective: The conventional chemical and physical methods for water disinfection include the application of ultraviolet (UV), chlorination, and ozonation. Water disinfection by electrochemical methods has been increasingly carried out recently. The goal of this applied-analytical research is to investigate the removal of E. coli bacteria, as the index of water microbial contamination, from drinking water by electrochemistry method.Materials and Methods: In this study, the contaminated water sample was prepared through adding 102 and 103 E. coli bacteria per ml of drinking water. The contaminated water entered into the electrochemical reactor and different conditions were studied, included pH (6, 7, and 8), number of bacterium (102 and 103 per milliliter), time (5, 10, 20, and 40 min), distance between electrodes (2, 2.5, 3, and 3.5 cm), and voltage (10, 20, 30, and 40 volts).Results: The findings indicated the indirect correlation between bacteria removal efficiency and the variable distances between two electrode. The results indicated the direct correlation between bacteria removal efficiency and the variables voltage and electrolysis times. The results showed that the best conditions for removal of 102 and 103 bacteria per milliliter obtained at pH 7, electrolysis time of 10 min, distance between electrodes 2 cm, in the voltage 20 and 30 volts, respectively.Conclusion: The results of this study indicate that voltage and electrolysis time have the most significant effect on electrolysis efficiency. Research findings showed that electrolysis is a promising method for removal of E. coli bacterium from drinking water.

Backgrounds and Objectives: Environmental activities unknown price and value caused establishing of some unique characteristics for mentioned commodities. One of these characteristics was existing gap between private and social cost and benefit. For assessing these activities different approaches include travel cost, willingness to pay and hedonic price had been suggested. According to Tehran’s air pollution problem, in this study Hedonic approach had was used for the assessment of healthy air on Tehran’s residential house price.Materials and Method: Hedonic approach is one of the methods that are used for evolution environmental goods. In this method, each good’s price is estimated as a functions of that good`s properties. To gather this study information 300 questionnaires has been collected by random sampling from different area of Tehran.Result: Results revealed that activities in order to reduce air pollutions, in addition to environmental value have economical value form the point of view of consumers. Also, results show that willingness to pay of every Tehran’s citizens for every square meter of house located in region with less pollution is between 1120 to 1350 thousands Rials.Conclusion: According to the obtained results can be said that, clean air as an environmental good from the viewpoint of consumers has economic value that can be calculated this value using methods such as Hedonic.

Background and Objectives: Anzali Wetland is one of the most important aquatic ecosystems of Iran which is located in south-west of the Caspian sea. This Wetland provides a suitable and non-market price habitat for valuable fish and aquatic animals which have an important role in the life cycle of this ecosystem. This study reports the results of some heavy metals contamination monitoring in superficial water of the Anzali Wetland, Iran.Materials and Methods: The samples were collected from three sites (east, center and west) of Anzali Wetland, in each site three stations existed and each sample replicated three times.Results: The results showed high heavy metal levels in eastern site of wetland, where there were high levels of contamination. The mean of heavy metals concentration in sediment from Anzali Wetland were in order as Cd 157.023, Pb 3.646 and Hg 300.692 ng /g dried weight, Zn 186.953 and Cu 44.452 mg /g dried weight in eastern site. The concentration levels of heavy metals in three sites were in order as follows: Zn>Cu>Hg>Cd>Pb.Conclusion: Concentrations of heavy metals in eastern zone reflected metal loadings from anthropogenic sources located at and in the vicinity of the sampling sites.

Bachgrounds and Objectives: Oil, gas and petrochemical are known as important sources of air pollutants and emission of green house gases. About 99 percent of sulfur dioxide in the air is produced from human resources. Although several samples have been taken from industries and refineries’ output by environmental experts and private companies, but accurate assessment is not available based on pollutant emissions on product levels (emission coefficients) and on the total amount of the annual emission which, can be used as basic modeling of air pollution and planning.Materials and Methods: This study was cross sectional and the output of the chimney measured with Testo 350 XL system. Performance standard was determined based on ASTM D6522 EPACTMO30- 41. The amounts of sulfur dioxide were measured from Tehran oil refinery’s outlet from the beginning of the march 2007 till the year 2008 for 20 months. Sampling was carried out on averaged range (9 am to 14 pm)Results: The results showed that Northern Distillation unit produced pollutants’ concentration more than 3 times in the southern Distillation unit. An emission of pollutants from Northern unit was, 2.8 times higher than the Southern unit. The northern emission factor was 5.6 times higher than the value obtained from southern unit. The Concentration, emissions and coefficient of sulfur dioxide in North catalyst convert unit were more than 2 times in comparison with the same South unit. These three factors in northern concentration breakers unit were 3, 2.6 and 2.6 times higher than the Southern concentration breakers unit‚ respectively. Discussion: Emission rate in all northern units is 2 to 3 times more than similar southern units. The production volumes in northern units are higher than the southern units and the southern units designed properly to remove more pollutants .The use of new technologies in production processes and application of the latest scientific resources can play a major role on pollutants’ reduction.

Background and Objectives: Linear alkyl benzene sulfonates are widely used as surfactants in formulated detergent products. Because of their use in household and industrial detergents, LAS is discharged into wastewater collection systems and subsequently entered to wastewater treatment plants. Therefore, it is important to determine the concentration of LAS with accuracy. They are usually determined by standard method which is time-consuming, tedious and requires great quantities of chloroform. IN 2006 E.Jurado et al proposed a simplified method for measurement of LAS. In the present work the standard method and E. Jurado simplified method was compared economically.Material and Methods: In this work NPV method was used for accounting the cost of initial investment, consumable material, non-consumable equipment and annual cost of staff and finally Net Present Value was calculated for them separately. The rate of interest was considered 15%.Results: calculation showed initial investment, annual cost of staff and materials for standard method 13351981, 499968 and 1710981 RLS, respectively. And these costs for simplified method were 12048202, 83328 and 58202 RLS, respectively. Finally NPV for standard method and simplified method were equal to 30360709 and 14681848 RLS.Conclusion: The method proposed by E. Jurdo et al is simple, time consuming and more economical than standard method .This technique can be suggested applying to the routine measurement of LAS in wastewater treatment plants.