Showing 27 results for Hadi
Elnaz Iravani, Mohammadhadi Dehghani, Amirhossein Mahvi, Noushin Rastkari,
Volume 6, Issue 2 (9-2013)
Abstract
Background and objectives: Bisphenol A (BPA) is an endocrine disrupting chemical that releases to the environment through effluents of its producing factory, pulp and paper mill factories, and plastics industry. The purpose of this study was to investigate adsorption isotherms of removing BPA from aqueous solutions using single walled carbon nanotubes (SWCNTs).
Materials and methods: This study was an empirical investigation. Our experiments were conducted discontinuously using 50 mL of sample in each test. The variables of this study were the contact time (5, 15, 30, 60, 90, 120 min), the initial concentration of BPA (2, 5 , 20, 50 mg/L), and pH (3, 5, 6, 9, 11). The concentrations of BPA were measured using UV-Vis spectrophotometer.
Results: The maximum adsorption capacity was found to be 71.42 mg/g. The results of our experiments showed that maximum adsorption capacity at equilibrium was achieved at t = 60 min and pH = 9. Moreover, increasing the initial concentration is associated with an increase in adsorption capacity until it becomes constant.
Conclusion: The BPA adsorption on SWCNT follows Freundlich-Langmuir isotherm.
Afsaneh Alinezhadian, Ahmad Karimi, Jahangard Mohammadi, Farzaneh Nikookhah, Mathias Niuman. Anderson,
Volume 6, Issue 3 (12-2013)
Abstract
Background and Objectives: In arid and semi-arid regions, wastewater reuse has become an important element in agriculture. However, irrigation with this resource can be either beneficial or harmful, depending on the wastewater characteristics. The aim of this research was to investigate the soil bacterial and crops quality irrigated with treated wastewater.
Material and Methods: This research was conducted on a maize field near the wastewater treatment plant in Shahr-e-kord in summer,2011. Plots were arranged in a randomized complete block design in 3 replications and 2 treatments, well water (W1) with fertilizer and effluent (W2).
Results: At the end of growth season, soil samples were collected from depth of 0-5 and 5-15 cm and plant samples consisting of old and new leaves and seeds were collected for bacteriological analysis. According to bacteriological analysis, total number of positive lactose bacteria, total and fecal coliforms in depth of 0-5 cm was 42% more than depth of 5-15 cm. In the case of old leaves, total number of coliform and fecal coliform was 88 and 40 MPN/100 mL respectively. Moreover, for new leaves, it was 38 and 2 MPN/100 ml respectively.
Conclusion: According the results, number of indicator bacteria in soil is decreased (about 35%) by passing time.
Mohamad Hadi Dehghani , Mamood Alimohammadi , Amir Hossein Mahvi, Noushin Rastkari, Masoome Mostofi, Maryam Gholami ,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objective: Various industries such as petrochemical, oil refinery, pharmaceutical, plastics, paper, steel and, resin produce a substantial of phenol and its derivatives. Wastewaters containing phenol need careful treatment before discharging into the environment due to their poor biodegradability and high toxicity. The objective of this study was to remove phenol by multiwall carbon nanotubes from aqueous solution. Materials and Methods: Adsorption process was implemented in a laboratory-scale batch with emphasis on the effect of various parameters such as contact time (5 to 120 minutes), pH (3- 11), initial concentration of phenol (5 - 50 mg/l) and the sulfate and chloride ions (20 - 200 mg/l) on adsorption process. To achieve a better realization of adsorption process, sorption kinetics and equilibrium isotherms were also determined. Results: The results indicated that maximum adsorption capacity occurred at concentration 50 mg/L and t =30 minutes. The uptake fluctuated very little in the pH range of 3–9, and at greater than 9 the absorption decreased suddenly. Moreover, the presence of sulfate and chloride ions had no effect on the process. It was found that adsorption kinetics and equilibrium data follow a pseudo-second-order kinetics model and a Freundlich isotherm model respectively. Conclusion: It is concluded that carbon nanotubes being effective in a wide range of pH, short time to reach equilibrium and the absence of competing ions on the absorption process can be used effectively in removing phenol from aqueous solution.
E Solgi, A Esmaili-Sari, A.r Riyahi Bakhtiari, M Hadipour,
Volume 8, Issue 1 (8-2015)
Abstract
Background and Objectives: Arsenic contamination is of great environmental concern due to its toxic effects as a carcinogen. In order to assess soil arsenic contamination and its distribution patterns, surface soil samples collected from the urban areas of Arak were analyzed. Materials and Methods: Totally, 62 surface soil samples were collected from depth of 0–20 cm of different locations including parks, green spaces, agricultural, roadsides, and squares of Arak City. The spatial distribution of arsenic in soil was mapped using GIS and kriging method. Results: The concentration of arsenic in the surface soil of Arak City was between 2.2- 10.8 mg/kg (average: 5.78 mg/kg). Spatial analysis showed that arsenic contamination enhances in the city center and there was an increasing trend from south to north. In addition, the mean arsenic concentration in the urban topsoil samples from Arak was lower compared with mean concentration for other cities around the world. Conclusion: It seems that arsenic in soil is controlled by natural and anthropogenic factors. The highest concentrations of arsenic in center and the north areas reflected arsenic loading is originated from anthropogenic sources such as vehicles and industrial processes.
Ar Mesdaghinia, S Nasseri, M Hadi,
Volume 9, Issue 3 (12-2016)
Abstract
Background and Objective: Exposure to chemicals such as heavy metals can be occurred through the route of drinking water consumption. Chromium is an important pollutant because of its role in the appearance of carcinogenic and non-carcinogenic health effects in humans. In this study, we studied the carcinogenic risk and non-carcinogenic hazard of chromium due to the consumption of bottled drinking water distributed throughout Iran.
Materials and Methods: The Hazard Quotient (HQ) and Excess Lifetime Cancer Risk (ELCR) indices were calculated. Monte-Carlo simulation technique was adopted for simulating uncertainty in the estimation of HQ and ELCR based on the input variables namely the concentration of pollutant, per capita water consumption, body weight, reference dose, biological availability, and source contribution factors.
Results: The average concentration of chromium in bottled waters determined was 4.79 ± 2.32 µg/L. The amounts of HQ and ELCR for the age groups of lower than 2, 2 to 6, 6 to 16 and over 16 years old were 0.000354, 0.00292, 0.00236, 0.00147 and 4.04×10-11, 5.99×10-10, 8.61×10-10 and 2.34×10-9, respectively.
Conclusion: In regard to the concentration of chromium in bottled waters in Iran, the incidence probability and the possibility of carcinogenic and non-carcinogenic effects by this pollutant due to the consumption of bottled water are considerably low and there is no health concern for any age groups.
R Nabizadeh Nodehi, Ar Mesdaghinia, S Nasseri, M Hadi, H Soleimani, P Bahmani,
Volume 9, Issue 4 (3-2017)
Abstract
Background and Objective: Water corrosion and scaling are known as destructive phenomenon of drinking water quality and water facilities. In this study, the groundwater tendency to corrosion or scaling in source water, water storage reservoirs and distribution system were studied. Simultaneous use of some qualitative and a quantitative index along with statistical analyses to assess the water scaling or corrosion tendency were investigated.
Materials and Methods: The data analysis of groundwater, water storage reservoirs and water distribution system in rural area of Kurdistan province were analyzed and the amount of Langelier (LI), Ryznar (RY), Pockorius (PSI) and Larson–Skold (LS) and CCPP indices were determined. Corrosion and scaling threshold for qualitative indices were determined based on CCPP index. The mean of indices was compared with the thresholds using independent t-test. ANOVA was used to assess the difference between the indices in different sources of water.
Results: The balance range for LI, RY and PSI found to be -0.1-0.05, 7-9 and 7.1-8.5. The mean CCPP for groundwater, reservoirs and networks were 9.27 ± 1.29, 9.13 ± 1.25, 11.25 ± 1.23, respectively. All three sources of water have some tendencies toward scaling; however, a significant balance status was confirmed statistically. According to Larson–Skold index, sulfate and chloride anions did not play a role in scaling process.
Conclusion: The use of qualitative indices with CCPP index can provide more accurate estimation of water tendency toward scaling or corrosion. The assessment of qualitative indices along with CCPP is recommended in drinking water corrosion monitoring studies.
Ar Mesdaghinia, S Nasseri, M Hadi, E Iravani, M Askari,
Volume 10, Issue 4 (3-2018)
Abstract
Background and Objective: Supply of safe drinking water to each community is one of the most important challenges in improving the general community’s health. Considering the importance of the research on water quality, identification of water quality research gaps was performed by reviewing the relevant studies through a systematic review for Iran.
Materials and Methods: In this study 638, 166, 300 and 1000 relevant articles were found on Scopus, SID, Magiran and Iranmedex databases, respectively. Out of 2104 articles, 1394 articles were excluded from the study. Finally, 710 articles were further reviewed.
Results: Monitoring of pollutants by a descriptive study was the main objective of the most studies (36.62%). Around 13% of the studies were performed on a laboratory scale. Organic pollutants in Iran have been concerned only in 17 provinces, and other provinces have not participated in this regard. Nitrate is studied in around one fifth of the total studies. Heavy metals were also considered as a parameter of concern in the studies carried out on monitoring drinking water resource quality.
Conclusion: This study reflects the research gaps and provides a basis for prioritizing water quality research in Iran. More actions and sound planning should be taken to monitor organic and inorganic pollutants. Chemical and microbial risk assessment, tracing the fate of pollutants and assessment of their ecological effects, investigations on advanced water purification processes, the use of bioremediation methods, identification of biological contaminant using biomarkers and molecular identification techniques are the most important research priorities that require more investigations.
M Hadi, M Solaimany Aminabad, M Amiri, M Arjipour,
Volume 11, Issue 3 (12-2018)
Abstract
Background and Objective: Treatment of hospital wastewaters has an important role in reducing the discharge of organics and pharmaceutical compounds into aquatic environments. Nowadays, advanced oxidation processes were extensively used for the removal of organic compounds from treated effluents. The study aimed to examine organic compounds removal from real treated effluent of a hospital treatment plant using a lab scale UV/H2O2/TiO2 process by optimizing the process.
Materials and Methods: The effluent characteristics including COD, TOC and DOC were measured and recorded. A hybrid advanced oxidation process (UV/H2O2/TiO2) was used for the removal of organic compounds. The experiments were designed using surface response methodology (RSM). The effects of the independent factors including pH, duration of UV irradiation, H2O2 and TiO2 concentrations on COD, TOC, DOC and the approximate cost of treatment were assessed by analysis of variance (ANOVA).
Results: The optimal condition was 7.2 for pH, 50 mg/L for H2O2, 100 mg/L for TiO2 and 19.65 min for irradiation time. This condition provided the maximum removal percentage for organic compounds with a minimum cost. The removal efficiency for TOC, DOC and COD were 63.9, 52.9, and 64.7%, respectively. The treatment cost was approximated to be $ 0.71 per one liter of the effluent.
Conclusion: Irradiation and H2O2 concentration had the greatest impact on the cost of the treatment. UV/H2O2/TiO2 process seems to be an expensive process for tertiary treatment of wastewater. However, further investigations are required to evaluate the cost effectiveness of the process for a full scale operation.
M Hadi, Z Aboosaedi, H Pasalari,
Volume 12, Issue 1 (5-2019)
Abstract
Background and Objective: Scaling and corrosion both are destructive to materials (usually metals) in water supply systems. A dataset (from 2002 to 2013) of groundwater resources (including springs, qanats, deep wells and semi-deep wells) were examined for water tendency to corrosion or scaling in rural regions of Kashan, a city in Isfahan, central Iran.
Materials and Methods: Water quality parameters including pH, temperature, Ca (mg/L), CO32- (mg/L), HCO3-(mg/L) and TDS (mg/L) were used to estimate water stability indices. Value of qualitative indices including Langelier (LSI), Ryznar (RSI), Puckorius (PSI) and trend of Calcium Carbonate Precipitation Potential (CCPP) as a quantitative index were calculated and analyzed for all water resources.
Results: Mean of LSI, RSI and PSI for all water resources were estimated to be 0.41±0.02, 6.39 ± 0.03, and 7.40±0.02, respectively. The CCPP value found to be 17.23±3.16, 15.66±1.38, 41.23±11.22, and 23.15±4.46 mg/L for springs, qanats, deep wells and semi-deep wells, respectively. The CCPP index was significantly increased from 2002 to 2013, with an average of 1.6 units per year.
Conclusion: A significant scaling tendency was observed. This tendency in decreasing order was observed in deep wells, semi-deep wells, springs and qanats. The estimated CaCO3 scale weight per cubic meter of water was 21 g on average, which may be problematic for water distribution systems. Water withdrawal management and reduction in TDS of water resources, perhaps through decrease in agricultural drainage, can be effective to reduce the scaling tendency.
S Abolli, M Alimohammadi, M Zamanzadeh, K Yaghmaeian, M Yunesian, M Hadi, Z Soliemani,
Volume 12, Issue 3 (12-2019)
Abstract
Background and Objective: Surface water and underground water quality in countries that facing dehydration have increased the interest of the community to use Household Water Treatment devices. The aim of this study was the evaluation of the quality of drinking water of Household Water Treatment devices and general distribution network in Garmsar, which is under the control of the water safety plan.
Materials and Methods: A descriptive cross-sectional study administered in 6 regions and 41 cities of Garmsar city in spring and summer seasons in 2018. Chemical tests performed according to the standard methods for the examination of water and wastewater, general measurements were performed using the multi-tube fermentation method and counting of heterotrophic bacteria by pour plate method. The results analyzed by using Excel and SPSS software.
Results: The average values during two seasons were reported as: EC= 1507 (μS/cm), TDS= 786.8 (mg/L), F= 0.048 (mg/L), residual free chlorine= 0.67 (mg/L), pH=7.9, total coliform= 0.16 (MPN/100 mL), fecal coliform= 0.14 (MPN/100 mL) and HPC= 112 (CFU/mL). No significant difference found between the chemical and microbial parameters in the general distribution network and the output of the Household Water Treatment devices during the two seasons.
Conclusion: Household water treatment devices did not affect the microbial burden but caused a change in the amounts of some chemical parameters. Drinking water from the distribution network, with the proper application of the water safety plan, is of good quality.
Hadi Entezari Zarch, Mohamad Javad Zoqi, Mohamad Reza Doosti, Somayeh Rahmani,
Volume 13, Issue 1 (4-2020)
Abstract
Background and Objective: Reactive Red 198 is a mono azo dye widely used in the textile industry of Iran. The toxicity of reactive dyes is higher than other dyes and causes disorders such as irritation, cancer and mutation in humans. The overall objective of this study was to determine the efficiency of a Constructed Wetland pilot system with conventional and baffled horizontal subsurface flow to remove Reactive Red 198.
Materials and Methods: In order to remove Reactive Red 198, two cells were constructed in parallel with 2 × 0.6 × 0.5 m. In the conventional and baffled cell, native straw of Phragmites australis was used. In the research process, COD concentration and reactive dye concentration were investigated. The effect of retention time and type of plant on the efficiency were also investigated.
Results: The results showed that the maximum removal efficiency of the Reactive Red dye 198 was obtained at 100 mg/L inlet pollutant concentration and 3.5 days retention time, which was related to the baffled cells. Also, the presence of the baffles in the constructed wetland system increased the removal efficiency. The presence of straw in both cells was directly affected the removal efficiency. The effect of the retention time in the conventional cell was more effective in removal efficiency than the baffled cell. The pollutant inlet concentration was also inversely correlated with the removal efficiency.
Conclusion: According to the results, it can be concluded that the baffled and conventional horizontal subsurface constructed wetland can be used for low concentrations and at low retention time as a well-functioning system in the removal of Reactive Red 198.
Mansour Shamsipour, Homa Kashani, Masud Yunesian, Kazem Naddafi, Mohammad Sadegh Hassanvand, Reza Saeedi, Mahdi Hadi, Alireza Mesdaghinia,
Volume 13, Issue 2 (8-2020)
Abstract
Background and Objective: In this study, we aimed to assess Iran’s position and trends for environmental health status among the countries of “Iran’s perspective document in 1404” according to the indicators used in Environmental Performance Index (EPI) report in 2018.
Materials and Methods: The score of indicators in environmental health area; air quality (including household solid fuels, exposure to PM2.5, and PM2.5 exceedance), water and sanitation (including drinking water and sanitation) and heavy metals (including lead) were extracted for all studied countries as well as for the last and baseline (generally ten years prior to last report) years from EPI 2018 database. According to EPI scores, the performance of the studied countries in each indicator was ranked. The percent change in the score of each indicator from baseline to current year was calculated and compared with the mean percent change for all studied countries.
Results: Iran ranked 7th regarding air quality in 2016. Also, it ranked 6th, 8th, and 9th in terms of household solid fuels, exposure to PM2.5, and PM2.5 exceedance, respectively. The EPI score for Iran regarding water and sanitation was 54.4 in 2005 and 58.74 in 2016 (percent change=7.98%). Iran ranked 21st in 2005 regarding lead exposure index. Although this index showed a growth of 100% in 2016, which is very desirable compared to the average growth of all countries (34.47%), but only leads to one step up in the ranking of Iran and was ranked 20th in comparison with other countries.
Conclusion: Totally, according to EPI 2018, Iran ranked 6th in the field of environmental health issues among 23 countries of “Iran’s perspective document in 1404”. However, there is uncertainty in the accuracy of the EPI raw data used for calculating index scores. Hence, caution should be exercised in their interpretation.
Arash Babaei, Maryam Bahrami, Masoomeh Maleki, Hadis Tavafi,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objective: Bioremediation and one of its main branches, namely phytoremediation, is one of the most important and basic processes for eliminating pollutants from the environment. Due to the large number of silica factories in Azandarian area of Malayer city and high soil silica pollution in this area, this study was conducted to compare the bioremediation effect of Fusarium oxysporum and Portulace olerace.L phytoremediation on silica uptake.
Materials and Methods: For this purpose, portulaca oleracea was cultivated in greenhouse conditions and different concentrations of silica and under the treatment of fungi in a completely random statistical design. For this purpose, portulaca oleracea cultivation was carried out under greenhouse conditions, fungal treatment and in different concentrations of silica in a completely randomized manner.
Results: The results showed that the fungus grew easily at high speed at 95% concentration of silica and was able to absorb 84.50% of the silica in the soil and the plant was able to absorb 80% of silica, the highest absorption rate of 69.71% and the highest rate of silica uptake in plant and fungus coexistence is 80% silica and 69.90%. The results showed that the fungus grew easily in the presence of silica with 95% concentration and could absorb 84.50% of silica in the soil. In the presence of 80% silica, the plant demonstrated the highest adsorption rate of 61.71%. The highest rate of silica uptake (69.90%) was reached at the 80% initial concentration of silica under the coexistence activities of plant and fungi.
Conclusion: In conclusion, silica exhibited a positive and significant effect on the physiological traits of Portulaca oleracea and also increased the amount of phenol, flavonoids, and anthocyanins. The coexistence of fungi and plants also increased the mentioned physiological traits in Portulaca oleracea. Also, the coexistence of plants and fungi showed a positive effect on silica adsorption, which can be effective in reducing silica contamination in the region.
Mahdi Hadi, Alireza Mesdaghinia, Simin Nasseri, Elnaz Iravani,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objective: The bibliometric analysis is the most effective way to study the scientific output and trend of research. The purpose of this study is to analyze the scientific output of the Institute of Environmental Research (IER) at Tehran University of Medical Sciences using bibliometric technique.
Materials and Methods: All related IER articles that have been indexed in Scopus and WoK were retrieved from the beginning of 2009 till November 23, 2019. The bibliometric data were extracted and analyzed using R software.
Results: The document production follows an increasing exponential trend with a rate of 10% per year. 807 documents were retrieved with an average citations of 19.26 per each document. The documents per author and authors per document were obtained 0.196 and 5.1, respectively. The highest citations to documents was in 2017 (35.5 citations). The most frequent keywords were found “Adsorption”, “Drinking water”, “Air pollution”, “Particulate matter”, “Risk assessment” and “Response surface methodology”. Thus, engineering-based studies are more prominent in the published studies. Health-based studies, including risk assessment studies, accounted for the most area of research. The largest numbers of international research collaboration were recorded with the United States, Switzerland, Canada and India. While, in the national scale, Shahid Beheshti University of Medical Sciences’ collaboration was prominent.
Conclusion: It is still necessary to promote the level of the IER’s international collaborations to raise its regional status. In addition, more attention should be paid to health-based topics like risk assessment studies. These studies need to be given higher priority in the action plan of the IER’s centers and research groups.
Narges Lasemi, Mahdi Hadi, Simin Nasseri,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objective: One of the most important factors affecting communities’ health is safe drinking water. The UN general assembly considers “ensure availability and sustainable water and sanitation for all “as one of the 17 goals of SDGs for the 2030 development agenda. Target 6.1 of SDGs aims to provide universal and equitable access to affordable drinking water and to provide safe drinking water for all households. Target 6.2 calls for an end to defecation in an open environment to ensure that each person has access to the toilet and safe disposal system. In current study, 143 Savadkooh villages with defects in water supply systems and health services were selected to update the indicators and implement sustainable development goals.
Materials and Methods: A checklist was designed to extract targets 6.1 and 6.2 based on the Joint Monitoring Program (JMP). Considering 7400 households, margin of error of 5%, confidence limit of 95%, and the most conservative mode for response distribution (50%), the sample size was determined (512 households). Samples were collected randomly from all villages and then analysis was performed by SPSS 19.
Results: In drinking water sector, 84% of people have access to safe services, while only 15% and 1% have access to basic services and unimproved services, respectively. In sanitation sector, 98.8% of people use safe services though only 0.2% utilize limited services. In hygiene sector, 98.8% of people are provided with safe services.
Conclusion: Lack of drinking water safety and failure to improve water resources’ quality are the main problems in the drinking water sector. Lack of access to sewage network, wastewater disposal in the land is the biggest health hazard in the region. This study can provide solutions to improve the health quality of affected community.
Farah Rashadi, Nahid Navidjouy, Ali Ahmad Aghapour, Mostafa Rahimnejad,
Volume 14, Issue 3 (12-2021)
Abstract
Background and Objective: Microbial fuel cell (MFC) is a new green technology that uses the catabolic ability of microorganisms to produce bioenergy while simultaneously removing organic matter and other wastewater contaminants. Electrode material is one of the factors affecting the performance of microbial fuel cells. The aim of this study was to investigate the performance of microbial fuel cells in COD removal and bioenergy production from synthetic and real beverage wastewater.
Materials and Methods: In this research, a two-chamber microbial fuel cell with Nafion membrane and aerated cathode was set up using two electrodes made of carbon felt and flat graphite after being contacted by synthetic wastewater with a concentration of COD 5000 mg/L and real beverage wastewater. Organic matter removal efficiency and voltage, power density and maximum current were determine.
Results: Experimental results showed that maximum COD removal efficiency of 92 % was achieved in synthetic wastewater and with a carbon felts electrode. In this condition, maximum voltage, power density and output current density of 469 mV, 175.28 mW/m2, and 855 mA/m2, were obtained, respectively. However, by using real industrial wastewater (beverage), maximum removal efficiency of COD, voltage, power density and output current density, related to carbon felt electrodes were obtaines as 84 %, 460 mV, 91/65 mW/m2, and 635 mA/m2, respectively.
Conclusion: The findings showed that synthetic wastewater outperforms microbial fuel cells in terms of bioelectric production and organic matter removal as compared to real wastewater (beverage). The reason for the decrease in the cell performance might be the presence of solids and other confounding pollutants in real wastewater.
Navid Ahmadi, Mozhgan Ahmadi Nodushan, Mohammad Hadi Abolhasani, Seyed Abbas Hosseini,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: The presence of PAHs in the environment can cause a problem as their presence has a deleterious effect on humans and animals. They also have the ability to cause tumors in humans and animals. Generally, to remove crude oil pollutants from seawater, various physicochemical and biological treatment methods have been applied worldwide. A biological treatment method using bacteria, fungi, and algae has recently gained a lot of attention due to its efficiency and lower cost. Chlamydomonas reinhardtii, microalgae have features such as a high proliferation rate, and cultivability in various water ecosystems.
Materials and Methods: In the present study, a total of 12 samples of synthetic oil wastewater were prepared at 2.5 g/L, 7.5 g/L, and 12.5 g/L that were called C1, C2 and C3.The gas chromatography/mass spectrometry (GC–MS) method was used for the determination of PAHs compounds in the samples. Furthermore, water samples were further analyzed for the amounts of biological oxygen demand (BOD), Chemical oxygen demand (COD), and total organic carbon (TOC). Chlorophyll A, biomass, amounts of nitrate, and nitrite were also measured. Statistical analysis was performed using SAS 9/8 software.
Results: Results indicated that the removal rates from crude oil by C.reinhardtii microalgae were 100% on the 14th day for the three compounds of phenanthrene, fluorine, and anthracene at all concentrations, and 97.8%, 93%, and 92.7% for naphthalene compound at concentrations of 2.5 g in 1L, 7.5 g in 1L, and 12.5 g in 1 L, respectively (p<0.05). In terms of nutrients (NO-2 and NO-3), the highest amount of nitrate removal was observed at a concentration of 2.5 g/L from crude oil (C1) (p<0.05). The highest biomass was observed in the C3 treatment (p<0.05). Moreover, the greatest decline in BOD was observed in treatment C3 at 47.4%, while the greatest COD and TOC decline were observed in C1 treatment with the value of 84% and 94%, respectively (p<0.01).
Conclusion: The results showed that the cultivation of C.reinhardtii in crude oil in terms of nutrient removal potential, hydrocarbon composition, improving water quality and production of suitable biomass can be an acceptable option for exploitation in the biological treatment process.
Mahdi Hadi, Maryam Hashemkhani, Elnaz Iravani,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: Researchers investigate and identify the gaps and frequency of studies related to specific knowledge by using scientometrics. The purpose of this study was to analyze the trend of scientific research in the field of climate change in Iran.
Materials and Methods: All articles affiliated with Iran in the field of climate change have been cited in Scopus databases from 1991 to December 9, 2019, and were retrieved by using keywords like "climate change", "global warming", "global change", "climate variability", "greenhouse gas". The data were analyzed using R software.
Results: The total number of documents was 2253. The trend of document production in the field of climate change in Iran follows an increasing exponential trend. Iran's collaboration with other countries in the field of climate change studies was significant so around 25% of scientific productions have been produced jointly with other countries. Keywords analysis showed a greater frequency for keywords including “downscaling”, “energy”, “global warming” and “uncertainty”. However, despite the importance of issues such as “adaptation” and “vulnerability” concerning climate change in Iran, the frequency of these keywords in climate change studies in Iran is low.
Conclusion: Based on the results of this study and considering the importance of climate change and its effects on the country, also the importance of greenhouse gases including CO2, and the rank of Iran as the eighth country in the emission of these gases, it is recommended to pay more attention to issues such as “vulnerability”, “adaptability”, analysis of “greenhouse gases production”, “management of energy consumption” and the use of “renewable energies” in future studies.
Hadi Niknejad, Fathollah Gholami-Borujeni, Khadijeh Sajjadpour, Samira Mojerlou, Reza Ghasemnejad, Mohammad Rafiee,
Volume 17, Issue 2 (9-2024)
Abstract
Background and Objective: Personal hygiene and adherence with health protocols in food preparation and distribution centers by operators are essential for controlling the transmission of infectious diseases. This study aimed to investigate the microbial contamination and compliance with health protocols among bakery workers in Mahmoudabad, Mazandaran, in 2020.
Materials and Methods: In a cross-sectional descriptive study, 149 samples were collected from the hands of workers in bakeries in Mahmoudabad. The microbial load was determined using the System Sure Plus device. Additionally, standard checklists, which included questions related to compliance with health protocols in the workplace, were used. The collected data was then analyzed using SPSS 26 software.
Results: Among the studied samples, 51.1%had a microbial load higher than 30 RLU (Relative Light Units), 28.86% had a microbial load of 10-30 RLU and 20.13% had a microbial load less than 10 RLU. Based on the results of the checklists, the rates of adherence to hand disinfection protocol, observance of social distancing, use of liquid soap, and use of a mask were 43.6%, 61.7%, 59.7%, and 53.7%, respectively. Additionally, data analysis revealed a significant relationship between business gown usage and microbial contamination on personnel's hands (p = 0.031).
Conclusion: Based on the results, it was evident that the workers' hand hygienewas in a concerning condition, posing a potential threat to their overall well-being. Therefore, individual health education and food safety practices should be improved, and inspections by environmental health monitors should be considered to ensure stricter public health standards.
Hadi Niknejad, Nima Kalvani, Mehdi Seyedirad, Alireza Ala, Reza Saeedi, Mehrnoosh Abtahi, Fathollah Gholami-Borujeni,
Volume 17, Issue 2 (9-2024)
Abstract
Background and Objective: There have been concerns about microbial contamination along the coastal cities in the north of the country, particularly in cities of Mazandaran province, which could pose health risks for swimmers and tourists. The present study aimed to quantitatively assess the risk of gastrointestinal diseases resulting from exposure to E. coli and enterococci bacteria during recreational activities on the beaches of Fereydunkanar.
Materials and Methods: In this cross-sectional descriptive study, 66 grab samples collected during the summer were analyzed to investigate microbial contamination in the recreational beach waters of Fereydunkanar.The Monte Carlo simulation method was used to calculate both daily and annual infection risks.
Results: The findings demonstrated that transmission of enterococci was more likely than that of E. coli in the swimming areas of these beaches. The average annual infection risk for E. coli was 0.41 for adults and 0.69 for children . Additionally, the annual risk of enterococci infection was 1 for adults and 0.99 children and, which exceeds the range advised by the WHO and EPA. These findings indicate that children have a higher infection risk compared to adults.
Conclusion: Unrestricted discharge of municipal and industrial wastewater effluents into sea and rivers can contribute to the presence of harmful microbes in beaches. By implementing effective environmental and recreational management strategies, it is possible to minimize the risk of public health hazards at recreational beaches while also preserving the natural beauty of these important public spaces.
