Showing 31 results for Type of Study: Applicable
A Beiki, M Yunesian, R Nabizadeh, R Saeedi, L Sori, M Abtahi,
Volume 9, Issue 1 (6-2016)
Abstract
Background and objectives: Swimming is one of the most popular sport fields and entertainments that has considerable benefits for human health, but on the other hand microbial water contamination in swimming pools through transmission and spread of infectious diseases is a significant threat against public health. In this study, microbial water quality of all public swimming pools in Tehran were assessed and effective factors on microbial water quality were analyzed.
Materials and Methods: This cross-sectional study with the analytical approach was performed in 2013. The whole public swimming pools in Tehran were inspected and water samples were taken for measurement of microbial indicators including thermotolerant coliforms, heterotrophic plate count (HPC), and physicochemical parameters affecting the microbial water quality including turbidity, free residual chlorine and pH and an integrated swimming pool microbial water quality index were used to describe the overall situation. Operational parameters with probable effects on microbial water quality were checked through inspection using a checklist.
Results: The assessment of the swimming pool microbial water quality indicated that the compliance rates of thermotolerant coliforms and HPC were 91.4 and 84.5%, respectively. Compliance rates of free residual chlorine, turbidity, Ph, and temperature were also obtained to be 82.7, 45.5, 85.6, and 65.4% respectively. Based on the integrated swimming pool microbial water quality index, the proportions of swimming pools with excellent and good microbial water quality were 39.6 and 50.4% respectively and the others had not proper microbial water quality. The parameters of water free residual chlorine and turbidity, swimmer density, water recirculation period, dilution amount, cleaning, usage rates of shower and disinfection basin and operation of water treatment systems had significant effects on the microbial indicators (P<0.05).
Conclusion: The study showed that the overall microbial water quality status of public swimming pools in Tehran was acceptable and analysis of the results determined the most efficient interventions for improvement of the microbial water quality of the pools.
N Rastkari, F Izadpanah ,
Volume 9, Issue 1 (6-2016)
Abstract
Background and Objective: Formaldehyde is a toxic volatile organic compound, which its removal from polluted air is essential. One of the techniques available for removing such compounds is photocatalytic degradation. The aim of this study was to investigate the photocatalytic degradation of gaseous formaldehyde on TiO2 nanoparticles coated on reduced graphene oxide
Materials and Methods: The synthesized reduced graphene oxide- TiO2 nanocomposite was characterized using SEM, EDS, and FTIR spectra. The photocatalytic activity of prepared reduced graphene oxide- TiO2 nanocomposite was investigated for degradation of gaseous toluene under different operational conditions such as different initial concentration, flow rate, and time.
Results: The photocatalytic degradation efficiency of the RGO-TiO2 nanocomposite was much higher than P25 TiO2. The photocatalytic degradation efficiency of the RGO-TiO2 nanocomposite decreased by increasing the flow rate so the flow rate is a key factor for the use of RGO-TiO2 nanocomposite as a photocatalyst. The results showed that the photocatalytic degradation rates decreased from 89 to 30% with increasing formaldehyde initial concentration from 0.1 to 1 ppm.
Conclusion: This research indicated that RGO-TiO2 nanocomposite can be effectively used as suitable photocatalyst to remove gaseous pollutants. One of the advantages of the as-prepared composite was using visible light instead of UV to activate the oxidation process.
H Meskini, E Sadeghi, A Nosrati, P Nosrati, M Bashiry,
Volume 9, Issue 2 (9-2016)
Abstract
Background and Objectives: Money as a common tool is exchanged between people all over the world. Thus, it can be a source of chemical and biological contaminations causing serious diseases. The purpose of this research was to determine bacterial contamination of the currency notes and coins collected in Kermanshah.
Materials and Methods: 160 currency notes and 96 coins were randomly chosen from different jobs and parts of the city. Total count experiment was done and bacteria were identified and isolated through standard methods.
Results: Average total count in 1000, 2000, 5000, 10000, and 20000 Rials currency notes were 147.6, 147.8, 148.5, 96.3, and 87.9 and in 500, 1000, and 2000 Rials coins were 104.66, 77.66, and 96.56 CFU/cm2, respectively. The research showed that currency notes carries more bacterial load than coins (P<0.05). Additionally, contamination to E. coli on money (13.7 %) and on coins (3.9%) were at maximum levels while Pseudomonas on currency notes was at the minimum level (1.6%) and coins contained 0.2% Enterobacter that was at the lowest amount.
Conclusion: In summary, the most important microorganisms isolated from currency notes and coins (E.coli and Staphylococcus aureus) were pathogenic, causing serious food poisoning and gastroenteritis infectious. Therefore, preventing food from cross contamination with money is necessary.
M Asghari, R Nabizadeh, H Norzad, H Mortezaee,
Volume 9, Issue 3 (12-2016)
Abstract
Background and Objective: Increasing air pollution and consequently adversely effects on the quality of life for many people has resulted in the use of the air quality indice for determination of the actual amount of pollutants and air quality, as one of the most important and effective measures for air quality control, to be considered further. The air quality health index (AQHI) is a new index related to air pollution developed in collaboration with Environment Canada and Health Canada, in 2001. The purpose of this study was to design and develop a software system for calculating AQHI for the first time in the country that calculates the health effects caused by the presence of several pollutants (NO2, O3,PM10, and PM2.5) at the same time with a new approach.
Materials and Methods: To achieve those aims, the software was designed and coded in Visual Basic. Net. After preparation of the software, it was tested using the real-time database of six air pollution monitoring stations in Tehran including Aghdasyeh, Setad Bohran, Shahrdari 4, Golbarg, Park-e- Roz, and Shahrdari 11.
Results: This program is a software package installed on the computer with the possibility of exporting Excel file. The performance of software testing was verified using real data.
Conclusion: The results of the verification tests show that the index calculated by the software introduced and presented in this study can be used as a useful tool to assess air quality.
M Jalili, M Mokhtari, Aa Ebrahimi, F Boghri,
Volume 9, Issue 3 (12-2016)
Abstract
Background and Objective: About 1.35×105 tons of pistachio waste are produced in annually Iran that can result in environmental problems if managed improperly. . The purpose of this study was to investigate in-vessel composting of pistachio residuals with addition of cow manure and dewatered sludge as a recycling alternative.
Materials and Methods: Pistachios wastes were combined with weight ratio of 5.5:10 (dewatered sludge: pistachio waste) and weight ratio of 1:10 (Cow manure: pistachio waste) to achieve the carbon to nitrogen ratio of 25:1. The parameters measured were pH, EC, percentage of moisture, total and volatile solids, ash, organic carbon, temperature, and phenol. The 20th edition of SPSS software was used for t-test statistical analysis and comparing the results with standards and Microsoft Excel 2007 was used for drawing the plots.
Results: During the 60-days process of in-vessel composting of pistachio residuals with addition of cow manure, the ratio of carbon to nitrogen reduced from 25:1 to 13:1, dewatered sludge from 25:1 to 14:1; phenol amount in cow maneuver decreased from 4980 to 254 ppm and in dewatered sewage sludge from 6100 to 254 ppm. The maximum temperature in cow manure and dewatered sewage sludge treatments in the composting process reached to 51.9 and 48.9 ˚C respectively.
Conclusion: Results showed that the produced compost with cow manure has a higher fertilizing value compared with the dewatered sewage sludge due to its better organic degradation.
Rs Hajimirmohammad Ali, H Karyab, Ha Jamali, Mm Emamjome, F Ansari Maleki, A Arezomand,
Volume 9, Issue 4 (3-2017)
Abstract
Improper and incorrect implementation of sewage collection networks can cause environmental and health problems. It also causes dissatisfaction in urban residents. The purpose of this study was to design a questionnaire for evaluating satisfaction level of urban residents from sewage collection network. Face validity index, content validity ratio and Cronbach-coefficient were used to evaluate validity and internal consistency. The evaluated indexes were assessed in acceptable levels. The designed tool that was included 25 variables can be used to assess satisfaction level by researchers and wastewater companies.
M Mokhtari, A Salehi Vaziri, T Zareyi, M Jalili,
Volume 9, Issue 4 (3-2017)
Abstract
Background and Objective: Dewatered sewage sludge is a by-product of wastewater treatment process which can cause health and environmental problems if not properly managed. The aim of this study was to determine the feasibility of composting of Yazd WWT dewatered sludge with windrow method using different treatments.
Materials and Methods: In this study, the dewatered sewage sludge was mixed with two treatments of agricultural wastes (straw) and green waste (leaves), respectively. The mixture was done based on weight ratio of 20:1 and 10:1 (agricultural waste: dewatered sludge, and green waste: dewatered sludge) to achieve a ratio of C/N:20. The windrows were built with a length of 2 m, width of 75 cm and height of 1.5 m. Composting process was controlled by measuring the temperature, humidity, volatile solids, ash, pH, EC, organic carbon and estimating the C/N ratio. The results were compared with those of the Institute of Standards and Industrial Research of Iran.
Results: After 100 days of composting, C/N ratio was 13.08±6.25 in the treatment with green waste and reached to 15.46±5.35 in the treatment with agricultural waste. The amount of volatile solids decreased to 19.8±14.01% and 20.71±16.06% in the treatments with green waste and agricultural waste, respectively. The amount of EC had an increasing trend in both treatments.
Conclusion: composting with both treatments was led to an improvement in indicators of organic fertilizers in dewatered sewage. However, the windrow containing green waste reached to the mature compost standards sooner than the windrow containing agricultural waste.
Sh Gorgani, A Bafkar, Se Fatemi,
Volume 9, Issue 4 (3-2017)
Abstract
Background and Objective: There are major mobile and non-mobile pollution sources due to human activities that can influence aquifers and reduce groundwater quality. Vulnerability assessment is an inexpensive procedure in to identify areas prone to the pollutants. Identification of these sources is essential in water resources management. Mahidasht Plain is one of the important regions of Kermanshah province and plays a significant role in the production of agricultural products. Water supply for agriculture may be at risk due to the indiscriminate withdrawal of groundwater resources of the plains, the recent droughts and potable water requirements. Therefore, analysis and evaluation of the area helps to make better decisions on proper management and control of water pollution.
Materials and Methods: Vulnerability, which is defined as the sensitivity of groundwater quality to pollution load, was applied and determined using intrinsic features of the aquifer. In this study, we have studied inherent vulnerability of the Mahidasht aquifer against pollution by using DRASTIC model and GIS. Seven parameters for the zoning of aquifer vulnerability was used in the DRASTIC method, including depth to the water table, net recharge, aquifer material, soil type, topography, impact of vadose zone and hydraulic conductivity. These parameters were prepared as seven layers of information in Arc GIS10 Software. The data collected for the purpose of this study were taken fromwells log, 44 piezometer in the area, pumping experiments and three rain-gauge stations. The layers prepared in Arc GIS10 software were weighted, ranked and eventually integrated.
Results: The DRASTIC index calculated for the plain ranged from 34 to 120 units. On this basis and according to the standards listed for DRASTIC index, the aquifer was in a vulnerable group with a low or no risk.
Conclusion: DRASTIC model output showed an inherent vulnerability of the aquifer. The model can be used as a primary tool in the development and management of water resources in the future. In addition, this model is not able to produce information about amount and type of pollutants. Therefore, it is recommended to examine the salinity zoning in the future research due to less rainfall and decreasing underground water level and consequently the higher probability of salinity in underground water. Additionally, the domestic and industrial wastewater, sewage irrigation and the fraction used for groundwater recharge should be considered in order to validate the results of Drastic model.
H Adab, A Atabati, R Esmaili, Gh Zolfaghari, M Ebrahimi,
Volume 10, Issue 1 (6-2017)
Abstract
Background and Objective: Optimum number of air quality monitoring stations in Mashhad is an essential task for management of the urban environment. However, real monitoring and accurate information on the status of air quality require proper spatial distribution of air quality monitoring stations in the city of Mashhad. The aim of the present study was to determine optimum site locations for air quality monitoring, including Downtown Pedestrain Exposure Station, Downtown Background Exposure Station, and Residential Population Exposure Station by three Multiple-Criteria Decision-Making (MCDM) techniques.
Materials and Methods: In the precent study, sites for new air quality monitoring stations t in Mashhad were determined based on a proposed protocol in the United States. Accordingly, the criteria effective for site selection such as population density, distance from existing stations, vicinity to vegitation, vehicle density and other factors were used by applying Analytic Hierarchy Process (AHP), Fuzzy set, and Probability Density Function (PDF).
Results: Location similarity of the sites proposed by decision making methods was evaluated to know its reliability. The compactness of distribution of the proposed sites were compared by applying spatial statistic methods auch as Average Nearest Neighbor (ANN) and Standard. The results from ANN indicated that fuzzy set mapped the suggested sites was fully scattered within the entire city of Mashhad and was statistically significant at 99% confidence level. The PDF method also offered the same spatial pattern as fuzzy set. Overall results of this study indicated spatial optimization of suggested sites location for fuzzy set and PDF.
Conclusion: The overall results of the decision-making methods used in this study indicated that it is necessary to increase number of air quality monitoring stations at Northwest of Mashhad due to the urban growth in the city. The results also showd the possibility of using Probability Density Function (PDF) as a method of decision-making in GIS for locating and ranking of new air quality monitoring stations.
H Irvani, H Shojaee - Farah Abady, M Shahryari, M Nakhaei Pour,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: Styrene monomer is a volatile organic compound that is used in the various industries. Due to the hazardous effects of this chemical substance on the environment and humans, control and elimination of this vapour is necessary. Therefore, the aim of this study was to remove the styrene vapors from air flow using photocatalytic activity of zinc oxide immobilized on ZSM-5 zeolite.
Materials and Methods: In this experimental study, the fabricated catalysts were characterized using analysis of BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Dynamic Concentrator System were used to generate styrene vapors at a certain concentration and flow, and then removal efficiency of the styrene vapors was investigated using UV/ZnO and UV/ZSM-5/ZnO.
Results: The results of XRD analysis and SEM images showed that produced zinc oxide had nano dimensions. In addition, these nanoparticles was successfully stabilized on ZSM-5 zeolite. The results of the photocatalytic removal showed that ZnO and ZSM-5/ZnO catalysts at the concentrations of 50 ppm eliminated the styrene vapor 14% and 37%, respectively.
Conclusion: Findings of this study showed that stabilization of zinc oxide nanoparticles on ZSM-5 zeolite had an ssynergistic effect on the photocatalytic degradation of styrene. According to this finding, the use of adsorption-photocatalyst hybrid systems can be an appropriate technique to remove styrene vapors and other similar pollutants.
A Moghaddam, M Mokhtari, R Peirovi,
Volume 10, Issue 3 (12-2017)
Abstract
Background and Objective: one of the steps in water treatment to protect microbial quality of water network is disinfection. Chlorine is one of disinfectants. It is necessary to maintain Free Residual Chlorine (FRC) between minimum and maximum throughout the distribution system in accordance to health standards. This study was aimed to optimize Chlorine dosage in water distribution networks using GANetXL model.
Materials and Methods: In this paper for the first time using an add-in called GANetXL optimization that uses a genetic algorithm, the Chlorine injection was optimized in a reference network based on dynamic connection to EPANET2 hydraulic and qualitative analysis in Excel software. The objective function is formulated such that the squared difference between computed chlorine concentrations and the minimum residual concentration at all monitoring nodes at all times is minimum. The decision variables were the optimized injection dose at boosters’ locations.
Results: The injection rate was obtained (minimum: 0, average: 183.87, maximum: 776.57 and total 4412.84 mg/min per a day) at the station as the number of generation was reduced to 200. Critical nodes formed 20% of the total nodes of network.
Conclusion: Based on the results, minimization of Chlorine whilst comply with FRC standard has both health and economical effects. The results can help the water distribution system management in terms of water quality (by maintaining FRC), health promotion and monetary.
N Golchinpour, N Rastkari, R Nabizadeh Nodehi, M Abtahi, A Azari, E Iravani, K Yaghmaeian,
Volume 10, Issue 4 (3-2018)
Abstract
Background and Objective: Triclosan is one of the substances as anti-microbial that is used in many of these pharmaceutical products. This compound can affect human such as reduction of thyroid hormone levels, antibiotic resistant, and increasing skin cancer. This study evaluated the performance nanophotocatalysis process UV/Xe/TiO2-GO on triclosan removal from aqueous solutions.
Materials and Methods: Synthesis of TiO2@GO and its structure was analyzed by SEM, EDX and FTIR. The effects of pollutant concentration, catalyst dosage, and contact time on the removal of Triclosan were studied by DOE software according to response surface methodology. Analysis of variance test was considered for the influence of parameters. Optimum process condition was determined by desirability factor.
Results: Optimum conditions regarding concentration of pollutant, contact time, and catalyst dosage were determined as 0.205 g/L, 14.898 min, and 0.487 mg/L, respectively. Maximum removal efficiency in optimum condition was 97.542 percent. The catalyst dosage was the most effective parameter in removal of Triclosan.
Conclusion: Using of TiO2@GO and xenon lamp had acceptable efficiency for the removal of Triclosan. The use of Xenon lamps alone was economically affordable.
R Barati Rashvanlou, M Farzadkia,
Volume 11, Issue 1 (6-2018)
Abstract
Background and Objective: Ultrasonic disintegration is a pretreatment process before stabilization and dewatering that degrades sludge and changes its physical and chemical characteristics. The aim of this study was to investigate the effectiveness of ultrasonic in enhancing hydrolyses, stabilization and dewatering of municipal raw activated sludge.
Materials and Methods: The samples were taken from returned activated sludge and then they were exposed to ultrasonic (Frequency: 20 and 40 kHz) in different times (0.5, 1, 3, 5, 10, 15, 30, and 60 min). The effectiveness of ultrasonic for hydrolysis, stabilization and dewatering processes were determined with measuring TS, TSS, CST, SRF, VS, nVS, VSss, and VSsol.
Results: VSsol was increased by 73% in 15 min and at frequency of 20 kHz, whereas VSsol increas was100% at 10 min and 40 kHz. The reduction of VS was observed at 15 min and 20 kHz. Then after, it was reached 18% after 60 min. For 40 kHz, VS reduction started at 10 min and reached 24% after 60 min. Specific resistance of sludge at two frequencies of 20 and 40 kHz and contact time of 1 min were decreased by 25 and 20% respectively. The capillary suction time at the frequencies of 20 and 40 kHz and contact time of 1 min was decreased 28 and 21%, respectively.
Conclusion: The optimum effectiveness of ultrasonic in hydrolysis of organic matter of raw biological sludge was at the contact time of 10 min and frequency of 40 kHz. The highest stabilization at the frequency of 40 kHz was observed at 60 min contact time. The best condition for sludge dewatering was at frequency of 20 kHz and contact time of 1 min.
R Mirzaei, M Yunesian, Ar Mesdaghinia, S Nasseri, M Gholami, E Jalilzadeh, Sh Shoeibi,
Volume 11, Issue 3 (12-2018)
Abstract
Background and Objective: Antibiotics are a group of emerging contaminants in the aquatic environment. Antibiotic residues threaten the human health and ecosystem in the low concentrations found in the environment. Hence, the present work has been conducted to investigate the occurrence and removal efficiency of most prescribed antibiotics including amoxicillin, penicillin, cefixime, cephalexin, ciprofloxacin, erythromycin and azithromycin detected in two urban wastewater treatment plants (WWTPs) in Tehran.
Materials and Methods: The present work is an applied research based on USEPA method no. 1694, to investigate pharmaceuticals residues in water by HPLC/MS/MS in year 2016. The differences between target antibiotics residues were investigated statistically. After the calculation of the removal efficiencies, the normality of the data was assessed. Then, parametric and non-parametric tests were used to compare the removal efficiencies in both WWTPs.
Results: There was not a significant difference between the influent and effluent concentrations of cefixime and azithromycin (in Ekbatan WWTP) and cefixime (in southern Tehran WWTP). There is a significant difference between the removal efficiencies of cephalexin (p=0.005) and erythromycin (p=0.002) in two WWTPs. The Highest median removal efficiencies were observed for cephalexin 94.41 and 99.47 in Ekbatan WWTP and southern Tehran WWTP, respectively.
Conclusion: In addition to the type of treatment processes, it is physicochemical properties of the selected compound has a significant influence on removal efficiencies.
M Ansari, T Dehdari, M Farzadkia,
Volume 11, Issue 3 (12-2018)
Abstract
Background and Objective: A scientific questionnaire for assessing the knowledge, attitude and judgment of people on waste management by municipalities has not been developed so far. Therefore, the purpose of this study was to design and validation of an instrument to assess the knowledge, attitude and judgment of people on waste management by municipalities.
Materials and Methods: This analytical study was conducted in District 21 of Tehran in 2017. The initial items of the questionnaire were designed based on previous studies and opinions of the team of specialists and people. Then, the face validity and the content validity of the designed questionnaire was examined. The face validity and the content validity was examined qualitatively and quantitatively, respectively. Finally, the reliability of the attitude and knowledge and evaluation of municipal performance items were measured by Cronbach's alpha and a test-retest method, respectively.
Results: The initial questionnaire had 43 items. In the face validity, 8 items were removed and 8 items were edited. In quantitative content validity, 7 items were excluded, with the content validity index of less than 0.79 and the content validity ratio less than 0.49. Pearson correlation coefficient obtained for knowledge component equal to (r=0.77, p<0.0001) and for component performance (r=0.93, p<0.0001), respectively. Cronbach's alpha coefficient was equal to 0.89 for items attitudes, which were in an acceptable level.
Conclusion: The questionnaire can be used as a valid research instrument to collect information on knowledge, attitude and judgment of people on waste management by municipalities.
M Banar, Ar Mesdaghinia, K Naddafi, Ms Hassanvand,
Volume 11, Issue 4 (3-2019)
Abstract
Background and Objective: Radon is a radioactive, odorless gas. Radon gas with the emission of alpha radiation and sticking to aerosols in the air can cause lung cancer. This study evaluated the concentration of radon in residential houses and public places in Firuzkuh city and compared the values with the recommended international guidelines.
Materials and Methods: Radon gas concentration was measured by passive measurements using CR-39 detectors. The detectors were placed in houses and schools of the city for three months. After this time, the detectors were located and placed in a 6.25% normal solution at 85 °C for 4 hours in a laboratory. After preparation, using an automatic scan and appropriate statistical method, the concentration of radon gas was determined.
Results: The results indicated that the average concentrations of radon gas in homes and public places were 137.74 and 110.17 Bq/m3, respectively. Comparing the results with the WHO guideline showed that 76.3% of the homes and 66.7% of the sites had a concentration above the guideline (100 Bq/m3).
Conclusion: The results of this study can be used to prepare the National Radon gas map in the country.
H Nik Nejad, H Pasalari, M Yegane Badi, J Abolghasemi, R Ghasem Nejad, M Farzadkia,
Volume 12, Issue 1 (5-2019)
Abstract
Background and Objective: Clinics, laboratories and health care centers are considered as one of the main waste generating sources in solid waste management. The problems associated with the generated health-care waste in clinics, laboratories and health care centers have been rarely investigated in Iran. Therefore, the present study was developed to investigate the status of health care waste in clinics, laboratories and health care centers of Mahmoudabad, Mazandaran in 2017.
Methods and Materials: This cross-sectional study was conducted to determine the status of solid waste management in 117 medical centers in Mahmoudabad, Mazandaran, 2017. The solid waste data in terms of waste generation rate, storage, collection, and disposal were surveyed through interview and questionnaire that were validated by Iran’s ministry of health.
Results: The average health-care waste generation in medical centers in Mahmoudabad was found to be 248 g/day. The mean and standard deviation for environmental health criteria in all medical centers were 248.3 and 41.1, respectively. In addition, there was a statistically significant difference between the amount of waste generation in private and governmental medical centers (p=0.111).
Conclusion: The results obtained from the present research indicated that the medical waste management in Mahmoudabad, particularly in private centers, face serious problems. Improper waste collection technology, mixing municipal and medical waste, requirement for training the personnel in medical waste management and surveillance can be considered as important concerns in health-care waste management in Mahmoudabad.
K Jafari, N Hafezi Moghaddas, Ar Mazloumi, A Ghazi,
Volume 12, Issue 3 (12-2019)
Abstract
Background and Objective: Groundwater resources are the most valuable resources of each country. Development of agricultural activities in Ardabil plain and over-use of fertilizers and pesticides, improper disposal of municipal sewage and industrial areas are responsible for groundwater pollution. Clean-up of groundwater resources is very difficult and expensive. One of suitable method in preventing groundwater contamination is determination of the vulnerable zones of an aquifer to manage water resources and sustainable development.
Materials and Methods: In this study for determining of vulnerability of aquifer Ardebil, information of 52 observational wells, 43 pumping tests, average of annual precipitation of 8 stations, 45 logs of exploration wells, land use map, topographic map and geological map have been gathered. Then, data layers of groundwater depth (D), Recharge (R), Aquifer media (A), Soil media (S), topography (T), impact of vadose zone (I) and hydraulic conductivity of aquifer (C) were prepared and overlaid based on DRASTIC method in ArcGIS software.
Results: Zoning map of DRASTIC method showed that DRASTIC index varied between 63 to 195 units. Areas with high vulnerability potential were characteristic with shallow depth groundwater, coarse-texture soil, thin soil and gentle topographic slope. Accuracy of the zoning map was evaluated by nitrate concentration map which showed the increase of DRASTIC index with nitrate concentration.
Conclusion: Northwestern and central parts of the Ardabil plain showed high vulnerability. The results of this study could help to reduce the environmental impact of contaminants on groundwater resources of the study area in future.
R Bayat, Kh Ashrafi, M Shafiepour Motlagh, Ms Hassanvand, R Daroudi,
Volume 12, Issue 3 (12-2019)
Abstract
Background and Objective: Despite the significant improve in air quality in Tehran in 2018 and reducing the average concentration of most pollutants, compared to previous years, air quality is still far from the WHO air quality guideline level and national air quality standards. The purpose of this study was to estimate the effects of air pollution on health in Tehran by considering the spatial distribution of particulate matter 2.5 micrometers or less in diameter (PM2.5) and population in determining exposure levels.
Materials and Methods: In this study, while introducing the GEMM concentration–response function and BenMAP-CE software, the mortality attributed to PM2.5 in Tehran and its distribution for 2017 and 2018 was calculated. Hourly PM2.5 from monitoring stations used to estimate the mean PM2.5 for 349 Tehran neighborhoods.
Results: The results showed that the average population weighted PM2.5 concentrations in Tehran in 2017 and 2018 was estimated to be 31.8 and 26.2 µg/m3 respectively. Using the GEMM function, about 7,377 (95% CI: 6,126-8,581) total mortality attributed to PM2.5 was estimated in adults in 2017 (> 25 years) and the figure for 2018 was estimated as 6,418 (95% CI: 5,918-6,753).
Conclusion: The spatial distribution of deaths attributable to PM2.5 showed that the total mortality rate per 100000 in the districts 16 and 18 of the Tehran municipality were higher than other districts and the lowest rate observed in the district 1.
H Niknejad, M Farzadkia, A Esrafili, M Kermani,
Volume 12, Issue 4 (2-2020)
Abstract
Background and Objective: 2,4 dinitrophenol is observed in sewage produced from chemical and petrochemical industries. Contamination of drinking water with these pollutants causes toxicity, health problems and change in taste and odor. The present study was developed to evaluate the efficiency of removal 2,4-DNP through dried sludge adsorbent and modified calcium chloride sludge adsorbent.
Materials and Methods: At first, sludge was dried at temperature of 60 °C. Next, CaCl2 was used to improve adsorption capacity. The removal efficiency of 2,4 dinitrophenol were determined by HPLC at wavelength of 360 nm. The effects of influencing factors including pH, initial pollutant concentration, contact time, and adsorbent dose were examined.
Results: The optimum pH of adsorption for both adsorbents was found to be 7. The optimum concentration of 2,4-DNP was 10 ppm. The results obtained from the present research showed that the removal of the contaminant using dried and modified sludge sorbent was increased from 72.6% to 86% at a dosage of 1.5 g. The adsorption kinetics were fitted with the pseudo second order kinetics model for both adsorbents. The isotherm data also showed that the adsorption of this pollutant on both adsorbents is fitted with the Freundlich model.
Conclusion: Results obtained from the present study indicated that the efficiency of the modified sludge ash is more than the non-modified sludge in 2,4 dinitrophenol removal. This can reduce adsorbent consumption in industrial treatment plants.
