Synthesis and Characterisation of Graphene Oxide for Water Purification

Industrial wastewater is filled with many pollutants, ranging from chemicals to harmful bacteria. This project aims to investigate the use of Graphene Oxide as an effective way to adsorb heavy metal ions, as well as the possible dye degradation and antibacterial properties of graphene oxide. Graphene oxide was synthesised with the modified Hummers Method. Three different degrees of oxidation of Graphene Oxide were produced. Heavy metal ion adsorption and organic dye degradation was tested using a colorimeter and UV-Vis spectrophotometer respectively. The bacterial tests were conducted using agar well diffusion. It was found that Graphene Oxide with the highest degree of oxidation is very effective in the adsorption of Fe3⁺ with an average of 99% adsorption rate, compared to Zn2⁺ and Cu2⁺ with an average adsorption rate of 60% adsorption and 50% respectively. Graphene oxide was also found to be very effective in degrading organic dyes. But it does not show any antibacterial properties against both gram positive and gram-negative bacteria in the dark. Graphene oxide is thus able to act as a chemical substitute to ultrafiltration and reverse osmosis water purification methods. It has the potential of being incorporated into filtration devices which can assist in curbing water poisoning caused by heavy metal ions and dyes.