Fabrication of Electrospun Nanofibers Membrane for Emulsified Oil Removal from Oily Wastewater

اكتسبت أغشية الألياف النانوية المصنعة بطريقة الغزل الكهربائي اهتمامًا كبيرًا بتطبيقات ترشيح المياه. في هذا العمل، تم تصنيع وتوصيف غشاء ألياف نانوية غير منسوج بطريقة الغزل الكهربائي. بعد ذلك، تم تقييم أداء الغشاء وخصائصه المضادة للترسبات في إزالة النفط المستحلب باستخدام نظام الترشيح القطعي. تم تصنيع الأغشية باستخدام محاليل بوليميرية ذات تراكيز مختلفة من البولي أكريلونيتريل (PAN) (8,11,14%) المذاب في N-N-Dimethylformamide  (DMF) ونتج عنه معدل ​​أحجام مختلفة من الألياف ، والمسامية ، وزاوية التلامس ، والنفاذية ، وفصل النفط ، و خصائص مضادة للترسبات. أظهرت تحليلات التشكل السطحي للأغشية المصنعة قبل وبعد إزالة النفط كبر حجم الألياف وتقليل كمية الترسبات وزيادة تدفق النفاذية. من ناحية أخرى، يؤدي تقليل حجم الألياف إلى زيادة فصل النفط. لوحظ أن غشاء الألياف النانوية غير المنسوج المصنع من 11% PAN/DMF هو الغشاء الأمثل لإزالة النفط المستحلب بسبب مساميته الجيدة ونفاذه مع قابلية فصل جيد للنفط. بالإضافة إلى ذلك، تم تنظيف أغشية الألياف غير المنسوجة المستخدمة للترشيح مسبقا بواسطة تقنية الغسيل العكسي باستخدام الماء المقطر الدافئ والتي كانت فعالة في الحفاظ على نفاذية الغشاء وقابلية فضل الزيت لمدة 7 مرات. النتائج تثبت الكفاءة الجيدة لغشاء الالياف النانوية المصنعة لإزالة النفط من الماء بنسبة ازالة نفط تصل الى 92.5% ومعدل جريان 120 LMH  The electrospun nanofibers membranes have gained considerable interest in water filtration applications. In this work, the fabrication and characterization of the electrospun polyacrylonitrile-based nonwoven nanofibers membrane are reported. Then, the membrane's performance and antifouling properties were evaluated in removing emulsified oil using a cross flow filtration system. The membranes were fabricated with different polyacrylonitrile (PAN) concentrations (8, 11, and 14 wt. %) in N, N-Dimethylformamide (DMF) solvent resulted in various average fiber sizes, porosity, contact angle, permeability, oil rejection, and antifouling properties. Analyses of surface morphology of the fabricated membranes before and after oil removal revealed increasing the fiber size, decreasing the fouling amount, and increasing the permeate flux. On the other hand, decreasing the fiber size resulting in increases the oil rejection. It was observed that 11 wt. % PAN based nonwoven nanofiber membrane was the optimum membrane for emulsified oil removal due to its good porosity, permeability with good oil rejection. In addition, fouled nonwoven nanofiber membrane cleaning was done by backwashing technique using warm distilled water which was effective in retaining the membrane permeability and oil rejection for 7 times. The obtained results confirmed an efficient performance of the fabricated nanofibers membrane for oil-water separation with oil rejection percentage of 92.5% and a permeate flux of 120 LMH.

The Effect of Electrospinning Parameters on Morphological and Mechanical Properties of PAN-based Nanofibers Membrane

The electrospun nanofibers membranes (ENMs) have gained great attention due to their superior performance. However, the low mechanical strength of ENMs, such as the rigidity and low strength, limits their applications in many aspects which need adequate strength, such as water filtration. This work investigates the impact of electrospinning parameters on the properties of ENMs fabricated from polyacrylonitrile (PAN) solved in N, N-Dimethylformamide (DMF). The studied electrospinning parameters were polymer concentration, solution flow rate, collector rotating speed, and the distance between the needle and collector. The fabricated ENMs were characterized using scanning electron microscopy (SEM) to understand the surface morphology and estimate the average fiber sizes. The membrane porosity percentage was measured using the dry-wet weight method. Also, a dynamic mechanical analyzer was used to determine the mechanical strength properties (tensile strength and Young's modulus) (DMA). The obtained results revealed that the polymer concentration and flow rate mainly affect the porosity and fiber size in ENMs. Increasing the polymer concentration improves the strength and flexibility, while the flow rate did not show a clear effect on the mechanical strength of ENMs. Both fibers collecting speed and spinning distance did not clearly impact the membrane morphology. ENMs flexibility significantly increased with increasing the collector speed and decreasing the spinning distance. Strong and flexible ENMs with small fibers can be fabricated using 10% PAN/DMF at a flow rate of 1 mL/h, collector speed of 140 rpm, and spinning distance of 13 cm

RIETVELD TEXTURE REFINEMENT ANALYSIS OF LINDE TYPE A ZEOLITE FROM X-RAY DIFFRACTION DATA

Rietveld method was used to conduct a texture refinement analysis for Linde type A zeolite prepared by hydrothermal conditions of 100 ºC for 4 h. Material Analysis Using Diffraction software, which is an open access/user-friendly software, was used to accomplish the analysis using the observed X-ray diffraction data. This study shows the feasibility of using Material Analysis Using Diffraction software for zeolite analysis because it has not been applied for zeolite before. Implementation of this software for the texture refinement analysis for zeolite can contributes to the field of zeolite preparation in term of adding more reliability to the experimental results. The X-ray diffraction results of the prepared zeolite concur well with the standard Linde type A zeolite. All parameters calculated by Rietveld refinement method for the prepared zeolite were close enough to those for the standard zeolite A. Also, ImageJ software was used for image analysis to obtain the average particle size for zeolite A sample

Enhanced Hydrophobic Double-Layer Nanofibers Membranes for Direct Contact Membrane Distillation

There are several uses for electrospun nanofiber membranes because of their unique properties. Electrospinning, under suitable conditions, has allowed for the successful fabrication of nanofibrous membranes. This research, a dual-layer membrane was prepared and applied in a direct contact membrane distillation (DCMD) system. Polyacrylonitrile (PAN) based electrospun nanofibers comprised the initial (base) layer. Hydrophobic electrospun nanofibers made from polymethyl methacrylate (PMMA) comprised the second (top) layer. The analysis was carried out using contact angle measurements and scanning electron microscopy (SEM) for the morphology and wetting of a series of two-layer nanofiber membranes that were made with different percentages of PAN: PMMA. The study examined how the permeate flux was affected by changes in feed concentration, feed temperature, and feed flow rate. and optimized within a logical framework. These included feed inlet temperatures between 35 and 55 oC, salt concentrations between 70,000 and 210,000 ppm, and rates of supply flow of 0.2, 0.4, and 0.6 L/min. DCMD findings for the (25 PAN:75PMMA) membrane displayed that the amount of salt it rejected was better than 99.356% with flux 51.872 kg/m2.h and a penetrate through conductivity lower down 334 µs/cm when performed under optimally supplied conditions (i.e., 70 g/L; 0.6 L/min; and 55°C)

Adsorption Isotherms and Kinetics Studies of Lead on Polyacrylonitrile-Based Activated Carbon Nonwoven Nanofibres

This paper examines the performance of a Direct Contact Membrane Distillation (DCMD) system experimentally and theoretically. The system uses a super hydrophobic electrospun nanofiber membrane to desalinate water. Investigations were carried out into how the feed concentration, feed flow rate, and feed temperature affected permeate flux. as system operating parameters to aid in comprehending the factors impacting the DCMD process. The application of DOE and Taguchi methods achieved statistical optimization of the DCMD process's performance. In addition, the study of mass and heat transport in DCMD was described by a theoretical model. While the feed concentration significantly affected flux, the feed's temperature and flow rate mostly dominated the impact on system performance. The created model numerically solved the DCMD process using MATLAB software, describing it as a system of nonlinear equations. Various operating conditions were used to investigate the efficiency of the superhydrophobic electrospun nanofiber membrane in treating 210 g/L NaCl salt water. Changing the feed temperature and concentration affected the hypothetically suggested path across the membrane, according to the simulation results presented in this paper. Excellent agreement was observed between the experiment results and the constructed model's predicted results. Every instance maintained a high salt rejection rate (over 99.9%). The DCMD produced a gain output ratio (GOR) of 0.87 and a temperature polarization coefficient of 0.78 to 0.91. The system achieved a maximum thermal efficiency of 73.5%

Activated Carbon Nanofiber Nonwovens: Improving Strength and Surface Area by Tuning Fabrication Procedure

Electrospun-based activated carbon nanofiber nonwovens (ACNFN) are interesting candidate materials for adsorption processes due to their high surface area and low flow-through resistance. However, the mechanical properties of these materials must be sufficient to withstand the conditions for use and to prevent breakage and fiber shedding. Improvements in the mechanical properties of the ACNFNs should not be accompanied by deterioration of other beneficial properties, however. In this research, improving the mechanical properties of ACNFN based on 14 wt % PAN/DMF was done by tuning the fabrication conditions. Carbonization occured at 600 °C for 2 h followed by steam activation at 750 °C for 1 h. We demonstrated the capability to generate ACNFN with high accessible surface area that reached 520 m 2 /g and acceptable mechanical strength (break strength, 0.9; 75 MPa, Young's modulus) for improved handling and use in different applications

Activated carbon nanofiber nonwoven for removal of emulsified oil from water

Activated carbon nanofiber nonwoven (ACNFN) has the potential for being high capacity and throughput sorbent for a variety of contaminants in water due to high porosity and permeability, respectively. In this work, we explore the removal of emulsified oil from water using ACNFNs in both a batch and flow-through mode. The ACNFNs were prepared by pyrolysis of electrospun polyacrylonitrile and characterized for specific surface area, hydrophobicity, and mechanical strength. The ACNFNs exhibit a removal efficiency of up to 95% in batch mode and outperform our control tests with non-activated carbon nanofiber nonwoven and a commercial granular activated carbon. Adsorption tests in a flow-through mode demonstrated characteristic breakthrough behavior with subsequent clogging. Removal efficiency increased with the thickness of the mat and with prolonged operation due to ripening