Fluorographite-co-polydimethylsiloxane coated polyvinylidene-fluoride membrane for desalination of highly saline water with humic acid in direct contact membrane distillation

Siyal, Muhammad Irfan,Kim, Jong-Oh Elsevier 2018 Environmental research Vol.167 No.-

<P><B>Abstract</B></P> <P>Membranes with amphiphobic properties are crucial for desalination of concentrated saline water with organic foulant by membrane distillation. In this research, we coated Fluorographite (FGi) particles on polyvinylidene-fluoride (PVDF) flat sheet membranes with 0.8% v/v polydimethylsiloxane (PDMS) as binder by filtration coating method. We evaluated its amphiphobicity via contact angles which were observed by DI water, canola oil and organic solutions as mimicking for oleophobicity. Surface modifications by FGi particles on the surface of membranes was introduced with PDMS binder which brought bifunctionality of amphiphobicity to enhance hydrophobicity and oleophobicity. We also investigated performance of coated membranes in direct contact membrane distillation (DCMD) with 1 molar concentrated NaCl solution along with humic acid being organic foulant and compared with virgin membrane (M1 membrane) and Liquid entry pressure (LEP) was also evaluated. LEP was measured by dynamic method which shown considerable improvement in coated membranes. M3 membrane showed overall better performance in terms of salt rejection higher than 99.87% and flux as compared to M1 membrane. Furthermore, the evaluation of surface characterizations was done by FESEM with EDX, AFM and FTIR. Surface morphology confirmed the coating of FGi on membrane surface while EDX evidenced increase in atomic percent of fluorine in turn F:C ratio.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Surface modifications by FGi particles with PDMS binder of PVDF microporous membranes shown improvement in DCMD. </LI> <LI> LEP with DI water & performance of M2-M4 modified membranes in DCMD was enhanced with 1M NaCl & 10 ppm HA feed solution. </LI> <LI> Amphiphobicity was evidenced by CA with low surface tension liquids upto 38 dyne/cm as well as with canola oil. </LI> <LI> EDX analysis proved enhancement in FC ratio and membrane surface analysis lead to understand enhanced performance in DCMD. </LI> </UL> </P>

A review of membrane development in membrane distillation for emulsified industrial or shale gas wastewater treatments with feed containing hybrid impurities

Siyal, Muhammad Irfan,Lee, Chang-Kyu,Park, Chansoo,Khan, Aftab Ahmed,Kim, Jong-Oh Elsevier 2019 Journal of environmental management Vol.243 No.-

<P><B>Abstract</B></P> <P>Investigations on membrane materials for membrane distillation (MD) and its applications have been ongoing since the 1990s. However, a lack of materials that produce robustly stable and up-to-the-mark membranes for MD for different industrial applications remains an ongoing problem. This paper provides an overview of materials developed for MD applications. Although key aspects of published articles reviewed in this paper pertain to MD membranes synthesized for desalination, future MD can also be applied to organic wastewater containing surfactants with inorganic compounds, either with the help of hybrid treatment processes or with customized membrane materials. Many industrial discharges produce effluents at a very high temperature, which is an available driving force for MD. However, there remains a lack of cost-effective membrane materials. Amphiphobic and omniphobic membranes have recently been developed for treating emulsified and shale gas produced water, but the problem of organic fouling and pore wetting remains a major challenge, especially when NaCl and other inorganic impurities are present, which further deteriorate separation performance. Therefore, further advancements in materials are required for the treatment of emulsified industrial wastewater containing surfactants, salts, and for oil or shale gas wastewater for its commercialized reuse. Integrated MD systems, however, may represent a major change in shale gas wastewater and emulsified wastewater that are difficult to treat.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Advancements in materials for membrane distillation </LI> <LI> Coating materials and surface modification technologies </LI> <LI> Shale gas produced water and challenges in wastewater treatment </LI> <LI> Superhydrophobic, Amphiphobic and Omniphobic membranes </LI> <LI> Integrated MD processes with other technologies and advancement needed </LI> </UL> </P>

Surface modification of glass fiber membranes by fluorographite coating for desalination of concentrated saline water with humic acid in direct-contact membrane distillation

Siyal, Muhammad Irfan,Khan, Aftab Ahmad,Lee, Chang-Kyu,Kim, Jong-Oh Elsevier 2018 Separation and purification technology Vol.205 No.-

<P><B>Abstract</B></P> <P>Amphiphobic materials are gaining popularity in many applications because they have self-cleaning properties. Self-cleaning substrates are important for applications in antifouling surfaces in seawater and antifouling membranes for desalination; membrane-based desalination and particularly distillation uses hydrophobic membranes. However, the lack of commercial amphiphobic membranes has prevented the exploration of customized membranes. In this research, we applied fluorographite (FGi) particles to glass fiber (GF) membranes with polydimethylsiloxane (PDMS) to render superhydrophilic filters into Amphiphobic membranes. The coating was applied via a dip/immersion method using hexane, a low-surface tension solvent, and PDMS paired with reaction assistants for the PDMS systems. The surface modifications introduced functionality to the membrane surfaces by the incorporation of FGi and PDMS, enhancing the evaluated amphiphobicity. Contact angles (CA) were observed using water and organic solutions to determine oleophobicity. We also evaluated the effects of the amount of FGi particles, PDMS, reaction assistants, and the drying and curing reaction times on the CA and liquid entry pressures (LEPs) of the coated membranes. The post-coating CA with water and the low-surface-tension liquid like dimethyl sulfoxide showed improved amphiphobicity. Furthermore, the surface characteristics were evaluated by Fourier-transform infrared spectroscopy and scanning electron microscopy to identify the chemical groups developed during coating and the morphological changes before and after membrane coating. Finally, the modified membrane was applied in direct-contact membrane distillation (DCMD) with a highly concentrated feed solution containing 1 M NaCl and 10 mg/L humic acid (HA) as an organic foulant. The DCMD results demonstrated the success of the coating in membrane distillation applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> FGi modified Glass fiber membrane was developed with dip coating using PDMS binder. </LI> <LI> Modified membrane proved enhanced amphiphobicity in DCMD with 1 M NaCl & 10 mg/L HA. </LI> <LI> PDMS in addition to FGi improved amphiphobicity upto surface tension of 44 dynes/cm. </LI> <LI> Improved morphologies were evidenced by SEM & FTIR on virgin and modified membranes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Optical Spectroscopic Analysis Techniques to Detect Elemental Profile of Human Teeth Dentine

Saifullah Jamali,Muhammad Aslam Khoso,Irfan Ali Sanjrani,Hussain Saleem,Tariq Ali Siyal,Muhammad Ashraf,Mansoor Ahmed Memon,Ghulam Murtaza,Zahid Hussain Arain,Zaheer Ahmed Ujjan,Muhammad Niaz Laghari International Journal of Computer ScienceNetwork S 2023 International journal of computer science and netw Vol.23 No.3

Numerous articles under the study and the examination of heavy metals in human teeth have been published in recent years. The heavy metal poisoning is a widespread issue emerged in toxicology area these days. It has been discovered that long-term exposure to heavy metals typically present in traces, in our everyday meals, drinking water, and in the environment as pollution causes heavy metal poisoning in human beings. Industrial effluents, Coal and Oil, as well as a variety of consumer items, such as cosmetics, can all cause this type of exposure. Teeth, which are often thought of as exoskeleton parts, store heavy metals with a high affinity and represent long-term exposure information. In this study, we have chosen and examined the sections of dentine instead, then examined the entire tooth. We have combined the work done on the examination of heavy metals in human teeth using several instrumental approaches e.g. "Optical Spectroscopic Techniques" to detect elemental profile of human teeth in the current study.

Hybrid organic-inorganic functionalized polyethersulfone membrane for hyper-saline feed with humic acid in direct contact membrane distillation

Khan, Aftab Ahmad,Siyal, Muhammad Irfan,Lee, Chang-Kyu,Park, Chansoo,Kim, Jong-Oh Elsevier 2019 Separation and purification technology Vol.210 No.-

<P><B>Abstract</B></P> <P>In this study, hybrid organic-inorganic functionalized polyethersulfone (PES) membrane was prepared for treating hyper-saline feed solutions containing humic acid (HA) foulant. The membrane modification was carried out by dip-coating with silica nanoparticles, followed by vacuum filtration coating with 1H,1H,2H,2H-perfluorodecyl triethoxysilane and polydimethylsiloxane. The membranes were characterized by field emission scanning electron microscope, atomic force microscope, Fourier transform infrared, and thermal gravimetric analyses. The evaluation of membranes with water contact angle, liquid entry pressure, direct contact membrane distillation (DCDM), and stability tests, proved the durable amphiphobic nature of the modified PES membrane (PDMS-FAS/SiNPs). The membrane performance was respectively better from that of commercial polypropylene (PP) and polyvinylidene fluoride (PVDF) membranes. In the DCMD of a feed solution of 1 M NaCl and 10 mg L<SUP>−1</SUP> HA, the flux of the PDMS-FAS/SiNPs membrane remained consistent (17 LMH), with a permeate conductivity of 33.96 µS cm<SUP>−1</SUP>. The optimized modified membrane showed better performance in terms of permeate flux, salt rejection, and anti-fouling behavior in DCMD. These wonderful results of functionalized PDMS-FAS/SiNPs PES membrane are attributed to the step-wise simple, and inexpensive dip-coating followed by vacuum filtration coating using efficient hybrid organic-inorganic material combination.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PES membrane functionalization using hybrid organic-inorganic material. </LI> <LI> Dip and vacuum filtration coating methods were used for membrane modification. </LI> <LI> Consistent rejection of hyper-saline feed solution containing humic acid. </LI> <LI> Functionalized PES membrane performance compared with other membranes. </LI> <LI> Modified PES membrane was more durable than commercially available PP and PVDF. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Amphiphobicity evaluation of fluorinated sillica modified polyethersulfone membrane by concentrating the emulsified feed in membrane distillation

Aftab Ahmad Khan,Muhammad Irfan Siyal,Chang-Kyu Lee,Chansoo Park,Jong-Oh Kim 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

Optimization of membrane modification using SiO₂ for robust anti-fouling performance with calcium-humic acid feed in membrane distillation

Khan, Aftab Ahmad,Khan, Imtiaz Afzal,Siyal, Muhammad Irfan,Lee, Chang-Kyu,Kim, Jong-Oh Elsevier 2019 Environmental research Vol.170 No.-

<P><B>Abstract</B></P> <P>The goal of this study was to prepare a robust anti-wetting and anti-fouling polyethersulfone (PES) membrane for the rejection of a highly saline (NaCl and CaCl<SUB>2</SUB>·2H<SUB>2</SUB>O) feed solution containing humic acid (HA) in direct contact membrane distillation (DCMD). Response surface methodology (RSM) was used to determine the optimum formulation of the used materials. The variable factors selected were polydimethyl siloxane (PDMS) and silica (SiO<SUB>2</SUB>); liquid entry pressure (LEP) and contact angle (CA) were selected as responses. Scanning electron microscopy (SEM) analysis confirmed the SiO<SUB>2</SUB> deposition and Fourier-transform infrared spectroscopy (FTIR) test evidenced the new functional groups i.e., Si–OH, siloxane, and C–F bond vibrations at 3446, 1099 cm<SUP>−1</SUP>, and 1150–1240 cm<SUP>−1</SUP> respectively on the membrane surface. The average roughness (Ra) was increased four times for the coated membranes (0.202–0.242 µm) as compared to that for pristine PES membrane (0.053 µm). The optimum PES-13 membrane exhibited consistent flux of 12 LMH and salt rejection (> 99%) with anti-fouling characteristic in DCMD using the feed solution of 3.5 wt% NaCl + 10 mM CaCl<SUB>2</SUB>·2H<SUB>2</SUB>O + 10 mg L<SUP>−1</SUP> HA. The PES-13 membrane may therefore be a key membrane for application in DCMD against CaCl<SUB>2</SUB>·2H<SUB>2</SUB>O-containing salty solutions with HA.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PES membrane was prepared for application in DCMD using silica nanoparticles. </LI> <LI> Response surface methodology was employed to optimize the coating formulation. </LI> <LI> Modified membranes were resistant to fouling against calcium-humic acid feed. </LI> <LI> The high fluxes for PES-13 membrane were recorded with all three feed solutions. </LI> </UL> </P>