Iranian Journal of

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Background and Objectives: Fresh leachate has a low pH and high amounts of BOD and COD which are mainly constituents with low weight molecular such as volatile fatty acids ( acetic and propionic acids) .Management and treatment of leachate is an important subject in sanitary landfill operation and performance.Th objective of this study is determining the efficiency of the integrated coagulation -flocculation and ozonation processes in fresh leachate treatment of Tabriz city.
Materials and Methods: Quantitive parameters of pH, BOD5, COD , alkalinity and TSS were studied based on standard methods.The study emphasizes of COD and TSS leachate removal.Alum , ferric chloride and PAC had been used as coagulants.
Results : Results indicated the superiority of Ferric chloride at the dosage of 1 g/l in pH 10 ,whichreduced 34% of COD and 54% of TSS.in the stage of ozonation the leachate sample coagulated by ferric chloride was treated by 3 g/h ozone gas at optimum pH and after 39 hours ozonation about 51% of COD and 18.2 % of TSS were reduced.
Conclusion: This study clearly indicates that there would be need to apply biological treatment (after coagulation - flocculation ) and ozonation , various advanced oxidation processes and / or other treatment methods for further reduction of COD in leachate and meeting discharge standards.

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Background and Objectives: Fluoride is widely used in industries such as manufacture of semiconductors, power plants, glass production etc and release to the environment via their effluents. The purpose of this sturdy was to compare the efficiency of low price adsorbents in fluoride removal from water.
Materials and Methods: The optimum values of pH, contact time and adsorbent dosage were determined and different concentrations of fluoride were experimented in lab scale conditions for bagasse, modified bagasse and chitosan. Then Langmuir and Freundlich coefficient were determined based on optimum conditions.
Results: The pH value of 7, contact time of 60 min and adsorbent dosage of 2 g/L were determined as optimum conditions for all three adsorbents. The most fluoride removal efficiency of 91% was obtained for modified bagasse in optimum conditions.
Conclusion: Based on data obtained in this study, it can be concluded that adsorption by modified bagasse is an efficient and reliable method for fluoride removal from liquid solutions.

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BackgroundsandObjectives: Environmental activitiesunknownprice 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.

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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: Particular importance of hazardous wastes is due to having characteristics such as toxicity, flammability, corrosively and reactivity. Some of the chemical wastes due to having hazardous materials must be collected and managed in a proper manner, since they are potentially harmful to the environment. Owing to the fact that educational centers have important roles in developing countries, so the main objective of the present study was to investigate, hazardous waste management in chemistry laboratories of Ministry of Science universities, in Tehran, Iran.   
Materials and Methods: Study area of this research includes all chemistry laboratories in Tehran universities which were covered by Ministry of Science. To obtain the number of samples, based on Scientific Principles and identification formula, 64 samples were calculated. In addition, sampling was done by Stratified sampling. Validated checklists were used for data gathering. Data analysis were done by Descriptive statistics (mean, frequency and etc.) and inferential statistics (kruskal- wallis test).
Results: results obtained in this study indicate that Sharif University by obtaining the mean score of 60.5 and Tehran University by obtaining the mean score of 4.5-6 are placed in best and worst rank, respectively. Beheshty, Alzahra and Tarbiat Moallem univesities by acquiring the mean score of 20-28.5 have a same position in ranking table. 
Conclusion: Results show that most of the studied laboratories do not have any collection program and only 26.5 percent of them have acceptable programs.The separation and storing program observed in about 12.5 percent . Hazardous wastes' management in chemistry laboratory of Tehran Universities was not in good status. And from the standpoint of management, only 12.5 percent of studied cases are in good status, while 75 percent was in undesirable status.

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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: Industrial processes are the major sources of environmental pollutants. Oil & gas processing are one of the industries which emitting several air pollution matters in to the atmosphere. The obtained results of CO₂ emission in one of the Gas Sweetening unit of Iranian south oil company based on the field and deskwork calculations is presented in this paper.
Materials and Methods: Fuel analysis method is the best method for CO₂ estimation from combustion sources. In this paper, CO₂ emission factor for gas sweetening plants is estimated based on this method.
Results: The obtained results showed that  total CO₂ emission in selected unit is about 922212/97 (kg/d) and CO₂ emissions for the separate parts of this unit are 579661/75, 12921/93 and 329629/29 for acid gas flare, gas flare and boilers respectively.
Conclusion: comparison between the separated parts of the studied units showed that emission of acid gas flare is higher than other sources (i.e about 63% of total CO₂ emission), and by using the EPA default CO₂ emission factors the CO₂ emitted 1/2 % lower than the actual emission in the mentioned unit.

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Backgrounds and Objectives: Improvement of water quality standards and inability of mono layer filters in producing such quality caused researchers attended to multi layer filters. Due to specific characteristics of anthracite and leca can improve removal of organic materials and Surface over flow rate. The aim of this research was evaluation performance of dual media filters (anthracite/leca) in removing of organic materials and turbidity from Ahvaz Water treatment plant
Materials and Methods: In this study two pilots built for investigation of mono layer filter and dual media filter performance. The researcher used sand in structure's media of mono layer filter and composition of anthracite, sand and leca in structure's media of dual media filter, respectively.  In this study single and dual layer filter pilot examined in term of organic matter and turbidity removal efficiency. 
Results: Results indicated that removal of organic matter by single layer filter (sand), dual media filter (anthracite,  and sand), dual media filter (leca and sand) was 7%,12%,4/2% respectively. And also Turbidity removal by single layer filter(sand), dual media filter (anthracite and sand), dual media filter (leca and sand) was also  69%, 80%, 74% respectively.
Conclusion: Results of this study showed that upgrading of Single layer to dual layer with anthracite and leca media can‘t show a significant affect in TOC 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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MicrosoftInternetExplorer4 Background and Objectives: Guilan province, with unique environmental values ​​of the Caspian Sea is located in the southwest of Caspian Sea. Disposal of untreated domestic sewage, industrial and agricultural surface water cause pollution of the Caspian Sea region and endanger the health of swimmers. This study performed to determine the microbial contamination of coastal water in Guilan. 
Materials and Methods: In this work, 21 sampling point in the Caspian Sea littoral provinces of Guilan were selected and microbial contaminations were assessed using   microbial indicators of fecal and total coliform. Parameters such as pH, temperature, and turbidity also monitored during the year. In this study, 122 samples were taken and then analyzed by statistical software.
Results: The results showed that the average values of total coliform and fecal coliform were 234.8 and  60 MPN per 100 ml, respectively. The fecal pollution appeared to be high in some stations. Also significant relationship between temperature, turbidity and microbial contamination was observed (P< 0.05).
Conclusion: The results revealed high total coliform in the two stations. The average fecal coliform of six stations were higher than the local standards.

 

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MicrosoftInternetExplorer4 Background and Objectives: Heat stress is considered as a serious threat to the health and safety of workers in many industries, including petrochemical and steel. Assessment of the heat stress is important from the disease prevention point of view and also for the safety and performance of workers at workplace. Although there are many indices to evaluate the heat stress, it is hard to select an applicable index for a wide range of weather conditions. The purpose of the study was to develop an optimal index based on physiological parameters in a petrochemical industry. 
Materials and Methods: The study was conducted in a petrochemical industry located in Assaluyeh (south of Iran). Twenty one healthy young men at different levels of fitness and heat acclimation volunteered to participate in the study. Physiological parameters including heart rate, systolic and diastolic blood pressure, skin temperature and oral temperature were measured during the working day over two consecutive weeks. Simultaneously, we measured the climatic parameters required to calculate the wet bulb globe temperature (WBGT), required sweat rate (SWreq), and the discomfort index (DI) indices.
Results: All the measurements took place on 2 sites: Kar (working place) and Paziresh (resting room). Our results showed  that the mean values of indices and physiological parameters   in Kar    for both acclimated and unacclimated groups were significantly higher than Paziresh (P<0.05). There was the strongest linear correlation between WBGT and heart rate (0.731), systolic blood pressure (0.695) and diastolic blood pressure (0.375) and skin temperature (0.451) respectively. The amounts of DI were 0.725, 0.446, 0.352, and 0.689 respectively. But the strongest linear relationship existed between SWreq and deep body temperature (0.766).
Conclusion:  There were significant differences in the present indices and physiological parameters of Kar and Paziresh, confirming the previous studies findings. Finally, WBGT was considered optimal index and the results revealed the almost perfect linear correlation between WBGT and heart rate. We propose WBGT can be the most applicable index for evaluating heat stress in this climate.  

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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).

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MicrosoftInternetExplorer4 Background and Objectives: Environmental pollution and health risks of dyestuffs extensively are caused by many industries. Nonbiodegradability of dyes is important so that different methods are studied for removing them. The use of white rot fungi is promising technique in this regard. Therefore, objective of this work is to investigate Rimazol Brilliant Blue Royal decolorization by immobilized Ganoderma sp. in sodium alginate from aqueous solution.
Material and Methods: This is an experimental study. First, the nutritional, environmental, and operational conditions of decolorization process were optimized. Then, efficiency of immobilized fungal cells was investigated. Experimental designs were provided using fractional factorial methods and quadratic model was fitted on decolorization data by MiniTab software.
Results: Our findings showed that type and concentration of carbon source, temperature, and pH were the most important factors affecting decolorization and statistically significant. Optimal conditions to 95.3 percent color removal were: glycerol as carbon source at 19.14 g/L temperature, 27 oC and initial pH, 6.26. Moreover, decolorization efficiency increased from 75 percent up to 95 percent by improving process and fungal immobilization.
Conclusion: Ganoderma fungus has suitable potential to decolorization. Besides, optimization and cell immobilization can improve its capability. Application of experimental design to research methodology is important because of decreasing in experiments and saving resources. It is suggested to use these potentials in environmental pollution control.

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MicrosoftInternetExplorer4 Background and Objectives: Formaldehyde is a toxic substance and harmful to human beings and the environmental health. Therefore, the effluents containing formaldehyde have to be efficiently treated before discharging into the environment. This study was aimed at investigating the efficiency of Electro-Fenton (EF) Process in pre-treating industrial wastewater containing high concentrations of formaldehyde.
Materials and Methods: The effect of the important operational variables including pH, current density, H₂O₂ dosage, and reaction time were evaluated on the degradation of 7500 mg/L formaldehyde using batch tests. The EFP batch reactor was consisted of a cylindrical glass column with 5.20 cm in internal diameter and 34.50 cm in height. Working volume of the reactor was 500 mL.
Results: The maximum formaldehyde removal was obtained at alkaline pH of 10, H₂O₂ concentration of 10 mM/min, current intensity 8.5 mA/cm2, and the reaction time of 6 minute. Furthermore, aerating the EFP cell could enhance the formaldehyde removal. Complete removal of formaldehyde was obtained under the abovementioned operational conditions.
Conclusion: This study demonstrated that the EFP is capable of reducing high concentration of formaldehyde (7500 mg/l) to the level suitable for biological post-treatment.

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MicrosoftInternetExplorer4 Background and Objectives: Wind-induced particulate air pollution from iron ore piles can causes environmental and economic problems for steel industries. In this experimental study, the effectiveness of various additives in reducing particulate air pollution from iron ore piles was investigated in a laboratory wind tunnel.
Materials and Methods:  The experimental set up consisted of a prismatic pile and a wind tunnel. Four different wind speeds of 4.3, 5, 7 and 11 m/s was used in the study  Municipal water, quick lime (2%), seawater, treated industrial wastewater and Polylatice (0.25%) were used as additives to stabilize the upper layer of the pile.
Results: Emission factors for non-stabilized (without additive) piles at 4.3, 5, 7 and 11 m /s wind speeds were 46.7, 73.2, 1025.4 and 13768.7 g/m², respectively. Stabilized piles with 2.6, 2.7, 2.8, 2.7 and 2.8 percent additive (moisture content of the upper layer of the pile) for municipal water, Polylattice (0.25%), treated industrial wastewater, seawater and quick lime (2%) indicated a decrease of 99.4%, 100%, 99.3%, 99.5% and 99.5% particulate emission reduction, respectively.
Conclusions: Proper selection and use of additives on iron piles has the potential for decreasing  more than 99% of the wind-induced particulate emissions. Operational factors such as covered area, spray frequency, pile geometry, seasonal adjustments related to ambient temperature and humidity, wind speed and operator training need to be an integral part of the pollutant reduction program.              

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Background and Objectives: Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat, and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards.
Materials and Methods: At present study, slaughterhouse wastewater after initial analysis was tested for survey of coagulation process using Poly aluminum chloride (PAC) at various doses (25-100 mg/L). Then we measured the concentrations of wastewater pollutants (BOD5, COD, TKN, TSS and fecal Coliforms). Later, we transferred the effluent to the electrocoagulation unit and we evaluated the removal efficiency of pollutants in the range 10 to 40 volts of electric potential during 60 min.
Results: It was found that the efficiency of chemical coagulation process using poly-aluminum chloride (PAC) as coagulant increases with increasing doses (from 25 to 100 mg/L) we achieved maximum removal efficiency during the chemical coagulation for parameters of BOD5, COD, TSS, and TKN at 100 mg/L of PAC equivalent to 44.78%, 58.52%, 59.9%, and 39.58% respectively. Moreover, the results showed that with increasing the electric potential and reaction time, the yield increases linearly so that maximum removal efficiency at a dose of 100 mg/L PAC, an electrical potential of 40 volts and a reaction time of 60 minutes for the parameters BOD₅, COD, TSS, and TKN was 99.18% 99.25%, 82.55%, and 93.97% respectively.
Conclusion: The experiments demonstrated the effectiveness of combined chemical coagulation and electrocoagulation processes for pollutants removal from the slaughterhouse wastewaters. Consequently, this combined process can produce effluent compliance with the effluent discharge standards.

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Background and Objectives: Legionella are gram-negative bacteria widely dispersed in natural and man-made water sources. Some Legionella species are pathogenic and could cause respiratory infections. Cultivation technique is the conventional method for the detection of Legionella spp. in aquatic samples. However, the method has low sensitivity and require prolonged incubation period. Therefore, Polymerase chain reaction (PCR) as a rapid method with extreme sensitivity is used. The present study was designed to evaluate the feasibility and sensitivity of PCR method for detection of Legionellas pp. in aquatic samples using three sets of primers.
Materials and Methods: In this study, 60 water samples were investigated for the presence of Legionella species using Nested- PCR technique. The sensitivity of this technique was evaluated for the detection of Legionella species in aquatic samples using three primer sets, including (LEG225-LEG858), (LEG448-LEG858), and (LEG448-JRP).
Results: The nested PCR assay revealed that detection percentage of Legionella in samples was 70 when LEG448-JRP primers were used, whereas this percentage reduced to 50 and 45 when we applied prime sets of LEG225-LEG858 and LEG448 - LEG858, respectively.
Conclusion: The results of the study showed that contamination of aquatic samples to the Legionella spp. could be easily and rapidly detected by nested PCR. However, selecting appropriate method for DNA extraction and choosing the primers are important factors in efficiency and sensitivity of detection method.

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Backgrounds and Objectives: Determination of arsenic(As) in drinking water has received increasing interest due to its detrimental effects on health. The aim of this research is to investigate effect of coating coral limestone using aluminum sulfate as an adsorbent on the arsenic(V) removal efficiency from aqueous solution. Materials and Methods: In this laboratory scale study, we prepared coral lime granules using mesh 30 during several stages. Then, we investigated the arsenate removal efficiency under different conditions and changing main factors including pH, contact time and amount of no coated and aluminum sulfate-coated adsorbent. Moreover, we fitted our results with Langmuir and Freundlich models and kinetic data with pseudo- first order, pseudo- second order and modified pseudo- first order models. Results: We found that increasing pH from 3 to 10 at arsenate concentration of 500 ppb and 5 g/l adsorbent and 120 min contact time, removal efficiency for no coated and coated adsorbent was reduced from 100 to 86.2% and from 100 to 92.2% respectively. Increasing concentration of both adsorbents from 1 to 5 g/l at contact time 120 min increased the removal efficiency from 76 to 99.2% and from 66.3 to 91.1% respectively. Arsenate removal efficiency was directly proportional with the amount of adsorbent and contact time and reversely proportional with the initial concentration of arsenate and pH. The removal efficiency of the coated adsorbent was more than uncoated adsorbent. Langmuir was the best sorption isotherm model for arsenate in these two processes and absorption kinetic was well described with second order models. Conclusion: Excellent removal efficiency, cost-effectiveness process, and lack of environmentally harmful substances make application of the Persian Gulf offshore corals a reasonable adsorbent to remove environmental contaminants such as arsenate.

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MicrosoftInternetExplorer4 Background and Objectives: Azolla Filiculoides as a non-living fern was used in a batch system to remove "Basic Blue 3", which is a cationic dye and a carcinogenic agent.
Materials and Methods: We used a batch system by applying certain concentrations of dye contaminant and in the presence of a certain amount of adsorbent under optimum conditions. The main groups presenting in the Azolla cell wall were evaluated by acidification and alkalization of Azolla's media and then potentiometric titration with standard basic and acidic solutions.
Results: It was observed that the removal efficiency of dye using non-living Azolla in accordance with the Langmuir isotherms was 82% for the initial dye concentration of 200 mg/lit under reaction conditions consisting of contact time 6 h, pH= 6, temperature 25 ˚C, and dose 5 g/lit. Q_max (maximum uptake capacity) by the activated Azolla at three temperatures 5, 25 and 50 ˚C was 0.732, 0.934, and 1.176 mmol/g respectively. ΔG (Gibbs free energy changes) was obtained for these temperatures as -0.457, -0.762, and -1.185 kJ/mol respectively.
Conclusion: Removal of basic blue 3 using Azolla is an economically and effective method.

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Background and Objectives: Wastewater contains various pathogens including viruses, bacteria, fungi, etc. These microorganisms can easily become airborne during normal operations of wastewater treatment plant and contaminate the neighborhood environment. The aim of this study was to investigate the type and density of bioaerosols in a petrochemical wastewater treatment plant in Iran.
Materials and Methods: In this cross sectional study, bioaerosols density was measured in different units of a petrochemical wastewater treatment plant according to the NIOSH 0800 method and the values measured were compared with background level (control area). For this purpose, air samples were collected on blood agar and dextro agar in Andersen single-stage sampler with air flow of 28.3 l/min for 10 minutes. Samples collected were shipped to the laboratory immediately and were incubated for 48 hours. Then, incubated samples were counted for colonies concentration.
 Results: Average concentration of bacteria and fungi bioaerosols measured were 731.70±185.49 and 28.43±10.58 (M±SD) CFU/m3 respectively throughout the wastewater treatment plant units. These values were 35 and 1.45 times higher than background level (Control area). The differences between average concentrations of bacteria in all units of wastewater treatment plant with control area were statistically significant.
Conclusions: Generally, it was found that the density of bioaerosols, especially bacteria was much higher than the background level. The maximum density was measured at aeration chamber, where the emission of bioaerosols could be reduced through replacing nozzle diffused aeration system.