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    A comprehensive review on the usability of black phosphorus in energy and wastewater treatment
    (Elsevier Inc., 2024) Kaya, Gul; Eskikaya, Ozan; Kucukosman, Ridvan; Ocakoglu, Kasim; Dizge, Nadir; Balakrishnan, Deepanraj; Singh Chohan, Jasgurpreet
    Increasing population and industrial development brings with it many problems that need to be solved, such as energy production, storage, saving, protection of limited reserves, and environmental pollution. Nanomaterials, which emerged with the introduction of nanotechnology into our lives, play an important role in many areas. The novel two-dimensional nanomaterial black phosphorus (BP) exhibits great potential in photocatalytic applications, energy technologies, and purification with properties such as broad light absorption spectrum, tunable direct band gap, and exceptionally high charge carrier mobility. This review gives a outline of the manufacturing techniques, structural, chemical, electrical and thermal properties of BP. Then, the success of BP derivatives with different dimensions and morphologies in environmental and energy applications is presented by comparing them with previous studies in these fields. The results show that heterojunction structures produced by combining BP with MoS2 and MOFs improve the electrochemical properties of BP, while carbonization processes increase its efficiency in battery and supercapacitor applications. Finally, in this review, a summary of BP's potential future uses, awareness of easy production methods, and its activities in environmental and energy applications are discussed in a broad context. © 2024
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    A novel green approach for Cr(VI) removal: application of tomato stem-based hydrochar assisted Fenton-like process
    (Taylor & Francis Ltd, 2024) Alterkaoui, Aya; Belibagli, Pinar; Gun, Melis; Isik, Zelal; Eskikaya, Ozan; Yabalak, Erdal; Dizge, Nadir
    Environmentally friendly catalysts have come to the forefront due to the cost of chemically produced catalysts and the formation of by-products harmful to the environment. Millions of tons of plant waste are produced every year, some of which is disposed directly. In this study, tomato stem hydrochar (TSCH) was produced from waste tomato stems by the hydrothermal carbonisation (HTC) method, and its use as a catalyst was investigated. The optimisation of Cr(VI) removal from water was carried out using a Fenton-like process with a TSCH catalyst and resulted in 100% of Cr(VI) removal efficiency at 10 mg/L of Cr(VI) concentration, pH 2.00, 0.2 g/L of TSCH catalyst, 10 mu L/L of H2O2 and 60 minutes of reaction time. Fenton-like thermodynamic and kinetic data were analyzed, and the results were found to comply with the second-order in Cr(VI) removal. The reusability of the TSCH catalyst in Cr(VI) removal was investigated and it was emphasized that it was reusable for more than 5 uses. In conclusion, TSCH, which is an environmentally friendly, inexpensive and effective catalyst for Cr(VI) treatment in a Fenton-like process, can be used as an alternative catalyst for wastewater treatment in terms of both waste management and economic and environmentally friendly.
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    Caustic recovery from caustic-containing polyethylene terephthalate (PET) washing wastewater generated during the recycling of plastic bottles
    (Nature Portfolio, 2025) Alterkaoui, Aya; Eskikaya, Ozan; Keskinler, Bulent; Dizge, Nadir; Balakrishnan, Deepanraj; Hiremath, Pavan; Naik, Nithesh
    To prevent water scarcity, wastewater must be discharged to the surface or groundwater after being treated. Another method is to reuse wastewater in some areas after treatment and evaluate it as much as possible. In this study, it is aimed to recover and reuse the caustic (sodium hydroxide, NaOH) used in the recycling of plastic bottles from polyethylene terephthalate (PET) washing wastewater. Chemical substances used in the industry will be significantly reduced with chemical recovery from wastewater. Ultrafiltration (UP150) and nanofiltration (NP010 and NP030) membranes were used for this purpose in our study. Before using nanofiltration membranes, pre-treatment was performed with coagulation-flocculation process to reduce the pollutant accumulation on the membranes. Different coagulants and flocculants were used to find suitable coagulants and flocculants in pre-treatment. The pre-treated wastewater using aluminum oxide, which supplied the highest chemical oxygen demand (COD) removal (76.0%), was used in a dead-end filtration system to be filtered through NP010 and NP030 membranes at different pressures (10-30 bar). In the same filtration system, raw wastewater was filtered through a UP150 membrane. Among these treatment scenarios, the best method that could remove pollutants and provide NaOH recovery was selected. After each treatment, pH, conductivity, COD, and NaOH analyses were performed. The maximum NaOH recovery (98.6%) was obtained with the UP150 membrane at 5 bar.
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    Comparison of Cr(VI) adsorption and photocatalytic reduction efficiency using leonardite powder
    (Pergamon-Elsevier Science Ltd, 2022) Arslan, Hudaverdi; Eskikaya, Ozan; Bilici, Zeynep; Dizge, Nadir; Balakrishnan, Deepanraj
    It is very important to treat Cr(VI) from the aquatic environment due to its toxic and harmful effects. Conventional treatment methodology involving biological pathways is generally ineffective for wastewater containing Cr(VI). Therefore, it is necessary to develop environmentally friendly and economical methods to remove Cr(VI) from the aquatic environment. In this study, leonardite, which is a natural mineral that has no harmful effects on the environment, was used for Cr(VI) removal. Leonardite was used in both adsorption and photocatalytic treatment systems by only pulverizing without any chemical treatment. Characterizations of leonardite were obtained using X-ray fluorescence (XRF), fouirer transform infrared spektrofotometre (FTIR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) analyses methods. The effects of solution pH (2-10), particle size (45-300 mu m), adsorbent dose (0.25-3 g/L), and initial concentration (10-30 mg/L) on Cr(VI) removal efficiency were investigated in both adsorption and photocatalytic experiments. In the adsorption process, a complete removal efficiency (100%) was obtained for 3 g/L of adsorbent dose with an initial Cr(VI) concentration of 10 mg/L at pH 2 for 2 h. In the photocatalytic process, 100% removal efficiency of Cr(VI) was obtained when four times less adsorbent dosage was used under the same conditions. In addition, the reuse of leonardite powder was also investigated under optimum experimental conditions. Leonardite powder preserved approximately 70% of its activity in the photocatalytic process while it lost 50% of its activity after 5 reuses in adsorption process.
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    Investigation of Antimicrobial Activity of Iron Oxide Nanoparticles (FeONPs) and Zinc Oxide Nanoparticles (ZnONPs) Produced with Aerial Part Extract of Cucumber
    (Springer, 2024) Alterkaoui, Aya; Eskikaya, Ozan; Ozdemir, Sadin; Yalcin, M. Serkan; Dizge, Nadir
    One of the most threatening factors to human and living health today, as in the past, is pathogens, which cause significant damage to health. Many materials are used to destroy such bacteria. The investigation of antibacterial properties of materials containing heavy metals produced with plant extracts continues. In this study, iron and zinc oxide nanoparticles (FeONPs and ZnONPs) were produced with cucumber aerial part extract. The nanoparticles have diameters ranging from 60 to 120 nm for FeONPs and 70 to 130 nm for ZnONPs. The antibacterial properties of the produced materials were investigated. The biological evaluation of the ZnONPs and FeONPs was also reported in this study. The antioxidant activity of ZnONPs and FeONPs was found 48.00%, and 40.65%, respectively, at 100 mg/L concentration. ZnONPs exhibited significantly antimicrobial activity than FeONPs. Both NPs showed excellent DNA nuclease activity and also E. coli cell viability was strongly inhibited at all tested doses. At 250 mg/L, ZnONPs inhibited P. aeruginosa and S. aureus biofilms by 90.1% and 94.0%, respectively. FeONPs also reduced biofilm formation against P. aeruginosa and S. aureus by 87.8% and 93.4% at 250 mg/L, respectively. However, when all the results were compared, it was observed that ZnONP had a slightly higher antioxidant effect than FeONPs. The antibacterial effect of cucumber, particularly extracted from its waste aerial parts, demonstrated promising potential in combating microbial infections. This effect is evidenced by the utilization of cucumber extract in the synthesis of nanoparticles, namely FeONPs and ZnONPs, which exhibited significant antibacterial properties. The study underscores the importance of exploring natural sources like cucumber in developing novel antimicrobial agents. Further research in this area could unveil additional mechanisms underlying cucumber's antibacterial activity and facilitate the development of effective antibacterial treatments derived from natural sources.
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    Investigation of the Effect of Sintering of Waste Welding Powder on Antioxidant and Antimicrobial Activity
    (Springer Int Publ Ag, 2022) Eskikaya, Ozan; Arslan, Hudaverdi; Ozdemir, Sadin; Gonca, Serpil; Dizge, Nadir
    The use of waste as a material that can be useful in other areas can reduce both waste generation and the need for resources. Welding powder with high heavy metal content should be used for other purposes. For this reason, the welding powder, which is frequently used in the metal industry and released after the welding process, is desired to be used as an agent against microorganisms in this study. Several biological activities of welding powder and its sintered forms also investigated. The welding powder and its sintered forms showed moderate antioxidant and antimicrobial activity. Welding powder without sintering is called WP. Welding powders sintered at 300 ?degrees C, 600?degrees C, and 900?degrees C are named as WP300, WP600, and WP900, respectively. DNA cleavage activity was tested, and it showed single-stand cleavage against pBR 322 plasmid DNA. They displayed excellent biofilm inhibition activity, and the biofilm inhibition of WP, WP300, WP600, and WP900 against S. aureus and P. aeruginosa were found as 99.34%, 99.21%, 98.99%, and 99.12% and 98.32%, 96.11%, 96.38%, and 95.39%, respectively, at concentrations of 500 mg/L, respectively. They also demonstrated significant cell viability activity against E. coli.
  • Küçük Resim
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    Investigation of the treatment and antibacterial properties of pollutant-containing water using black phosphorus blended polyethersulfone membranes
    (Elsevier Ltd, 2024) Eskikaya, Ozan; Kucukosman, Rıdvan; Ozdemir, Sadin; Yalcin, M. Serkan; Ocakoglu, Kasım; Dizge, Nadir
    The most important problem of membrane processes is clogging and therefore the reduction of their useful life. In order to eliminate such problems, the production of composite membranes is an option in membrane treatment systems. In this study, the usability of black phosphorus (BP) in membrane treatment systems, and its effect on antibacterial and treatment performance were studied. BP blended PES membranes (BP@PES) produced by loading BP into the polyethersulfone (PES) membranes were used for the treatment of bovine serum albumin (BSA) and Escherichia coli (E. coli). For this purpose, BP was added at three different amounts (0.5 %, 1.0 %, and 2.0 %) into PES membranes. Membranes with different BP amounts produced were named as 0.5%BP@PES, 1.0%BP@PES, and 2.0%BP@PES. After the production of these composite membranes, they were used in the dead-end filtration system and compared with the PES membrane without BP (bare PES). The removal effectiveness of bare PES was found to be 53.40 % in the BSA rejection results, and it was discovered to be 60.90 %, 97.15 %, and 100 % for 0.5%BP@PES, 1.0%BP@PES, and 2.0%BP@PES, respectively. The antioxidant activity of BP was 70.86% at 100 mg/L. Newly prepared BP caused single-strand DNA nuclease abilities at 50, 100, and 200 mg/L. BP showed the effective antimicrobial activity. The most antimicrobial activity was determined as a minimum inhibitory concentration (MIC) value of 8 mg/L against E. hirae and 100 % E. coli viability inhibition activity was achieved at 50 and 100 mg/L after 90 min exposure. BP also inhibited the biofilm formation of P. aeruginosa at 87.19 % and S. aureus at 90.28 % at 50 mg/L. Thus, both the effect of BP on membrane performance and its antibacterial properties were investigated. Pure water fluxes, BSA and E.coli rejection performances, and antibacterial properties of all membranes used in the membrane filtration system were investigated in detail. It is recommended to further investigate BP-containing membranes with different production techniques.
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    Photocatalytic activity of calcined chicken eggshells for Safranin and Reactive Red 180 decolorization
    (Pergamon-Elsevier Science Ltd, 2022) Eskikaya, Ozan; Gun, Melis; Bouchareb, Raouf; Bilici, Zeynep; Dizge, Nadir; Ramaraj, Rameshprabu; Balakrishnan, Deepanraj
    One of the most important problems affecting the environment today is the inability to adequately treat wastewater containing dyes. Among of the many treatment processes used in the treatment of dye-containing wastewater, photocatalytic based wastewater treatment processes attract the attention of scientists as a new, economically feasible, and promising approach which has been in practice for a few decades. However, in order to use these processes in wider areas, cheap and effective catalysts are still being developed today. In this study, the photocatalytic activity of eggshell-CaO produced from waste chicken eggshells was investigated for decolorization of Safranin (Basic Red 2) and Reactive Red 180 (RR180) dyes. First, sintering process was applied to the waste chicken eggshells at different temperatures (300, 600, 900 degrees C) in order to observe CaO formation from the eggshells. Second, the parameters such as photocatalyst amount, pH, concentration of dyes, and reaction time were optimized on dye removal efficiency in photocatalytic experiments. The optimum conditions were performed under visible light and found to be 1 g/L of catalyst amount (sintered at 900 degrees C), original solution pH (6.80 for Safranin and 6.60 for RR180), and 5 mg/L of dye concentration. The photocatalytic removal efficiencies of Safranin and RR180 dyes were 100% and 97.90%, respectively, under the determined optimum experimental conditions. The adsorption efficiency of the dyes that could be realized during the photocatalytic experiment was measured as 20.99% and 9.99% for Safranin and RR180 dyes, respectively.
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    Production of Waste Tomato Stem Hydrochar (TS-HC) in Subcritical Water Medium and Application in Real Textile Wastewater using Photocatalytic Treatment System
    (Springer Int Publ Ag, 2022) Alterkaoui, Aya; Eskikaya, Ozan; Gun, Melis; Yabalak, Erdal; Arslan, Hudaverdi; Dizge, Nadir
    Dye-containing wastewater emerges in many fields, especially in the textile industry. This type of wastewater has to be treated because of its negative effects on the environment. The treatment of wastewater containing dyes employs a variety of treatment techniques. However, it is important to use treatment systems that use nanoparticles of biomaterial origin. In this study, the use of photocatalytic treatment system with hydrochar obtained from tomato stems (TS-HC) in the purification of Methylene Blue (MB) and Remazol Brilliant Blue R (RBBR) dyes was investigated. For the optimization of the photocatalytic treatment system, light source, pH, TS-HC amount and initial dye concentration were tested. Furthermore, TS-HC reuse tests were carried out at the found optimal conditions and it was determined that both dyes had 10 reuse cycles. Optimum conditions for MB dye was obtained by adding 1 g/L catalyst into the solution with a pH value of 8 and an initial concentration of 15 mg/L, and 100% dye removal efficiency under UVA light. 97.4% dye removal efficiency was obtained by adding 2 g/L catalyst to the wastewater (pH 2) containing 15 mg/L RBBR dye under UVA light. Characterization analyzes with SEM, EDX and XRD of hydrochar obtained from waste tomato stem were performed. As a result of the photocatalytic experiments, TS-HC catalyst was used in the decolorization of real wastewater. It has been determined that the catalyst can decolorize the dye-containing real wastewater up to the lower limit of the appropriate value (260 Pt-Co) of the Turkish Water Pollution Control Regulation.
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    Reuse of waste welding powder in Fenton-like process for RO16 dye removal and Cr(VI) reduction
    (Springer, 2024) Bulut, Hande; Eskikaya, Ozan; Belibagli, Pinar; Isik, Zelal; Arslan, Hudaverdi; Dizge, Nadir
    Waste minimization is one of the important issued nowadays. In this study, the usability of waste welding powders (WWPs) was investigated in the Fenton-like process for Cr(VI) and reactive orange 16 (RO16) dye removal from aqueous solution. Solution pH, amount of catalyst, amount of H2O2, initial pollutants concentrations, reaction time and temperature parameters were optimized. 100% RO16 dye removal efficiency was obtained at pH: 2, dye concentration: 100 mg/L, catalyst amount: 1 g/L, and H2O2 amount: 2.5 & mu;L/L. Besides, 99.7% Cr(VI) removal efficiency was obtained at pH: 2, Cr(VI) concentration: 10 mg/L, catalyst amount: 0.25 g/L, and H2O2 amount: 2.5 & mu;L/L. In addition, the characterization of WWP was also carried out by SEM, EDX, XRD, XRF, and zeta potential analyses. WWP can be considered to be a viable catalyst for both dye and Cr(VI) removal from aqueous solution. WWP's effectiveness was also tested in real wastewater. As a result of the experiments with real wastewater, 100% removal efficiency was obtained both textile wastewater for 60 min and Cr(VI) containing wastewater for 45 min. These results have revealed that WWP is a promising catalyst for the treatment of real wastewater.
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    The Usability of Polymer-Doped Black Phosphorus (BP@PVDF) as a Photocatalyst for Dye Removal in a Photocatalytic System
    (Springer/Plenum Publishers, 2024) Eskikaya, Ozan; Kucukosman, Ridvan; Ocakoglu, Kasim; Dizge, Nadir; Deepanraj, Balakrishnan; Senthilkumar, Natarajan
    It is well known that water with dye content needs to be treated to remove the environmental and health hazards it poses. In this study, the refinability of the photocatalytic treatment process with a photocatalyst containing black phosphorus, which is a popular material recently, was investigated. Black phosphorus (BP) was synthesized directly from red phosphorus at 180 degrees C using the recyclable liquid phase method in an ethylenediamine medium. Microstructural characterization of the samples was carried out by SEM, HR-TEM, BET and XRD techniques. A composite material was synthesized in a polymer-containing solution (Polyvinylidene fluoride; PVDF) to prevent the BP from being easily separated from the water and from being deformed. The obtained polymer-doped BP (BP@PVDF) as a photocatalyst was successfully removed from Methylene Blue (MB) dye in the photocatalytic system. As a result of the photocatalytic experiments with BP@PVDF, the removal efficiency of MB dye (10 ppm) was 93.49% after 1 h of the solution with a pH value of 7 under visible light. In addition, after 10 reuses in reuse experiments, the removal efficiency of the material decreased by 30.25%. Even in this case, 65.83% removal efficiency was obtained even in the 10th reuse of the reused BP@PVDF. Experimental and reuse results suggest that the synthesized material is an excellent photocatalyst with advantages such as both performance and reusability.
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    Use of welding powder as a low-cost adsorbent for waste motor oil removal
    (Wiley, 2024) Eskikaya, Ozan; Belibagli, Pinar; Bouchareb, Raouf; Isik, Zelal; Dizge, Nadir
    Waste motor oil (WMO), which has no stable form or structure, causes major environmental problems and damage to the ecosystem once it is disposed to the environment. Because of the high toxicity of contents in such effluent, it must be treated before being discharged into the receiving environment. In recent years, the valorization and the use of waste materials to remove toxic pollutants is of great importance to researchers and diverse industries. In this study, the usability of waste welding powder (WWP) as an adsorbent for waste oil removal was investigated. For this purpose, investigating the usability of material, which is generated as industrial waste, in wastewater treatment will lead to the evaluation of waste. The effects of temperature, pH, WWP amount, and initial WMO amount were investigated. According to the adsorption studies, 1 g WWP/L of the processed adsorbent was able to effectively remove 95.05% of WMO (100 mg) at a pH of 2 at 30 degrees C. Stereo microscopy images showed a large amount of oil adsorbed on the WWP surface. The different WWP properties were determined by adsorption isotherm (Harkins-Jura), kinetic (pseudo-second order), and thermodynamic (Delta G: -5.1 kJ mol-1) experiments. It is thought that WWP, which is a low-cost and waste material, can be used as a promising adsorbent in WMO removal. Wastewater containing waste motor oil (WMO) has high toxicity and must be treated before being discharged into the receiving environment. Weld powders (WWP) are the most suitable candidate for WMO removal due to their advantages such as low cost and easy separation. According to the experimental results, a removal efficiency of 95% shows that WWP can be used as a promising adsorbent in WMO removal. image