Browsing by Author "Ozguven, A."

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Effect of Some Medium Parameters on Brilliant Blue G Biosorption by Amberlite Resin/Agaricus Campestris
(Springer, 2021) Yonten, V; Ozguven, A.; Ahmed, A. A.; Akcay, M. E.
In this research, two biocomposite materials, namely Amberlite IRA-400 Cl resin/A. campestrisand Amberlite 4200 Cl resin/A. campestris, were used to perform the biosorption of Brilliant Blue G from aqueous solution. The biosorption of dye was evaluated by using a batch system. In addition, the effect of some physicochemical and kinetic parameters of the medium such as pH, temperature, contact time and initial concentration was determined. In this research, pH (3-11), adsorbent dosage (0.3 g), initial dye concentration (10-150 mg L-1), temperature (298-318 K) and contact time (10-95 min) were investigated. In the 95th minute, biosorption reaches a maximum of 137.18 mg/g at the highest temperature (318 K). Brilliant Blue G biosorption increased for both materials and at pH 11 values reached 149 mg/g on IRA-400 Cl resin/A. campestrisand 142 mg/g on IRA-4200 Cl resin/A. campestris. The characterization of adsorbents was done by scanning electron microscopy, element detection X-ray and Fourier transform infrared spectroscopy. The adsorption isotherms were examined for the biosorption process. The Harkins-Jura isotherm shows better fit than the other isotherms for IRA-4200 Cl resin/A. campestris, and the Freundlich isotherm is a better fit in the temperature range studied than the other isotherms for IRA-400 Cl resin/A. campestrisbiocomposite. Thermodynamic values such as enthalpy, change in entropy and Gibbs free energy were measured, and the biosorption process was found to be spontaneous and endothermic. As a result, IRA-400 Cl resin/A. campestrisis a suitable biosorbent and has more typical proximity than IRA-4200 Cl resin/A. campestrisbiocomposite for biosorption of Brilliant Blue G from aqueous solutions.
“Assessment of Spatiotemporal Water Quality Variations, Impact Analysis and Trophic Status of Big Soda Lake Van, Turkey
(Springer, 2020) Ozguven, A.; Demir Yetis, A.
The study was conducted in order to assess the spatiotemporal variations of selected water quality parameters, impact analysis, and trophic status on the Edremit shores of Lake Van. Water samples were collected from 10 representative sampling stations taken from the influent, effluent, and from Lake Van itself in order to analyze the physicochemical parameters in both dry and wet seasons. The trophic status of the lake was determined using Carlson trophic state index. Impact analysis was conducted based on the method most commonly used in management strategies related to surface waters in Turkey. The results of the study show that five factors obtained from principal component indicated that the parameters responsible for water quality changes were mostly related to salts and soda, physicochemical parameters, point and diffuse pollutions discharge, and other organic pollutants. In the impact analysis pH, COD (chemical oxygen demand), BOD (biological oxygen demand), and TP (total phosphorus) (except for EC (electrical conductivity)) parameters were found to have medium impact, while DO (dissolved oxygen) and TN (total nitrogen) parameters had no impact. The pH, EC, SO4−2, Cl−, TP, COD, and BOD values measured at 10 sampling stations were considered to be Class IV according to national regulations. The final trophic status of lake, according to the Carlson trophic index, was assessed to be eutrophic. Understanding this variation is important so as to develop new ways to resolve issues of sustainable water management. In addition, it is considered essential to prepare guidelines for the trophic status of Lake Van. © 2020, Springer Nature Switzerland AG.