علي اشرف درخشان

   In recent years, microbial fuel cells (MFCs) have attracted considerable attention as promising technologies for simultaneous wastewater treatment and bioelectricity generation. However, the performance of proton exchange membranes (PEMs), as one of the key components of MFC systems, is still limited by challenges such as oxygen crossover, low proton conductivity, and high internal resistance. In the present study, eucalyptus plant extract was utilized as an environmentally friendly bio-based additive for the modification of sulfonated polyether sulfone (SPES) membranes in order to improve their physicochemical and electrochemical performance in MFCs. For this purpose, SPES membranes containing different concentrations of eucalyptus extract (EE) including 0.5, 1, and 1.5 wt% were fabricated and compared with the bare membrane. Various characterization techniques including FTIR, ATR-FTIR, SEM, water uptake (WU), cation exchange capacity (CEC), water contact angle (WCA), dissolved oxygen (DO) analysis were employed to investigate membrane properties. Furthermore, electrochemical performance was evaluated using polarization curves, power density (PD), current density (CD), COD removal, and coulombic efficiency (CE). FTIR and ATR-FTIR analyses confirmed the successful incorporation of EE into the membrane structure. SEM images revealed that the modified membranes exhibited more compact and homogeneous morphologies compared to the bare membrane. In addition, incorporation of EE enhanced membrane hydrophilicity, improved CEC, and reduced oxygen crossover. Among all fabricated membranes, the membrane containing 1 wt% EE exhibited the best overall performance. This membrane achieved the highest PD of 193.4 mW m?² and maximum CD of 716.2 mA m?². Moreover, the highest COD removal (89.16%) and CE (76.11%) were also obtained for this membrane. The enhanced performance can be attributed to improved hydrophilicity, enhanced proton tra  ort capability, higher CEC, and lower oxygen permeability. Overall, the obtained results demonstrated that EE can effectively improve the performance of SPES membranes for MFC applications and provides a promising approach for the development of sustainable and environmentally friendly PEMs.   

In this study, the adsorption–desorption behavior of the metal–organic frameworK MIL-101(Cr) and its ionic liquid-modified samples was analytically investigated. >  

   Abstract: Pollution of water resources from industrial wastewater containing persistent organic compounds has become a serious environmental challenge. Conventional treatment methods and common polymer membranes such as polyether sulfone (PES) face problems such as fouling and limited efficiency in removing persistent pollutants. This research aimed to prepare a novel photocatalytic membrane through surface modification with superior performance and self-cleaning properties. In this regard, the surface of polyether sulfone membranes was coated using TiO?-chlorophyll photocatalytic nanoclay to overcome the limitation of TiO? activity in the ultraviolet region and to use visible sunlight for its activation. In this study, TiO?-chlorophyll nanoclay was first synthesized chemically. Then, the surface of PES-based membranes was modified using aqueous suspensions containing different proportions (0.01 to 0.03 wt%) of this nanoclay through coating. The characterization of the nanocomposite and modified membranes was performed using Fourier transform infrared (FTIR), emission reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The performance of the membranes was evaluated in terms of pure water flux, pollutant removal efficiency (direct dye), fouling resistance, and reusability. The results showed that surface modification with nanoclay caused a shift in the optical absorption band of TiO? from 380 to about 480 nm and a significant increase in the hydrophilicity of the membrane surface (a decrease in the contact angle from 74 to 54 degrees). The optimized membrane (M-0.02) with 0.02 wt% nanoclay increased the pure water flux from 17.7 to 50.8 L/m²·h, and the direct dye removal efficiency under visible light reached 93%, while this efficiency was only 64% in the dark. This difference indicates a significant contribution of photocatalysis to the removal process. The membrane also showed a flux recovery ratio (FRR) of over 85%, indicating its excellent self-cleaning property. The results of stability tests also indicated the stable performance of the photocatalytic layer in successive use cycles. Overall, the results of this study indicate that the surface modification of PES membrane with TiO?-chlorophyll nanoclay is a sustainable, biocompatible and efficient solution for the effective treatment of industrial wastewater, especially dye-bearing wastewater.   

Polymeric nanofiltration membranes have shown significant efficacy in rejecting heavy metals from wastewater. However, fouling remains a key challenge, leading to a decline in the performance of these membranes. This research is dedicated to the modification of polyacrylonitrile (PAN) nanofiltration membranes using the deep eutectic solvent L-menthol:ethylene glycol with the aim of reducing fouling and increasing the membrane’s permeate flux. The presence of hydrophilic functional groups was confirmed using Fourier-Transform Infrared Spectroscopy (FT-IR) analysis of the Deep Eutectic Solvent (DES) and the resulting modified membranes. Scanning Electron Microscopy (SEM) imaging and Energy-Dispersive X-ray Spectroscopy (EDX) were employed to investigate the morphology, porosity, pore size distribution, and water contact angle. The modified membranes exhibited a lower water droplet contact angle compared to the pristine membrane due to the hydrophilicity imparted by the nanoparticles, decreasing from 87.6 degree for the pristine membrane to 69.2 degree for the modified membrane containing 0.3% nanoparticles. Furthermore, the pore size in these membranes significantly increased, which consequently led to an improvement in membrane flux. The PAN/DES0.3 membrane modified with 0.3% w/w of the Deep Eutectic Solvent (DES) demonstrated the highest flux, recovery rate, and lowest fouling propensity. The modified PAN membrane showed the highest heavy metal ion rejection rates, achieving 98.11% for Pb2+ and 96.43% for Mn2+. Conversely, the lowest rejection rates for the same metals were observed in the unmodified PAN/DES0.3 membrane, measuring 38.82% and 36.1% for Pb2+ and Mn2+ , respectively. Consequently, the modified PAN membranes demonstrated heavy metal rejection exceeding 96%   

I sincerely thank God, Merciful and Almighty, for the divine guidance and i  iration that enabled me to pursue this path and reach this academic level. I sincerely thank my supervisors, Prof Ali Akbar Zinatizadeh, and Dr. Sirus Zinadini, as well as my advisers, Dr. Sara Ivani, and Dr. Mehdi Khiadani, for their invaluable support and insightful recommendations throughout this project, which significantly contributed to its success. I sincerely thank the referees for their thorough review of this thesis and my supportive friends and colleagues for the enjoyable moments we shared. It is worth mentioning that the completion of this thesis owes to the knowledge, patience, and extraordinary attention of these magnanimous professors, and I once again thank them. And I am thanking God for putting these magnanimous professors on the path to completion of this project. And in the end, I sincerely appreciate my parents for their massive support at all stages of life.      

   حذف همزمان كربن و مواد مغذي (CNP) در يك بيوراكتور واحد از نظر حجم راكتور و مصرف انرژي از اهميت بالايي برخوردار است.از اين رو، در اين مطالعه، دو راكتور زيستي لجن فعال (AS) و لجن فعال با رشد چسبيده ثابت (IFAS) با پيكر­بندي تقسيم بندي شده، جهت حذف همزمان كربن و مواد مغذي از پساب سنتزي رب گوجه فرنگي و در نهايت مقايسه عملكرد دو راكتور مذكور به كار گرفته شد. در اين مطالعه تأثير دو متغير مستقل بر عملكرد بيوراكتورها مورد بررسي قرار گرفت. براي ارزيابي عملكرد فرآيند هشت پاسخ مختلف در طول 13 اجرا در شرايط آزمايشي مختلف طراحي شده توسط نرم افزار Design Expert Software ارزيابي شد. تأثير دو متغير مستقل شامل زمان ماند هيدروليك   (HRT)، سرعت جريان هوا (AFR) بر عملكرد بيوراكتور از نظر حذف اكسيژن محلول شيميايي (COD)، حذف نيتروژن كل (TN)، پساب   -NO3، حذف N-NH4 و كدورت پساب بررسي شد. HRT هاي 4، 8, 12 ساعت و AFR هاي 2، 3 و 4 ليتر در دقيقه براي مدل­سازي عملكرد بيوراكتور مورد بررسي قرار گرفت. بازده حذف PO4،   COD، TN وN-NH   در شرايط بهينه با HRT 12ساعت و AFR 3 ليتر در دقيقه براي راكتور AS به ترتيب17.89 و   92.94 و 50.069 و 50.423درصد بود كه اين بازده حذف در راكتور IFAS به ترتيب88.91 و98.85 و40.75 و30.97 درصد بود. براي بررسي پايداري عملكرد دو راكتور مذكور تحت شرايط بهينه به‌دست ‌آمده هر دو راكتور به مدت يك ماه مورد بررسي قرار گرفتند، كه بيوراكتورها عملكرد تقريباً پايداري از خود نشان دادند. نتايج نشان داد كه راندمان حذف COD در هردو راكتور به دليل ساختار منحصر به فرد راكتور مورد استفاده بالاي 90 درصد بود، در حالي كه حذف مواد مغذي تابع شرايط آزمايش بود. با بررسي كلي نتايج به دست آمده مي­توان نتيجه گرفت كه اولا ساختار منحصر به فرد راكتور مورد استفاده نقطه قوت اصلي اين مطالعه است كه سبب بالا بردن كارايي هردو حالت راكتور شد. ثانيا از مقايسه كلي داده­ها نتيجه گرفت كه علاوه بر ثابت بودن شرايط حاكم بر هردو راكتور و كارايي بالاي هردو، مي­توان با اختلافي چشمگير به برتري نسبي راكتور IFAS اذعان داشت.   

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  The main goal of this thesis is to prepare

   Water is a vital resource for humans, both for consumption and the production of goods. Today, with the rapid development of industries, water pollution caused by heavy metals has become one of the most significant environmental problems and a key goal of wastewater treatment. Among the methods for water purification, membrane filtration has garnered considerable attention. In this study, we conducted the fabrication and investigation of polyethersulfone-based nanocomposite membranes using the phase inversion process, incorporating graphite carbon nitride nanoparticles and nanoparticles functionalized with salicyl aldehyde, indigo, and indigo carmine. This study aims to examine the impact of adding nanoparticles on heavy metal removal and anti-fouling properties. We performed Fourier transform infrared spectroscopic analysis, X-ray diffraction, and scanning electron microscopy to study the structure of nanoparticles and verify the functionalization of nanoparticles. Additionally, scanning electron microscope analysis, contact angle measurements, and porosity assessment were conducted to investigate the structure of nanocomposite membranes. The fabricated membranes were evaluated for pure water flux, the ability to remove Cu+2 heavy metal ions, antifouling properties, and flux recovery ratio against a milk powder solution. The results demonstrate an increase in the hydrophilicity and pure water flux of nanocomposite membranes when nanoparticles are added, primarily due to the presence of hydrophilic functional groups on their surface. Surface scanning electron microscope images and cross-sections of the nanocomposite membranes show that all the produced membranes possess an asymmetric structure, characterized by a compact, thin, and dense upper layer and a porous bottom layer with finger-like structures. Regarding the filtration of copper nitrate solution, nanocomposite membranes containing 0.5%wt of g-C3N4/Indigo and g-C3N4/IndigoCarmin displayed removal efficiencies of 97.43% and 98.35%, respectively. The membrane containing 1.5%wt of g-C3N4/Salicylaldehyde exhibited a 98.05% removal of copper ions, significantly outperforming the pure polyethersulfone membrane and nanocomposite membrane containing unmodified nanoparticles, which achieved removal efficiencies of 37.23% and 70.65%, respectively. This makes the modified nanofiltration membranes highly suitable for practical applications. The flux recovery ratio for nanocomposite membranes containing 1.5%wt of g-C3N4/Salicylaldehyde, 0.5%wt of g-C3N4/IndigoCarmin, and 0.5%wt of g-C3N4/Indigo was found to be 86.58%, 90.16%, and 79.93%, respectively. These values indicate superior antifouling properties compared to the pure polyethersulfone membrane, which achieved a 61.44% flux recovery ratio. Keywords: Membrane filtration, Graphite carbon nitride, Wastewater treatment, Surface properties, Antifouling

  AbstractCurrently,fossil fuel are the main source of energy supply in the world. But due to theincreasing need for energy and the limitation of fossil resources and the environmental pollution, caused by burning them,the desire to use clean energy, such as solar, wind, geothermal, hydrogen andbiomass energy instead of fossil fuels, has increased. Biomass is the fourthlargest source of energy in the world and supplies about 14% of the world'senergy, and the production of energy from these renewable materials reduces theemission of carbon dioxide in the atmosphere. Microbial fuel cell (MFC) is alsobio- electrochemical system (BES) which, in addition to generating electricity,also treats wastewater. Of course, electricity generation is the most importantapplication of MFC. But, the production rate of this energy in MFC is low.Various methods are used to solve this problem. Such as the use of differentnanoparticles to increase the amount of electricity produced, higher protonconductivity and coulombic efficiency and reduce manufacturing costs comparedto commercial Nafion membrane. Therefore, the main objective of this study isto fabricate and modify an innovative cost-effective proton exchange membraneto improve proton transfer, increase  power generation and coulombic efficiency. Therefore, in this study, EP-PWA/SPESnanocomposite membranes were synthesized and characterized by loading differentpercentages (0.1, 0.3, 0.5, 1, 1.5 wt.%) of new EP-PWA nanoparticles. EDAX,MAP, FT-IR, SEM, XRD and CA analysis were performed to investigate theperformance of nanoparticles o  synthesized membranes with different percentages. The results showedthat EP-PWA nanoparticle has a very good perfprmance. The performance of themembranes made in MFC was evaluated in terms of power density, COD removal,water absorption and coulombic efficiency. The Experimental results showed thatSPES membrane with 0.5 wt.% of   EP-PWA nanoparticlewas selected as the optimal membrane and showed the maximum power density, CODremoval, water absorption and coulombic efficiency of 107.69 mW.m2,90.79%, 79.85%, 65.18% respectively. The observed properties indicated higherpower density, water absorption and coulombic efficiency and lower oxygenpermeability in the synthesized membranes compared to the commercial Nafion 117membrane. The obtained results showed that the optimal membrane M3(EP-PWA/SPES 0.5 wt.%) due to the increase in the efficiency of the system andthe significant reduction in construction costs, has the potential tosignificantly   improve the productivity of microbial fuelcell (MFC).     

During the last century, a huge amount of wastewater wasdischarged into rivers, lakes and coastal areas. Given the existing challenges,applicable technologies such as microbial fuel cell (MFC) is commonly employed totreat wastewater. However, this technology suffers from the high cost andlow proton exchange capacity related to the usage of Nafion membranes. Consideringthese shortcomings, the main aim of this study is to fabricate and modify aninnovative proton exchange membrane for improving transfer of proton,increasing power generation and coulombic efficiency. There are numerous methods for proton exchange membranemodification. One of them is doping nanoparticles. In this study, the novel Pu-HPCPnanoparticle and Pu-HPCP/SPES nanocomposite membranes with various loading ofthe referred nanoparticle (0.1, 0.3, 0.7, 1,1.5 wt. %) were synthesized andcharacterized. FT-IR, SEM, TGA analysis were done to characterize synthesizednanoparticle. The results showed that the Pu-HPCP nanoparticle had good thermalstability and asymmetric structure. The performance of the fabricated membraneswas investigated in the MFC as power generation and coulombic efficiency. Theexperimental results demonstrated that, the SPES membrane with 1 wt.% ofPu-HPCP nanoparticle had the maximum power generation and coulombic efficiencyof 35 mW.m-2 and 69%, respectively. The observed properties of lowbiofouling, low oxygen permeability, high power generation, high COD removaland coulombic efficiency (CE) indicated that the 1wt.% Pu-HPCP/SPES membranehas potential to improve significantly the productivity of MFCs.  

In this research, the efficiency of simultaneous adsorption/photocatalyst system in the color decomposition and removal has been investigated. The composite from of MCM-22 zeolite, titanium dioxide and cerium metal nanoparticles and curcumin natural compound has been used. TiO2 nanoparticle has been layered by the reaction of the zeolite and titanium butoxide solution and then, the cerium metal was fixed on it using cerium nitrate salt. The photocatalyst reactor has been slurry type and the experiments were conducted in the presence of visible light using xenon lamp. Morphology and chemical analyses were investigated using FESEM, FT-IR, XRD, DRS, PL, Zeta potential and TGA. The efficiency of this system was evaluated by considering the operating conditions including cerium metal concentration, photocatalyst loading, initial contaminant concentration and pH of the contaminant solution on the contaminant degradation reaction rate of the contaminant and the total contaminant loading raduction of the solution, and basad on this result, the optimum conditions were obtained. Furthermore, the performance of the simultaneous process system in methylene blue dye removal was compared with the individual adsorption and photocatalytic process. By using the spectrophotometry method, the maximum dye removal was obtained in the feed concentration of 5 ppm, the photocatalyst concentration of   2.5 g / L and   H=11. Finally, the dye removal results were 11, 32 and 96%   in the photocatalyst   rocess, the adsorption process, and the simultaneous adsorption / photocatalyst system, respectively.

  AbstractThe leading purpose of thisdissertation is flux increment and foulingdiminution of the PES nanofiltration membranes using diazonium chemistry. Inpart one, diazonium-induced grafting was applied to in situ surfacefunctionalization of PES membrane through covalent attachment of anilineoligomers. The process involves gradual reduction of oligomer diazonium saltswhich yields a superhydrophilic layer of branched aniline oligomers (BAO)grafted on membrane surface. Oligomeric modified membrane was indicated greatperformance of high water permeation flux (93.6 kg/m2.h), as well ashigh FRR (99%) and low Rir (0.9) after fouling with powder milk protein for 90min. BAO modified membrane exhibited exceptional super hydrophilicitywettability with a surprising water contact angle of 0 ?. Roughness parameters inthe modified membrane significantly alleviated, that was demonstrative thesmooth surface in the BAO modified membrane.In part two, we quantified the effect of radically andcoupling treatment on the performance and structure of nascent PES nanofiltration membrane with utilization of4,4-diaminodiphenyl sulfone as precursor starting for diazonium-inducedgrafting. Different functional groups were introducedto the surface of radically and coupling modified membranes via aryldiazoniummethodology. Both of treatments depicts improvement of membrane performance interms of permeability and antifouling capability but, Procurable results ofcoupling treatment are more successful than radically treatment. The couplingtreatment causes that, the permeation flux of coupling modified membrane 3.85times was improved compared to nascent PESnanofiltration membrane. Evaluation of the interactions of membranes surface with powdermilk protein for characterization of fouling resistance was accomplished usingof dead-end filtration system, that the coupling modified membrane indicated high efficiency in antifoulingcapability against protein (FRR=91.35%, Rr=77.56, Rir=8.64).Cross-flow filtration system was used to evaluation stability ofcoupling modified membrane for long time (16h). This test showed almost steadyflux for prolong time of 16h (9.70% flux reduction), that these results wasexhibition of fantastic antifouling performance of the coupling modifiedmembrane.   In part three, firstly couplingmodified PES (CPES) was synthesized by efficient coupling methodology using4,4-diaminodiphenyl sulfone as precursor starting. Then, the CPES/PES blendmembranes were produced at five various compositions via the >In part four, firstly aniline modified PES (APES) was prepared bychemical reduction of aryldiazonium salts using atmospheric oxidized dark brown aniline as precursor starting. Subsequently, in order to obtain appropriate APEScontent, the APES/PES blend membranes were fabricated at three differentcompositions by phase-inversion procedure. The membranes performanceexperiments revealed, that the incorporation of APES could be impressivelyelevated permeated pure water flux so that, the membrane with 25 Wt.% APESshowed the water permeation flux of 70.6 kg /m2.h(at operational pressure of 3 bar) that higher than nascent PESnanofiltration membrane (17.4kg /m2. h.). Incorporation of 25 wt.% APES was incurthat, the antifouling capability of modified membrane was greatly improvedcompared to original membrane.Part five describes the filtration performance of licoriceaqueous solution by coupling-PES and 25 wt.% APES/PES modified membranes that, wasverified systematically and compared to original NF PES membrane. The efficacyof operational pressure and cross-flow velocity on permeation flux andrejection were evaluated. All experiments were employed in a lab scalecross-flow filtration equipment with effective area of 40 cm2