Showing 29 results for Ahmadi
M Ahmadi, H Ganjidoust, B Ayati,
Volume 1, Issue 2 (10 2009)
Abstract
Background and Objectives: Upflow Sludge Blanket Filtration (USBF) system is a modification of the conventional activated sludge process that incorporates an anoxic zone with an upflow sludge blanket filtration clarifier in one bioreactor. It has no inherent capacity limits and is used in a wide range of applications in municipal, industrial and agricultural wastewater treatment. The main objective of this study was to evaluate the performance of a continuous USBF reactor for the treatment of sugar industrial wastewater.
Materials and Methods: Sixty liter laboratory pilot scale plant was made of plexiglass consists of 14 liter anoxic zone, 38 liter aerobic zone and 8 liter clarifier. Used molasses for raw wastewater was obtained from Varamin Sugar Company. During the study, the wastewater has been initially fed to anoxic zone of the bioreactor. It mixed with recycled activated sludge returned from the clarifier and the mixed liquor entered into aerobic zone of the bioreactor. From aeration zone, the mixed liquor passed through the sludge zone at the bottom of the clarifier which was then separated by upflow sludge blanket filtration and then the clear water discharged from the system. To complete the internal circulation loop, collected activated sludge at the bottom of the clarifier was recycled to the anoxic zone.
Results: Experimental studies indicated that average removal efficiency of COD with HRTs from 21 to 26 hours in the aerobic zone and from 8 to 10 hours in the anoxic zone were from 77 to 97 percent depended on input feed (1000 to 30000 mg/L).
Conclusion: USBF as an advanced biological process had a proper COD removal efficiency for the biological treatment of sugar industries wastewater compared to other researchers methods.
M Ahmadimoghadam, H Amiri,
Volume 3, Issue 2 (6 2010)
Abstract
Backgrounds and Objectives: Formaldehyde and phenol are key precursors in the industrial manufacture of resins. Toxicity of these compounds prevents function of microbial populations, so they affect the biological treatments. The aim of this study was investigation of TOC removal from phenol-formaldehyde resin manufacturing wastewater by electrocoagulation using Al- electrodes.
Materials and Methods: This study is the laboratory scale experiment was conducted as a pilot. Wastewater sample was adjusted in the desired pH, electrical conductivity and current density, then it was placed in to the reactor contains four electrodes in aluminum. The electrodes were connected to a DC power supply (0-40V, 0-3A). Samples were collected for TOC determination in the middle of cell at regular time intervals. Collected samples were analyzed using TOC analyzer.
Results:The results indicated that the optimum conditions for the removal of TOC were current density 75 A/m2, solution pH 4 and Conductivity 3 mS/cm. In this condition energy consumption was found 22.5 kWh m-3 after 60 min reaction.
Conclusion: This study shows that electrocoagulation of wastewater from phenol-formaldehyde resin manufacturing can be used as a pretreatment process.
M Malakootian, N Jafarzadeh Haghighi Fard, M Ahmadian, M Loloei,
Volume 3, Issue 2 (6 2010)
Abstract
Backgrounds and Objectives: Untreated leachate is discharging into the environment in the many countries of worldwide. Leachate treatment methods have not been unified so far due to variable composition of leachate. Moreover, the uncontrolled management of leachate, cause many environmental dissociates. The aims of this study apply the Fenton process to decrease the pollutants of Kerman leachate.
Materials and Methods: Rawleachatewas obtained fromcompactor vehicles used for the collection of Kerman city solid waste, before final disposal. In order to removal of biodegradable organic compounds, a rector was built based on characteristics of landfill Kerman city and raw leachate underwent anaerobic treatment in this pilot. In the next stage, treated leachate in the pilot, was affected by Fenton process. The optimized parameters in Fenton process including pH, reaction time and dosage of H2O2 and Fe2+ were also studied.
Results: The results showed that TSS, BOD5 and COD decrease to 62*, 96*and 89*, respectively, after 60 days treatment in the pilot. BOD5/COD ratio also decreased from 0.6 to 0.2 in anaerobic treated leachate. In optimum condition (pH=3, reaction time=75 min, Fe2+=1400 mg/L and H2O2 = 2500 mg/L) maximum COD removal was 78 * by Fenton process. BOD5/COD ratio increased from 0.2 to 0.51 which showed an increase in biodegradability of leachate as a result of Fenton process.
Conclusion: anaerobic biologically treatment followed by Fenton processes could be assumed as an efficient process that could improved the leachate quality. Biological treatment to reduce leachate pollution alone was not enough. The most important Fenton process advantage is reduction of refractory and toxic leachate compounds and increasing leachate.s biodegradability.
S Ahmadi, A.a Karbord, E Einanlo, H Aubi Zade, M Zarei,
Volume 4, Issue 1 (24 2011)
Abstract
Backgrounds and Objectives:Indusrial noise exposure is the most common hazardous agent in the world.This study has been done to determine the prevalence associated with occupational noise in car smoothers at qazvin.
Materials and Methods: The study group composed of 50 subjects who were selected out of a total of 218 car smoothing workshops.Background information,exposure time and...with a questionnaire collected.Noise exposure and hearing loss were measured by noise dosimeter model CEL-280 and audiometer model OB 288 Madsen.
Results: The mean of age and work experience were 38.7 and 21.5 respectively.Noise exposure and total hearing loss were measured 98.2±3.4 dB(90-104dB) and 22.1±9.16 dB respectively. Spireman correlation was significant between right and left ears(P<0.05 ,R=0.87).Total hearing loss were measured natural(NIHL!25) in 64 percent(32 person),slight(26! NIHL!40)in 34 percent(17 person) and moderate (41! NIHL!60) in 2 percent (1 person).The most and the least hearing loss were measured 42.4(4000 HZ) and 37.1(8000 HZ) dB in left and right ear respectively. The chi square analysis was significant between hearing loss,work experience and age(P=0.015).ANOVA analysis was not significant between noise exposure and hearing loss(P=0.09).
Conclusion:Considering NIHL and severe noise exposure , the necessity for improvement of controlling and protection measures has prime importance.
N Delbazi, M Ahmadi Moghadam, A Takdastan, N Jaafarzade Haghighi Fard,
Volume 4, Issue 3 (1 2011)
Abstract
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.
Gholamreza Goudarzi, Mohamadjavad Mohammadi, Kambiz Ahmadi Angali, Basir Mohammadi, Zahra Soleimani, Aliakbar Babaei, Abdolkazem Neisi, Sahar Geravandi,
Volume 6, Issue 1 (5-2013)
Abstract
Background and Objectives: According to the WHO estimates, air pollution is accounted for about 800000 premature death of cardiovascular and respiratory disease and lung cancer resulted from air pollution throughout the world approximately 150000 cases of those deaths occur in south Asia. The studies conducting on short-term and long-term effects are reported in terms of admission rate, consulting with a physician, number of a particular disease, death, and years of the lost life (YOLL). We used Air Q2.2.3 (Air Quality Health Impact Assessment) Model to evaluate adverse health effects caused by NO2 exposure in Ahvaz City during 2009. NO2 reacts with ammonia, moisture, and other compounds to form small particles. These small particles penetrate deeply into sensitive parts of the lungs and can cause or worsen respiratory disease, such as emphysema and bronchitis, and can aggravate existing heart disease, leading to increased hospital admissions and premature death.
Materials and Methods: First the data required was collected from Ahvaz Environment Organization and Meteorological Organization. Then, this data were processed by Excel software through correcting temperature and pressure, coding, averaging and filtering. Finally, the data processed were entered to Air Q model. This model is a valid and reliable WHO-proved tool to estimate the potential short term effects of air pollution. This model includes four screen inputs (Supplier, AQ data, Location, Parameter) and two output screens (Table and Graph).
Results: It was found that the Meteorological and Environment Organization stations have had the maximum and minimum NO2 concentration respectively. Moreover, the annual, summer, and winter average and 98cile of this pollutant was 27, 6, 43, and 115 µg/m3 respectively. The cumulative number of myocardial infarction resulted from NO2 exposure was estimated to be nine persons per year. This value for the cardiovascular death was found to be 19 cases. Finally, the COPD cases was estimated to be seven per year.
Conclusion: Air Q software calculated relative risks, attributable proportion, and baseline incidence using data processed by Excel and presents the output as the cause specific deaths. It is noteworthy that there is no model that can estimate all of the pollutants health effects simultaneously. Cumulative number of persons for acute MI attributed to NO2 exposure was 9 in 2009. Moreover, 51% of this number occurred in the days with concentrations lower than 60 µg/m3. It should be noted that 72% of this value are corresponded to the days with concentrations below 90 µg/m3. The total cumulative number of cardiovascular death attributed to exposure with NO2 during one year of monitoring was 19 persons. 60% of these cases have occurred in days with NO2 levels not exceeding 90 µg/m3. Cumulative number of hospital admission of COPD attributed to exposure with NO2 during one year of monitoring was 7 persons.87 % of these cases have occurred in days with NO2 levels not exceeding 110 µg/m3.
Mehdi Ahmadi Moghadam, Parviz Mahmoudi,
Volume 6, Issue 1 (5-2013)
Abstract
Background and Objectives: Exceeding the standard level in most cases, Tehran air pollution has become a national environmental challenge. Therefore, it is crucial to analyze Tehran air-pollution data set during 2000-2009 for trend analysis.
Materials and Methods: In this study, we collected the hourly data of Tehran air pollution during 2000-2009 recorded by monitoring station of Tehran Air Pollution Control Company and statistical methods was used to determine the trend of the five pollutants, including: CO, PM10, SO2, NO2 and O3.
Results: The results indicate that average annual concentration of PM10, CO, NO2, SO2 and O3 has changed from 91, 11.18, 102.6, 46.8, and 22.1 at monitoring station in 2000 to 88 µg/m3, 3.64 ppm, 66.1 ppb, 21.4 ppb, and 83 ppb in 2009 respectively.
Conclusion: Our findings revealed that although the air quality in Tehran has improved in term of particulate matter, SO2 and NO2 during this decade as a result of government's recent program in air pollution control, ozone concentration has increased.
Sn Alavi Bakhtiarvand, M Ahmadimoghadam, I Parseh, N Jafarzadeh, M Chehrazi, Mostafa Chorom,
Volume 7, Issue 1 (7-2014)
Abstract
Background and Objectives: Soil polluted with total petroleum hydrocarbon (TPHs) is a great threat to human health. Phytoremediation, the use of vegetation for treatment of contaminated soils, is an attractive and cost-effective alternative to reduce pollutant from soil. This paper evaluates the effects of the plant and nutrients on the removal of TPHs from soil. Material and methods: Soils were collected at depth of 0-30 cm, and then polluted with 1 and 2.5 % w/w of crude oil. After preparing the experimental pots, Rhizosphere microbial number, plant biomass, and residual TPHs were determined. TPHs and heterotrophic bacterial number were measured by GC and HPC method respectively. Data were analyzed using the Statistical Package for Social Sciences (SPSS 17 for Windows) software and Excel. Results: It was found that the average percent of TPH removal in planted soil (28.42%) was higher than that in unplanted soil (12.2%) (p<0.05). Moreover, the average percent of TPH removal in treatments received nutrient and free nutrient treatments was 35.5and 17.7% respectively. Conclusion: Generally compared with the other studies, high clay and salinity of the experimental soil had a negative effect on phytoremediation efficiency. Finally, regarding to the high clay and salinity of the experimental soil, the phytoremediation efficiency was relatively desirable.
M. Arbabi, M.a. Ahmadi, M. Sedehi,
Volume 7, Issue 3 (5-2014)
Abstract
Background and Objectives: Bakery’s yeast industry wastewater contains various pollutants and is generally characterized with high chemical oxygen demand (COD), dark color, high-nitrogen and sulfate and non-biodegradable organic pollutants. Having persistent soluble colored compounds (called melanoidins), effluent from yeast industry is a major source of water and soil pollution. The aim of this study was to evaluate advanced oxidation efficiency using Fenton process for COD and color removal from bakery’s yeast wastewater. Materials and Methods: This was an experimental- laboratory scale study. In this study, the effect of time and Fenton concentrations were tested for COD and color removal from bakery’s yeast wastewater. The sample used for this study was yeast effluent from Separator 2 with initial concentrations of COD and color of 5300 mg/L and 6950 pt-co respectively. In order to obtain the optimum operating conditions of the process, Taguchi analysis method was used. Experiments were carried out in five stages of the time in the range of 15, 30, 45, 60 and 75 min with various concentrations of hydrogen peroxide (e.g., 0.02, 0.04, 0.06, 0.08, and 0.1 molar) and concentrations of Fe2+ (e.g., 0.01, 0.02, 0.03, 0.04, and 0.05 molar) at pH = 3. Jar test method was used to determine the best operating conditions including: reaction time, dosages of hydrogen peroxide and Fe2+. Results: According to Taguchi method and SN-ratio analysis, the best H2O2/Fe2+ dosages were 0.08/0.04 molar at pH 3 and in reaction time of 30 min for removal of COD and color. For these conditions, the maximum COD and color removal efficiencies were 63 and 69 percent respectively. Based on the results, with increasing reaction time, there was no perceptible change in the removal efficiency. Conclusion: It can be concluded that Fenton’s oxidation method can be used successfully, as an alternative option to the design and choice of color and COD removal from strength industrial wastewaters e.g., bakery’s yeast industry.
B. Kakavandi, M. Mokhtari, R. Rezaee Kalantari, E. Ahmadi, N. Rastkari, M. Fatehi, A. Azari,
Volume 7, Issue 3 (5-2014)
Abstract
Background and Objectives: Phenol is one of priority pollutants produced through leather, paint, resin, and pharmaceutical industries and it can contaminate groundwater after entering to the environment. Hence, it is necessary to use a suitable method for its removal. The aim of this study was synthesize and efficiency evaluation of magnetic nanocomposite of activated carbon powder-zero valent iron/silver (PAC-Feo/Ag) in the removal of phenol from aqueous solution. Material & Methods: Reduction method was used for converting bivalent iron to zero valent iron and co-precipitation method for depositing of iron on activated carbon. For coating silver on nano zero valent iron, rapid mixing at high temperature was used. The adsorbent was characterized using SEM, TEM, and XRD techniques. Then, the impact of pH, contact time, agitation speed, temperature, adsorbent, and initial phenol concentration were evaluated and optimized by one factor at the time method. Reaction kinetics and isotherms were also determined. Results: It was found that PAC-Feo/Ag has cubic and intertwined structure and has a diameter in the range from 40 to 100 nm. The optimum conditions for phenol removal by PAC-Feo/Ag were as pH=3, 90 min contact time, 200 rpm agitating speed and adsorbent concentration equal to 1 g/l. Isotherm and kinetic equations showed that the experimental data of phenol adsorption onto PAC-Feo/Ag are correlated to the Langmuir (R2>0.969) and pseudo-second order (R2<0.965) models, respectively. Conclusion: Under optimum conditions, modified adsorbent by zero valent iron and silver with maximum efficiency of 97% has quickly and effectively ability in removal of phenol and it can be easily separated from the solution sample by magnet because of its magnetic properties.
Gh. Goudarzi, S Geravandi, S Saeidimehr, M.j. Mohammadi, M Vosoughi Niri, Sh. Salmanzadeh, K Ahmadi Angali, A.k. Neisi, A.a. Babaei,
Volume 8, Issue 1 (8-2015)
Abstract
Background and Objectives: According to the estimates of W.H.O., approximately 150000 persons are annually affected by early death of cardiovascular, respiratory disease, and lung cancer resulted from air pollution in south Asia. The short-term and long-term effects are reported as hospital admission, consulting with a physician, number of special disease, death and years of life lost (YOLL). The purpose of this paper is to discuss the effects of PM10 pollution on human health. AirQ 2.2.3 (Air Quality Health Impact Assessment) Model was used to evaluate adverse health effects caused by PM10 exposure in Ahvaz during 2009. Long-term exposure with suspended particulates are expressed as decreasing personal life. The prevalence of bronchitis and reduced lung function in children and adults, even at annual average concentrations of particulate matter below 20 µg/m3 (PM2.5) and 30 µg/m3 (PM10) have been observed. Major sources of emissions resulting from human intervention in particulate matter are road traffic (25-10%), stationary combustion (55-40%), and industrial processes (30-15%). Materials and Methods: First, PM10 data was collected from Ahvaz Environment Protection Organization and Meteorological Organization. Then, raw data were processed by Excel software.. Finally, data processed were inputted to AirQ model. This model proved to be a valid and reliable tool to estimate the potential short-term effects of air pollution. This software is provided by the World Health Organization and is used to quantify the health effects of air pollution. This model consists of four input screens (Supplier, AQ data, Location, Parameter) and two output screens (Table, Graph). Results: The highest and lowest PM10 concentration was reported for Headquarter and Naderi stations respectively. Moreover, the annual, summer, and winter means and 98 decimal of this pollutant in Ahvaz City was measured as 261, 376, 170, and 1268 µg/m3 respectively. Total death toll contributed to PM10 was estimated as 1165 cases in 2009. Conclusion: Using data processing in Excel, AirQ software calculates relative risks, attributable proportion, and baseline incidence and the final output would be displayed in the form of death toll. It is noteworthy that there is no model that can estimate the effect of all pollutants together and simultaneously. In addition, it was found that the annual PM10 emission mean, the summer mean, winter mean, and 98 percentile were 261, 376, 170, and 1268 µg/m3 in Ahvaz City. Cumulative number of persons for total number of deaths attributed to PM10 exposure was 1165 in 2009 Out of which, 44% has occurred in the days with concentrations lower than 250 µg/m3. It should be noted that 62% of this value is corresponded to the days with concentrations below 350 µg/m3. The total cumulative number of cardiovascular death attributed to the exposure with PM10 during one year of monitoring was 612 persons. On the other hand, 52% of these cases have occurred in days with PM10 levels not exceeding 300 µg/m3. Cumulative number of Hospital Admissions Respiratory Disease attributed to exposure with PM10 during one year of monitoring was 1551 persons Out of which, 36 % occurred in days with PM10 levels not exceeding 200 µg/m3.
M Ahmadi-Pirlou, M Ebrahimi-Nik, M Khojastehpour, Sh Ebrahimi,
Volume 9, Issue 4 (3-2017)
Abstract
Background and Objective: Solid waste management has always been one of the major challenges of large cities. Conversion of waste to energy in the form of biogas is known to be an appropriate solution. The aim of this study was to investigate the effect of total solids (TS) content and alkaline pretreatment on biogas production from municipal solid waste (MSW).
Materials and Methods: Experiments were done in 1 L glass bottles at 37 °C with different TS contents (5, 10, and 15%), each in 3 replications based on a completely randomized design. Comparison of means was used for interpretations of the result. The volume of the produced biogas, the amount of methane, and changes in pH were measured on a daily basis. In order for better mixing, the digesters were manually shaken for 30 seconds every day. TS, volatile solids (VS), carbon and nitrogen of the feedstock were determined according to APHA standard methods.
Results: The highest methane yield and VS reduction was observed in 5% TS. Therefore, this TS was chosen for alkaline pre-treatment. The results showed that pre-treatment with NaOH significantly improved biodegradability of MSW. In 25 days, the production of biogas was 30.38% higher than that of the untreated digester. The highest methane yield was 83.35 mL/g TS and 132 mL/g TS from the control and the pretreated digesters, respectively.
Conclusion: The results of the lab experiments showed that the TS of 5 % and the alkaline pre-treatment, significantly improved biodegradability of MSW and consequently increased biogas and methane yield.
F Ahmadi, N Rastkari, P Sadighara, Gh Jahed Khaniki,
Volume 10, Issue 3 (12-2017)
Abstract
Background and Objective: Aluminum (Al) is a neurotoxic agent and this element is being associated with Alzheimer disease. The use of semi-rigid packaging has been increased in recent years. In these packages, the main layer is aluminum. The purpose of this study was to determine the Al concentration in foods packaged in semi-rigid packaging in during storage time.
Materials and Methods: Al concentration of the samples (Joje kabab, khorake morgh, khoresh gheymeh, n=36) was determined at different storage times (0, 60, 120, and 180 days after packaging). Aluminum was determined by ICP-OES after wet digestion method of the samples. A two-way analysis of variance was used to analyze the results with respect to time and food factors.
Results: The effect of storage time on Al concentration was significant p˂0.001. The samples that were stored longer had significantly higher aluminum concentrations. The highest concentration was determined in Joje kabab (3.27 ±0.93 ppm( and lowest Al content was determined in khoresh gheymeh (1.04 ± 0.16 ppm). The results showed that Al concentration of the foods packaged in semi-rigid packaging increased significantly during storage.
Conclusion: Considering the present state of knowledge and the suggested provisional tolerable daily intake of 1 mg/kg body weight per day of according to World Health Organization, Al leaching from semi-rigid packages may add low doses of Al into the diet.
N Dorostkar Ahmadi, M Shafie-Nikabadi, S Babaie Kafaki,
Volume 11, Issue 4 (3-2019)
Abstract
Background and Objective: Today pollutants related to refineries and base oil products have caused many concerns about environment. Among these, the share of lubricants as one of the oil products is undeniable for causing environmental problems, harmful pollutants for men and global warming. Recently LCA as a beneficial tool is provided for finding solution to the environmental problems. The aim of this study was to evaluate and compare environmental impacts of lubricants and its ingredients (oil based and additives). Additionally, it was attempted to identify the pollutants caused by the lubricants in order to replace them by environmentally friendly components.
Materials and Methods: In this study, the system boundary was first identified and then the life cycle assessment steps were carried out for vehicle lubricants. Finally, the results were analyzed using SimaPro software based on the Eco Indicator 95.
Results: Results showed that although additives made up about 20 percent of the lubricants, more than 80 percent of the environmental pollutants were related to them. These materials have a significant impact on greenhouse gas emission and global warming as 91% of CO2 emission (7.81kg) of lubricants is related to the additives. Also, these materials emit 0.00913 kg C2H4 and 0.0368 kg SPM, which can make summer and winter smog. The car lubricants cause heavy metals (3.95×10-5 kg Pb) to be released into water and release of carcinogenic substances (4.2×10-6 kg B(a)P), which a very low percentage of it is allocated to base oil.
Conclusion: The most important environmental pollution of vehicle lubricants was caused by the additives. Since the percentage of each additive to lubricants includes antioxidant (40%), antiwear (23%), detergents (20%) and viscosity modifier (17%), thus, the company must seek to change these types of additives and replace them with the components with lower environmental impact in their production cycles.
S Fallah Jokandan, M Yegane Badi, A Esrafili, A Azari, E Ahmadi, H Tarhandeh, M Kermani,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: The activities of various industries produce a wide range of pollutants and toxic compounds. One of these compounds is the catechol, a cyclic organic compound with high toxicity and resistant to degradation. Therefore, the purpose of this study was to investigate efficiency of powder activated carbon magnetized with Fe3O4 nanoparticles in the removal of catechol from aqueous solutions by response surface methodology.
Materials and Methods: The co-precipitation method was used to synthesize magnetic powder activated carbon and its properties were analyzed by SEM and XRD analysis. Then, the effect of the parameters such as pH, contact time, absorbent dose, initial concentration of catechol and temperature on the efficiency of adsorption process were investigated using a response surface methodology (Box–Behnken). The residual concentration of catechol was measured by HPLC at 275 nm.
Results: The results showed that the maximum efficiency of the adsorption process was obtained at concentration of 20 mg/L, pH=3, contact time 90 minutes, at 25 °C and absorbent dose of 1.5 g/L. The study of isotherm and kinetics showed that the experimental data of the catechol adsorption process correlated with the Langmuir and pseudo-second order models, respectively. Thermodynamic study of the reaction also expresses the Exothermic and Spontaneous process.
Conclusion: The results showed that the adsorption process using powder activated carbon magnetized with Fe3O4 nanoparticles at acidic pH had better efficiency. As a result, the studied process as an effective, rapid and inexpensive method for removal of catechol from aqueous solutions is proposed. Due to its short reaction time, it is economically affordable process.
A Ahmadi Orkomi, A Kamkar, Z Aghajani,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: Since mobile resources are the most important sources of air pollution in the metropolis of Rasht and due to the importance of air pollution in wet weather condition in Rasht, this research was carried out in a specific area to determine the pattern governing the change in the monthly emissions of pollutants on a small scale, using the results obtained from that area.
Materials and Methods: In this study, the amount of air pollutants was estimated on a small scale by continuous monitoring of traffic throughout the year (four days per month and six hours per day) and using MOVES software.
Results: The maximum annual average emissions of CO and NOx in the study area were 15.76 (between Gas and Razi squares) and 2 (between Imam Hossein Square and Nirou Daryaee square) g/(m.hr), respectively. In addition, the results showed that the average monthly emission of NOX throughout the year in each of the sections was constant and the average monthly emission of CO in the first half and the second half of the year was constant, and its value in the first half was higher than that in the second half.
Conclusion: Hourly distribution of CO emission in different months was affected by events and, in general, the pattern of people's life styles. But the hourly distribution for NOX was roughly constant throughout the year. Also, according to the results, with a single measurement (for CO) and twice measurement (for NOX) of traffic instead of monthly measurements, the pollutant emission estimation in other parts of the city was possible with an acceptable accuracy. Because the generalization of the method used in this study to estimate the emission of pollutants in all roads of the city is not reasonable and cost-effective.
Ali Ahmadi Orkomi, Melika Mirchi,
Volume 13, Issue 2 (8-2020)
Abstract
Background and Objective: Since people spend a lot of time indoors, assessment of Sick Building Syndrome (SBS)is the first step to improve working and living conditions in closed environments. This study wasconducted to evaluate the SBS symptoms among staff in Razi Hospital of Chalous, to identify the affecting environmental parameters on these symptoms and to provide solutions to reduce the symptoms of SBS.
Materials and Methods: This descriptive-analytical study was conductedrandomly among 72 out of 240 hospital’s staff. Questionnaire MM040EA was used to collect demographic data, SBS symptoms and affecting environmental factors. Statistical analysis was carried out using Pearson’s Chi-squared test and Fisher's exact test in Excel software.
Results: 60% of people showed moderate to severe SBS symptoms. Fatigue, headache, and sneezing were the most common symptoms among staff, with 85%, 75%, and 63%, respectively. Significant correlation was observed between SBS symptoms and room temperature fluctuations (p <0.001), low ambient temperature (p = 0.037), unpleasant odor (p = 0.043) and gender (p = 0.011) with significance level of α=0.05.
Conclusion: Investigating the influence of work environmental related factors on the general symptoms of SBS as well as on fatigue, headache and sneezing symptoms showed room temperature fluctuation and unpleasant odor as the most important driving factors. These symptoms were mainly due to the improper air conditioning system operation at the hospital to control the temperature. Therefore, it is expected that the prevalence of SBS among staff can be reduced significantly by improving the ventilation system performance, especially in winter.
Reza Kheiri Soltan Ahmadi, Habib Nazarnejad, Farrokh Asadzadeh,
Volume 14, Issue 4 (3-2022)
Abstract
Background and Objective: With the industrialization of communities, population increase and use of surface water, river pollution has been increased by agricultural, industrial pollutants and urban wastewater. Therefore, investigation of river pollution for regional and environmental planning is of great importance. To evaluate surface water pollution, a number of surface water quality indices have been investigated.
Materials and Methods: Iran water quality index for surface water resources (IRWQISC) approach was used to evaluate the water quality of the Mahabadchai river, Iran. Sampling was carried out along the Mahabadchai river based on some criteria such as approximately to drainage areas for landfills/domestic and agricultural effluents.
Results: Pearson correlation coefficient between physical, chemical and microbial parameters of water showed that fecal coliform, BOD, COD, nitrate, ammonium, phosphate, turbidity and total hardness had a significant positive relationship with each other at 99% confidence. According to this index, upstream samples of the river are classified as good, mid-stations relatively good to moderate category, and downstream samples of the river are classified as relatively bad.
Conclusion: Based on the relationship between each variable, fecal coliform, BOD, COD, ammonium, and turbidity were more effective in determining the IRWQISC. Most of the examined variables showed low concentrations in upstream areas of the river while their concentration gradually increased along the river to downstream areas, especially close to urban and industrial districts.
Ali Ahmadi Orkomi,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: Greenhouse gas emission estimation and submitting a regular national report on climate change has been underway since 2003. Given the importance of this issue, estimating emissions at the provincial level and assessing local emission management capacities will make the country more agile in reporting and emission control.
Materials and Methods: The greenhouse gas emission in four sectors as energy, industry, agriculture, forestry and other landuse and wastes and all sub-sectors of these areas was determined in Guilan Province. The annual emission has been estimated using the 2019 activity data and the IPCC (Intergovernmental Panel on Climate Change) software.
Results: The gross and per capita greenhouse gases’ emission of the province are 18.5 Mt and 7.31 tons per year carbon dioxide equivalent, respectively, so that the annual ecological supply of forests to capture greenhouse gases is estimated at 2 Mt. The thermal power plants, residential consumption (except electricity) and transportation sectors are the major emission sectors in the province with 36, 23 and 19% share, respectively. Out of four scenarios, the wind farms development scenario (nominal capacity 3 GW) and 10% energy savings in the residential sector reduce greenhouse gas emissions by 9% and 2.9%, respectively. The cumulative impact of all the proposed scenarios by 2030 will also lead to a 13% reduction in emissions compared to the current situation.
Conclusion: Considering the existing capacities in the clean power generation and energy saving in the residential sector, it is possible to reduce the emission of greenhouse gases by 13% by 2030. Since the proposed scenarios are regionalized and do not depend on management decisions in other provinces, they have good feasibility. Consequently, if clean power generation plans are established in other provinces and energy consumption management in the transport sector is applied at the national scale, it may be expected that the country's minimum commitments (4% reduction compared to 2010) will be met.
Gholamali Javedan, Hamid Reza Ghaffari, Zoha Heidarinejad, Nahid Zeraei, Somayeh Hoseinvandtabar, Fateme Pourramezani, Mehrdad Ahmadi,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: The aim of this study was to investigate the concentration of potentially toxic elements (arsenic, lead, copper, cadmium and mercury) in black tea imported to southern Iran and to assess the risk of carcinogenic and non-carcinogenic exposure to consumers.
Materials and Methods: For this purpose, 94 samples of black tea from 15 brands imported from India in 2021 were selected. Heavy metals concentrations were measured using an atomic absorption spectrometer (GBC model SAVANTAA). After determining the concentration of heavy metals in black tea samples, health risk assessment was determined using Montocarlo simulation technique.
Results: According to the results, the average concentrations of heavy metals namely arsenic, lead, copper, cadmium and mercury were 0.03±0.02, 0.02±0.16, 15.67±7.69, 0.02±0.01 and 0.006±0.005 mg/kg, respectively. The hazard quotient (HQ) of the heavy metals arsenic, lead, copper, cadmium and mercury were 1.07×10-2, 6.37×10-3, 3.45×10-5, 2.05×10-2 and 7.19×10-4, respectively.
Conclusion: Therefore, according to the findings, it can be concluded that the concentrations of potentially toxic elements (arsenic, lead, copper, mercury and cadmium) in black tea were consistent with the standard level of Iran and World Health Organization. Additionally, the average carcinogenic risk index for arsenic metal was 4.49×10-6, which is much lower than the acceptable level of carcinogenic risk (10-6). Therefore, the concentrations of five potentially toxic elements in the studied black tea did not show any significant risk for consumers.
