Showing 233 results for Co
Reza Kheiri Soltan Ahmadi, Habib Nazarnejad, Farrokh Asadzadeh,
Volume 14, Issue 4 (3-2022)
Abstract
Background and Objective: With the industrialization of communities, population increase and use of surface water, river pollution has been increased by agricultural, industrial pollutants and urban wastewater. Therefore, investigation of river pollution for regional and environmental planning is of great importance. To evaluate surface water pollution, a number of surface water quality indices have been investigated.
Materials and Methods: Iran water quality index for surface water resources (IRWQISC) approach was used to evaluate the water quality of the Mahabadchai river, Iran. Sampling was carried out along the Mahabadchai river based on some criteria such as approximately to drainage areas for landfills/domestic and agricultural effluents.
Results: Pearson correlation coefficient between physical, chemical and microbial parameters of water showed that fecal coliform, BOD, COD, nitrate, ammonium, phosphate, turbidity and total hardness had a significant positive relationship with each other at 99% confidence. According to this index, upstream samples of the river are classified as good, mid-stations relatively good to moderate category, and downstream samples of the river are classified as relatively bad.
Conclusion: Based on the relationship between each variable, fecal coliform, BOD, COD, ammonium, and turbidity were more effective in determining the IRWQISC. Most of the examined variables showed low concentrations in upstream areas of the river while their concentration gradually increased along the river to downstream areas, especially close to urban and industrial districts.
Fatemeh Tabatabaei, Roya Mafigholami, Hamid Moghimi, Sanaz Khoramipour,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: Microplastics can have harmful effects on living things, including humans. These particles have been identified in all water, soil, and food sources. Among these, freshwater resources are more important, because they are considered a water source for humans through drinking water treatment plants (DWTPs). Therefore, this study investigates the performance of Tehran DWTPs in removing these particles.
Materials and Methods: In this study, the performance of three DWTPs in Tehran in removing these particles was investigated. In most studies worldwide, particles larger than 1 µm were examined, but in this study, nanoplastic particles smaller than 1 µm, as well as the effect of the warm and cold seasons of the year on the concentration of these particles were also examined.
Results: According to the results of the study, the amount of micro and nanoplastic particles at the inlet of treatment plants in the warm season of the year was 2569 ± 309 to 3918 ± 425 MP/L, and the output was 1492 ± 32 to 2279 ± 146 MP/L, which indicates an increase in these particles in the warm season. As a result, the studied treatment plants were only able to remove 32.1 to 59.9% of these particles. In addition, using electron microscopy, MPs were classified into three categories in terms of appearance: fiber, fragment, and film. This study completes the knowledge of MPs in this area.
Conclusion: Based on the results of this study, Tehran DWTPs have poor performance in removing these particles.
Asghar Yavari, Mehdi Moradi Nazar, Seyedeh Maryam Sharafi, Amir Hossein Nafez, Meghdad Pirsaheb,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: It is important to determine the quality of the compost to use compost properly. The aim of this study was to determine the effect of mixing ratio of bulking agent on stability and maturity indices in poultry waste compost.
Materials and Methods: Two piles of sawdust mixture with poultry wastes and volume ratios of 1:1 (W1) and 2:1 (W2) were prepared by Windrow method and a pile containing poultry manure was used as control (W0). In order to determine the stability and maturity indices in compost, the most important physicochemical and biological parameters were studied.
Results: The thermophilic phase lasted about 7 weeks for W1 and about 4 weeks for W2. The initial C/N ratios in the W0, W1 and W2 were 27.10, 31.40 and 56.24, respectively, which eventually reached less than 20. The reduction of organic matter in the three piles was 8.30%, 62.59% and 85.53%, respectively. The thermophilic phase caused a sharp decrease in the population of indicator and pathogenic microorganisms in all piles. The highest dehydrogenase activity in W1 pile was 2.95 mgTPF/gDW.h and by decreasing temperature until the last day, its value decreased to 0.29 mgTPF/gDW.h.
Conclusion: The best ratio for mixing sawdust with poultry manure was 1:1 (v:v). Microbial and enzymatic activities are useful parameters for monitoring poultry composting process and determining the rate of compost stability, and the use of this compost in agriculture will improve soil quality.
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.
Azim Rabieimesbah, Soheil Sobhanardakani, Mehrdad Cheraghi, Bahareh Lorestani,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants produced by anthropogenic activities that contaminate all environmental matrices, including soils, and can enter the food chains. Therefore, this study was conducted for the analysis of PAHs compounds content in agricultural soils of Hamedan city, west of Iran, in 2021.
Materials and Methods: a total of 36 surface soil specimens were collected from 12 sampling sites in agricultural soils and after extraction of analytes based on the soxhlet method, the gas chromatography/mass spectrometry (GC–MS) method was used for the determination of PAHs compounds in the samples. Furthermore, soil samples were further analuzed for the amounts of pH, electrical conductivity (EC), and total organic carbon (TOC). Statistical analysis was performed using SPSS software.
Results: Results showed that 16 PAHs (∑16PAHs) total concentrations ranged from 435 to 3292 µg/kg with an average value of 1806 µg/kg. PAHs with higher molecular weight (≥ 4 rings) were dominant in PAHs profiles accounting for 78%. Based on the results, the mean concentrations of all 16 PAHs were lower than MPC established by MHWaS. Furthermore, the mean concentrations of Pyr, B(a)A, Chy, B(b)F, B(k)F, B(a)P, and B(ghi)P were higher than the MPC established by the Iranian Department of Environment.
Conclusion: Based on the results obtained, as the mean contents of some PAHs were higher than the MPC, therefore, periodic monitoring of soil contamination with PAHs is recommended for the environmental and human health aspects.
Seyyed Reza Karimi, Nabiollah Mansouri, Lobat Taghavi, Mazaher Moeinaddini,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: The city of Tehran is always exposed to adverse consequences due to the establishment of various sources of heavy metals. Therefore, the purpose of this study is to identify the types of heavy metals in airborne particles and the origin of heavy metals in the 21st district of Tehran.
Materials and Methods: According to the EPA standard, 5 stations from District 21 of Tehran were selected for sampling. Using the ASTM D4096 method and using a high volume sampling pump, 50 samples of total airborne particles were collected. The samples were transferred to the laboratory and the concentration of heavy metals was measured by ICP-OES. The UNMIX source model was used to identify heavy metal sources.
Results: The average concentration of heavy metals in 1400 is a decreasing trend including Li according to the concentration of heavy metals in the air in the SPECIATE database, the role of light vehicle sources was 47 percent 34 percent on the street and 18 percent at the airport.
Conclusion: The source of light vehicles exhibited the highest share of emissions and the element aluminum showed the highest concentration among heavy metals in Region 21. Therefore, the UNMIX source model can correctly identify index elements and priority sources for contaminant control.
Elham Asrari, Hedieh Deyhim,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: The application of ultraviolet photolysis in the removal of microbial contamination can develop the use of wastewater sources. In this research, the efficiency of UVC-LED for removing Escherichia coli was evaluated in pulsed radiation mode with continuous radiation.
Materials and Methods: In order to conduct this research, 4 UVC-LEDs with a short wavelength of 12 MW were used to produce ultraviolet rays. LEDs create waves with a wavelength of 260-280 nm. The distance between the LED and the plates was considered to be about 0.5 cm, 1 cm, and 2 cm. In order to investigate the effect of discontinuous radiation on UVC-LED performance, 2 Hz and 1 Hz frequency were used. In this case, the power source is connected 2 times and 1 time respectively in every second. The variables of radiation time (t) in seconds, radiation distance (d) in centimeters, and radiation frequency (f) in Hz were used for valuation.
Results: The results showed that in discontinuous irradiation, although the effectiveness increases with the increase of irradiation time, and practically at times higher than 280 seconds, bacteria do not remain in the samples, but the performance of discontinuous irradiation compared to continuous irradiation in removing bacteria at irradiation intervals of 1 cm, 0.5 cm and time 20 s has only achieved logarithm 4 or in other words 99.99% removal, which is considered the weakest performance of continuous radiation. Also, in the discontinuous radiation mode, after 280 s time and 2 cm distance, the radiation performance towards the complete removal of bacteria is equal to the logarithm of 6 or 99.999%, which is equal to the amount of bacteria removal in continuous radiation.
Conclusion: The efficiency of pulsed radiation was greater as compared to continuous radiation.
Pegah Gheshlaghi, Ehsan Kamrani, Abolfazl Naji, Moslem Daliri,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: Nowadays, the demand for seawater desalination plants (SDPs) has risen worldwide. However, there is a lack of knowledge on the effects of discharging the SDPs brines into the Persian Gulf marine environment and its aquatics health. Therefore, this research was performed to examine the effects of SDPs brines discharged from this facility in the ecosystem of the Persian Gulf on survival and electrolytes in the Blue swimmer crab, Portunus segnis (Forskal,1775) under laboratory conditions.
Materials and Methods: Brines of two types of active SDPs in Hormozgan were collected; then,75 crabs of (P.segnis), with mean (±SD) carapace width of 9.71±2.18 cm and total weight of 61.22±1.04 g, were collected and transported to the laboratory from the Bandar Abbas coast. As a completely randomized design, the samples were tested in 5 treatments (with three repetitions). Mortality was recorded, and at the end of the experimental period (60 days),the level of some electrolytes of the hemolymph (sodium, calcium, magnesium, and potassium) was measured.
Results: Crabs' survival percentage in treatments containing SDPs effluent decreased compared to control (86%), which was more evident in RO 100% and MED 100% treatments with 46.7% and 40%, respectively (p <0.01). The examined electrolyte levels in treatments containing SDPs brine increased compared to control, which were more significant for RO 100% and MED 100% treatments (p <0.01).
Conclusion: This study showed that the SDPs brines would have physiological consequences on aquatic organisms. In nature, the synergy of SDPs effluents with other sources of ecological stress will have severe impacts. Therefore, the necessary regulations and actions should be taken to minimize the environmental effects of SDPs.
Zohreh Akbari Jonoush, Abbas Rezaee, Ali Ghaffarinejad,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: This study aimed to provide an effective electro-catalytic system for the simultaneous reduction of nitrate and disinfection of contaminated water by the electro-catalytic performance of Ni-Fe/Fe3O4 cathode.
Materials and Methods: At first, the Ni-Fe electrode was synthesized by the electro-deposition process. Then its physical properties were analyzed by scanning electron microscopy (FESEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, and photoelectron X-ray spectroscopy (XPS). Simultaneous disinfection and reduction of nitrate were performed under the following conditions: 15 mg Fe3O4 nanoparticles, pH 6.5, NaCl 10 mM, 50 mg/L nitrate, 105 CFU/mL and current density 4 mA/cm2.
Results: According to the results obtained in the absence of nitrate, 100 % of Escherichia coli bacteria were disinfected after 12 minutes. In the presence of nitrate, the time of complete disinfection increased to 120 minutes. In the absence of bacteria, 83% of nitrate was removed in 240 minutes, and in the presence of bacteria, the nitrate reduction efficiency increased slightly to 88%. In the nitrate reduction process, nitrite (0.22 mg/L) and ammonium (3.6 mg/L) were produced. In the presence of bacteria, the amounts of nitrite and ammonium produced increased to 0.42 mg/L and 7.3 mg/L.
Conclusion: The results show the outstanding ability of Ni-Fe/Fe3O4 electrode in electro-catalytic reduction of nitrate and disinfection of contaminated water separately and simultaneously with high efficiency and high selectivity to nitrogen.
Parisa Mohammad Hosseini,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: Due to the negative effects of municipal waste, the need for proper management and selection of appropriate solutions to minimize these effects is strongly felt. One of the methods of recycling waste is preparing compost from organic materials. The purpose of this study is to evaluate the environmental impacts of the two options of implementation and non-implementation of the Karaj compost plant project.
Materials and Methods: Based on the obtained results, the project implementation was determined by gaining more points (0.181) in terms of sustainability and having the least destructive environmental effects, and the project was not implemented by gaining more points (-0.155) in terms of sustainability and having more environmentally destructive effects.
Results: Based on the obtained results, the first option (project implementation) was determined as the best option by gaining more points (0.181) in terms of sustainability and having the least destructive environmental Impacts and the second option (non-implementation of the project) was determined with a lower score (-0.155) in terms of sustainability and more environmental damage than the first option.
Conclusion: According to the research findings, the results of the rapid impact assessment matrix and sustainability model are consistent in confirming the superiority of compost plant performance over non-implementation.
Zohreh Naderi, Hiwa Hossaini, Meghdad Pirsaheb, Akbar Barzegar, Sara Kianpour,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: Toluene is one of the most important volatile organic compounds that threaten human health and introduce many environmental problems. Therefore, the present study aims to determine the performance of a biofilter based on pine cones/compost to remove toluene vapors from polluted air streams.
Materials and Methods: In this research, a biofilter with a volume of 19.468 L was designed and built. The biofilter bed consisted of two parts 26 cm in height and packed with a mixture of compost and pine cones in 1:1 volumetric ratio. After inoculating the bed with sludge from a municipal wastewater treatment plant and making it compatible with toluene, the performance of the biofilter in different parts of the bed was investigated at the inlet toluene concentrations of 2.5-5.5 g/m3 and Empty Bed Retention Times (EBRTs) of 1.3, 1.7, and 2.43 min. Also, the results were analyzed statistically.
Results: At EBRT of 2.43 min and different inlet toluene concentrations of 2.5-5.5 g/m3, the removal efficiency reached 100 percent. Also, the removal efficiency decreased with the reduction of EBRT. The results showed that removal efficiency was higher in the first part of the biofilter bed relate to the second part. At an inlet toluene concentration of 2.62 g/m3 and EBRT of 1.7 min, the maximum elimination capacity (ECmax) of 2.74 g/m3.min was obtained.
Conclusion: In all experimental conditions the outlet concentration of pine-cone/compost biofilter was below the WHO standard (260 µg/m3). Also, the high elimination capacity of biofilter verified its capability toward toluene removal from polluted gas streams.
Hedieh Chorom, Nabiollah Mansouri, Mohammad Hassan Behzadi,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: This study aims to develop a quantitative model for the performance evaluation of urban green buildings using exploratory and confirmatory factor analysis.
Materials and Methods: Criteria and sub-criteria related to green building were collected, then to content validity and reliability of the primary questionnaire were confirmed by a panel of 11 experts. The final questionnaire with 8 main criteria and 26 sub-criteria was provided to 295 green building users to model the performance of the green buildings. Content validity and Cronbach's alpha were used for validity and reliability of the initial questionnaire, Expletory Factor Analysis was employed to identify factor structure and Confirmatory Factor Analysis was utilized to examine factor loadings and goodness of fit.
Results: The final questionnaire included 8 main criteria and 26 secondary criteria. The internal consistency of the test was adequate (alpha>0.6); the chi-square test for EFI analysis was equal to 0.09 and RMSEA<0.05 and the CFI index was equal to =0.98.
Conclusion: The results showed the designed 8-factor model could predict the impact of green building performance by 81.64%. EFI and CFI analysis confirmed the fitting of the model too.
Zahra Lotfi,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants with teratogenic, mutagenic and carcinogenic potential, which can pose potential risks to the environment and human health. Therefore, this study was conducted for the analysis of PAHs compounds content in surface soil samples of the disposal site of the wastes resulting from the activity of oil refining units (Nuruddin Abad, Garmsar) in 2022.
Materials and Methods: In this research, surface soil samples were collected from 8 sampling sites in the study area. After the extraction of analytes based on the soxhlet method, the gas chromatography/flame ionization detector (GC-FID) method was used for the determination of PAHs compounds in the samples. Statistical analysis was performed using SPSS software.
Results: The results showed that the concentrations of Naphthalene (Nap), Acenaphthene (Ace), Benzo[b]fluoranthene (BbF), Dibenz[a,h]anthracen (DBA), Benzo[g,h,i]perylene (BP) and Indeno[1,2,3‐c,d]pyren (Ind) were less than the quantification limit of the measurement method <0.01 mg/kg. total concentrations of 16 PAHs compounds ranged from 56.55 to 92.06 mg/kg.
Conclusion: The results showed that the concentrations of Acenaphthylene (Acy), Fluorene (Flu), Phenanthrene (Phen), Anthracene (Ant), Fluoranthene (Flt), Pyrene (Pyr), Chrysene (Chr), Benz[a]anthracene (BaA), Benzo[k]fluoranthene (BkF), Benzo[a]pyrene (BaP) were higher than MPC established by the Iranian Department of Environment. Also, the concentrations of Acy, Flu, Phen, Ant, Pyr, Chr, BaA, BkF, and BaP were higher than MPC established by MHWS. As the mean contents of some PAHs were higher than the MPC, therefore, periodic monitoring of soil contamination with PAHs is recommended for the environmental and human health aspects.
Arezoo Mahmoudi, Seyyed Alireza Mousavi, Danial Nayeri, Parastoo Darvishi,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: The consequence of using coagulant materials such as aluminum sulfate and ferric chloride in the coagulation unit of conventional water treatment plants can generate plenty of sludge that contains large amounts of coagulant, which in addition to environmental risks, will also possess disposal costs. Today, intending to preserve the environment and reduce treatment costs, researchers emphasize the recovery and reuse of coagulants from sludge. In this regard, the present study was proposed and implemented to recover and reuse water treatment plant sludge as a low-cost coagulant in wastewater treatment.
Materials and Methods: This research is an experimental-laboratory study. In order to recover the coagulant from the collected sludge, acid hydrolysis method was used. The physicochemical characteristics of the recovered sludge were also determined using FTIR, FE-SEM, and BET analysis. Moreover, the efficiency of recovered sludge in different doses (50 to 300 mg/L) on wastewater treatability in terms of COD, TSS, VSS, turbidity, phosphorus, and coliform indices was compared with aluminum sulfate, ferric chloride coagulants, also the results of the study were analyzed and presented using Excel software (version, 2016).
Results: According to the results, the prepared sludge had no crystalline structure with amorphous morphology. In addition, recovered coagulant from water treatment sludge has demonstrated high efficiency for wastewater treatment, so 66.6%, 82.49%, 79.66%, 80%, 65 %, 99.18% of COD, turbidity, TSS, VSS, phosphorus, total coliform were removed at the highest dosage of recovered coagulant (300 mg/L), respectively. Furthermore, the recovered coagulant dosage had a significant effect on the performance of the coagulation and flocculation process in wastewater treatment.
Conclusion: The results showed that recovered coagulant from the sludge of the water treatment plant can be considered an acceptable option with appropriate effectiveness in the wastewater treatment processes.
Maryam Delfani, Maryam Mohammadi Rouzbahani, Nasrin Choobkar, Noushin Salimi,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: Today, oil and gas industries are important resources for obtaining energy and income. During the production of oil and gas, very complex compounds that include organic and inorganic substances, petroleum hydrocarbons and aromatic and aliphatic compounds are transferred to the environment. benzene, toluene, ethylbenzene and xylenes, which are called BTEX for short, are very important monoaromatic pollutants. Therefore, the present study was conducted to investigate the effect of exposure to BTEX on some clinical factors of the exposed people in the oil warehouse and office workers in Kermanshah National Oil Products Distribution Company.
Materials and Methods: This cross-sectional study was conducted in 2018. The samples of this study include the personnel working in the oil warehouse and the office staff of the National Oil Products Distribution Company in Kermanshah. After completing the demographic information of the participants in terms of the inclusion criteria and after collecting the results of the physiological tests of the employees, SPSS19 software was used for statistical analysis.
Results: The results of the present study showed that the spirometric indices decreased in the workers exposed to BTEX compounds, but it was not statistically significant. Also, the number of red blood cells (6.73%) was significantly lower in non-administrative employees, as well as red white blood cells (6.61%), SGOT (10.14%) and SGPT (5.09%) in non-administrative employees. It has been more.
Conclusion: The number of platelets was higher in office workers. Considering the dangers of BTEX pollution for human health, it is recommended to use preventive measures such as using a special mask and a shift work system.
Fariba Ebrahimi Fini, Farzam Babaei Semiromi, Mohammad Reza Tabesh, Mahdi Jalili Ghazizade, Amir Hushang Heidari,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: The critical step of policymaking and planning for the local governments to select appropriate waste management methods, is comprehensive information on solid waste generation. Waste generation rate and composition may vary from year to year because many factors influence it. This research identified the most important factors influencing the future of household waste generation and composition in Tehran, and how these factors affect each other.
Materials and Methods: This research is based on future studies methods which are carried out using a combination of quantitative and qualitative models. Due to the nature of this research, structural analysis, Micmac software and Delphi survey were used.
Results: In this regard, after holding many meetings with 22 of the experts as the statistical population of the research, 14 effective factors were identified. The influential factors were then analyzed in the framework of the Cross-impact matrix in the Micmac software. The results showed that what can be understood from the state of the dispersion page of the variables indicated the system instability, with most of the variables dispersed around the diagonal axis of the screen.
Conclusion: Finally, considering the high scores received by direct and indirect influences, 10 key factors were identified. “Economic Growth”, “Digital Transformation and Technological Advances”, “Amendment of Existing laws, Enactment and Implementation of New and Specialized Laws”, and “Increased Awareness about waste and Attraction of Citizen Participation through Education and Provision of Information” were identified among these 10 factors as the driving forces influencing generation and composition, of household waste in Tehran in the Next Twenty Years.
Mohsen Ansari, Mahdi Farzadkia,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: Today, the issue of health aspects in urban waste management, especially recycling, has received a lot of attention during Covid-19 around the world. Therefore, the purpose of this research is to investigate the knowledge, attitude, and performance of workers of one of the waste recycling centers in Tehran metropolis regarding health aspects during the spread of Covid-19.
Materials and Methods: This was a descriptive-analytical cross-sectional study and the study population was all workers working in one of the recycling centers of Tehran Municipality. The data collection tool was a researcher-made questionnaire with validity and reliability in four sections: demographic, knowledge, attitude, and practice of workers toward Covid-19 and solid waste.
Results: Findings of the study showed that the highest number of workers employed were in the age group of 20 to 40 years (60 percent). The level of knowledge was about 80 percent and the lack of awareness was 20 percent. The level of workers' positive attitude, negative attitude, and lack of attitude were 79.71, 14.56, and 5.72 percent, respectively. The level of positive practice among workers was about 67.43 percent and the negative practice was 32.57 percent.
Conclusion: The results clarified that in order to succeed in waste management programs in recycling centers, municipal waste managers should pay more attention to educational aspects, especially through the focus on programs and their development and adaptation for different age groups, especially 20 to 40 years.
Hamid Kariab, Mohammad Mehdi Emamjomeh, Sheida Zakariaie,
Volume 15, Issue 4 (3-2023)
Abstract
Background and Objective: Due to the presence of heavy metals (HMs), sludge produced in industrial wastewater treatment plants (WWPT) is classified as special waste and can cause adverse health effects. The present study aimed to identify special wastes and assess the risk associated with the presence of HMs in the sludge of WWTP from an Industrial City.
Materials and Methods: Identifying the special wastes was conducted using a checklist, and classification was performed in accordance with the Basel Convention. Ecological risk assessment was done by determining the geo-accumulation and ecological indexes. The estimation of health risk was done by determining HQ and ELCR indexes.
Results: The highest amount of special waste was allocated to sludge with a value of 3900.0 kg/month. Chromium was detected in the highest concentration (95.89 ± 52.15 mg/kg). The level of chromium and nickel pollution was evaluated in the low range, and cadmium was very severe. The ecological risk of lead was estimated in a significant range and was very high for cadmium. The HQ was less than 1, and the ELCR for inhalation and dermal exposure was estimated to be lower than the acceptable risk level of WHO.
Conclusion: The present study showed that the largest amount of special waste is dedicated to sludge. Although the concentration of HMs was lower than the acceptable limits, the sludge had a high ecological risk level. Therefore, the accumulation and transfer of sludge must be carried out under the provisions of the Basel Convention and environmental considerations.
Anasheh Mardiroosi, Hanieh Fakhri, Ali Esrafili, Masoumeh Hasham Firooz, Mahdi Farzadkia,
Volume 15, Issue 4 (3-2023)
Abstract
Background and Objective: Pharmaceutical compounds can cause potential risks to aquatic and terrestrial organisms. So far, different methods have been used to eliminate these pollutants, photocatalytic processes are one of the most efficient processes to eliminate pharmaceutical compounds. In this study, the efficiency of a novel MOF-based nanocomposite, PMo/UiO-66 as a photocatalyst for amoxicillin degradation under visible light irradiation was evaluated.
Materials and Methods: The study of the chemical decomposition of amoxicillin using the PMo/UiO-66 system was conducted at different stages. First, the PMo/UiO-66 MOF nanocomposite was synthesized using the solvothermal method, then the properties of the synthesized nanocomposite were investigated using XRD, FTIR, and SEM techniques. The effect of different operational parameters such as pH (3, 6, and 9), catalyst concentration (15, 20, 25, and 30 %w/w), initial concentrations of amoxicillin (20, 30, 40, and 50 mg/L) at different times on the removal efficiency was investigated. The reusability of the catalyst for four cycles was assessed.
Results: The results showed that PMo/UiO-66 nanocomposite at pH 6, 25 %w/w nanocomposite concentration, and the amoxicillin concentration of 20 mg/L led to complete decomposition of amoxicillin after 120 min. The kinetic of amoxicillin removal followed the first-order model. Reusability tests showed that the photocatalytic efficiency of the synthesized catalyst was not substantially reduced after four cycles.
Conclusion: The current study confirmed that the PMo/UiO-66 system has an appropriate efficiency for photocatalytic removal of amoxicillin under optimized test conditions.
Mohadeseh Bodaghi, Tayebeh Rasolevandi, Amir Hossein Mahvi, Hossein Azarpira,
Volume 15, Issue 4 (3-2023)
Abstract
Background and Objective: Due to the presence of infectious diseases and parasitic contamination in kindergartens, it is very important to observe the health points in these centers. This cross-sectional analytical study was conducted to investigate the environmental health status of Saveh kindergartens in 2020.
Materials and Methods: A checklist with 133 questions was designed, including 57 questions specific to the conditions of the coronavirus, taken from the instructions for the second step of the fight against the coronavirus and 76 questions from regulation 150/920318. All active kindergartens (9 cases) in the study were included, and the answers to the questions as yes, no, and not applicable were recorded and using SPSS software, independent T, chi-square, and one-way ANOVA was analyzed.
Results: The results obtained from the analysis of the checklist showed that the compliance of the health status of all kinds of kindergartens with the regulations of 150/920318 has a percentage of total desirability that includes personal hygiene (81/4%), food hygiene (63%), tools and equipment hygiene (66/5%), building hygiene (78%), health education (90%), considerations regarding disinfectants and disinfectants based on alcohol (92%) and considerations regarding bleaches (94%). There was no significant relationship between the per capita of each child and the different items on the checklist (p>0/05).
Conclusion: This study showed that the general environmental health status of kindergartens in Saveh was favorable and only two variables of hygiene of tools and equipment (66/5%) and food hygiene (63%) were the least desirable among the studied factors that should be considered.
