Showing 14 results for Koohi
M Hadi, R Shokoohi, A.m Ebrahimzadeh Namvar, M Karimi, M Solaimany Aminabad,
Volume 4, Issue 1 (24 2011)
Abstract
Background and Objectives: widely use of antibiotics as therapy and uncontrolled discharge of them to receiving waters increased the percentages of antibiotic resistant bacteria in various environments which may cause problems in therapy. The aim of this study was to investigate the antibiotic resistance of E. coli, K. pneumoniae and P. aeruginosa bacteria isolated from urban and hospital wastewaters. Nine antibiotics namely Chloramphenicol, Ciprofloxacin, Trimethoprim Sulfamethoxazol, Gentamycin, Ceftizoxime, Nalidixic Acid, Ceftazidime, Ceftriaxon and Cefalexin were investigated in this study.
Materials and Methods: through a cross-sectional descriptive study the isolation of bacteria from hospital and urban wastewater samples was performed by microbiological identification techniques. The resistance to nine antibiotics was tested by application of the standard disc diffusion technique and zone-size interpretation chart of Kirby-Baeur. Non-parametric Mann-Whitney test was used to assessing two environments differences.
Results: The resistance percentage of E. coli to studied antibiotics was significantly less (ranged from 1.81 to 51.02%) than the resistance percentage of P. aeroginosa (ranged from 3.57 to 61.76) and K. pneumoniae (ranged from 6.45 to 91.83%). the highest resistance to antibiotics studied was for K. pneumonia in comparison with others. E. coli, K. pneumonia and P. aeroginosa bacteria showed the highest resistance to CAZ, SXT and CN, respectively. The study showed the resistance rate in hospital wastewater is more than urban wastewater.
Conclusion: Easy access and uncontrolled usage of antibiotics cause discharge of antibiotics to wastewaters and consequently diminish the drugs' effectiveness. High concentration of antibiotic and diversity in wastewater of hospital in comparison with urban wastewater causes to transfer resistant agents between bacteria and increased the multiple resistances.
Reza Shokoohi, Salah Azizi, Said Amir Ghiasian, Javad Fredmal,
Volume 7, Issue 2 (10-2014)
Abstract
Background and Objectives: Pentachlorophenol (PCP) is an organic compound and phenolic derivatives categorized as priority pollutants that have harmful effects on humans, animals, and plants in low concentrations. Therefore, PCP removal from water and wastewater is very important. The aim of this study was to assess the efficiency of A. niger fungus biomass in PCP absorption. Materials and Methods: This was an experimental study in which different steps of the experiments were performed. A. niger strain was prepared from Persian Type Culture Collection of Iranian Research Organization for Science and Technology (IROST). After activation in potato dextrose agar (PDA) culture plates, fungi were incubated for 7 to 10 days at 25 °C. The prepared A. niger biomass was modified by NaOH and then it was used for PCP absorption assay. The concentration of PCP was measured using high-performance liquid chromatography. Results: The findings of present study showed that contact time is an important and effective factor in the PCP absorption rate. Two hours was selected as the optimum retention time in this experiment and after that the removal percentage did not raise significantly. The results of PCP absorption in different pH demonstrated that the adsorption efficiency decreases by rising pH and initial PCP concentration. The effects of contact time, pH and initial PCP concentration on the absorption process was significant (P-value <0.001). Conclusion: The results show that absorption efficiency increases by rising retention time under constant conditions. In addition, at low pH the modified A. niger biomass could be a good absorber for PCP.
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.
Abdolmotaleb Seid Mohammadi, Ghorban Asgari, Reza Shokoohi, Parastoo Shahbazi,
Volume 13, Issue 3 (11-2020)
Abstract
Background and Objective: Considering the importance of alkalinity in pH regulation and its buffering role, in this study, the effect of inlet wastewater alkalinity on the efficiency of the anaerobic unit of the wastewater treatment plant. Moreover, a superior chemical compound in providing alkalinity to wastewater was investigated.
Materials and Methods: This study was performed in the treatment plant to determine the relationship between input alkalinity and removal efficiencies of COD, BOD5 and TSS. In order to determine the optimal alkali material for superb anaerobic wastewater performance, four common chemical substances including, NaOH, Na2CO3, Ca(OH)2 and MgO were selected and examined using One Factor At Time (OFAT) test method.
Results: According to the results maximum removal efficiencies were obtained 62, 66.6 and 71.2% for COD, BOD5 and TSS, respectively under alkaline condition of 1260 mg/L CaCO3. Furthemore, the optimal dose to supply one unit of alkalinity by Na2CO3, Ca(OH)2 and MgO were 0.53, 0.54 and 0.3 mg/L, respectively. These values were obtained 5 min contact time and mixing rate of 150 rpm. However, for NaOH the optimal dose supply was obtained 0.35 mg/L for 3 min contact time and mixing rate of 100 rpm.
Conclusion: In conclusion, the performance of anaerobic baffled reactor is highly related to the supply of influent alkalinity to the reactor. In addition, the use of MgO can be considered as a suitable alkaline substance to neutralize acidic wastewater and provide alkalinity for ABR system.
Shahla Karimian, Sakine Shekoohiyan, Gholamreza Moussavi,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objective: Landfills as municipal solid waste are considered as the source of pollution. The present study aimed to assess the ecological risk of heavy metals in Tehran landfill soil and the adjacent residential area.
Materials and Methods: Having consulted with the specialists and considered the waste processing facilities, 12 sampling points were selected and sampled in four seasons. Soil samples were digested using HNO3: HClO4: HCl: HF. The levels of metals were measured using ICP-OES which further applied for the calculation of ecological risk. Kolmogorov-Smirnov, Kruskal-Wallis, and Pearson correlation coefficient analyses were run to determine the significant differences between metals concentrations in various seasons and sampling points.
Results: Metal concentration showed to follow theorder: Al > Fe > Mn > Zn > Cr > Pb > Cu >Ni > Co > As > Cd. Kruskal-Wallis results and pairwise comparison showed a statistically significant difference between metal concentrations across sampling points and seasons, especially in rainy seasons. Pearson correlation coefficient displayed a strong relationship between the mean concentrations of Cu - Pb, Cu - Zn, and Pb - Zn with obtained values of 0.932, 0.874, and 0.883, respectively. Cu exhibited the highest contamination factor at the compost and fermentation sites (13.2 and 9.89, respectively). The geo-accumulation index proved the anthropogenic sources of pollution. The potential ecological risk index (ERI) for the sampling sites ranged from 67.3 to 154, with the order of Cd > Cu > Pb > Ni > As > Cr > Zn > Co > Mn.
Conclusion: Due to the obtained moderate to severe ecological risk and exceeded background concentrations of heavy metals, it can be concluded that metal changes and soil pollution are both affected by landfill activities.
Sakine Shekoohiyan, Mobina Hadadian, Mohsen Heidari,
Volume 14, Issue 3 (12-2021)
Abstract
Background and Objective: Changes in the quantity and quality of waste produced as a result of compliance with health protocols are the result of the COVID-19 outbreak. The present study aimed to determine the quantity of personal protection equipment produced in Tehran and people’s knowledge of its management.
Materials and Methods: The present cross-sectional and descriptive-analytical study was carried out on 2560 participants in Tehran through an online survey in spring 2020. Based on the percentage of using masks and gloves, the amount of produced waste was calculated, and Mann-Whitney and Kruskal-Wallis statistical tests were run to explore the relationship between the variables.
Results: The overall Cronbach's alpha coefficient of the questionnaire was 0.94, and the rate of mask and glove use was 90.7% and 65.7%, respectively. 70.3% and 52% of the population used two masks and one pair of gloves on a daily basis. The number of daily produced masks and pairs of gloves was 14530407 and 5262666, respectively. Mann-Whitney U-test showed a statistically significant difference between gender and marital status with people’s knowledge of waste management (p <0.05). Kruskal-Wallis test showed a significant difference between the economic status and people’s knowledge of separating the produced waste (p <0.05). People with an increasing income tended to separate the waste more.
Conclusion: Due to the high volume of personal protective wastes and the lacking knowledge of one-third of the participants about the transmission of the virus through contaminated waste, it is necessary to raise awareness of breaking the virus transmission chain.
Mohamad Mehdi Ghorbaninejad Fard Shirazi, Sakine Shekoohiyan, Gholamreza Moussavi, Mohsen Heidari,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: Among the emerging contaminants, microplastics threaten public health. This study aimed to determine microplastic and mesoplastics in soil of residential areas adjacent to Tehran Landfill and assess its ecological risk.
Materials and Methods: The present descriptive cross-sectional study was conducted on 20 shallow and deep soil samples from residential areas near the Tehran landfill in July 2021. The microplastics were floated in NaCl and ZnCl2 solutions, and the mesoplastics were separated manually. The identification of physical and chemical properties of polymers was performed by stereomicroscope and FTIR analysis, respectively.
Results: The average amount of micro-plastics in shallow and deep soils estimated 76±34.98 and 24.7±19.79 particles/kgsoil, respectively. The average amount of mesoplastics obtained 5.25±2.91 and 3.55±1.09 particles/kgsoil, in shallow and deep soils, respectively. Paired-samples T-test showed significant differences between shallow and deep soil in terms of plastic particles (p<0.001). The most abundant microplastic particles were the fragment-shaped with the particle size of 0.1-0.5 mm and LDPE polymer types with the percentage of 37.75, 44.64, and 46.15, respectively. Mesoplastic particles, the 0.5-1 cm film-shaped particles and LDPE polymer types with the percentage of 62.76, 61.46, and 50.7 were found as the most prevalent. Microplastics and mesoplastics' potential ecological risks value in all sampling points was less than 150, indicating low ecological risk.
Conclusion: Despite the low PERI of microplastics and soil mesoplastics in residential areas, the Eri index for LDPE was high. Thus, Ecological risk is probable if control measures are not taken against plastic pollution.
Hengameh Tarviji, Sakineh Shekoohiyan, Gholamreza Moussavi, Mohsen Heidari,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: In some villages of Mazandaran, drinking water may be polluted with various pollutants, especially heavy metals (HMs), due to the shallow depth of drinking water sources and the proximity of these sources to farmlands. Therefore, this study aimed to measure the HM pollution level of drinking water in some villages of Mazandaran province and to assess the attributed health risks.
Materials and Methods: HMs content of drinking water in 30 villages with separate water sources in Mazandaran province was measured. Concerning the HMs concentration and toxicity, and exposure route through water drinking, carcinogenic and non-carcinogenic risks were assessed using a Monte-Carlo simulation-based method.
Results: The concentration values of arsenic, cadmium, chromium, nickel and lead in water were <1/0-4.26, < 0.05, <0.15-3.74, <0.3-10.89, and <0.8-4.68 µg/L, respectively. The hazard index (HI) values for non-carcinogenic risk due to the exposure to HMs through drinking of water in various age groups ranged from 3.04E-04 to 9.94E-04. Values of cumulative excess lifetime cancer risk (ELCRT) for As and Cr were 9.72E-08 and 6.13E-08, respectively.
Conclusion: The results of this study showed that, fortunately, the concentration of metals in drinking water in the studied area was much lower than the national standards and the attributed health risk. Therefore, the drinking water sources in the studied villages had acceptable quality. However, due to the existence of rice paddies in some villages of Mazandaran province, continuous monitoring of pollution levels in the drinking water sources of these areas is essential.
Ehsan Aghayani, Sakine Shekoohiyan, Ali Behnami, Ali Abdolahnejad, Mojtaba Pourakbar, Hamed Haghnazar, Vahideh Mahdavi, Amir Mohammadi,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: Heavy metals in water can pose risks to human health. Therefore, it is necessary to monitor and measure metals to ensure the health of consumers.
Materials and Methods: This study aimed to measure heavy metals such as arsenic, lead, cadmium, chromium, zinc, and mercury in water resources and urban water distribution networks in spring and summer of 2021 in Maragheh city. Accordingly, 25 samples were taken to investigate the presence of heavy metals. The presence of these metals in water sources was investigated using qualitative maps and finally, by evaluating the health risk caused by the presence of these metals, their effect on the health of consumers has been studied.
Results: Examining the concentration of metals in water resources upstream of the dam shows a relatively high concentration of metals, especially arsenic (13.2 µg/L). Despite this, the amount of arsenic after the water treatment plant and in the distribution network is reduced to an insignificant level. On the other hand, the results show that the amount of zinc metal in the network is higher than in the reservoir of the dam, and its concentration in the dam is equal to zero and in the network, it reaches the highest value of 578 µg/L. Finally, the health risk assessment shows that the calculated THI values for all samples vary between 0.01 and 0.99.
Conclusion: Based on the calculated health risk, there is no threat to the health of consumers regarding heavy metals in Maragheh drinking water. Also, these results double the necessity of additional studies regarding the leakage of zinc metal from the pipes and accessories of the city's drinking water distribution network in the future.
Mahboobeh Motalebi, Gholamreza Moussavi, Sakine Shekoohiyan,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: Vacuum Ultraviolet (VUV)-based advanced oxidation is a new category of advanced purification processes, so this study aimed to compare the efficiency of VUV and Ultraviolet-C (UVC) processes in combination with H2O2 and PMS in degrading Remdesivir.
Materials and Methods: The photoreactor was investigated with VUV and UVC lamps in combination with H2O2 and PMS for Remdesivir degradation. Also, the effect of variables such as solution pH, H2O2 dose, Remdesivir concentration, the presence of radical scavengers and anions, as well as hydraulic retention time was considered in the continuous process of Remdesivir removal.
Results: The findings showed that the optimal pH in the processes of VUV, UVC, and their derivatives was equal to 7. By adding 1 mM of PMS and H2O2 to the VUV process, the degradation efficiency of Remdesivir was increased from 92.2 ± 0.4% to 98.3 ±2.1% and 100 ± 0.3%, respectively, after 30 min. Also, in the UVC process combined with H2O2 and PMS, the degradation efficiency reached 77.8 ± 1.5 and 85.2 ± 1.3% after 40 min, respectively. The degradation kinetics in the examined processes were as follows: VUV/H2O2 > VUV/PMS > VUV > UVC/H2O2 > UVC/PMS > UVC. The hydroxyl radical was the main reactive oxygen species that led to the decomposition of Remdesivir. The continuous operation of VUV/H2O2 showed that the removal efficiency of Remdesivir reached 94.7 ±0.8% after 40 min.
Conclusion: Considering the high rate of Remdesivir degradation by adding H2O2, the VUV/H2O2 process can be introduced as an efficient technology for the removal of antiviral drugs.
Samaneh Dehghan, Mohammad Ali Zazouli, Abolfazl Hosseinnataj, Masoome Sheikhi, Ali Koohi,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: Nowadays, recycling is one of the ways to save mankind from the mass of waste it produces, and waste separation from the source is the first and most important link in the field of urban waste recycling. Since the necessity and basis of recycling is people's participation in separation plans from the source, the present study was conducted to investigate the awareness, attitude, and performance of the people of Mazandaran province regarding the source separation of household waste in 2021.
Materials and Methods: The present study was a descriptive-analytical and cross-sectional study, and the tool used in it was a researcher-made questionnaire including three dimensions of knowledge, attitude, and performance, the link of which was provided online to qualified people. The qualitative content validity of this questionnaire was confirmed by 8 environmental health experts in the field of the research subject. The reliability of the tool was also estimated through the Retest Method. Furthermore, the values of Cronbach's alpha coefficient for the three dimensions of awareness, attitude, and performance were calculated. In the following, the samples were selected in virtual groups based on the available sampling method and through the distribution of the questionnaire link online. Analysis of variance was used to compare the mean scores in the levels of variables, Pearson's correlation test was used to examine the relationship between the scores of awareness, attitude, and performance dimensions, and linear regression was used to examine the effect of independent variables. Finally, the data was analyzed in SPSS software (version 22).
Results: For the entire study population (305 people), the range and mean score of awareness were 0-6, and 5.03±1.18 respectively, the range and mean score of attitude were 17-85 and 61.01± 9.45, and the range and mean score of performance were 6-30 and 11.43±5.19, respectively. Also, there was a significant correlation between the mean scores of the dimensions of awareness and attitude (correlation coefficient=0.70), awareness and performance (correlation coefficient=0.68), and attitude and performance (correlation coefficient=0.63).
Conclusion: The results of this study, which was conducted to measure the knowledge, attitude, and performance of the people of Mazandaran province regarding the separation of household waste from the source and waste recycling, and with a survey of 305 households in this province, showed that although the most of people have a piece of proper knowledge and attitude related to the importance of separation and recycling of solid waste, they have not participated much in the plans of waste separation from the source. Therefore, in order to increase the level of people's performance, it is recommended to develop incentive programs in the field of source separation, including awarding prizes or applying discounts on waste charges, as well as providing suitable containers for waste separation to households for free by the municipality to encourage waste separation.
Sakine Shekoohiyan, Mojtaba Pourakbar, Asghar Zohdi Shiran, Farshid Ghanbari, Mostafa Mahdavianpour, Ehsan Aghayani,
Volume 16, Issue 4 (3-2024)
Abstract
Background and Objective: The development of the automobile industry has caused various pollutants to enter the environment, one of which is fluoride. Therefore, this study aims to improve the fluoride removal from wastewater pre-paint units of the automotive industry to achieve discharge standards to surface waters.
Materials and Methods: The study is descriptive and on an applied scale, which has been carried out to compare the efficiency of the chemical coagulation process using lime and alum, as well as the electrocoagulation process using aluminum anodes in the presence of lime to remove fluoride.
Results: The results of real wastewater characteristics showed that the pH of wastewater is in the range of 6.1 to 6.3, and its fluoride concentration is in the range of 45 to 55 mg/L. The results of the experiments show that in the most optimal possible state in the chemical coagulation process, it is possible to achieve fluoride removal efficiency in the range of 76 to 81 percent. However, the removal efficiency in the electrocoagulation process using an aluminum anode at a concentration of 5 mol/L of calcium ions, and current density of 20 A/m2 after reaction time of min 20 to 99% can also be achieved.
Conclusion: Considering the high fluoride removal rate (more than 99%) in the electrocoagulation process in the presence of calcium ions, this process can be introduced as an efficient technology for fluoride removal.
Zahra Khodarahmi, Sakine Shekoohiyan, Mohsen Heidari,
Volume 16, Issue 4 (3-2024)
Abstract
Background and Objective: Given the concern about the presence of microplastics in the air and settled dust, and the lack of a standard approach for their detection, it is necessary to investigate the methods and techniques used to study this type of pollution in Iran. Therefore, this study aimed to systematically review the methods and techniques used for sampling, quantification, and characterization of microplastics in the air and settled dust in indoor and outdoor environments in Iran.
Materials and Methods: In this systematic review, the keywords Microplastic*, Air*, Atmosphere*, Dust, Indoor, Outdoor, Iran, and their corresponding Persian equivalents were searched until Dec 1, 2023, in Scopus, PubMed, Web of Science, Google Scholar, Magiran, and SID databases. Obtained articles from the databases were analyzed in order to find the eligible ones.
Results: Overall, 175 articles were found in the initial search, and after removing the duplicates and nonrelevant, 13 eligible articles were included in the study. In most of the studies, the samples were digested with H2O2, and the microplastics were mainly analyzed using a variety of microscopes and µRaman spectroscopy. The abundance of microplastics in the indoor environment was much higher than in the outdoor environment.
Conclusion: The results of this study showed that there is the required equipment for the sampling and analysis of microplastics in air and settled dust in Iran, and these pollutants have been detected in both indoor and outdoor environments.
Faezeh Sadeghi, Sakine Shekoohiyan, Mohsen Heidari,
Volume 17, Issue 2 (9-2024)
Abstract
Background and Objective: The Goharzamin iron mine in Sirjan has the largest iron ore reserves in the Gol Gohar area. This study aimed to assess the life cycle of iron ore extraction from this mine using the Life Cycle Assessment (LCA) method due to the extensive activities in the area and the lack of comprehensive studies.
Materials and Methods: The LCA evaluated the impacts of iron ore extraction from the Goharzamin mine on human health, ecosystem quality, and resource depletion. The boundary system included the drilling and blasting processes. Following the cradle-to-gate model and an attributional approach, the production of 1 ton of iron ore was considered a functional unit. Impact and damage assessment were conducted using SimaPro software and the ReCiPE method at mid and end-point levels.
Results: The findings revealed that transportation by trucks with a capacity exceeding 20 tons accounted for the highest environmental burden in all categories (51.1%), particularly in overburden removal. The detrimental impacts of transportation on ionizing radiation (human health), land use, and freshwater eutrophication potentials (ecosystem quality) exceeded 95%. Carbon-14 emissions, agricultural land occupation, and BOD5 and COD releases resulting from iron ore extraction were identified as the key pollutants in these impact categories. The average damage to human health, ecosystem quality, and resource depletion was found to be 89.8%, 5.5%, and 4.6%, respectively.
Conclusion: To mitigate the negative impacts of transportation, it is advisable to enhance environmental sustainability by utilizing trucks that adhere to Euro 5 standards or higher, as well as exploring the use of renewable energies.
