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Showing 18 results for Hadi
Maryam Khodadadi, Alireza Mesdaghinia, Simin Nasseri, Mohammad Taghi Ghaneian, Mohammad Hassan Ehrampoush, Mahdi Hadi,
Volume 3, Issue 2 (Spring, 2016)
Abstract
Background: Data mining (DM) is an approach used in extracting valuable information from environmental processes. This research depicts a DM approach used in extracting some information from influent and effluent wastewater characteristic data of a waste stabilization pond (WSP) in Birjand, a city in Eastern Iran.
Methods: Multiple regression (MR) and neural network (NN) models were examined using influent characteristics (pH, Biochemical oxygen demand [BOD5], temperature, chemical oxygen demand [COD], total suspended solids [TSS], total dissolved solid [TDS], electrical conductivity [EC] and turbidity) as the regression input vectors. Models were adjusted to input attributes, effluent BOD5 (BODout) and COD (CODout). The models performances were estimated by 10-fold external cross-validation. An internal 5-fold cross-validation was also used for the training data set in NN model. The models were compared using regression error characteristic (REC) plot and other statistical measures such as relative absolute error (RAE). Sensitivity analysis was also applied to extract useful knowledge from NN model.
Results: NN models (with RAE = 78.71 ± 1.16 for BODout and 83.67 ± 1.35 for CODout) and MR models (with RAE = 84.40% ± 1.07 for BODout and 88.07 ± 0.80 for CODout) indicate different performances and the former was better (P < 0.05) for the prediction of both effluent BOD5 and COD parameters. For the prediction of CODout the NN model with hidden layer size (H) = 4 and decay factor = 0.75 ± 0.03 presented the best predictive results. For BODout the H and decay factor were found to be 4 and 0.73 ± 0.03, respectively. TDS was found as the most descriptive influent wastewater characteristics for the prediction of the WSP performance. The REC plots confirmed the NN model performance superiority for both BOD and COD effluent prediction.
Conclusion: Modeling the performance of WSP systems using NN models along with sensitivity analysis can offer better understanding on exploring the most significant parameters for the prediction of system performance. The findings of this study could build the foundation for prospective work on the characterization of WSP operations and optimization of their performances with a view to conducting statistical approaches.
Hamid Reza Azimzadeh, Reza Ali Fallahzadeh, Mohammad Taghi Ghaneian, Seyed Ali Almodaresi, Hadi Eslami, Mahmoud Taghavi,
Volume 4, Issue 1 (Winter, 2017)
Abstract
Background: The phenomenon of dust is a serious environmental problem in dry and semi dry regions. It has a destructive effect for the residents of such regions. Over two-thirds of Iran is in areas of dry and semi-dry climate conditions.
Methods: In this research, dust fall measurements were taken in 41 stations across Yazd city using a marble dust collector (MDCO) located in different parts of the city. Next, the chemical characteristics of dust were determined using the XRF method. Finally, levels of dust fall across the 4 seasons of the year and status of the constituent elements of dust were determined through ArcGIS software and the Kriging technique. The Raster calculator function was used to make determinations of the effects of dust fall at each of the stations over the course of the year. Remote sensing system, along with maps taken from Landsat and the band combination technique were processed using ENVI software to extract vegetation density and building density maps of the studied region.
Results: Results showed that spring had the highest level of dust fall with a value of 200 g/cm2. In total, in 109 km2 of the studied region had average dust fall of 110 g/m2 that contributed to 12 057 tons of dust over Yazd city in 2015. The constituent elements of the dust fall according to decreasing amounts were as follows: Si>Ca>Al>C>Mg>Fe>K>Na>S>Ti>Cl>P>Mn>Sr>Zn.
Conclusion: These results indicate accuracy of the Kriging technique for application in dust zoning. The factors of vegetation and green space were determined as effective on adsorbing dust. Increased building density and height of buildings also contributed to development of dust fall.
Mahmoud Zarei, Nader Djafarzadeh, Leila Khadir,
Volume 5, Issue 2 (Spring, 2018)
Abstract
Background: Conserving water for human survival and providing future security are important issues that need to be addressed.
Methods: In this study, a zeolite modified with hexadecyl trimethyl ammonium bromide (HDTMA-Br), a cationic surfactant, and its application in removing direct blue 129 (DB129) was examined. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were used to characterize both modified and unmodified zeolites. The effects of operational parameters such as the amount of adsorbent, initial dye concentration and pH on the removal efficiency of the dye were examined.
Results: The results showed that in the initial dye concentration of 50 mg/L, the optimum amounts of adsorbent and pH were 0.3 g and 7, respectively. Increasing the dye concentration from 20 to 100 mg/L resulted in the reduction of the removal efficiency from 100% to 79% in the contact time of 90 minutes. The results indicated the highest attracting correlation with Langmuir model. The maximum adsorbent capacity obtained from Langmuir model was 25 mg/g. The kinetics of the dye adsorption on the modified zeolite followed pseudo-second-order kinetics model. Calculated thermodynamic parameters showed that Gibbs free energy changes (DGo) at temperatures of 20 and 45°C were -29.41 and -35.20 kJ/mol, respectively.
Enthalpy (DHo) and entropy changes were equal to 41.181 kJ/mol and 0.241 J/mol K, respectively. The results showed that the processing was a spontaneous endothermic reaction. The process modeled by artificial neural networks (ANN) showed that the experimental results can be accurately modeled using neural network model. The correlation coefficient found between the experimental and the model results was 0.951.
Conclusion: Due to the low cost, high abundance and availability of zeolite, the removal efficiency of this adsorbent can be increased to desirable levels by modifying.
Asadollah Karimi, Esmaeil Fatehifar, Reza Alizadeh, Hadi Soltani,
Volume 5, Issue 4 ( Autumn 2018)
Abstract
Background: Spent caustic contains noxious components such as sulfide species and also high chemical oxygen demand content (COD). Oxidation of these materials to caustic and sulfate species is mostly the rate-controlling step within catalytic oxidation of spent caustic.
Methods: In this study, the kinetics of catalytic oxidation of spent caustic and the regeneration methodology of the sulfidic spent caustic were investigated. The kinetics of catalytic oxidation of spent caustic was studied in the presence of a heterogeneous catalyst. The developed mathematical model was verified via the batch bubble column reactor. The elementary and non-elementary models based on the genetic algorithm were
used to obtain the rate coefficient and kinetic order.
Results: The experiments were carried out at various conditions. The results indicated that the error of objective function of the non-elementary and elementary models was 3.01% and 134.96%, respectively.
Conclusion: According to the results, the non-elementary model had rational outcome compared to the elementary one. Also, non-elemental model is more concordance with experimental results.
Fatemeh Davoodi, Mohammad Hadi Naji,
Volume 5, Issue 4 ( Autumn 2018)
Abstract
Background: Due to the adverse effects of artificial preservatives on food and its harmful effects on human health, researchers have been considering replacing these materials with natural substances. In this study, the effect of pomegranate peel extract (PPE) on the stability and antifungal activity of the
walnut kernel was studied.
Methods: The pomegranate peel was extracted by the solvent and water-solvent method. The extracted sap was evaluated using the antioxidant assay by 2,2-diphenylpicrylhydrazyl (DPPH) assay. The results showed that the extracted sap had 40.11 mg/g dry phenol and 47.27% free radicals scavenging. Four
concentrations (0%, 2%, 6%, and 10%) of pomegranate liquid extract were prepared and studied for 90 days for the walnut kernel coating. Walnut kernels were coated on days 1, 15, 30, 60, and 90, and examined for moisture, acidity, peroxide, conjugated diene, and anisidine tests. Data were analyzed
using SPSS version 21.
Results: By increasing the extract concentration from 2 to 10%, the stability of the walnut kernel during storage was increased. Acidity in the samples with 10% PPE coating, decreased from 0.18 to 0.11 on the first day until the 15th day, and increased to 0.48 from day 15 to 90. The results showed that the moisture content and acidity increased with increasing the extract concentration. By increasing the extract concentration up to 10%, the sustainability indices, including peroxide, anisidine, and conjugated diene were significantly decreased. At 90 days, by increasing the concentration of pomegranate extract from 2% to 10%, the count of molds and yeasts was reduced from 3.59 to 2.29 CFU/g. The count of molds and
yeasts in the uncoated samples was 5.81 CFU/g.
Conclusion: According to the results, PPE can increase the stability and antifungal activity of walnut, therefore, the health quality of the product increases.
Hadi Negahdari, Sirus Javadpour, Faramarz Moattar, Hashem Negahdari,
Volume 5, Issue 4 ( Autumn 2018)
Abstract
Background: Today, the effects of environmental pollution on human life and human needs, which reduces the level of community health caused by traffic noise in large cities, are clearly visible by creating irritation and pathogenic conditions. The aim of this study was to assess the risk of noise pollution
resulted from central traffic in Shiraz by analyzing its indicators and related components.
Methods: By specifying the high traffic jam in Shiraz, the sound and its frequency in 156 points of the city were analyzed using a sound analyzer (Tes-1358C model). The sound pressure levels (LA and LP) and the one and one-third octave band were continuously measured in A and C networks. Then, data were extracted and analyzed using Excel 2016 and Minitab 18.1. Eventually, phon and sone indexes were calculated for the heavy traffic jam in some of the central streets of Shiraz and the results were statistically calculated and their charts were prepared with comfort disturbance ranges.
Results: The highest harmful frequency of traffic in Shiraz was 50 Hz and 83.3 dB. The sound pressure level ranged from 70 to 92.7 dB in network A and 87.8 dB in network C. The maximum sound level was 87 phon and the maximum sone was 26 at 14 stations.
Conclusion: According to the results, the sound pressure levels exceeded the environmental standards of Iran and the values of phon and sone were higher than the standard of comfort at night and day.
Abdoliman Amouei, Hourieh Fallah, Hosseinali Asgharnia, Abbas Mousapour, Hadi Parsian, Mahmoud Hajiahmadi, Asieh Khalilpour, Hajar Tabarinia,
Volume 7, Issue 1 (Winter 2020)
Abstract
Background: Nowadays, uncontrolled use of chemical fertilizers in agriculture is one of the reasons for the entry of heavy metals into the environment. In this study, the heavy metals contamination of the soils enriched with compost and chemical fertilizers in the North of Iran and its ecological risk assessment
were evaluated.
Methods: In this study, 108 soil samples were collected from agricultural soils of some places of Babol in Mazandaran province. An atomic absorption spectrophotometer (PG-990) was used to determine the concentrations of lead, cadmium, and zinc in the soil samples. The assessment of soil contamination was performed by the contamination factor, degree of contamination indices, and the potential ecological risk of the heavy metals. Data were analyzed using SPSS version 22. Descriptive and chi-square tests were used to compare the mean with existing standards. Significant level was considered at P < 0.05.
Results: The highest lead concentration (35.7 ± 9.5 mg/kg) was observed at 5-cm depth, and the maximum cadmium (1.1 ± 0.2 mg/kg) and zinc (88 ± 22.6 mg/kg) concentrations were observed at 15-cm depth. The results showed that lead, cadmium, and zinc concentrations in the agricultural soils enriched with compost fertilizers were acceptable, but agricultural soils enriched with chemical fertilizers indicated higher content than those enriched with compost fertilizers and higher than the maximum allowable concentration. The maximum contamination degree, pollution index, and potential ecological risk in the agricultural soils enriched with the chemical fertilizers were 15.77, 1.97, and 293.48, respectively, and these soils had low potential pollution and moderate ecological risks.
Conclusion: According to the results, it is necessary to use compost fertilizers for the agricultural soils enrichment.
Yalda Basim, Ghasemali Mohebali, Sahand Jorfi, Ramin Nabizadeh, Mehdi Ahmadi Moghadam, Ata Ghadiri, Nematollah Jaafarzadeh Haghighi Fard,
Volume 7, Issue 2 ( Spring 2020)
Abstract
Background: Biodegradation of hydrocarbon compounds is a great environmental concern due to their toxic nature and ubiquitous occurrence. In this study, biodegradation potential of oily soils was investigated in an oil field using indigenous bacterial consortium.
Methods: The bacterial strains present in the contaminated and non-contaminated soils were identified via DNA extraction using 16S rDNA gene sequencing during six months. Furthermore, total petroleum hydrocarbons (TPH) were removed from oil-contaminated soils. The TPH values were determined using a gas chromatograph equipped with a flame ionization detector (GC-FID).
Results: The bacterial consortium identified in oil-contaminated soils (case) belonged to the families Halomonadaceae (91.5%) and Bacillaceae (8.5%), which was significantly different from those identified in non-contaminated soils (control) belonging to the families Enterobacteriaceae (84.6%), Paenibacillaceae (6%), and Bacillaceae (9.4%). It was revealed that the diversity of bacterial strains was less in oil-contaminated soils and varied significantly between case and control samples. Indigenous bacterial consortium was used in oil-contaminated soils without need for amplification of
heterogeneous bacteria and the results showed that the identified bacterial strains could be introduced as a sufficient consortium for biodegradation of oil-contaminated soils with similar texture, which is one of the innovative aspects of this research.
Conclusion: An oil-contaminated soil sample with TPH concentration of 1640 mg/kg was subjected to bioremediation during 6 months using indigenous bacterial consortium and a TPH removal efficiency of 28.1% was obtained.
Maryam Meserghani, Mahnaz Nikaeen, Ahmad Jonidi Jafari, Mohammad Hadi Dehghani, Bijan Bina,
Volume 7, Issue 3 ( Summer 2020)
Abstract
Background: Discharging wastewaters containing antibiotic into the environment causes some adverse effects on the human health and other organisms. The present study investigated the efficiency of electropersulfate combined with hydrogen peroxide (H2O2) process as a chemical oxidation in amoxicillin (AMX) degradation.
Methods: Optimization of the significant operational independent variables was explored for removal of AMX. Central composite design (CCD) was employed as a statistical tool for experimental design. High-performance liquid chromatography (HPLC) was used for measuring AMX concentration. The most effective factors of the electro-persulfate and H2O2 on the removal efficiency of AMX such as initial concentration of AMX, initial pH, PS/H2O2 molar ratio, and the current density were measured.
Results: The optimum conditions for electro-persulfate removal efficiency of AMX to reach the degradation efficiency of higher than 95.28 ± 2.64% at reaction time of 60 minutes were obtained at pH = 4.23, AMX concentration = 31.9 mmol/L, current density = 39 mA/cm2, and PS/H2O2 molar ratio = 0.82. AMX degradation was satisfactorily predicted by the quadratic model with high possibility and confidence level of 95%. The quadratic model had high regression coefficients (R2 = 0.9964 and R2 adj = 0.9926), which was totally acceptable. The removal efficiency of AMX reduced from 87.3 ± 6.1 to 25.9 ± 9 as pH increased from 5.5 to 7.
Conclusion: According to the results, the electro-persulfate and H2O2 process can be suggested as the most effective, high efficient, and in-situ chemical oxidation for degradation of AMX.
Fatemeh Yousefi, Gholamreza Asadikaram, Saeid Karamouzian, Moslem Abolhassani, Vahid Moazed, Mohammad Hadi Nematollahi,
Volume 8, Issue 1 (Winter 2021)
Abstract
Background: Alterations in the methylation levels of tumor suppressor genes are considered as one of the essential aspects of malignancies. The present study explored the association of O6-methylguanine- DNA methyltransferase (MGMT) gene promoter methylation, as a tumor suppressor, with some organochlorine pesticides (OCPs) in primary brain tumor (PBT) patients. Methods: The present study was conducted on a total of 73 PBT patients. The patients’ serum was analyzed using gas chromatography for seven OCP derivatives. The methylation-specific PCR (MSP) method was also used to determine the methylation status of the MGMT promoter. Results: The current findings demonstrated that the methylation of MGMT promoter occurred in 22 out of 34 glioma cases (64%), but in only one out of 35 meningioma cases. No MGMT promoter methylation was observed in other PBT, hemangioma, and anaplastic medulloblastoma stages. Besides, there were significant associations between MGMT methylation and γ-HCH (odds ratio [OR]: 1.50; 95% CI: 1.03- 2.40, P= 0.04), 4,4DDE (OR: 1.44; 95% CI: 1.01- 2.05, P= 0.02), 2,4 DDT (OR: 1.23; CI: 1.04- 1.45, P= 0.03), and 4,4DDT (OR: 1.46; CI: 1.23- 2.15, P= 0.02) in glioma patients. Conclusion: The results of the study suggested that the hypermethylation of the MGMT promoter in glioma patients is associated with increased OCPs in their serum, especially γ- HCH, 4,4DDE, 2,4DDT, and 4,4DDT. Moreover, it may lead to the hypermethylation of the MGMT promoter gene. Hence, it can be concluded that exposure to OCPs may potentially induce glioma.
Mohammad Sarmadi, Mehdi Bakhtiyaridovvombaygi, Seyed Mohammad Ahmadi-Soleimani, Hossein Ebrahimipour, Mohammad Reza Rezaiemanesh, Hadi Alizadeh-Siuki, Somaye Barzanouni, Mahdieh Torkzadeh, Mohammadreza Askari, Sajjad Rahimi,
Volume 10, Issue 1 (Winter 2023)
Abstract
Background: Despite the mass vaccination of people in countries, preventive health guidelines of coronavirus disease 2019 (COVID-19) are still one of the most critical factors for pandemic control. The objectives of this study were to assess the overall use of face masks and investigate the diverse kinds of face masks used among pedestrians in northeast Iran.
Methods: This cross-sectional study was designed in Torbat Heydariyeh, northeastern Iran, from February 19 to May 13, 2020. A total of 223 848 pedestrians were selected from 25 points of the city, using a multistage sampling method in 10 stages. Descriptive statistics were presented with frequencies and percentages. Chi-square test and Fisher exact test were used to assess the association between two categorical variables.
Results: The overall percent of face mask usage was 78.68%. Women used face masks considerably higher than men (88.32% vs. 69.02%, P<0.001). Among the male and female pedestrians who used the mask, 6.27% and 2.04% wore face mask incorrectly, respectively. Surgical masks (73.7%) were the most common face masks worn by pedestrians. Overall, the face mask usage was significantly lower during a.m. (88.34%) compared to p.m. (78.52%) (P<0.001). Also, the face mask usage was significantly higher in the center sections of the city (86.49%) compared to the outskirts (43.67%) (P<0.001).
Conclusion: Women use face masks significantly more than men. Using educational programs and establishing laws and regulations to prevent pandemics in cities is considered as a key factor.
Fatemeh Sahlabadi, Akbar Eslami, Nadali Alavi, Mohsen Sadani, Marzieh Torabbeigi, Mahdokht Arshadi,
Volume 10, Issue 1 (Winter 2023)
Abstract
Background: Tetrabrombisphenol A (TBBPA) is one of the major brominated flame retardants (BFRs) used in waste mobile phone printed circuit boards (WMPPCB) that accounts for approximately 60% of the total BFR market.
Methods: The potential of TBBPA removal from WMPPCB leached solution was investigated using micelle-enhanced ultrafiltration (MEUF) in the presence of cationic, anionic, and nonionic surfactants. The efficiency of several parameters including surfactant concentration, transmembrane pressure (TMP), pH, and TBBPA concentration, was evaluated to improve the MEUF. The optimal conditions were used to assess the MEUF for removing TBBPA in a real sample.
Results: The cationic surfactant cetylpyridinium chloride (CPC) showed better performance than other surfactants in removing TBBPA due to its electrostatic interactions with anionic forms of TBBPA. The removal efficiency of TBBPA increased from 48.99% to 99.10% by adding a surfactant (less than the critical micelle concentration). Increasing the pH in the range of 5 to 11 increased the efficiency of TBBPA removal due to the increase in the TBBPA solubility in the micelles. TMP had the most significant effect on permeate flux compared to other parameters but did not significantly affect the TBBPA removal efficiency. The MEUF process effectively removed (above 99%) TBBPA in the concentration range of 20 to 80 mg L-1 under optimal conditions. The HPLC-UV analysis of the real sample indicated the removal efficiency of 100% of TBBPA.
Conclusion: MEUF using CPC is a critical performance technology for removing TBBPA from the leached solution of electronic waste.
Omar Amahmid, Youssef El Guamri, Youness Rakibi, Mohamed Yazidi, Bouchra Razoki, Khadija Kaid Rassou, Hanane Achaq, Safia Basla, Mohamed Amine Zerdeb, Meriyam El Omari, Oulaid Touloun, Saïd Chakiri,
Volume 10, Issue 1 (Winter 2023)
Abstract
Background: Wastewater reuse in agriculture can potentially result in adverse health implications including parasitic diseases spread. Trichuris, Ascaris, and Giardia are major pathogenic parasites of concern associated with this practice. This review investigated their occurrence in wastewater, and environmental components reached through wastewater application, including irrigated soil and grown crops. Exposure pathways and evidence for health risks were also explored.
Methods: Several databases (Google Scholar, PubMed, Science Direct, Scopus, Web of Science, and ResearchGate) and other sites were searched for published literature up to 2021. The searched keywords include wastewater reuse, soil-transmitted helminths (STHs), Ascaris, Trichuris, Giardia, crop contamination, soil contamination, health risk, epidemiological studies, exposure pathways, and risk mitigation. Overall, 160 papers have been yielded. After screening for relevance, 60 studies were considered for inclusion.
Results: Giardia, Ascaris, and Trichuris were frequently detected in wastewater with up to 5 × 105 cysts/L and 5.73 × 103 eggs/L. Concentrations of 750 eggs/100 g and 2.8 × 104 cysts/100 g were reported in wastewater irrigated soil. Ascaris was reported in irrigated crops with up to 70 eggs/kg versus 6.6 × 103 cysts/kg for Giardia, depending on the type of crops. Epidemiological studies provided evidence supporting the increase of ascariasis, trichuriasis, and giardiasis diseases related to the exposure to wastewater irrigated soil and crops.
Conclusion: The findings suggest that wastewater reuse in agriculture leads to contamination of soil, and crops with pathogenic parasites, increasing health risks in the exposed groups. To remedy this issue, protection measures, including a multi-barrier approach, can be applied to mitigate the health risks engendered by wastewater reuse for irrigation.
Nabaa Shakir Hadi,
Volume 11, Issue 1 (Winter 2024)
Abstract
Background: This study examined the effects of the Al-Rustumiya sewage treatment station on the heavy metals (Fe, Zn, and Mn) that pollute the Diyala River.
Methods: Samples of water, sediment, and aquatic vegetation were collected monthly from Diyala River at four locations between March 2022 and February 2023. The samples were collected using standard sampling methods and analyzed with an atomic absorption spectrophotometer.
Results: The order of heavy metals in water was: Fe > Mn > Zn, both in the dissolved and particulate phases. The sediment was ordered in the exchangeable and residual phases: Fe > Mn > Zn, while in aquatic plants, the order in leaves was: Fe > Zn > Mn, and in roots: Zn > Fe > Mn. According to the findings, the particulate phase of water contained greater quantities of heavy metals than the dissolved phase. The sediment concentrations in the residual phase exceeded those in the exchangeable phase, while the roots of aquatic plants had higher concentrations than their leaves.
Conclusion: As Al-Rustumiya station’s streams flow into the river, the concentrations of heavy metals in the water increase. This has a deleterious effect on aquatic life and the agricultural area on both sides that rely on the river’s water for irrigation. This research concentrates on the destiny and processes of
transmission in the lotic aquatic system for heavy metals (Fe, Zn, and Mn). As there is a cumulative effect from these metals, appropriate measures are necessary by the relevant agencies to address this problem.
Habib Ansari Samani, Masumeh Rouzbahani, Hadis Dalvandi, Reza Sadeghi,
Volume 11, Issue 1 (Winter 2024)
Abstract
Background: Despite the detrimental environmental and distributional effects of economic activity in Iran, these effects are not uniform across provinces. Environmental degradation and income inequality are increasing in some provinces of Iran. This study aimed to determine the causal relationship between environmental degradation and income inequality in provinces. It investigates whether environmental degradation is a cause or consequence of income inequality.
Methods: Data were collected from official statistical publications in Iran. Then, two simultaneous regression models were estimated to investigate the causal relationship between environmental degradation and income inequality. Finally, Granger causality tests were performed to verify the results.
Results: The results show a one-way causality from income inequality to environmental degradation, and environmental degradation is not the cause of income inequality. While income inequality leads to environmental degradation, other factors are at play in causing income inequality. Income inequality, per capita gross domestic product (GDP), and industrial structure increase environmental degradation. Energy intensity, education, and environmental government budget reduce environmental degradation. Environmental degradation, education, and per capita GDP negatively impact income inequality, while the environmental protection budget and taxation worsen income inequality.
Conclusion: To reduce environmental pollution and income inequality, policies should be adopted that aim to improve the level of education, increase per capita income, increase the budget for environmental protection, reduce polluting industrial structure, and reduce energy intensity. Also, attention should be paid to better management and improvement of the quality of life in different regions of the country to improve the compatibility of different parts of the society with the environment.
Alyaa Jumaah Hadi, Thamer Ahmed Mohammed, Aida Tayebian,
Volume 11, Issue 3 (Summer 2024)
Abstract
Background: Special attention should be given to the seepage in dams since it may cause failure. Seepage is not considered in the total risk factor calculated using the International Commission of Large Dams (ICOLD), the United States Bureau Reclamation (USBR) while the description of the dam seepage condition is given a weightage in the Brazilian method.
Methods: Haditha Dam, Iraq, was constructed on varying degrees of limestone beds of the Euphrates and Ana formations. Therefore, seepage from the dam should be continuously monitored and accurately measured. In the present study, a methodology was proposed to overcome the problem of inconsistent seepage data. The inconsistent seepage rates can be replaced by the predicted seepage rates obtained from SEEP/W model.
Results: The predicted seepage rates for different water levels in the reservoir of Haditha Dam were found in association (R2 = 0.96). In addition, the value of mean absolute error (MAE) for the model accuracy was found to be 0.0106. According to the Brazilian index, the weightage for the seepage condition of Haditha dam was in the second category and equal to 3.
Conclusion: For Haditha Dam, the seepage data cannot be used in the dam risk assessment since it was inconsistent with gaps, and it can be replaced by the consistent predicted seepage rates predicted by SEEP/W model. Generally, the aging and other dam problems result in increasing seepage rate. This highlights the importance of efficient management that follows resilient monitoring and surveillance programs that ensure dam safety.
Zhila Alimardani, Khadijeh Hajimiri, Fatemeh Jafari, Gholamreza Sadeghi,
Volume 11, Issue 3 (Summer 2024)
Abstract
Background: Nowadays, one of the most serious environmental concerns is the appropriate management and disposal of municipal waste, which can lead to significant environmental consequences. This study aimed to examine the determinants of source waste separation behavior (SWSB) among high school students applying the theory of planned behavior (TPB).
Methods: In this descriptive study that was performed in 2022 via an online survey, 689 questionnaires were completed by students in 10 randomly selected high schools in Abhar, Iran. The data were analyzed by IBM SPSS Amos version 23. To assess the predictive determinants of SWSB, a structural equation model (SEM) was used.
Results: Subjective norm was found to be the best predictor of high school students’ source waste separation (SWS) intention. The TPB had a prediction power of 68% and 74% for predicting waste separation from the source intention and behavior, respectively.
Conclusion: According to the results of this study, subjective norm has the greatest impact on separation intentions (regression weight = 0.550; SE = 0.08; CR = 6.863; and P < 0.0001). Educational administrators are suggested to pay special attention to the role of significant others, such as teachers, parents, and peers in their planning to improve waste separation behavior at the source in schools.
Muliyadi Muliyadi, Purwanto Purwanto, Sri Sumiyati, Hadiyanto Hadiyanto, Sudarno Sudarno, Budiyono Budiyono, Budi Warsito,
Volume 11, Issue 4 ( Autumn 2024)
Abstract
Background: The lack of understanding of how pollutant removal occurs in biofilter reactors and bacterial community dynamics makes this worthy of study. This review explores biofiltration processes, commonly used biofilter types, bacterial community dynamics, and pollutant removal mechanisms in biofilters.
Methods: This review used data from previous studies published on Scopus, EBSCO, and ProQuest, categorized into parameters such as the biofiltration process, types of biofilters, bacterial community dynamics, and pollutant removal mechanisms. The data were narrated, analyzed in a table, and presented in a review.
Results: In the biofilter reactor, microorganisms cover the medium, allowing pollutants to flow through gaps and contact the biofilm layer. As the biofilm thickens, adhesion weakens, leading to new colonies. Submerged-bed biofilters, trickling filters, and packed column aeration and gasification systems effectively remove nutrients from aquatic environments. Biofilter bacterial communities are categorized by filter layer depth, with fast-growing, less specialized communities in the upper layer and more specialized communities in the bottom layer. Pollutant biodegradation depends on various factors such as nutrient availability, oxygen concentration, pH, bioavailability of contaminants, and physical and chemical characteristics of the biomass.
Conclusion: A biofilter reactor uses microorganisms to cover a medium, allowing pollutants to flow through gaps and contact a biofilm layer that degrades organic compounds. Submerged-bed biofilters, trickling filters, and packed column aeration systems can effectively remove pollutants. Biofilter bacterial communities are categorized by filter layer depth, with fast-growing, less specialized communities in the upper layer, and more specialized communities in the bottom layer.
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