Recovery of copper ions from waste waters by using flow-through electrochemical reactor

Cilj ovog rada bio je elektrokemijskim putem ukloniti bakar iz modelne otopine bakar(II)-sulfata pomoću elektrokemijskog protočnog reaktora. Korišten je elektrokemijski reaktor napravljen od pleksiglasa dimenzija 3 cm x 3 cm x 10 cm. Prilikom odabira materijala za izradu elektroda ispitana su svojstva različitih materijala metodom cikličke voltametrije i metodom rotirajuće disk elektrode. Kao katodni materijal izabran je čelik, dok je kao anodni materijal izabrano olovo. Elektroliza je provedena pri konstantom naponu od 2,5 V kod sedam različitih brzina protoka tijekom dva sata. Određeni su koeficijenti prijenosa mase, km za svaku brzinu protoka i oni su se kretali u granicama od 0,458*10^-3 cm s^-1 do 2,466*10^-3 cm s^-1. Osim pomoću km prijenos mase u reaktoru okarakteriziran je i preko bezdimenzijskih veličina (Sh, Re i Sc) uz pomoć kojih je određena korelacijska jednadžba. Ispitivanja su pokazala da djelotvornost uklanjanja bakra pri naponu od 2,5 V raste s porastom brzine protoka i to u rasponu od 38,42 % do 92,92 %. Specifična potrošnja energije izražena po volumenu tretirane otopine raste s porastom brzine protoka u rasponu od 2,3 W h L^-1 do 6,5 W h L^-1 dok specifična potrošnja energije izražena po masi uklonjenog bakra pada s porastom brzine protoka u rasponu od 4804,96 W h kg^-1 do 2596,92 W h kg^-1.The goal of this work was to use an electrochemical process to remove copper from a model solution of copper(II)-sulphate by using of flow through electrochemical reactor. The reactor was made of acrylic glass with dimensions 3 cm x 3 cm x 10 cm. A different materials were tested by using cyclic voltammetry method and rotating disc electrode in order to select suitable electrode materials. A steel has been selected as the cathode material and a lead has been selected as the anode material. The performance of the electrochemical reactor was investigated by using different flow rates during two hours at 2.5 V. The mass transport coefficient, km, has been determined for each flow rate and its values were found to be between 0.458*10^-3 cm s^-1 and 2.466*10^-3 cm s^-1. Additionally, mass transport phenomena were analysed by using dimensionless numbers (Sh, Re and Sc) that were fitted to the equation: Sh = aRe^b Sc^(1/2). The experiments carried out in this work has shown that the efficiency of copper removal increases from 38.42 % up to 92.92 % by increasing the flow rate. The specific energy consumption per volume of treated water increases from 2.4 W h L^-1 up to 6.5 W h L^-1, while specific energy consumption per mass of removed copper decreases from 4804.96 W h kg^-1 up to 2596.92 W h kg^-1 by increasing the flow rate