Article
Chemistry, Physical
Nicole Longtin, Daniela Oliveira, Aishwarya Mahadevan, Varun Gejji, Carmen Gomes, Sandun Fernando
Summary: In this study, a unique configuration of Spirulina-based microalgal fuel cell was tested, showing highest performance on day seven during the exponential growth phase. Additionally, the highest power density was achieved when three fuel cells were connected in parallel.
JOURNAL OF POWER SOURCES
(2021)
Article
Biotechnology & Applied Microbiology
Adriyanus Ivan Pratama, Hanifah Nuryani Lioe, Nancy Dewi Yuliana, Masahiro Ogawa
Summary: The umami compounds in the acid-hydrolysate of Spirulina were investigated in this study. The Spirulina hydrolysate was found to have a higher umami intensity compared to unhydrolyzed one. A specific umami fraction was obtained by ultrafiltration and chromatography, containing high concentrations of succinic acid and free L-glutamic acid, as well as abundant glutamyl peptides.
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2022)
Article
Environmental Sciences
Hadiyanto Hadiyanto, Amnan Haris, Fuad Muhammad, Norma Afiati, Adian Khoironi
Summary: This study examined the interaction between Styrofoam and S. platensis, revealing that Styrofoam stress can stimulate the growth of S. platensis and induce changes in the functional groups of Styrofoam. The results suggest that Styrofoam can serve as a nutrient source, particularly carbon, for S. platensis photosynthesis, but it may also cause damage to the cells of S. platensis.
Article
Agronomy
Zeinab A. Shedeed, Saly Gheda, Sara Elsanadily, Khadiga Alharbi, Mohamed E. H. Osman
Summary: This study evaluated the improvement of growth, photosynthetic capacity, and yield of Lupinus luteus by using Spirulina platensis extract. The results showed that the lower concentration of the extract had a positive effect on growth and phytohormonal level, while the higher concentration inhibited growth.
Article
Environmental Sciences
Mousa O. Germoush, Maged M. A. Fouda, Mohamed Kamel, Mohamed M. Abdel-Daim
Summary: The study demonstrated the potential therapeutic effect of Spirulina platensis against MC-LR-induced toxic effects in male Wistar rats, by alleviating oxidative damage in liver and kidneys, cardiotoxicity, and neurotoxicity. Spirulina restored normal levels of serum markers and normalized tissue antioxidant biomarkers, mitigating organ toxicities induced by MC-LR.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Energy & Fuels
Duygu Elma Karakas, Murat Akdemir, A. E. Atabani, Mustafa Kaya
Summary: In this study, a Pd-Co catalyst supported by Spirulina Platensis waste was successfully utilized for the methanolysis reaction of NaBH4, and subsequently tested as an electrode material for a supercapacitor, exhibiting high hydrogen generation rate and gravimetric capacitance values.
Article
Biotechnology & Applied Microbiology
Daniela Zapata, Catalina Arroyave, Lorena Cardona, Adriana Aristizabal, Charlotte Poschenrieder, Merce Llugany
Summary: Cultivating Spirulina in dairy wastewaters showed higher levels of phytohormones compared to synthetic medium, with low light intensity promoting longer and thicker filament growth, especially in cheese whey. This method allows for cost-effective production of biomass and phytohormones while treating dairy wastewaters.
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2021)
Article
Polymer Science
Rodrigo Martins, Claudia Mouro, Rita Pontes, Joao Nunes, Isabel Gouveia
Summary: This article presents the first production of nanofibers through electrospinning of polyvinyl alcohol (PVA) and Spirulina platensis extracts. The extracts were obtained using ultrasound-assisted extraction with a natural deep eutectic solvent (NADES) and water. The nanofibers formed with 5% and 20% (v/v) of NADES/Spirulina extract showed promising antioxidant activities, with the highest activity observed for NADES/Spirulina and PVA nanofibers (47%). Additionally, these nanofibers exhibited the highest antimicrobial activity (89.26%). Principal Component Analysis revealed positive correlations between the antioxidant and antimicrobial activities, extract content, viscosity, conductivity, and nanofiber diameter.
Article
Thermodynamics
Bin Wang, Zhixia He, Bo Zhang, Yibing Duan
Summary: In this study, hydrothermal liquefaction of spirulina platensis using biochar-based catalysts was investigated. Results showed that Ni/BC was the most favorable catalyst for bio-oil production, with significant improvement in bio-oil yield at low temperatures. Furthermore, Ni/BC demonstrated excellent denitrification effect on bio-oil.
Article
Chemistry, Inorganic & Nuclear
Yan Zheng, Bo Zhang
Summary: The study investigates the potential of using wastewater from sewage sludge dewatering as a solvent to convert microalgae into biocrude. Results show higher biocrude yield in wastewater solvent compared to pure water, indicating potential for increased production. The enhancing mechanism of wastewater solvent on liquefaction is discussed, highlighting the significance of this recycling strategy for utilization of organic wastewater in sewage sludge treatment.
INORGANIC CHEMISTRY COMMUNICATIONS
(2021)
Article
Energy & Fuels
Janakan S. Saral, Panneerselvam Ranganathan
Summary: In this study, catalytic hydrothermal liquefaction of Spirulina platensis using red mud as a catalyst was investigated. The catalyst significantly influenced the biocrude yield and quality, with process conditions such as temperature, reaction time, slurry concentration, and catalyst-to-biomass ratio playing important roles in maximizing the biocrude yield. By analyzing the biocrude components and investigating various process parameters, it was found that nitrogen-containing compounds were not prominent in biocrude from catalytic hydrothermal liquefaction.
BIOMASS CONVERSION AND BIOREFINERY
(2022)
Article
Food Science & Technology
Hani Shkolnikov Lozober, Zoya Okun, Avi Shpigelman
Summary: The study focused on the gel characterization of Spirulina protein concentrate (SPC) and utilized high-pressure homogenization (HPH) before thermal gelation to improve gel properties. Gelation was found possible at pH 6.5 but not at more acidic pH due to insufficient protein solubility. The application of HPH at 50 MPa increased protein solubility by 91% and improved gel stiffness while decreasing the gelation point.
INNOVATIVE FOOD SCIENCE & EMERGING TECHNOLOGIES
(2021)
Article
Multidisciplinary Sciences
Sueilha F. A. Paula, Bruna M. E. Chagas, Maria I. B. Pereira, Adriano H. N. Rangel, Cristiane F. C. Sassi, Luiz H. F. Borba, Everaldo S. Santos, Estefani A. Asevedo, Fabiana R. A. Camara, Renata M. Araujo
Summary: This study reports the energetic characterization of Spirulina platensis biomasses cultivated under autotrophic and mixotrophic conditions, using cheese whey waste. The results show that it is possible to decrease the formation of nitrogen compounds by manipulating growth conditions and temperature. The biomass produced by S. platensis can be used for the production of high-quality bio-oil and valuable chemicals.
Article
Food Science & Technology
Mengwei Wang, Xiangning Lu, Xing Zheng, Wei Li, Lijuan Wang, Yuemiao Qian, Mingyong Zeng
Summary: This study aimed to develop a novel 3D printing material using Spirulina platensis residues. The rheological properties, microstructure, and texture characteristics of the residues were investigated. The printing process could be realized under ambient conditions. The development of this microalgae residue ink promotes the high-value and comprehensive utilization of microalgae in the food industry.
FOOD RESEARCH INTERNATIONAL
(2023)
Article
Food Science & Technology
Ridvan Arslan, Salih Aksay
Summary: This study investigated the sensorial and physicochemical properties of yogurt colored with phycocyanin from Spirulina platensis. The highest preference was for yogurt colored with 0.5% Spirulina, which also had the highest protein content at 29.25 g/100 g DM. As Spirulina content increased, L*, a*, and b* values decreased, and Delta E value increased. Overall, Spirulina can be used to enrich yogurt as a natural functional ingredient due to its high nutritional and pigment content.
JOURNAL OF FOOD PROCESSING AND PRESERVATION
(2022)
Review
Chemistry, Analytical
Cafer Saka
Summary: This review provides a comprehensive study on the detection techniques and quantitative determination methods of CQ and its related metabolites. Various methods such as chromatography, electrophoresis, electroanalytical, spectroscopic, and immunological methods are extensively discussed. It aims to provide a better understanding of the use of CQ for therapeutic purposes in the COVID-19 outbreak.
CRITICAL REVIEWS IN ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Analytical
Cafer Saka, Gulten Elci Olcenoglu, Omer Sahin
Summary: The petroleum coke sample (PCS) was successfully modified for the first time by oxygen plasma treatment (OPT), increasing the new active groups containing oxygen on the PCS surface, and removing malachite green dye from the aqueous medium.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Analytical
Ibrahim Tegin, Cafer Saka
Summary: This study investigated the removal of methylene blue by both raw and modified clay, with the modified clay showing significant improvements in adsorption capacity. The modification process included calcination, acid treatment, and second calcination, with factors such as calcination temperature and acid/base concentration affecting the adsorption capacity. Characterization of the clay was done by SEM and FTIR, and Langmuir and Freundlich isotherm models were used to analyze the results.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
(2023)
Article
Environmental Sciences
I Tegin, M. S. Batur, O. Yavuz, C. Saka
Summary: This study investigates a low-cost and economical heat-treated clay sample as a potential adsorbent for the removal of Cu(II), Pb(II) and Cd(II) ions from aqueous solutions. The results show that the adsorption ability of the heat-treated clay adsorbent is significantly improved compared to the raw clay sample.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
(2023)
Article
Environmental Sciences
Cafer Saka, Yavuz Yardim, Omer Sahin, Orhan Baytar
Summary: This study investigates the application of chestnut shell-based activated carbon in iodine adsorption and as an electrochemical double-layer capacitor material. The results show that chestnut shell-based activated carbon exhibits excellent performance in adsorption and capacitor properties.
INTERNATIONAL JOURNAL OF PHYTOREMEDIATION
(2023)
Article
Chemistry, Physical
Yasar Genel, Ilyas Genel, Cafer Saka
Summary: Activated carbons synthesized from the ash tree were found to be effective adsorbents for removing methylene blue from aqueous solutions. The carbonaceous materials exhibited mesoporous structures and active functional groups. The highest adsorption capacities were obtained with chemical activation using zinc chloride and sodium hydroxide.
FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES
(2023)
Article
Chemistry, Physical
Cafer Saka
Summary: This study focuses on the production of two-stage metal-free catalysts from pistachio shells. The first stage involves the production of activated carbon (AC), while the second stage involves the production of catalysts doped with heteroatoms through hydrothermal heating of the obtained activated carbon with nitric acid. The metal-free catalysts are then used for hydrogen production from sodium borohydride (NaBH4) in methanol.
Article
Materials Science, Multidisciplinary
Cafer Saka, Ibrahim Tegin, Kubra Kahvecioglu
Summary: This study focuses on enhancing the adsorption capacity of activated carbon by sulphur doping, using almond shells as the base material. The results showed that sulphur doped activated carbon exhibits high adsorption performance for Cd(II) and follows Langmuir isotherm and pseudo-second-order kinetic models.
DIAMOND AND RELATED MATERIALS
(2023)
Article
Environmental Sciences
Kubra Kahvecioglu, Ibrahim Tegin, Omer Yavuz, Cafer Saka
Summary: In this study, activated carbon based on almond shells was produced through microwave heating and then modified with phosphorus and oxygen through hydrothermal heating. The modified activated carbon showed improved adsorption efficiency for Cd(II) and Pb(II) ions. The results indicated that the modified activated carbon follows Langmuir isotherm and pseudo-second-order kinetics for adsorption of both Cd(II) and Pb(II).
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Chemistry, Physical
Cafer Saka
Summary: The surface properties of graphitic carbon nitride (GCN) were enhanced by doping with sulphur (S), boron (B), and oxygen (O). Metal-free GCN catalysts with heteroatom dopants showed improved surface functional groups and a carbon defect structure. These catalysts were used for hydrogen production from sodium borohydride (SB) methanolysis, resulting in a 2.2-fold increase in H2 production compared to GCN. The HGR value obtained with B, O, and S doped GCN was 9166 ml min-1g-1. XPS, SEM-EDX, TEM, FTIR, and XRD analyses were performed to investigate the structural properties of the catalysts, and the activation energy (Ea) for B, O, and S doped GCN was determined to be 28.89 kJ mol-1.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Cafer Saka
Summary: Hybrid kaolin-g-C3N4 heterostructure particles were fabricated and phosphorus and oxygen doped kaolin-g-C3N4 metal-free catalyst was synthesized for the first time for effective hydrogen production from sodium borohydride methanolysis. The catalyst showed a hydrogen generation rate of 5500 ml min-1g-1 and an activation energy of 31.90 kJ mol-1. The kaolin-g-C3N4 and doped catalysts were characterized by various techniques, and a mechanism for hydrogen production was proposed.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Materials Science, Multidisciplinary
Cetin Murtazaoglu, Ibrahim Tegin, Cafer Saka
Summary: In this study, activated carbon (AC) was produced from pistachio shells using potassium hydroxide (KOH) activation, and then modified with hydrogen peroxide (H2O2). The modified AC (KOH-AC-H2O2) was found to effectively adsorb Cu (II) and Zn (II) ions from wastewater, with adsorption behavior in accordance with the Langmuir isotherm model.
DIAMOND AND RELATED MATERIALS
(2023)
Article
Chemistry, Physical
Yavuz Yardim, Cafer Saka
Summary: This study investigated the thermal activation of Chlorella vulgaris and Spirulina platensis microalgae using potassium hydroxide (KOH) in a carbon dioxide (CO2) atmosphere, followed by the hydrothermal interaction with nitric acid to form nitrogen and oxygen-doped activated carbons. These carbons were then used to fabricate electrochemical supercapacitors. The morphological properties of the obtained pores were characterized by transmission electron microscopy (TEM), and the electrochemical properties were evaluated by cyclic voltammetry (CV) in different electrolytes. The results showed that the nitrogen and oxygen-doped electrode based on Spirulina platensis microalgae exhibited the highest specific capacitance of 99.53 Fg(-1) in a 1 M H2SO4 electrolyte, while the supercapacitor based on the activated carbon electrode from Chlorella vulgaris microalgae showed the highest specific capacitance of 156.04 Fg(-1) in a 1 M KCl electrolyte.
FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES
(2023)
Article
Energy & Fuels
Cafer Saka, Ibrahim Tegin, Kubra Kahvecioglu, Omer Yavuz
Summary: In this study, a two-step method was employed to produce an effective adsorbent for the adsorption of cadmium (Cd) (II) and lead (Pb)(II). The method involved the preparation of activated carbon (AC) from almond shells using microwave heating and potassium hydroxide (KOH), followed by nitrogen and oxygen doping through hydrothermal treatment with nitric acid. The resulting materials were characterized and their adsorption performance, mechanism, kinetics, and thermodynamics were evaluated. The nitrogen- and oxygen-doped ACs exhibited good adsorption capacity for Cd (II) and Pb (II), with values of 106.38 mg/g and 76.33 mg/g, respectively.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Environmental Sciences
Cafer Saka
Summary: In this study, phosphorus and boron-doped graphitic carbon nitride/zeolite catalysts were prepared under three-step heating conditions. The catalysts were characterized using various techniques, and it was found that they can be used as metal-free catalysts for hydrogen production from sodium borohydride in methanol. The hydrogen production rate for these catalysts was measured to be 6250 ml min(-1) g(-1), which is reported for the first time in the literature.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
