Review Paper
Golshan Moradi; Sirus Zinadini; Masoud Rahimi
Abstract
The research on membrane-based filtration technology for water treatment has expanded in recent years. Membrane fouling is a major challenge that decreases the permeability and decreases the lifetime and selectivity of the membrane. Recently, it was found that fouling mitigation and better control of ...
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The research on membrane-based filtration technology for water treatment has expanded in recent years. Membrane fouling is a major challenge that decreases the permeability and decreases the lifetime and selectivity of the membrane. Recently, it was found that fouling mitigation and better control of membrane fouling can be attained under the application of the electric field. This paper provides an overview of the application of the electric field to the filtration process and its antifouling mechanism. Utilization of conductive polymeric membranes and application of electric field in membrane bioreactors are reviewed as well. The presented review demonstrates that the introduction of negative charge into the membrane surface via preparing conductive membranes or applying an external electric field onto the membrane surface suggests several advantages. These are fouling alleviation, better control of membrane fouling, an increase of membrane resistance to cake deposition on the membrane surface, and superior possible applications such as better salt rejection and antibacterial activity.
Review Paper
Ali Hosseinian Naeini
Abstract
It is becoming increasingly evident that numerous nations are teetering on the edge of a crisis induced by environmental issues, posing threats to the well-being of both humans and animals. Diverse factors characterized by vivid hues, like air pollution and fluctuations in water quality, contribute to ...
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It is becoming increasingly evident that numerous nations are teetering on the edge of a crisis induced by environmental issues, posing threats to the well-being of both humans and animals. Diverse factors characterized by vivid hues, like air pollution and fluctuations in water quality, contribute to a multitude of issues and can adversely impact the environment at large. Given the current heightened demand for freshwater reserves, there exists a more urgent necessity to devisepragmatic approaches for treating wastewater. One prospective technique entails the utilization of polymer nanocomposites to avert impurities such as heavy oils, cosmetics, and oil-based paints. These adjuncts leverage state-of-the-art nanotechnologies, such as carbon nanotubes and activated carbon, showcasing significant efficacy in refining water resources. Concurrently, striking a balance between financial viability and environmental benevolence. Moreover, the employment of adsorption methodologies proves to be highly efficacious in decontaminating tainted water reservoirs by eradicating organic pollutants, employing an array of substances as adsorbents for this purpose. Exemplars of thriving adsorbents include dendritic polymers MXenes, which manifest distinctive characteristics like heightened surface area and porosity, coupled with enhanced reusability and structural integrity when amalgamated with polysaccharides. Generally, the application of polymer nanocomposites as adsorbents for organic contaminants holds promising potential in innovating novel, cost-effective techniques for purifying water and shielding against chemical impurities.
Research Paper
Ali Sardar Shahraki; Mahdi Safdari; Ebrahim HamidZadeh; Mawladad Khairi
Abstract
All-inclusive growth in all sectors along with structural reforms in institutions can lead to development. In this regard, the agricultural sector plays a key role in the development of Iran owing to its specific status. The development of the agricultural sector with a sustainability approach can greatly ...
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All-inclusive growth in all sectors along with structural reforms in institutions can lead to development. In this regard, the agricultural sector plays a key role in the development of Iran owing to its specific status. The development of the agricultural sector with a sustainability approach can greatly contribute to the development of other sectors, too. In this respect, Sistan and Baluchestan province has a special role to play in the regional economy due to its specific climatic and geographical conditions for agriculture. Therefore, this research aimed to formulate mechanisms and strategies for the development of sustainable agriculture in this province. The research adopted the gray multi-attribute decision-making technique (GRA) for modeling. Data were collected with a questionnaire filled out by experts and farmers in 2020. Based on this, 5 options and 28 indicators were finalized based on the opinions of expert experts. The software package of MCDMSOLVER.2018 was used for modeling. The results derived from the experts showed that choice taxing resource-intensive and polluting agricultural activities was ranked the top with a final score of 0.8134. Also, the use of cooperative methods and processes in the development and extension of sustainable agricultural activities was ranked second with a score of 0.71. The next ranks were for educating farmers and supporting their membership in sustainable agriculture groups and providing specific research and support services in the field of sustainable agriculture with scores of 0.571 and 0.519, respectively. The lowest ranks were assigned to Adjusting the price of products in the market in favor of healthy and ecological products, encouraging and attracting the cooperation of private and non-governmental national and international institutions in the field of sustainable agriculture, such as FAO or the Global Environment Facility and social security and retirement insurance for farmers with scores of 0.334, 0.333, and 0.298, respectively. The farmers ranked taxing on resource-intensive and polluting agricultural activities and using participatory methods and processes in the development and promotion of sustainable agricultural activities at the top with scores of 0.722 and 0.576, respectively.
Research Paper
Fatemeh Hoveidamanesh; Zahra Beagom Mokhtari-Hosseini; Toktam Shenavaei Zare; Hashem Akhlaghi
Abstract
The existence of arsenic in water is one of the main problems of the world, especially in developing countries. One of the methods suggested for removal of arsenic is the use of adsorbents. In this study, natural Sabzevar zeolite was modified with HDTMA-Br, HCl, NaCl and FeCl3.6H2O for the adsorption ...
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The existence of arsenic in water is one of the main problems of the world, especially in developing countries. One of the methods suggested for removal of arsenic is the use of adsorbents. In this study, natural Sabzevar zeolite was modified with HDTMA-Br, HCl, NaCl and FeCl3.6H2O for the adsorption of arsenic. It was found that zeolite modified with FeCl3.6H2O was best for the removal of arsenic. Contact time (h), pH, zeolite particle size (mesh) and amount of zeolite (g) as the important parameters were optimized by Taguchi method. The optimum values for these parameters were contact time of five h, pH=3, and 100-200 mesh particles. The maximum adsorption capacity of 99.5% was obtained at optimum condition. Reactivation of the modified zeolite using HCl showed that the reactivated zeolite adsorbed 98% of the arsenic, a slight decrease compared to the original material. The presented adsorption process is a green and economical process for removing arsenic from water and contaminated groundwater.
Research Paper
Ahmad Sabzali; Fatemeh Mohammadi; Zeynab Sadghzadeh; Mona Eghbali Gharehbelagh
Abstract
Treatment of pharmaceutical wastewaters, especially compounds resistant to biological degradation, is very important, and various methods have been introduced to treat such wastewaters on a laboratory and experimental scale. A new designed reactor consisting advanced oxidation and activated carbon adsorption ...
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Treatment of pharmaceutical wastewaters, especially compounds resistant to biological degradation, is very important, and various methods have been introduced to treat such wastewaters on a laboratory and experimental scale. A new designed reactor consisting advanced oxidation and activated carbon adsorption was undertaken for treating toxic pharmaceutical wastewater containing p-Nitrochlorobenzene (pNCB) in the pilot scale. During Paracetamol manufacturing some pNCB may be remained without any chemical changes depended on reaction condition. The effluent from reactor may have some concentration of the pNCB, which can cause a lot of problems if discharged directly into the environment. Organic substance and pNCB concentration of the influent and effluent of the reactor was investigated for 30 days in two phases. The first phase of operation included the achievement of stable conditions and the second phase included the survey of removal efficiency by changing the operational parameters. Raw wastewater was entered directly into the reactor through overhead distillation column in process of Paracetamol manufacturing. The wastewater flow ranged from 3.8 to 16 m3/day during two phases. The average efficiencies for the pNCB concentration removal were 99.4 % for the phase I and 98.0% for phase II. COD removal efficiency of 97.8% was achieved for the reactor. Although oxidation process is effective in removing pNCB, but the most effect was related to absorption process. This study demonstrates that application of Simultaneous ozonation and adsorption processes is effective for treating wastewater containing pNCB.
Research Paper
Hossein Shahin; Afshin Eghbalzadeh; Mitra Javan
Abstract
Vertical drops are widely implemented in hydraulic structures such as irrigation canals, wastewater collection systems, and stepped spillways to dissipate flow kinetic energy while enhancing aeration and promoting dissolved oxygen levels. Depending on local topography, these structures serve to reduce ...
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Vertical drops are widely implemented in hydraulic structures such as irrigation canals, wastewater collection systems, and stepped spillways to dissipate flow kinetic energy while enhancing aeration and promoting dissolved oxygen levels. Depending on local topography, these structures serve to reduce the kinetic energy of falling water and to regulate the flow velocity within canals and irrigation networks. In this study, a three-dimensional numerical simulation was performed to investigate the flow pattern over a vertical drop featuring a sudden contraction under various contraction ratios. The simulation employed the RNG k-ε turbulence model in conjunction with the volume of fluid (VOF) method to capture free surface dynamics. The computational model was validated against experimental data, yielding acceptable levels of accuracy based on average percentage error (APE) and root mean square error (RMSE) metrics. Moreover, results indicate that a reduction in the contraction ratio leads to an increase in the falling jet thickness and hydraulic jump height, accompanied by a decrease in the water jet length. These changes promote enhanced energy dissipation, which is critical for reducing the kinetic energy of the flow in hydraulic structures such as irrigation canals, wastewater collection systems, and spillways. The findings suggest that optimizing the contraction ratio is an effective design parameter for improving energy dissipation efficiency and overall hydraulic performance.
Research Paper
Soroush Esmaeili-zadeh; Babak Lashkar-Ara
Abstract
Increased demand for freshwater and climate change effects have shifted focus to water resource management, highlighting the crucial role of dams in addressing supply and demand challenges. One of the primary challenges associated with newly constructed dams is effectively monitoring them during the ...
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Increased demand for freshwater and climate change effects have shifted focus to water resource management, highlighting the crucial role of dams in addressing supply and demand challenges. One of the primary challenges associated with newly constructed dams is effectively monitoring them during the initial phase of impounding. This study investigates the combined performance of the first impoundment period of the Balaroud earth-fill dam concurrently with the final embankment levels of the dam structure. It also explores the simultaneous effects of these factors on the monitoring and stability of the Balaroud dam, providing hydrometric data measurements throughout the process. Analysis of data from the instrumentation located at the critical section of the dam revealed minor variations in the majority of standpipe piezometers and rock piezometers during the initial months of impounding. These variations were exclusively influenced by the embankment of the dam structure. Following the completion of the embankment and the subsequent rise in the reservoir level, the trend of pore water pressure changes has become aligned with fluctuations in the reservoir level. The analysis of data from the embankment piezometer and total pressure cells shows a downward trend in the pore water pressure ratio at the beginning of the impounding phase, which subsequently increased following the completion of the embankment activities and the rise in the reservoir level. During the impounding period, both the maximum pore water pressure ratio and the reliability ratio against liquefaction and internal erosion have remained within permissible and acceptable limits. Additionally, a decreasing trend in the arching ratio was observed in relation to the rising embankment level until its completion. However, as the reservoir level increased and the saturation zone expanded, the arching ratio began to rise again, indicating effective stress transfer within the dam structure despite localized arcing at specific instrumentation points.
Research Paper
Hassan Koohestani; Abolfazl Gohariyan Bajestani
Abstract
Due to the increase in water pollution, especially heavy metals, many ways have been proposed to absorb and remove them. So far, various adsorbents have been used to remove pollutants. Semi-coke, a carbonaceous material, is susceptible to use as an adsorbent due to its unique properties, such as good ...
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Due to the increase in water pollution, especially heavy metals, many ways have been proposed to absorb and remove them. So far, various adsorbents have been used to remove pollutants. Semi-coke, a carbonaceous material, is susceptible to use as an adsorbent due to its unique properties, such as good specific surface area and porosity. Therefore, in this study, it was added to a solution containing lead ions after preparing semi-coke particles. The effect of various parameters such as pH, adsorbent dosage, and contact time on the ability of semi-coke to absorb lead ions was investigated. The results showed that semi-coke has a negative surface charge so that it can absorb small ions on its surface by an electrostatic attraction. The optimal pH values, adsorbent dosage, and contact time were obtained by investigating the results as 5, 2.0 g, and 60 min, respectively. Under optimal conditions, semi-coke could absorb 94 % of lead ions from the solution.
Research Paper
Maryam Hafezparast; Sadaf Gord; Rasool Ghobadian
Abstract
Due to climate change and rising global temperature, the occurrence of extreme floods and drought events has intensified. In this regard, in 2019, heavy rainfall occurred in Kermanshah province. The Gharasoo river runs through the city of Kermanshah in western Iran. The Doab-Qazanchi area is located ...
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Due to climate change and rising global temperature, the occurrence of extreme floods and drought events has intensified. In this regard, in 2019, heavy rainfall occurred in Kermanshah province. The Gharasoo river runs through the city of Kermanshah in western Iran. The Doab-Qazanchi area is located on the Gharasoo River at the crossroads of the Razavar and mereg Rivers to the Gharasoo River and there is no hydrometric station in this area. In this research, floods with different return periods of 2, 5, 20, 50, 100, 200, 500 and 1000 years with Creager and regional flood frequency analysis (RFFA), and the random forest machine learning method using the physical and hydrological characteristics of the surrounding watersheds are predicted. The SCS method was implemented for the flood on 03/04/2019 and it showed that the occurred flood is equivalent to a 25-year flood in this region. The predicted values estimated a lower discharge than the soil conservation service (SCS) method. The random forest (RF) method, as a machine learning method compared to old statistical methods, has a good performance in predicting the flood discharge using the physical and hydrological indicators of the catchment area, and by determining the priority of different features, it predicts the flood discharge well.
Research Paper
Mohsen Pourkhosravani; Fatemeh Jamshidi Gohari
Abstract
The present study aimed to assess the water quality of six selected aqueducts using Schoeller and Wilcox diagrams and GIS, including Khanaman, Ahmadabad Daafeh, Saadatabad, Kourke, Kazemabad and Fadak in Rafsanjan in 2018. For the study, statistics and information on water quality indices such as sodium, ...
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The present study aimed to assess the water quality of six selected aqueducts using Schoeller and Wilcox diagrams and GIS, including Khanaman, Ahmadabad Daafeh, Saadatabad, Kourke, Kazemabad and Fadak in Rafsanjan in 2018. For the study, statistics and information on water quality indices such as sodium, calcium, magnesium, sulfate; bicarbonate, chlorine, electrical conductivity (EC), total hardness (TH), Arsenic, Nitrate, Ph and total dissolved solids (TDS) for 2018 were received from the Kerman Regional Water Organization (KRWO). The most suitable and unsuitable water quality for drinking and agricultural purposes was determined for the aqueducts of Khenaman and Fadak. From obtained results and Schoeller and Wilcox diagrams, Khenaman aqueduct showed good quality that is acceptable for drinking water (C2-S1). Based on the Schoeller and Wilcox diagrams, the water quality of the Fadak aqueduct ranged from "unsuitable" and "completely unsuitable" to "saline water" (C4-S4). Overall, the groundwater in the study area is generally suitable for irrigation and drinking purposes, with some exceptions that require cautious use. However, evaluating groundwater quality remains essential to ensure its safe and sustainable utilization. Utilizing GIS maps for water quality assessment can enhance the efficiency and accuracy of water quality management, and the water quality database can be easily updated for ongoing monitoring.
