Akademik Veri Yönetim Sistemi
Tezin Türü: Doktora
Tezin Yürütüldüğü Kurum: Gazi Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği, Türkiye
Tezin Onay Tarihi: 2022
Tezin Dili: Türkçe
Öğrenci: Meryem Gören
Asıl Danışman (Eş Danışmanlı Tezler İçin): Atilla Mirati Murathan
Eş Danışman: Nihan Kaya
Özet:
In this study, the removal of Rhodamine B dye from aqueous solution was investigated by using pine cones, which is an agricultural waste. The untreated pine cones were activated chemically and thermally using HNO3, KOH and NaOH. In addition, heat-activated pine cones were chemically reactivated by treating them with ZnCl2, H3PO4, H2SO4 and KOH. The study demonstrated that adsorption of Rhodamine B dye on chemically activated pinecone with HNO3 was found to be more effective than thermally activated. Furthermore, among these chemical activating agents, acidic ones seem to be more effective than basic ones because acidic activation increased the adsorption capacity of the adsorbent. The organic structure of the pine cone deteriorated due to the high temperature during the thermal activation, and therefore, the removal of the dye has been reduced. Based on the graphs obtained by applying all the experimental data to the isotherm equations, it was observed that the adsorption process with HNO3 activated pine cone and thermally activated pine cone were in good agreement with the Langmuir isotherm model. The pseudo-second order kinetic model was determined according to the R2 correlation coefficient values as the kinetic model that gives the best fit for the adsorption of the pine cone activated with HNO3. Thermodynamic parameters Gibbs free energy change (ΔGo ), standard enthalpy change (ΔHo ) and standard entropy change (ΔSo ) for HNO3 activated pinecone revealed that the adsorption process is endothermic. The negative Gibbs free energy change and positive ΔHo values indicated that the adsorption process occurs spontaneously under normal conditions. The positive ΔHo and ΔSo values for pine cone activated carbon demonstrated that the adsorption process is endothermic and spontaneous, while the positive ΔGo values proved that the adsorption process leads to an increase in Gibbs free energy and is not spontaneous. Consequently, the results showed that HNO3 activated pinecone can be used for the removal of Rhodamine B dye from aqueous solutions.
Key Words : Adsorption, pine cone, activation, activated carbon, Rhodamine B