Elektrokemijsko uklanjanje iona metala upotrebom protočne ćelije

master's thesis

• Title (english): Electrochemical removal of metal ions using a flow-through electrochemical cell
• Author: Ivana Sever
• Mentor: Marijana Kraljić Roković (mentor)
• Committee member: Marijana Kraljić Roković (predsjednik povjerenstva)
• Committee member: Helena Otmačić Ćurković (član povjerenstva)
• Committee member: Lidija Furač (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2016-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Environmental Protection in Chemical Engineering

Abstract

Svrha ovog rada bila je ukloniti bakar iz modelne otopine bakrovih iona elektrokemijskim putem pri čemu je korišten protočni reaktor sa pločastim elektrodama. Elektrodni materijali je odabran na način da su provedena ispitivanja metodama cikličke voltametrije, kronoamperometrije, kronopotenciometrije te rotirajuće disk elektrode uz korištenje troelektrodnog sustava. Nakon ispitivanja kao najbolji katodni materijal se pokazala platina, zlato, olovo i čelik. S obzirom na visoku cijenu platine i zlata, kao katodni materijal izabran je čelik. Olovo je izabrano kao anodni materijal jer se u području pozitivnih potencijala na površini olova formira stabilan sloj PbO2 koji katalizira reakciju razvijanja kisika. Nakon odabira elektrodnog materijala izradio se elektrokemijski reaktor te je provedena elektroliza kod tri različite vrijednosti napona i tri različita protoka elektrolita. Pri tome je određen koeficijent prijenosa mase koji je varirao od 1,887x10^-3 cm s^-1 do 7,183 x10^-3 cm s^-1 . Određene su i bezdimenzijske veličine (Sh, Re i Sc) koje su stavljene u odnos kako bi se okarakterizirao prijenos mase u reaktoru. Pri tome su kod različitih napona dobiveni različiti parametri jednadžbe Sh=aRe^bSc^1/3 . Postotak uklonjenog bakra veći je od 96% za sve slučajeve, osim za najmanju brzinu protoka uz 2,5 V, pri čemu djelotvornost uklanjanja bakra raste s porastom napona i protoka. Specifična potrošnja energije elektrolize izražena po masi uklonjenog bakra raste s porastom napona te pada s porastom brzine protoka, a kretala se u granicama od 4937 W h kg^-1 do 10.281 W h kg^-1.

Abstract (english)

The aim of this work was to remove copper from a model solution of copper ions using a flow through electrochemical reactor with parallel plate electrodes. Different materials were tested by using cyclic voltammetry, chronoamperometry, chronopotentiometry and rotating disc electrode with a three-electrode system. Platinum, gold, led and steel have shown the best properties in order to be used as cathode material. Considering the high price of platinum and gold, chosen cathode material was steel. Led was chosen as anode material due to the formation of PbO2 in positive potential range and catalytic activity for oxygen evolution reaction. After choosing the appropriate electrode materials, the reactor was assembled and the performance of the electrochemical reactor was investigated at three different voltage values and three different flow rates. In this experiment mass transfer coefficient was determined to be between 1,887x10^-3 cm s^-1 and 7,183 x10^-3 cm s^-1. Dimensionless numbers (Sh, Re and Sc) were correlated to characterize mass transport properties of the electrochemical reactor and they were fitted to the equation Sh=aRe^bSc^1/3. Removal efficiency of copper was higher than 96% for all experiments with the exception of lowest flow speed and voltage of 2.5 V. The removal efficiency increased with increase of voltage and flow rate. Specific energy consumption decreased with the voltage and flow rate decrease in the range from 4937 W h kg^-1 to 10 281 W h kg^-1.

• Keywords: bakar; ciklička voltametrija; kronoamperometrija; kronopotenciometrija; otpadna voda; rotirajuća disk elektroda; protočni elektrokemijski reaktor; kataliza; prijenos mase; potrošnja energije
• Keywords (english): copper; cyclic voltammetry; chronoamperometry; chronopotentiometry; wastewater; rotating disc electrode; flow through electrochemical reactor; catalysis; mass transport; energy consumption
• Language: croatian
• URN:NBN: urn:nbn:hr:149:688902
• Study programme: Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra primijenjene kemije (magistar/magistra primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Repository: Repository of Faculty of Chemical Engineering and Technology University of Zagreb
• Created on: 2017-10-05 11:05:45