Yazar "Senthilkumar, Natarajan" seçeneğine göre listele

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    Enhanced biogas yield in anaerobic digestion of citric acid wastewater by pre-treatment: The effect of calcium hydroxide precipitation and electrocoagulation process
    (Elsevier, 2024) Belibagli, Pinar; Akbay, Habibe Elif Gulsen; Arslan, Salih; Mazmanci, Birgul; Dizge, Nadir; Senthilkumar, Natarajan; Balakrishnan, Deepanraj
    During the production and use of citric acid (CA), which is frequently used in food, chemistry, metallurgy and other related industries, wastewater with high organic load and acidity is generated. Discharge of these wastewaters into the receiving environment without adequate purification causes serious pollution problems. However, treating such wastewater with hybrid processes allows both the formation of valuable by-products and an increase in the degree of purification. In this study, the biogas production potential of citric acid wastewater (CAWW), which was pre-treated by chemical precipitation and electrocoagulation (EC) processes, was investigated. Pre-treatment experiments were designed using Box-Behnken Design (BBD) and chemical oxygen demand (COD) concentrations after hydrated lime (Ca(OH)2) precipitation and EC processes were determined as 4960 mg/L and 5120 mg/L, respectively. The pre-treated CAWW were finally used for the secondary treatment by anaerobic digestion (AD) process. After AD process COD degradation determined as 67% and 98% for Ca (OH)2 precipitation and EC process, respectively. In addition, the biogas production of the pre-treated CAWW increased approximately 2 and 7 times for the Ca(OH)2 precipitation and EC processes, respectively, compared to the untreated. The methane (CH4) content of the produced biogas increased by 18% and 50% for Ca(OH)2 precipitation and EC processes, respectively. According to 48-hour acute toxic test result, daphnia mortality decreased from 50% concentration of CAWW after AD, even 10% concentration is non-toxic to daphnia. In conclusion, the complementarity of Ca(OH)2 precipitation and EC processes with AD promoted both the removal of organics from wastewater and the production of valuable by-products.
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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.