Environmental Engineering / Çevre Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4321
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Article Citation - WoS: 2Citation - Scopus: 1Dynamics of Co2 Consumption, and Biomass and Lipid Carbon Production During Photobioreactor Cultivation of the Diatom Cyclotella(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2023) Ökten, HaticeUnderstanding of CO2 delivery and consumption dynamics in algal photobioreactors are critical to unravel microalgae’s full potential for bioproduct generation and carbon capture from flue gas streams. This study aims to expand our current understanding by cultivating the diatom Cyclotella under controlled process conditions of a bubble column photobioreactor and analyzing CO2 consumption dynamics in real time using results from an online CO2 sensor connected to the reactor exhaust. Two sets of experiments were conducted: they served to contrast the influence of silicon and nitrate (Si&N colimitation) and Si limitation, and the light availability, respectively. CO2 consumption was calculated based on the mass balance around the reactor inlet and outlet gas streams. Biomass samples and lipid extracts were analyzed for carbon (C) content to determine biomass-C and lipid-C concentrations. The outlet CO2 concentrations varied significantly with cultivation time and process conditions. More than 15% to 65% of the CO2 introduced left the reactor in the exhaust at any instance based on the set CO2 transfer rates. The highest average daily capturing efficiency was 60%. Nutrient limitation regimes imposed generated unique CO2 consumption profiles undiscernible by the biomass-C analysis, i.e. unlike Si limitation, N limitation had more immediate detrimental effects on C consumption. Final biomass-C concentration increased with increasing N and light availability, 275 mg/L vs. 336 mg/L, and 270 mg/L vs. 501 mg/L, respectively. Biomass-C based capturing efficiency approximations resulted in 20% to 40% underestimation. Under Si-limited conditions, the higher light intensity increased the final lipid-C to biomass-C ratio by two times (from 20% to 40%) and the final lipid-C concentration and peak productivity by four times (from 56 mg/L to 216 mg/L, from 7 to 30 mg/L-day, respectively). This study demonstrates online exhaust CO2 concentration-based analysis’s unique capabilities for assessing carbon availability and capture, organic-C production, and its diversion to biomass and lipid production.Article Citation - WoS: 3Anaerobic Co-Digestion of Tannery Solid Waste: Optimum Leather Fleshing Waste Loading(2020) Bayrakdar, AlperIn this study, loading of optimum leather fleshings was investigated with four identical batch reactors with different fleshings and treatment sludge ratios (0:1, 0.25:1, 0.35:1, 0.50:1) to contribute to the state of art of the biogas production from tannery solid wastes. Results showed that lipids-containing leather fleshings boosted the methane production potential. However, H2S inhibition and volatile fatty acids accumulation were the main concern in the anaerobic digestion of these wastes. The modified Gompertz model was applied to the batch tests data to determine the kinetic constants of anaerobic digestion of tannery solid wastes. It was calculated with the model outputs that the ultimate methane production potential and maximum methane production rate in reactors having mixing ratio of 0.35:1 and 0.5:1 (dry basis) were highly similar. 0.35 was found to be an optimum leather fleshing and treatment sludge ratio with a 54% more methane production potential than that of control reactor in this study.Article Citation - WoS: 1Arsenate Removal From Groundwater by Air-Injected Ec With Al Ball Anodes: Effects of Operational Parameters(Pamukkale Üniversitesi, 2020) Gören, Ayşegül Yağmur; Öncel, Mehmet Salim; Kobya, MehmetTreatment of arsenate from groundwater by electrocoagulation (EC) reactor with air supply unit using Al ball electrodes were studied in this paper. Influence of some operating variables, for instance, applied current (0.075-0.3 A), initial pH (5.5-8.5), air flow rate (0-6 L/min), size of Al ball electrodes (5-10 mm), and height of electrode in EC reactor (2-8 cm) on the As(V) removal efficiency were evaluated. The As (V) removal efficiency increased with the increment of applied current, air flow, electrode altitude in EC reactor, and EC time while its removal efficiency decreased with the increment of size of Al ball electrodes. The maximum As(V) removal percentage, minimum operating cost and energy consumption were found as 98.68 %, 0.609 $/$m^3$ and 3.7694 kWh/$m^3$ at pH of 7.5, current density of 0.30 A, size of Al balls of 7.5 mm, height of electrode in EC of 5 c†m, and air flow rate of 6 L/min, respectivelyArticle Citation - WoS: 5Color Removal From Yeast Production Industry Wastewater Using Photo-Fenton Process(Pamukkale Üniversitesi, 2019) Baycan, Neva; Can, BegümThe yeast production industry wastewaters contains high amount of chemical oxygen demand (COD), brownish color and recalcitrant organic components. In this work, one of the yeast production plant wastewaters operating in the Aegean Region, the color removal were studied with using Photo-Fenton (H2O2/Fe(II)/UV) oxidation processes. In this study, the Box-Wilson statistical experimental design method applied to optimization of decolorisation of the yeast production industry wastewater. For this reason, the initial oxidant and catalyst concentrations and pH of water were chosen as the experimental parameters on decolorisation. Color removal was observed during the experimental studies. Complete color removal (E=100%) was achieved with the addition of 2400 mg/L H2O2 and 121 mg/L Fe(II) at 3.7 pH after 120 min. of exposure to the UV irradiation.