230 likes | 240 Views
This research study presents a green and sustainable method for water purification using sensitized ZnO nanoparticles. The project addresses the severe water pollution in Palestine due to contaminants like industrial dyes, pesticides, and heavy metals. By utilizing light-sensitive semiconducting materials and natural solar energy, the study aims to achieve complete mineralization of organic contaminants. Various experiments on UV irradiation, ZnO characterization, and photo-degradation processes are discussed to develop an efficient and eco-friendly purification technique.
E N D
PHOTODEGRADATİON OF WATER-ORGANİC CONTAMİNANTS WİTH SAFE SENSİTİZED ZnO NANOPARTİCLES: A GREEN SUSTAİNABLE METHOD FOR WATER PURİFİCATİONPresented by: Amani Zu’biCoauthors: Ahed Zyoud & Hikmat HilalChemistry Department / An-Najah N. University, Palestien1 ICAME-2017 Yildiz University
The problem to solve • Palestine suffers serious shortages in pure water supplies. • Due to the abuse of ground water resources practiced by settlers. They also dispose their sewage randomly into Palestinian areas • Most commonly: (Industrial dyes, phenolderivatives herbicides, pesticides, insecticides, drugs … ec) and heavy metals. • Contaminants reach ground & surface water • Severe pollution occurs. • Purification & recycling of water is needed. ICAME-2017 Yildiz University
Different types strategies are used to remove contaminants. But expensive or not efficient. • Recently: Natural solar energy has been examined for complete mineralization. • Core issue is developing light-sensitive semiconducting materials to catalyze photo-degradation ICAME-2017 Yildiz University
The Idea of Semiconductors Band Diagram: Semiconductor with Non Doping T > 0 Conduction band (Partially Filled) EC EF EV Valence band (Partially Empty) ICAME-2017 Yildiz University
How Semiconductors catalyze photodegradation: Semiconductor absorbs photon with (hν > Eg), electron is excited to conduction band, & positive hole remains valence band. electron-hole formation. ICAME-2017 Yildiz University
UV Irradiation Experiments Using ZnOSchematic Mechanism of Photo-Excitation ZnO (Semiconductor) by UV Light ICAME-2017 Yildiz University
The purpose: Using lab prepared ZnO nano-powder and using it in degrading organic contaminants (Methyle Orange) under solar simulator light using the UV fraction (~4%), taking into account: 1- efficiency 2- recyclability 3- cost 4- environmental safety 5- working under natural conditions. ICAME-2017 Yildiz University
ZnO Characterization ICAME-2017 Yildiz University
Electronic absorption spectrum for lab-prepared ZnO powder (aqueous suspension). ICAME-2017 Yildiz University
PhotoluminescenceSpectra Photoluminescence emission spectrum measured for ZnO powder (in suspension). ICAME-2017 Yildiz University
X-ray Diffraction (XRD) of ZnO ICAME-2017 Yildiz University
Scaning Electron Micrograph images forZnO 17 nm ICAME-2017 Yildiz University
Solar Simulator Photodegradation Experiments Measuring The %degradation Turn over number Quantum yeild underdifferent Experiment conditions ICAME-2017 Yildiz University
Methyl Orange ICAME-2017 Yildiz University
intensity 19.0 mW/cm Profiles of photo-degradation reaction for aqueous methyl orange (100 mL, 10 ppm) at different pH values, using ZnO catalyst (0.1g) at room temperature with total radiation Effect of pH on photo-degradation process ICAME-2017 Yildiz University
Effect of temperature Profiles of photo-degradation reaction of methyl orange solution (100 mL, 20 ppm) at different temperatures, using ZnO catalyst (0.1 g) and total irradiation intensity of 19.0 mW/cm2 at pH ~7 ICAME-2017 Yildiz University
Effect of CO2 and other gas flows Effect of gas streams on methyl orange photo-degradation. Reactions were conducted using methyl orange solution (100 mL, 20 ppm) under 19.0 mW/cm2 irradiation using ZnO (0.1 g) with continuous stirring at 20oC with different gas flows: (a) exposed to air only (b) air flow (c) N2 flow open system (d) CO2 and air flows together (e) CO2 flow (f) closed system with nitrogen flow (g) N2 and CO2 flows together. ICAME-2017 Yildiz University
Effect of contaminant concentration ICAME-2017 Yildiz University
Effect of catalyst nominal amount on photo-degradation process ICAME-2017 Yildiz University
Effect of light intensity on the photodegraation process ICAME-2017 Yildiz University
Catalyst re-use experiments ICAME-2017 Yildiz University
Complete mineralization ICAME-2017 Yildiz University
Thank You ICAME-2017 Yildiz University