Determination of heavy metal ion concentration by electrochemical methods : bachelor thesis

U ovom radu je ispitana mogućnost uklanjanja Cu 2+ iona iz vodene otopine CuSO 4 ×5H 2 O elektrokemijskim putem tj. procesom elektrotaloženja na elektrodi od Pt. Svrha mjerenja je bila snimanjem potenciodinamičkih polarizacijskih krivulja (i-E ovisnosti) u otopinama poznatih koncentracija (c = 1.0, 2.5, 5.0, 7.5 i 10 mM) te očitavanjem graničnih difuzijskih struja (i d ) odrediti nepoznatu koncentraciju Cu 2+ iona u CuSO 4 ×5H 2 O otopini. i-E ovisnosti su snimane u području potencijala od potencijala otvorenog strujnog kruga do –3.0 V uz različite brzine promjene potencijala (1, 5, 10, 20 i 50 mV/s). Kod većih koncentracija Cu 2+ iona, na površini Pt elektrode se taloži deblji sloj crvenkasto-smeđe prevlake bakra. Nadalje, granična difuzijska struja, i d , raste linearno s porastom koncentracije Cu 2+ iona u otopini elektrolita. Konstruiran je dijagram i d = f(c) te su određene nepoznate koncentracije Cu 2+ iona u tri nasumično pripremljene CuSO 4 ×5H 2 O otopine. Ustanovljeno je da se elektrokemijskim putem uspješno mogu ukliniti Cu 2+ ioni iz vodenih otopina te odrediti njihova koncentracijaIn this paper, the possibility of removing heavy metal ions, specifically Cu 2+ ions from an aqueous solution of CuSO 4 ×5H 2 O by electrochemical means (i.e. electrodeposition on the Pt electrode), was investigated. The purpose of the measurement was to determine the unknown concentration of Cu 2+ ions in CuSO 4 ×5H 2 O solution by recording potentiodynamic polarization curves (i-E dependences) in solutions of known concentrations (c = 1.0, 2.5, 5.0, 7.5 and 10 mM) and reading the limiting diffusion currents (i d ). i-E dependences were recorded in the potential range from the open circuit potential to –3.0 V at different scan rates (1, 5, 10, 20 and 50 mV/s). At higher concentrations of Cu 2+ ions, a thicker layer of copper coating is deposited on the Pt electrode surface. Furthermore, the limiting diffusion current, i d , increases linearly with increasing concentration of Cu 2+ ions in the electrolyte solution. A diagram i d = f(c) was constructed and unknown concentrations of Cu 2+ ions in three CuSO 4 ×5H 2 O solutions were determined. Heavy metal ions can be successfully electrochemically removed from polluted waters and their concentration can be determined