Showing 18 results for Abadi
Z Kheradpisheh, H Movahedian Atar, M Salehii Najafabadi,
Volume 4, Issue 4 (2 2012)
Abstract
Background and Objectives: Cyanide is a highly toxic compound which is Normally found in numerous industries, such as electroplating wastewater. Release of this compounds in to the Enviroment has a lot health hazards.The Purpose of this study is to Determine the efficiency of electrochemical oxidation method for Cyanide removal from industrial wastewaters
Materials and Methods: This study conducted in a pilot system experimentally .In this study the effect of pH, voltage and operation time on total cyanide removal from industrial wastewaters by Electrochemical Oxidation was investigated by applying a Stainless Steel as a Anode and copper as a cathode .
Results: The average percentage removal of cyanide was about 88 with SD=2.43. The optimal condition obtained at voltage of 9V and pH=13 and The operation time of 90 minutes.The volume of sludge which formed in this condition was about 20 percent of a one liter pilot reactor.
Conclusion: the results statistically confirmed the significant relationship between
input and cyanide concentration removal efficiency (p< 0.05), and confirmed The this confirmed The relation between cyanide & cyanat oxidation and hydroxyl ions consumption 1:2.( L.Szpyruowicz). therefore the best pH is 12.5-13.5 by Considering the need of alkaline environment to remove cyanide.
Maasoumeh Ravanipour, Roshanak Rezaei Kalantary, Mahdi Farzadkia, Samireh Hashemi-Najafabadi, Ali Esrafily,
Volume 5, Issue 4 (15 2013)
Abstract
MicrosoftInternetExplorer4
Background and Objectives:The poor accessibility of microorganisms to PAHs in soil has limited success in the process of
bioremediation as an effective method for removing pollutants from soils.
Different physicochemical factors are effective on the rate of biodegradation.
The main objective of this study is to assess effects of nutrient and salinity
on phenanthrene removal from polluted soils.
Materials and Methods:The
soil having no organic and microbial pollution was first artificially polluted
with phenanthrene then nutrients and salinity solution in two concentrations
were added to it in order to have the proportion of 10% w:v (soil: water).
After that a microbial mixture enable to degrade phenanthrene was added to the
slurry and was aerated. Finally, the residual concentration of Phenanthrene in
the soil was extracted by ultrasonic and was analyzed using GC. We measured the
microbial populationusing MPN test. This study was conducted based on the two
level full factorial design of experiment.
Results: MPN test
showed that the trend of microbial growth has experienced a lag growth. The
full factorial design indicated that nutrient had the maximum effect on
bioremediation the rate of phenanthrene removal in the maximum nutrients -
minimum salinity solution was 75.14%.
Conclusion: This study
revealed that the more nutrient concentration increases, the more degradation
will be happened by microorganisms in the soils. However, salinity in the
concentration used had no effect on inhabitation or promoting on the
Phenanthrene removal.
Mohammad Esmaeilzadeh, Edris Bazrafshan, Mahnaz Nasrabadi,
Volume 6, Issue 1 (5-2013)
Abstract
Background and Objectives: Tous gas power plant as an emission source of gas pollutants is located in the northwest of Mashhad City. This power plant is located in the neighborhood of various (linear, point and area) sources of pollution including Tous thermal power plant, Tous industrial town and motor vehicles hence, it is not possible to determine precisely and accurately the share of these gases emission contribution at this power plant using conventional instruments. Therefore, we used modeling in order to estimate the dispersion of the pollutants emitted from this power plant.
Materials and Methods: we used Screen 3 software using data of exhaust fume concentration, mass emission, chimney features of each unit, meteorology data, and fuel types consumed in order to model dispersion of NOx and SO2 emitted from Tous gas power plant having V94.2 turbine equipped with DLN torches.
Results: Maximum concentration of NOx and SO2 at the distance about 30 km from the power plant was 1.08 and 3.69 µg/L respectively. The results of dispersion modeling of pollutants indicated that in most cases emission of air pollutants towards southeast. Conclusion: The NOx and SO2 concentration measured revealed that the concentration of these pollutants is lower than the standards of Clean Air Act.
Zhila Moradi-Khatoonabadi, Yahya Maghsoudlou, Hamid Ezzatpanah, Morteza Khomeiri, Mehdi Aminafshar,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objective: Milk and milk products are very suitable medium for growing microorganisms (e.g. Bacillus cereus). B. cereus is spore former bacilli, which easily survives during pasteurization and makes several problems in dairy industries. The aim of this study was to investigate aerobic spore and B. cereus of receiving raw milk from three UF plants. Materials and Methods: Samples were gathered from raw milk transport tankers arrived to plants during 30 days in winter. Also, the swab test was used for detection of B.cereus residual on milk contact surfaces. Results: High contamination level of aerobic spores (AeSC) and especially B.cereus were found in most samples compared with the criteria established by national and international standards. Although total viable count (TVC) in samples from industrial farms (IF) was lower than those from traditional farms (TFs) and milk collection centers (MCCs), considerable AeSC and B.cereus were transmitted to the UF plants from IFs. The highest and lowest TVC and B.cereus were found in samples from IFs and MCCs, respectively. In addition, our investigation in IFs revealed that teats contamination to soil and feces, as well as contaminated bedding might were the most important sources of B. cereus and AeSC of raw milk. Moreover, the results of swab tests confirmed that the “cleaning in place” system may not remove B.cereus effectively. Conclusion: It seems that for classifying raw milk quality, AeSC might be used as a more effective quality factor than TVC. Management commitment is effective to improve quality by balance between the amount and quality of receiving raw milk. This leads to the lower contamination in dairy plants and final products.
Fatemeh Hashemi, Hatam Godini, Ghodratolah Shams Khorramabadi, Loqman Mansouri,
Volume 7, Issue 2 (10-2014)
Abstract
Background and Objective: Phenol presence in water and wastewater is interesting because of its stability in environment and health problems. Therefore, it must be removed for water pollution prevention. The aim of this study was to evaluate phenol adsorption from aqueous solutions using walnut green hull. Materials and Methods: This was an experimental study in which walnut green hull was used as biosorbent with a range of mesh 40. In this study, stock solution of phenol was prepared and effects of effective parameters such as pH (4,6,8, and10), contact time (3-60 min), adsorbent dosage (0.25-5 g/L), and initial phenol concentration (10,20,40, and 50 mg/L) on adsorption process were evaluated. Moreover results were evaluated using Langmuir and Freundlich isotherms and first order and pseudo-second order kinetics. All experiments were conducted in double and the mean adsorption rate was reported. Results: The maximum adsorption capacity of 30.30 mg/g corresponded with Langmuir model. Kinetic evaluation indicated that the adsorption of phenol by the walnut green hull clearly followed the pseudo-second order reaction. It was found that increasing contact time and adsorbent dosage would lead to increasing of adsorption of phenol and increasing pH and initial phenol concentration lead to decreasing of phenol adsorption. Maximum phenol removal was achieved at pH 4, with more than 99.9 % efficiency. Conclusion: The results of this study show that the walnut green hull can be used effectively in phenol removal, because walnut green hull is agriculture waste and is produced annual in high volume hence, it can be used as adsorbent in phenol removal from wastewater.
A Azhdarpoor Esfanabadi, P Mohammadi, M Dehghani,
Volume 7, Issue 4 (1-2015)
Abstract
Background & Objectives: Excessive discharge of hazardous materials such as nitrogenous and organic compounds into the environment has negative impacts on the health of the aquatic environment. The main objective of this research was focused on evaluating the feasibility of using modified SBR reactor for the removal of nitrogenous compounds and chemical oxygen demand (COD). Materials & Methods: The experiments were performed using an up-flow continuous reactor with intermittent effluent. At first, four different cycles including aeration, settling, and decant (3, 4, 6, and 8 h) were designed for the performance of the reactor. Then, the efficiency of each cycle was determined for different concentrations of COD (250-1500 mg/L) and ammonia (40-100 mg/L). Results: Data demonstrated that all cycles had very good performances for the removal of COD. The average COD removal efficiencies of phases 1 through 4 were 91.7, 91.5, 92, and 92.7% respectively. The average NH4+ removal efficiencies of phase 3 and 4 were 92.7 and 95.8% respectively. Conclusion: The performance of phase 4 (with the cycle of 8 h) for the removal of nitrogen compound and COD was particularly high. The combination of anoxic and aerobic cycles in the reactor and providing nitrate as an electron receptor had the best performance for the removal of nitrogen from wastewater. Therefore, the continuous up-flow reactor was a good alternative to batch reactor in removing nitrogen compound and COD simultaneously.
M.s Mansoury, H Godini, Gh Shams Khorramabadi,
Volume 8, Issue 2 (8-2015)
Abstract
Background and Objective: Natural organic matters (NOM) are known as precursors to disinfection byproducts. As conventional treatment processes cannot get disinfection by-product standards, novel methods have been increasingly applied for the removal of disinfection by-products precursors. The UV/ZnO process is one of the advanced oxidation processes using photocatalytic technology. The present study aims to investigate the effect of UV/ZnO photocatalytic technology on the NOM removal from aqueous solution. Materials and methods: This study was conducted in a lab-scale batch photocatalytic reactor. The volume of reactor was 1liter and covered with UV lamps. Peristaltic pump was used for complete mixing. Humic acid is a key component of natural organic matter and it was used in this study. Each of the samples taken from the UV/ZnO process and other processes were analyzed for their UV absorbance at 254 nm by spectrophotometric. Initial concentration of Humic acid, contact time, pH, and UV irradiation were investigated. Results: The highest efficiency of the UV/ZnO photocatalytic process for removal of Humic acid from aqueous solution was achieved at initial concentration = 2 mg/L, contact time = 120 min, UV irradiation = 3950 µw/cm2, and pH=3. In this process, the removal efficiency for 2 mg/L humic acid was 100 % at 2h retention time. Conclusion: The research showed that performance of system was increased by increasing contact time and UV irradiation and was decreased by increasing HA initial concentration and pH and UV radiation with ZnO agent could not remove NOM lonely. Photocatalytic system using zinc oxide immobilized on glass have high performance to remove humic acid from aqueous solution. The UV/ZnO process was efficient and environmental friendly for natural organic matter removal.
P Baratpour, G Moussavi, A Alahabadi, E Fathi, S Shekoohiyan,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: With industrial development and population growth, the emerging contaminants enter into the natural water resources. Therefore, adsorption potential of Ammonium Chloride-induced activated carbon (NAC) to remove metolachlor pesticide from contaminated water was investigated in this study.
Materials and Methods: The effects of operational conditions including solution pH, NAC concentration, metolachlor initial concentration and contact time on the removal of metolachlor by Ammonium Chloride-induced activated carbon (NAC) and standard activated carbon (SAC) were studied.
Results: Over 92.4% of 50 mg/L metolachlor was adsorbed using 0.3 g NAC/L within 5 min, and by increasing the reaction time to 60 min the removal efficiency reached to 100%. Under similar experimental conditions, standard activated carbon (SAC) could only adsorb 20% of metolachlor within 5 min and increase of contact time to 40 min caused the improvement of metolachlor adsorption onto SAC to 48%. The adsorption onto SAC was not influenced by the contact time over 40 min. Kinetic analysis showed that experimental adsorption data for both NAC and SAC were best fitted to the pseudo-second-order model. The maximum adsorption capacities of metolachlor onto NAC and SAC calculated by the Langmuir model were 344.8 and 238.1 mg/g, respectively.
Conclusion: Generally, these results showed that developed NAC was an efficient adsorbent with high removal efficiency for eliminating the halogenated pesticides from the contaminated water streams.
S Bita, M Mesbah, A Shahryari, M Ghorbanpoor Najafabadi,
Volume 10, Issue 3 (12-2017)
Abstract
Background and Objective: Nanoparticles are already widely used in technology, medicine and consumer products, but there are limited data on their effects on the aquatic environments. The aim of this study was to evaluate the response of antioxidant defense system in common carp gills exposed to silver nanoparticles, which are produced by bioreduction method.
Materials and Methods: Common carp fish were exposed to the silver nanoparticles at concentrations of 0.11, 1.13 and 5.67 mg/L for 14 days. A treatment without silver was considered as a control. After sampling, 1 g of gill was weighed and homogenized in 5 mL phosphate buffer. The homogenized samples were analyzed for measuring the activity of catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), total antioxidant capacity (TAC) and malondialdehyde (MDA).
Results: CAT activity in gill at the concentrations of 1.13 and 5.67 mg/L AgNPs was significantly reduced compared to that of the control (p<0.05). When the activities of GSH and TAC of different treatments and the control were compared, no significant difference (p>0.05) was observed. Activity of SOD and MDA of all treatments sampled at different days was fluctuated, that is, it was either increased or decreased. However, superoxide dismutase activity was significantly higher in exposure to concentrations of 5.67 mg/L and 1.13 mg/L.
Conclusion: According to the results, fish gills are one of the most susceptible organs of oxidative damage in exposure to silver nanoparticles. This can affect the health of common carp and thus increase the risk of disease in the fish.
M Abadi, Aa Zamani, A Parizanganeh, Y Khosravi, H Badiee,
Volume 10, Issue 3 (12-2017)
Abstract
Background and Objective: Mercury (Hg) contamination in marine ecosystems is a major threat to human health in the developing countries like Iran. The main route of mercury exposure is from consumption of fish and seafood. Upon entering mercury in human bodies, Hg is converted into methyl mercury, which may lead to serious implications including neurological disorders, reproductive abnormalities, kidney failure, emotional instability, gingivitis and tremors. Therefore, research on mercury concentrations in marine ecosystems (water and fishes) can be help to protect human health and reduce the risks of mercury contamination.
Materials and Methods: In this study in order to evaluate the concentrations of Hg in water and fish, water samples (36 stations), fish tissue livers (n=33) and muscles (n=33) of four fish species from the Caspian Sea (southern coasts) were collected and analyzed. For determination of Hg in water and fish samples, Voltammetry and GF-AAS techniques were used, respectively.
Results: The results showed that the average Hg concentration detected in water samples was 1.657 (μg/L) and in fish muscle and liver tissues were 68.636 and 125.606 (μg/g.dw), respectively. The bioaccumulation factor showed that mercury concentrations from water to fish are in the range of 14 to 80 times. The highest levels of mercury in water and fish were observed in the southwest coasts of the Caspian Sea.
Conclusion: According to USEPA and SPPA (China) standards, more than 58 % of the water samples collected from the southern coasts of the Sea was polluted by mercury. However, the average concentrations of mercury in fish samples were less than the standards by WHO and EPA.
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.
Sh Goodarzi, Gh Shams Khoramabadi, M Esmaty, Ma Karami, A Hossein Panahi,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: Wastewater from pharmaceutical industry has high chemical oxygen demand as a result of the presence of organic drugs and antibiotics. In order to meet the environmental requirements, several treatment methods like chemical and electrochemical methods have been widely applied due to their high ability to remove organic compounds from pharmaceutical wastewater. Therefore, the present study aimed to evaluate the efficiency of chemical coagulation/Electro-Fenton treatment method to degrade the organic matter-containing pharmaceutical industry wastewater.
Materials and Methods: The experimental tests were carried out using batch mode. The chemical coagulation process was evaluated as a function of aluminum chloride concentration (25-300 mg/L) and pH (3-10). The effluent from chemical coagulation process was transferred to Electro-Fenton reactor. Effects of H2O2 concentration (100-4000 mg/L), reaction time (up to 120 min), voltage (10-30 V), and pH (3-10) were evaluated. The removal efficiency was determined in term of COD removal.
Results: The results showed that the highest removal of COD in the chemical coagulation was 49% (coagulant dose of 200 mg/L, and pH of 7). In addition, the Electro-Fenton process could be eliminating of 93.5% of COD at the optimum conditions concentration (100 mg/L H2O2, voltage of 20, pH of 3, and contact time of 30 min).
Conclusion: According to the results, it can be concluded that the combination of chemical and electrochemical processes was found to be effective methods for treatment of pharmaceutical wastewater in comparison to the application of each process separately. To reach to the maximum removal efficiency, the environmental parameters should be carefully controlled at their optimum values in each single process.
Reza Nazarpoor, Masumeh Farasati, Abolhasan Fathaabadi, Mohamad Gholizadeh,
Volume 13, Issue 1 (4-2020)
Abstract
Background and Objective: Synthetic wetlands are engineering systems that use natural plants, soils and organisms to purify municipal polluted water and remove nitrate.
Materials and Methods: In this study, three systems were considerd as soil culture, three systems as plant cultivation on floating plates and three other systems without plant and porous bed as. The experiments were done three times within six months. The hydraulic retention times were 1, 3 and 5 days. The experimental design consisted of a factorial split-plot design. The analysis of variance showed that the efficiency of nitrate removal was affected by the type of constructed wetland, HRT, and temperature changes (p≤0.01).
Results: At the HRT of 1 day, the average efficiency of nitrate removal by the soil culture, plant cultivation on floating plates and control were 14.34%, 12.09% and 10.51%, respectively. At the HRT of 3 days, the average efficiencies were 17.62%, 15.76% and 13.54%, respectively. At the HRT of 5 days, the efficiencies were increased and they were 17.75%, 17.66% and 16.08%, respectively.
Conclusion: The results showed that the soil culture were more efficinet in removing nitrate .Also, the Cyperus alternifolius plant has the potential of nitrate phytoremediation.
Arezoo Balighian, Mitra Ataabadi,
Volume 13, Issue 2 (8-2020)
Abstract
Background and Objective: Hexavalent chromium is reported to be highly toxic, mutagenic and carcinogenic; hence treatment of water and wastewater contaminated with this element by low-cost and environmentally friendly methods is of great importance. Therefore the aim of present study was to evaluate the efficiency of Fe(II) modified bentonite for hexavalent chromium removal from a simulated wastewater.
Materials and Methods: In this study, Fe(II) modified bentonite was synthesized. Structure and morphology of bentonite were investigated by XRD and SEM techniques. Experiments were carried out as central composite design with three input parameters namely initial hexavalent chromium, pH and adsorbent dosage at 5 levels. Finally, the results were assessed by adsorption isotherm models.
Results: The findings revealed that complete removal efficiency of Cr (VI) achieved at pH of 2, initial hexavalent chromium concentration of 20 mg/L and adsorbent dose of 5 g/L. The adsorption isotherm model found to fit well with Langmuir isotherm model and revealed that the monolayer adsorption of hexavalent chromium at adsorbent surface was happened. The equilibrium data better fitted the Langmuir isotherm model suggested a monolayer adsorption nature of the modified bentonite.
Conclusion: The findings in this study showed the promise of use of Fe(II) modified bentonite for Cr (VI) removal. Moreover, response surface methodology can be used as an effective method to optimize hexavalent chromium removal from wastewaters.
Samira Sheikhi, Hassan Aslani, Reza Dehghanzadeh, Ammar Maryamabadi,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: Chlorpyrifos (CPF), an organophosphate pesticide, has been widely used in the agricultural industry and may cause environmental damage. The present study aimed to evaluate the potential application of Fe(VI) and Fe(VI)/PMS processes for oxidation of CPF in water after pretreatment with ferric chloride coagulant.
Materials and Methods: This study was performed in two phases including coagulation and flocculation process and advanced oxidation process (AOP). In the first phase, the coagulation process was performed for turbidity removal by ferric chloride (FeCl3). In this phase, using a central composite design (CCD) with R software, the combined effect of four variables including initial turbidity, initial pH, coagulant dose and contact time was investigated. The supernatant from this process was transferred to the next phase for further analysis. In the AOP phase, the effect of Fe(VI) and Fe(VI)/PMS oxidants were investigated separately.
Results: In the first phase (coagulation and flocculation), FeCl3 showed the highest efficiency (95.79%) at alkaline pH (pH=8). In the next phase (AOP), the results showed that the degradation efficiency of Fe(VI)/PMS process was higher compared to sole Fe(VI) process at all pHs. Also, by examining the reaction kinetics, it was found that after the coagulation process by FeCl3, the removal rate in the Fe(VI)/PMS process is 1.5 times higher than the Fe(VI) process.
Conclusion: Due to the high removal efficiency and higher degradation rate of Fe(VI)/PMS process, this technique can be used as a relatively effective method in removing chlorpyrifos from aqueous solution.
Alireza Zand Abbas Abadi, Mehrdad Cheraghi, Soheil Sobhanardakani, Bahareh Lorestani, Maryam Kiani Sadr,
Volume 16, Issue 4 (3-2024)
Abstract
Background and Objective: Monitoring of pollutants in urban ecosystems is of particular importance. Therefore, this study was conducted to evaluate the capability of Robinia pseudoacacia and Pinus elderica for biomonitoring of Pb, Cr and Ni in urban areas of Hamedan in 2023.
Materials and Methods: A total of 36 soils and 72 plant samples were collected from 12 sites. The contents of elements were determined using ICP-OES. Also, the values of PI, PLI, BAF, and CR indices were computed.
Results: The highest values of Pb, Cr, and Ni (mg/kg) in soil samples with 72.2, 67.5 and 101 values belonged to the commercial, industrial, and commercial sites, respectively. The highest average content of analyzed elements in unwashed and washed leaves/needles for Pb both belonged to the commercial areas; for Cr and Ni, all belonged to the industrial areas. The average values of PI followed the descending order of Cr > Ni > Pb. The average values of PLI varied from 1.22 to 1.34. Moreover, BAF values of Pb, Cr, and Ni of R. pseudoacacia leaves and P. elderica needles were found to be in the range of 0.100-1.00. Also, the highest mean values of CR of Pb and Cr were both found in P. elderica; and the highest mean value of CR of Ni was found in R. pseudoacacia.
Conclusion: R. pseudoacacia and P. elderica could be used as suitable and efficient species for monitoring and remediation of toxic elements from soil and air in polluted ecosystems.
Ehsan Manavipour, Akbar Eslami, Abbas Shahsavani, Ahmad Alahabadi, Reza Saeedi, Fatemeh Shokri Dariyan, Mehrnoosh Abtahi,
Volume 17, Issue 1 (6-2024)
Abstract
Background and Objective: In today's society, preparing healthy food has become challenging due to the variety of food production methods. Oil is produced in several ways in our country. In the cold pressing method, there is insufficient monitoring of the manufactured product. The aim of the present study is to investigate the physicochemical characteristics and the levels of heavy metals of industrial oil compared to cold-pressed oil.
Materials and Methods: In this research, 54 samples of sunflower, sesame, and canola oil produced by both cold pressing and industrial refiningmethods were prepared. Their physicochemical characteristics, including refractive index, acid value, iodine value, saponification value, peroxide value, anisidine value, as well as the concentrations of lead, iron, arsenic and copper were determined. Additionally, the effect of storage time on these characteristics was investigated.
Results: The Iodine number showed the highest deviation from the standard (61%), with an average of 136.70 gI/100g for the cold-pressed oil and 134.48 gI/100g for industrially refined oiland. The average value of the physicochemical characteristics, except for the saponification value, were higher in the cold-pressed oil samples compared to the industrially refined oil samples, but the observed difference was not statistically significant. An investigation into the effect of storage time on physicochemical properties revealed a significant increase in peroxide value (p<0.01) and anisidine (p <0.05) in both oil groups over a two-month period. The average concentration of arsenic, lead, iron and copper in the studied oils was 0.03, 0.78, 0.05 and 0.05 mg/kgoil, respectively. A deviation from the standard was observed only in one sample of cold-pressed sunflower oil, with an arsenic concentration of 0.11 mg/kgoil).
Conclusion: Based on the obtained results, the refined industrial oils exhibited more favorable chemical characteristics and stability. It is suggested that cold-pressed oils should be consumed within a short period of time. For frying purposes, refined industrial oils are preferable.
Mohammad Hssanabadi, Mohammad Sadegh Hassanvand, Mohammad Khanizadeh, Sasan Faridi, Adel Mokammel, Bita Malekian Esfahani, Ali Ahmadi Orkomi, Fatemeh Momeniha,
Volume 17, Issue 3 (12-2024)
Abstract
Background and Objective: The initial step in managing methane emissions is quantification. This study aims to comprehensively investigate the methods for estimating and measuring methane gas emissions in municipal solid waste landfills.
Materials and Methods: This systematic review includes studies published in English and Farsi between January 2005 and May 2023. English-language articles were included from PubMed, Web of Science, and Scopus databases, while Persian-language articles were included from SID, Majiran and Google Scholar.
Results: After evaluating the studies, 90 studies providing information on methods for measuring and estimating methane gas emissions in urban landfills were selected. The results showed that emission estimates based on widely used models like LandGEM and IPCC, despite being lower in cost and providing faster results, are often associated with relatively high uncertainty. Therefore, quantitative and qualitative methods of direct measurement are preferred for accurately determining methane emissions from landfills. The most commonly used methods for measuring greenhouse gases, especially methane from landfills, include direct reading equipment and closed flux determination chambers.
Conclusion: Estimating greenhouse gas emissions from primary sources allows responsible authorities to understand the current status of methane emissions and to formulate reduction strategies. The findings of estimated methane emissions from landfills can differ significantly from the actual measurements in some situations. Therefore, while these estimation methods are useful, fast and cost-effective tools, their inherent uncertainties should be considered when using them.
