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Öğe A hybrid process for leachate wastewater treatment: Evaporation and reverse osmosis/sequencing batch reactor(Wiley, 2022) Bouchareb, Raouf; Isik, Zelal; Ozay, Yasin; Karagunduz, Ahmet; Keskinler, Bulent; Dizge, NadirIn this study, a hybrid process for leachate wastewater treatment including evaporation and reverse osmosis (RO) membrane or biological treatment systems was suggested. Experiments were performed on a real landfill leachate wastewater. The leachate was subjected to evaporation; as a result, a distillate was obtained containing less organic matter and less substantial amounts of other pollutants, as ammonium salts and total phenols were removed. Tests were carried out at different evaporation temperatures and times. The initial leachate pH was adjusted and optimized. For optimum conditions, each of chemical oxygen demand (COD), total phenol, and ammonium salt concentrations were reduced to 99.99%, 95.00%, and 83.00%, respectively. The distillate of the first stage of the proposed process was then exposed to RO membrane system, as a first study, under different transmembrane pressure of 20, 30, and 40 bar and at different pH values of 7, 8, and 9. As a second suggested treatment system, the distillate was subjected to a biological treatment process for 30 days as a retention time, pH = 6, and room temperature 25 degrees C +/- 1 degrees C. At the end of the research study, a comparison was conducted between results obtained with RO membrane separation and biological treatment system as two distinct treatment systems proposed for leachate landfill wastewater treatment. Although both systems were effective for landfill leachate wastewater treatment, however, with the RO membrane separation system, COD removal efficiency reached 99.99%. In the other hand, with biological treatment process, COD elimination was as much as 90.00%. Certainly, evaporation and RO are not novel ways of landfill leachate treatment; however, few studies have attempted to use similar combined system for landfill leachate wastewater treatment and attained effective results of treated water. Practitioner Points A hybrid process of evaporation and RO membrane or biological treatment systems was suggested for leachate wastewater treatment. For optimum conditions, COD, total phenols, and ammonium salt reductions were achieved to 99.99%, 95%, and 83%, respectively, after the first evaporation stage. The distillate of the first stage of the proposed process was then exposed to RO membrane system and biological treatment system. Different transmembrane pressure and different pH values were optimized for RO.Öğe Antifouling and antibacterial performance evaluation of polyethersulfone membranes modified with AZ63 alloy(Iwa Publishing, 2023) Ozay, Yasin; Alterkaoui, Aya; Kahya, Kursat; Ozdemir, Sadin; Gonca, Serpil; Dizge, Nadir; Ocakoglu, KasimAntibacterial membranes have attracted researchers' interest in recent years as a possible approach for dealing with biofouling on the membrane surface. This research aims to see if blending AZ63 Mg alloy into a polyethersulphone (PES) membrane can improve antifouling and separation. The composite membranes' pure water flux continued to increase from pristine PES to PES/AZ63 2.00 wt%. The results showed that PES/AZ63 2.00 wt% membrane supplied the highest permeate flux of E. coli. The steady-state fluxes of AZ63 composite membranes were 113.24, 104.38 and 44.79 L/m(2)h for PES/AZ63 2.00 wt%, 1.00 wt%, and 0.50 wt%, respectively. The enhanced biological activity of AZ63 was studied based on antioxidant activity, DNA cleavage, antimicrobial, anti-biofilm, bacterial viability inhibition and photodynamic antimicrobial therapy studies. The maximum DPPH scavenging activity was determined as 81.25% with AZ63. AZ63 indicated good chemical nuclease activity and also showed moderate antimicrobial activity against studied strains. The highest biofilm inhibition of AZ63 was 83.25% and 71.63% towards P. aeruginosa and S. aureus, respectively. The cell viability inhibition activity of AZ63 was found as 96.34% against E. coli. The photodynamic antimicrobial therapy results displayed that AZ63 demonstrated 100% bacterial inhibition when using E. coli.Öğe Antimicrobial and antioxidant activity of phenolic extracts from walnut (Juglans regia L.) green husk by using pressure-driven membrane process(Springer India, 2023) Arslan, Hudaverdi; Koc, Eda Ondul; Ozay, Yasin; Canli, Oltan; Ozdemir, Sadin; Tollu, Gulsah; Dizge, NadirIn this study, antioxidant (DPPH and metal chelating), DNA cleavage, biofilm, and antimicrobial properties of extracted phenol from the walnut green husk (WGH) and its different concentrate and permeate samples were evaluated. For maximum phenolic compound extraction from the WGH first, the effects of solvent type (deionized water, methanol, n-hexane, acetone, and ethanol), solvent temperature (25-75 degrees C), and extraction time (0.5-24 h) were optimized. Then to concentrate phenolic compounds a pressure-driven membrane process was used with four different membrane types. The phenol contents of the concentrate samples were found to be microfiltration (MF) concentrate 4400 mg/L, ultrafiltration (UF) concentrate 4175 mg/L, nanofiltration (NF) concentrate 8155 mg/L, and reverse osmosis (RO) concentrate 8100 mg/L. LC-MSMS was used to determine the quantification of phenolic compounds in permeate and concentrate streams. In addition, all of the concentrate samples with high phenol content showed a high antioxidant activity as 100% with MF concentrate, UF concentrate, NF concentrated and RO concentrated. Likewise, concentrate samples were found to have very high antibiofilm activity as 82.86% for NF concentrate againts S. aureus, 85.80% for NF concentrate against P. aureginosa, 80.95% for RO concentrate against S. aureus, and 83.61% for RO-concentrate against P. aureginosa. When the antimicrobial activity of the extracted phenol from WGH and its different concentrate and permeate samples were evaluated by micro dilution and disk diffusion methods, it was found that the ability of the concentrate samples to inhibit bacterial growth was much higher than permeate ones. In addition, extracted phenol from WGH and its different concentrate and permeate samples showed significant DNA nuclease activity.Öğe Development of Ruthenium Oxide Modified Polyethersulfone Membranes for Improvement of Antifouling Performance Including Decomposition Kinetic of Polymer(Springer, 2023) Yigit, Basak; Ozay, Yasin; Emen, Fatih Mehmet; Kutlu, Emine; Ocakoglu, Kasim; Dizge, NadirIn this study, RuO2-embedded PES membrane was prepared and it was used for protein separation. The antifouling properties of the fabricated composite membranes were also investigated using bovine serum albumin (BSA) as protein solution. The mean roughness increased proportionally by introducing RuO2 particles. The porosity of the composite membranes was higher than that of the pristine PES membrane. On the other hand, composite membranes has smaller average pore size after addition of RuO2 particles. The blending of RuO2 particles to the PES membrane caused to increase the hydrophilicity. The contact angle was measured 76.67 +/- 1.21 degrees, 73.23 +/- 0.84 degrees, 70.28 +/- 0.77 degrees, and 67.13 +/- 0.80 degrees for pristine PES, PES/RuO2 0.50 wt%., PES/RuO2 0.75 wt%., and PES/RuO2 1.00 wt%, respectively. The pure water flux of the membranes decreased from 439.7 to 379.3 L/m(2)/h for the pristine PES and PES/RuO2 1.00 wt%. The pore size was calculated as 16.47 nm for the pristine PES and pore size decreased up to 6.05 nm when RuO2 particles increased up to 1.00 wt%. BSA fluxes were 84.1 +/- 2.1, 86.3 +/- 2.5, and 93.9 +/- 3.2 L/m(2)/h for pristine, PES/RuO2 0.50 wt%, and PES/RuO2 0.75 wt% membranes, respectively. PES/RuO2 1.00 wt%. membrane supplied the lowest BSA flux (73.6 +/- 3.1 L/m(2)/h). BSA rejection efficiencies increased from 45.5 +/- 1.8% to 92.6 +/- 1.5% when blended RuO2 particles increased from 0 to 1.00 wt%. The results depicted that R-ir values decreased while R-r values increased after the blending of RuO2. The thermal studies of the PES/RuO2 membranes were also performed by DTA/TG. The Activation Energy (E-a) values of the PES/RuO2 membranes were found to be 57.67-641.34 kJ/mol for Flynn-Wall-Ozawa (FWO) and 55.13-659.10 kJ/mol for Kissenger-Akahira-Sunose (KAS).Öğe Fabrication and characterization of polyethersulfone membranes functionalized with zinc phthalocyanines embedding different substitute groups(Elsevier, 2021) Bilici, Zeynep; Ozay, Yasin; Yuzer, Abdulcelil; Ince, Mine; Ocakoglu, Kasim; Dizge, NadirIn this study, a novel polyethersulphone (PES) composite membrane incorporated with two different zinc phthalocyanines (ZnPc), tetra-iodo and octa(2,6-diphenylphenoxy), was fabricated through the phase inversion approach. Three different concentrations of zinc phthalocyanines (0.5, 1.0, and 2.0 wt.%) were blended into the PES membrane. The morphology and performance of the fabricated composite membranes were systematically studied by scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) mapping, atomic force microscopy (AFM), porosity, water contact angle, antifouling, and rejection measurements. Hydrophobicity of the pristine membrane decreased from 79.67 degrees to 77.03 degrees and from 79.67 degrees to 67.57 degrees after blending of 2.0 wt.% tetra-iodo ZnPc (TI-ZnPc) and octa(2,6-diphenylphenoxy) ZnPc (DP-ZnPc), respectively. Furthermore, the porosity and mean pore radius decreased due to the introducing of ZnPc. Porosity of the pristine membrane decreased from 60.60 % to 44.96 % and 42.21 % after blending of TI-ZnPc and DP-ZnPc, respectively. Mean pore size of the pristine membrane decreased from 22.70 nm to 9.11 nm and 17.93 nm after blending of TIZnPc and DP-ZnPc, respectively. BSA filtration mostly affected the flux of pristine membrane and caused it to decrease from 133.5 to 87.1 L/m(2)h (relative flux reduction (RFR) of 34.7 %). RFR decreased up to 19.2 % and 17.3 % for TI-ZnPc 2.0 wt% and DP-ZnPc 2.0 wt% composite membranes. Pristine PES membrane rejected 45.8 % BSA. However, TI-ZnPc 2.0 wt% and DP-ZnPc 2.0 wt% composite membranes supplied 91.0 % and 70.6 % BSA rejections, respectively. In comparison to pristine PES membrane, the total resistance (R-t) values of the composite membranes decreased. The pristine PES membrane showed the lowest flux recovery ratio (FRR, 71.89 %) against BSA, while all-composite membranes showed promising antifouling properties. FRR increased up to 97.44 % and 89.06 % for TI-ZnPc 2.0 wt% and DP-ZnPc 2.0 wt% composite membranes, respectively. The pristine PES membrane showed the lowest FRR against activated sludge, while all composite membranes showed promising antifouling properties. Moreover, ZnPc-embedded PES composite membranes were irradiated with appropriate wavelengths of light in the presence of oxygen to generate reactive oxygen species to clean fouled membranes' surface. The results showed that photo-cleaning was very effective to recover membrane flux.Öğe Improvement in performance of g-C3N4 nanosheets blended PES ultrafiltration membranes including biological properties(Elsevier, 2021) Sert, Buse; Ozay, Yasin; Harputlu, Ersan; Ozdemir, Sadin; Yalcin, M. Serkan; Ocakoglu, Kasim; Dizge, NadirThis study aims to investigate the modification of polyethersulphone (PES) membrane with graphitic carbon nitride (g-C3N4) nanosheets for improving the antifouling and separation performance. The nanocomposite membranes were fabricated with blending of different g-C3N4 nanosheets (0.50, 1.00, and 2.00 wt%) into PES and they were synthesized by the phase inversion method. The fabricated g-C3N4 nanosheets and composite membranes were analyzed for their morphology. Scanning electron microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) mapping were used to detect the distribution of g-C3N4 nanosheets on membrane surface, whereas surface roughness of membrane was evaluated by atomic force microscopy (AFM). The composite membrane surface was found to be hydrophilic (67.54 degrees), while the water flux of the composite membrane was found to be 254.8 L/m(2)/h for 2.00 wt% g-C3N4/PES membrane. The bovine serum albumin (BSA) separation tests indicated that the composite membrane supplied 98.5% BSA rejection ratio. Moreover, a significant improvement in antifouling characteristics were verified from BSA filtration experiments. g-C3N4 was also investigated for some of its biological properties such as antioxidant, antimicrobial, DNA cleavage, biofilm inhibition, and bacterial viability effect. g-C3N4 showed good free radical scavenging activity and moderate chelating activity at 500 mg/L. It was also determined that single-strand DNA cleavage activities occurred at all tested concentrations. g-C3N4 exhibited significant antibiofilm activity and inhibitory effects on E. coli vitality as 90.9%, 97.1%, and 98.9% at 250, 500, and 1000 mg/L, respectively. This study provides a simple and useful guideline to create a UF membrane resistant against organic fouling and expand its practical applications for wastewater treatment.Öğe Investigation of the antifouling properties of polyethersulfone ultrafiltration membranes by blending of boron nitride quantum dots(Elsevier, 2021) Sert, Buse; Gonca, Serpil; Ozay, Yasin; Harputlu, Ersan; Ozdemir, Sadin; Ocakoglu, Kasim; Dizge, NadirThis study aims to investigate the modification of polyethersulfone (PES) membrane with boron nitride quantum dots (BNQD) for improving the antifouling performance. The composite membranes were synthesized by blending different amounts of BNQD (0.50, 1.00, and 2.00 wt.%) into PES with the non-solvent induced phase separation (NIPS) method. UV-vis absorption, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were used to characterize BNQD. Moreover, porosity, pore size, contact angle, permeability, bovine serum albumin (BSA) rejection, and antifouling properties were determined for composite membranes. The enhanced biological activity of BNQD was investigated based on antioxidant, antimicrobial, anti-biofilm, bacterial viability inhibition, and DNA cleavage studies. The BNQD showed 19.35 % DPPH radical scavenging activity and 76.45 % ferrous ion chelating activity at 500 mg/L. They also exhibited good chemical nuclease activity at all concentrations. BNQD had moderate antibacterial activity against all tested microorganisms. Biofilm inhibition percentage of BNQD was determined as 82.31 % at 500 mg/L. Cell viability assay demonstrated that the BNQD showed strong cell viability inhibition 99.9 % at the concentration of 1000 mg/L. The porosity increased from 56.83 +/- 1.17%-61.83 +/- 1.17 % while BNQD concentration increased from 0 to 2.00 wt%. Moreover, the hydrophilicity of BNQD nanocomposite membranes also increased from 75.42 +/- 0.56 degrees to 65.34 +/- 0.25 degrees. The mean pore radius is far slightly changed from 16.47 +/- 0.35 nm to 19.16 +/- 0.22 nm. The water flux increased from 133.5 +/- 9.5 L/m(2)/h (for pristine membrane) to 388.6 +/- 18.8 L/m(2)/h (for PES/BNQD 2.00 wt% membrane). BSA flux increased from 38.8 +/- 0.9 L/m(2)/h to 63.2 +/- 2.7 L/m(2)/h up to 1.00 wt% amount of BNQD nanoparticles.Öğe Investigation of two different size microplastic degradation ability of thermophilic bacteria using polyethylene polymers(Taylor & Francis Ltd, 2023) Akarsu, Ceyhun; Ozdemir, Sadin; Ozay, Yasin; Acer, Omer; Dizge, NadirThere are several studies stating that many types of microplastics cannot be retained completely by conventional wastewater treatment systems. Therefore, it is necessary to prevent the discharge of these microplastics to the ecological system. The objective of this study was to investigate the biodegradation ability of two different size of PE (50 and 150 mu m) by using two Gram-positive, spore-forming, rod-shaped, and motile thermophilic bacteria, called strain Gecek4 and strain ST5, which can hydrolyse starch, were isolated from the soil's samples of Gecek and omer hot-springs in Afyonkarahisar, Turkey, respectively. Phenotypic features and 16S rRNA analyzing of strains also studied. According to these results, Gecek4s and ST5 were identified as Anoxybacillus flavithermus Gecek4s and Bacillus firmus ST5, respectively. Results showed that A. flavithermus Gecek4s could colonise the polymer surface and cause surface damage whereas B. firmus ST5 could not degrade bigger-sized particles efficiently. In addition, morphological changes on microplastic surface were investigated by scanning electron microscopy (SEM) where dimensional changes, irregularities, crack, and/or holes were detected. This finding suggests that there is a high potential to develop an effective integrated method for plastic bags degradation by extracellular enzymes from bacteria.Öğe Nanocellulose synthesis from Tamarix aphylla and preparation of hybrid nanocellulose composites membranes with investigation of antioxidant and antibacterial effects(Elsevier, 2022) M'barek, Islem; Isik, Zelal; Ozay, Yasin; Ozdemir, Sadin; Tollu, Gulsah; Moussaoui, Younes; Dizge, NadirNanotechnology takes place in almost every stage of our lives and it has also started to find application in membrane technologies. In order to overcome the fouling phenomenon, which is the main problem of membrane processes, composite membranes containing metallic nanoparticles (NPs) with antibacterial properties are produced. Therefore, research continues to find environmentally friendly, inexpensive, and abundant materials to prevent membrane fouling. This study focused on the valorization of vegetable biomass Tamarix aphylla for nanocellulose (NC) synthesis which was coated subsequently with silver (NC-Ag NPs) and iron (NC-Fe NPs) nanoparticles to acquire the hybrid composites for ultrafiltration membrane preparation. The coated NC with metal NPs and synthesized membranes were characterized by SEM, EDX, FTIR, and XRD. The antioxidant and antimicrobial activities of NC and its coated forms with NPs were evaluated. It was found that significant scavenging abilities against the DPPH radical reached the maximum of 82.94% at 200 mg/L. The abilities of the three samples (NC, NC-Ag NPs, NC-Fe NPs) for DNA cleavage were tested and important outcomes were recorded. Furthermore, the antimicrobial abilities of the composites were examined by the microdilution procedure and they exhibited good ability. The biofilm inhibition rates of the composites were determined, where the highest biofilm inhibition against S. aureus and P. aeruginosa was recorded for NC-Ag NPs as 63.85% and 81.20%, respectively. Briefly, among the tested NC and NPs coated NC, NC-Fe NPs exhibited significant antimicrobial potential compared to the others. Thus, it may be promising hybrid nanocellulose complexes for antifouling membrane preparation.Öğe Photocatalytic Decolorization of BR18 and RR180 Dyes by Semiconductor Diode Laser Using CuO for Wastewater Treatment(Springer Int Publ Ag, 2022) Polat, Baris; Bilici, Zeynep; Ozay, Yasin; Kucukkara, Ibrahim; Dizge, NadirIn this study, the use of copper(II) oxide (CuO) powders as catalyst and continuous wave (CW) multimode semiconductor diode laser (450 nm) was investigated for decolorization of Basic Red 18 (BR18) and Reactive Red 180 (RR180) aqueous dye solutions. The effects of laser power (0.5-2.5 W), pH of solution (2-10), CuO catalyst loading (0.25-1.50 g/L), H2O2 concentration (0.28-2.22 mg/L), initial dye concentration (20-60 mg/L) were studied systematically. Maximum removal efficiency was observed as 100% for RR180 and 94.34% for BR18 under the optimum conditions. Kinetic analysis of BR18 and RR180 dye decolorization reaction indicated that the overall rate order of the reaction was the pseudo first order. CuO demonstrated satisfactory reuse capability as the catalyst for five consecutive cycles without any decrease in its activity for RR180 dye.Öğe Polyethersulfone membranes modified with CZTS nanoparticles for protein and dye separation: Improvement of antifouling and self-cleaning performance(Elsevier, 2021) Ocakoglu, Kasim; Dizge, Nadir; Colak, Suleyman Gokhan; Ozay, Yasin; Bilici, Zeynep; Yalcin, M. Serkan; Ozdemir, SadinIn this study, a novel polyethersulphone (PES) nanocomposite membrane incorporated with copper zinc tin sulfide (Cu2ZnSnS4) nanoparticles (CZTS NPs) was prepared through the phase inversion method. First, the samples containing different copper and zinc ratios in CZTS stoichiometry were prepared and characterized. The effect of copper and zinc ratio changes were examined on the photocatalytic properties of both NPs and nanocomposite membranes. The photocatalytic effect was tested and BR18 dye was degraded at 88.0% efficiency when exposed to visible light for 180 min in the presence of CZTS1.0 NPs catalyst. The results also exhibited that CZTS NPs blended membrane showed good self-cleaning performance. Second, we investigated the antioxidant, DNA cleavage, and biofilm inhibition activities of CZTS NPs. The antimicrobial activities of CZTS NPs were tested against seven microbial strains. The highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and chelating activities were found as 81.80 +/- 1.75% and 72.19 +/- 4.63%, respectively. CZTS NPs exhibited double-strand DNA cleavage activity at 500 mg/L. They showed significant biofilm inhibition as 92.15 +/- 5.67% against Staphylococcus aureus. CZTS NPs displayed moderate antimicrobial effects against tested microorganisms. Third, CZTS NPs were blended in polyethersulphone (PES) membrane and the morphology as well as performance of the fabricated nanocomposite membranes were systematically investigated by SEM-EDX, porosity, water contact angle, antifouling, and rejection measurements. The water flux of resulting nanocomposite membranes was markedly enhanced due to the introducing of CZTS NPs. Meanwhile, the nanocomposite membranes demonstrated remarkable antifouling properties (flux recovery ratio similar to 94%) in contrast with the bare PES (flux recovery ratio similar to 51%) when BSA was filtrated. The high retention of BSA (100%) as well as high permeation flux (73.8 +/- 9.8 L/m(2)/h) of the CZTS2.00 wt% membrane demonstrated that the constructed nanocomposite membrane possessed the characteristics of a promising membrane for purification of proteins.Öğe Preparation of ZnO nanorods or SiO2 nanoparticles grafted onto basalt ceramic membrane and the use for E. coli removal from water(Elsevier Sci Ltd, 2021) Saleh, Mohammed; Gonca, Serpil; Isik, Zelal; Ozay, Yasin; Harputlu, Ersan; Ozdemir, Sadin; Yalvac, MutluThis article addresses the fabrication of a novel and eco-friendly ceramic membrane based on basalt powder via press and sintering methods with a pore size of 1.5-2 mu m. The basalt ceramic membrane (BCM) was grafted by SiO2 nanoparticles (50-60 nm) and ZnO nanorods (2.2 mu m). The water permeability for the prepared membranes was measured 345.3, 701.4, and 801.9 L/m(2) h bar for bare BCM, SiO2-BCM, and ZnO-BCM, respectively. The prepared membranes were used in Escherichia coli (E. coli) removal, and 100% E. coli removal efficiency was achieved at a transmembrane pressure of 0.5 bar for all membranes. The antimicrobial activities of the solid surfaces for BCM, SiO2-BCM, and ZnO-BCM were also studied using E. coli as a model test microorganisms. The antimicrobial activities for bare BCM, SiO2-BCM, and ZnO-BCM were 20.57%, 74.90%, and 100%, respectively. The results are of great importance in terms of the reusability of membranes and the prevention of biofilm formation in wastewater treatment processes.Öğe Synthesis of mesoporous magnetic Fe3O4 nanoparticles with different pore sizes and investigation of dye adsorption capacities(Taylor & Francis Inc, 2024) Ulusal, Fatma; Bilici, Zeynep; Ozay, Yasin; Ozdemir, Nalan; Dizge, NadirThis study synthesized mesoporous magnetic Fe3O4 nanoparticles with two pore sizes. First, two different pore sizes of SiO2 were synthesized using polyethylene glycol with molecular weights of 6000 kDa and 35,000 kDa. Next, mesoporous SiO2 was used as a template, and Fe3O4 was coated with a precursor. Then, the silica present in mesoporous SiO2 was leached. The adsorption capacities of the prepared mesoporous magnetic Fe3O4-NPs were compared using an azo cationic dye, Basic Red 18. Parameters such as solution pH, adsorbent amount, and dye concentration were optimized in the adsorption experiments. Additionally, the reusability of Fe3O4-NPs was investigated. The optimum conditions for P6-Fe3O4-NPs were the original pH, 0.5 g/L dose, 50 ppm dye concentration, 60 min contact time, and 100% removal efficiency. For P35-Fe3O4-NPs, the optimal conditions were original pH, 0.75 g/L dose, 20 ppm dye concentration, and 60 min of contact time, with 100% removal efficiency. The second-order kinetic model and Langmuir isotherm were found to be suitable for describing the adsorption of both nanoparticles. Under the optimum conditions, complete dye removal efficiency was achieved for both nanomaterials. Furthermore, in the real wastewater, the adsorption experiment utilizing P6-Fe3O4-NPs yielded a 98% efficiency in color removal at 620 nm.Öğe Synthesis of PES membranes modified with polyurethane–paraffin wax nanocapsules and performance of bovine serum albumin and humic acid rejection(IWA Publishing, 2023) Sert, Buse; Kaya, Gul; Ozay, Yasin; Alterkaoui, Aya; Ocakoglu, Kasım; Dizge, NadirMembrane fouling is a serious handicap of membrane-based separation, as it reduces permeation flux and hence increases operational and maintenance expenses. Polyurethane–paraffin wax (PU/PW) nanocapsules were integrated into the polyethersulfone membrane to manufacture a composite membrane with higher antifouling and permeability performance against humic acid (HA) and bovine serum albumin (BSA) foulants. All manufactured membranes were characterized by scanning electron microscopy (SEM), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), and contact angle. The contact angle of the pristine polyethersulfone (PES) membrane was measured 73.40 + 1.32. With the embedding of nanocapsules, the contact angle decreased to 64.55 + 1.23 for PES/PU/PW 2.0 wt%, and the pure water flux of all composite membranes increased when compared to pristine PES. The pristine PES membrane also has shown the lowest steady-state fluxes at 45.84 and 46.59 L/m2 h for BSA and HA, respectively. With the increase of PU/PW nanocapsule ratio from 0.5 to 1.0 wt%, steady-state fluxes increased from 51.96 to 71.61 and from 67.87 to 98.73 L/m2 h, respectively, for BSA and HA. The results depicted that BSA and HA rejection efficiencies of PU/PW nanocapsules blended PES membranes increased when compared to pristine PES membranesÖğe The effect of pre-treatment methods on membrane flux, COD, and total phenol removal efficiencies for membrane treatment of pistachio wastewater(Academic Press Ltd- Elsevier Science Ltd, 2022) Ozay, Yasin; Dizge, NadirIn this study, the effect of pre-treatment methods was investigated for membrane treatment of pistachio processing wastewater (PPW). Chemical coagulation, electrocoagulation, and electrooxidation processes were tested as the pretreatment methods to understand the effect of pretreatment on membrane performance. Alum (Al-2(SO4)(3).18H(2)O), iron (III) chloride (FeCl3.6H(2)O) and iron(II) sulfate (Fe(SO4).7H(2)O) were used as coagulant and anionic polyelectrolyte was used as flocculant. Al-Al and Fe-Fe electrode pairs were used in the electrocoagulation experiments while platinum (Pt), boron doped diamond (BDD), and graphite were used in the electrooxidation experiments. UP150, NF270, and NF90 were used as the membranes. Chemical oxygen demand (COD) and total phenol removal efficiencies from wastewater were determined by considering membrane flux. For chemical coagulation experiments, the highest COD removal efficiency was determined as 44.9% for Al-2(SO4)(3).18H(2)O at 1000 mg/L when the wastewater pH value was 8.0. However, the highest total phenol removal efficiencies were obtined as 62.5% at 4000 mg/L for FeCl3.6H(2)O at pH 8. For electrocoagulation experiments, the highest COD and total phenol removal efficiencies were determined as 63.9% at pH 4.0 and 74.2% at pH 7.0, respectively, for 100 A/m(2) current density when aluminum electrode pairs were used. For electrooxidation experiments, the highest COD and total phenol removal efficiencies were determined as 61.2% at pH 4.0 and 83.1% at pH 10, respectively, for 200 A/m(2) current density when BDD-Pt electrode pairs were used. Raw PPW and pre-treated PPW with chemical coagulation, electrocoagulation, and electrooxidation processes were progressively further treated with ultrafiltration (UP150) and nanofiltration (NF270, NF90) membranes to improve COD and total phenol removal efficiencies. The results showed that the permeate of NF90 membrane supplied the highest COD (96.0%) and total phenol removal (97.5%) efficiencies for the raw wastewater. However, COD and total phenol removal efficiencies were determined as 98.6% and 100% for electrocoagulation + NF90, 97.9% and 100% for electrooxidation + NF90, 96.6% and 100% for chemical coagulation + NF90, respectively. The steady-state fluxes for NF90 membranes were 2.9, 7.0, and 8.6 L/m(2)h after chemical coagulation, electrooxidation, and electrocoagulation, respectively. The results depicted that electrocoagulation and electrooxidation were the most suitable pre-treatment methods for water recovery using NF90 membrane.
