Iranian Journal of

Background and Objective: The purpose of this study was to use the HELP model to estimate the leachate generation rate and its pattern in a landfill located in the semi-arid region of Iran.
Materials and Methods: The input data for the model were collected through fieldwork. To evaluate the accuracy of outputs, the actual amount of leachate production has been measured on-site for 10 months. In addition, sensitivity analysis was conducted to find out the most important parameters in leachate generation in the landfill.
Results: The results showed that the model was able to estimate the rate of leachate generation with an accuracy of 75.5% and the correlation between the model's estimated values and actual values was 60%. In addition. the sensitivity analysis showed that the most important factors affecting the leachate generation in the landfill were waste moisture content and rainfall, respectively.
Conclusion: The model showed satisfactory performance in the prediction of leachate generation in the arid area. The model showed that the moisture content of the waste significantly contributes to leachate generation in Karaj landfill and therefore, it is suggested to identify and implement procedures to reduce the moisture content of the waste at the source of generation.

Background and Objective: Access to safe water is critical for protecting human health. Turbidity is one of the main physical parameters that affect the quality of water from both health and aesthetical points of view. Therefore, waters should be treated based on the standards set for turbidity before consumption. This study was performed to determine the performance of a bench-scale baffled filter system for removing the turbidity, microbial population, and total organic carbon (TOC) from the contaminated water.
Materials and Methods:  A lab-scale Plexiglas baffled filter consisting of five compartments with a total working volume of 2 L was designed and constructed. The polyurethane foam cubes were used as filter media. The effect of turbidity (10, 50, and 100 NTU) and surface overflow rate (SOR: 7.5, 10 and 15 m/h) was investigated on the performance of the developed system.
Results: A direct relationship between turbidity, TOC, and microbial density was observed in the inlet water. The efficiency of the baffled filter in the removal of turbidity and the period of the filter operation run both enhanced as the SOR was either decreased or the inlet turbidity was increased. In addition, almost complete removal of TOC from the inlet water was noticed.
Conclusion: The results of the present study indicated that the baffled filter system with sponge media can be a novel and effective method for the removal of turbidity, microbial contaminants and TOC from the natural surface water.

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.

Background and Objective: Chlorpyrifos (CPF), an organophosphate pesticide, has been widely used in the agricultural industry and may cause environmental damage. The present study aimed to evaluate the potential application of Fe(VI) and Fe(VI)/PMS processes for oxidation of CPF in water after pretreatment with ferric chloride coagulant.
Materials and Methods: This study was performed in two phases including coagulation and flocculation process and advanced oxidation process (AOP). In the first phase, the coagulation process was performed for turbidity removal by ferric chloride (FeCl₃). In this phase, using a central composite design (CCD) with R software, the combined effect of four variables including initial turbidity, initial pH, coagulant dose and contact time was investigated. The supernatant from this process was transferred to the next phase for further analysis. In the AOP phase, the effect of Fe(VI) and Fe(VI)/PMS oxidants were investigated separately.
Results: In the first phase (coagulation and flocculation), FeCl₃ showed the highest efficiency (95.79%) at alkaline pH (pH=8). In the next phase (AOP), the results showed that the degradation efficiency of Fe(VI)/PMS process was higher compared to sole Fe(VI) process at all pHs. Also, by examining the reaction kinetics, it was found that after the coagulation process by FeCl₃, the removal rate in the Fe(VI)/PMS process is 1.5 times higher than the Fe(VI) process.
Conclusion: Due to the high removal efficiency and higher degradation rate of Fe(VI)/PMS process, this technique can be used as a relatively effective method in removing chlorpyrifos from aqueous solution.
 

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.

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.
 

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.
 

Background and Objective: In this research, considering the importance of the adverse effects of the Covid-19 disease and identifying the environmental factors involved in its outbreak, the effects of environmental factors and compliance with health guidelines on outbreak and mortality of Covid-19 have been evaluated.
Materials and Methods: This research was a descriptive-analytical study on confirmed patients with Covid-19 in Alborz province in 2019. In this study, outbreak rate and death due to Covid-19, compliance with health guidelines, air pollutants concentrations, air pollution indicators, and the meteorological conditions of Alborz province were daily collected for 2019. All data were analyzed in IBM SPSS Statistics v26 software with Pearson, Spearman, Kruskal-Wallis, one-way variance ANOVA analysis tests, and negative binomial regression statistical models.
Results: The results of the regression model showed that in the mortality rate due to Covid-19, the variables of average temperature(p=0.042), humidity(p=0.048), rate of Covid-19 infection(p=0.001), and compliance with health guidelines(p=0.007) are significant. However, in the model of the rate of infection with Covid-19, only compliance with health guidelines(p=0.001) was significant. Pearson's and Spearman's correlation coefficients for infection rate, compliance with health guidelines, wind speed, and concentrations of carbon monoxide, PM_2.5, and SO₂ with the death rate due to corona, were 0.575, -0.411, -0.206, 0.211, 0.114 and -0.158.
Conclusion: The results showed that in addition to compliance with health guidelines, some atmospheric factors and air pollutants also impact the rate of infection and mortality caused by Covid-19.
 

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.
 

Background and Objective: One of the largest sources of methane emissions is landfills, and various models have been developed to predict landfill methane production and emissions. The main goal of this research is to utilize the inverse Gaussian model to estimate g methane greenhouse gas emissions and model it using field data. This study introduces a simple method to estimate the amount of methane emissions based on ambient methane concentrations.
Materials and Methods: In this research, the methane emission rates from landfill were estimated for warm (July) and cold (February) seasons using a sampling campaign from 27 stations and standard inverse Gaussian dispersion equations. Monte Carlo simulation was also employed. To determine the model, an optimization-based method, along with inverse scattering modeling, was utilized to process surface emission monitoring data.
Results: The model results indicated during the cold (February) and warm (July) seasons, the methane emission rates were estimated at 1696.99 and 16.53 g/s, respectively. These findings confirm that the methane production and emission during the cold season were lower than in the warm season, likely due to reduced temperature and bacterial activity.
Conclusion: The method used in this study, the inverse Gaussian dispersion model, can be applied to estimate methane gas emission rates from other landfills. However, it necessitates the permanent recording of data and the use of daily or weekly averages in calculations to mitigate potential errors and enhance the accuracy of modeling.
 

Background and Objective: One of the major challenges in the calcium looping process is the loss of CO₂ capture capacity of calcium-based sorbents during consecutive cycles due to increased sintering mechanism. This article aims to improve the performance of carbonation conversion in different cycles by employing hydration and acidification methods.
Materials and Methods: Following the preparation of both  CaO-based and modified sorbents, scanning electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller analyses were employed to verify the proper preparation of the sorbents and examine their structures. Subsequently, the adsorption performance of different samples was assessed using a thermogravimetric analyzer device .
Results: The results of the carbonation reaction showed that the effective conversion rates for the raw and modified sorbents, employing acidification and hydration methods, at the end of the first cycle were 75%, 86%, and 73%, respectively. By the twentieth cycle, these rates decreased to 24%, 38%, and 26%, respectively. This decline indicates an improvement in the sorbent's capture capacity, attributed to the formation of calcium acetate, resulting in a more stable and porous structure. The findings from utilizing raw limestone sorbents and their modified versions through acidification and hydration techniques demonstrated a decrease in sorbent capture capacity by 69, 58, and 67% across twenty cycles. This highlights the enhanced sorbent stability achieved with the acidification method.
Conclusion: Based on obtained results, acidification method can be considered as one of the most efficient approaches for improving the performance of calcium oxide sorbents.
 

Background and Objective: The increase in waste at integrated urban waste centers, along with the problems and adverse environmental consequences due to their inappropriate establishment have become more apparent. This research was conducted with the aim of determining and investigating environmental pollution in urban waste integration management centers.
Materials and Methods: This research investigated the environmental pollutants in the integrated waste center in Koohak at various distances ranging from 0 to 900 meters. Four main criteria—waste, water pollution, air pollution and sound pollution—were determined, each with 16 sub-criteria. The map of each criterion and sub-criteria were multiplied by the coefficients they received from the weights obtained using the Analytical Network Process (ANP) method. By combining the criteria using the Weighted Linear Combination (WLC) method and superimposing them, finally, the studied area was ultimately classified into three classes: inappropriate, medium, and suitable.
Results: Air pollution, with a weight of 0.26, had the highest rating compared to the other three criteria. Noise pollution (0.25), water pollution (0.24) and waste-related criteria (0.23) were ranked next. The results of the Kruskal-Wallis test indicated a significant difference in pollutant concentrations between different stations (p<0.05). Additionally, the results show that the average concentration of pollutants at distances of 0-300 meters differed significantly from those at all other distances (p<0.05). After determining the suitable zones using the WLC method, the results showed that 62.5 percent of the criteria were approved by the environmental organization.
Conclusion: By examining the results of the methods used in this research, it can be concluded that the combination of ANP and WLC methods provide effectivee results. However, uncertainty in subjective decisions and time constraints in decision-making have posed challenges in assessing waste collection in integrated urban waste centers.
 

Background and Objective: In recent decades, the issue of crop product safety has led to develop methods for analyzing pollutants in crops. In the present study, ultra-trace amounts of lead (II) ions were measured in lettuce and water samples collected from Shahmirzad, located in Semnan province, an area known for its lead-containing mineral mines.
Materials and Methods: After sampling and pre-preparation, the lead content in each sample was extracted using solid phase extraction with modified silica gel. The recovery percentage of lead was then determined using atomic absorption spectroscopy.
Results: Optimization of key parameters such as pH, adsorbent amount, analyte flow rate, and volume resulted in a recovery rate of 104%. The experiments also demonstrated a very low limit of detection (LOD) of 1.14 ng/mL, a concentration factor of 250, high analyte selectivity of the adsorbent in the presence of interfering ions, and a high adsorbent capacity of 2.93 μg/g.
Conclusion: The evaluation of experimental data indicates that the current study provides a highly selective method that can be applied to the extraction and recovery of various analytes from different sample types.