Presence of Arsenic, Lead and Zinc in the Cleaning Process of Returnable Glass Bottles and Assessment of the Effectiveness of the Chelating Agent Used

Studies have shown the presence of trace amounts of heavy metals in numerous brands of soft drinks but have failed to explain the source of these heavy metals. This study aimed at determining the amount of heavy metals in the cleaning process of the Returnable Glass Bottles (RGBs) and assessing the effectiveness of EDTA used as a chelating agent. Total number of 18 samples from detergent unit and chelating unit were analyzed using Total X-ray Fluorescence (TXRF) and the amount of chelating agent required for complete complexation of the heavy metals determined via complexiometric titration. The effectiveness of the chelating agent was established using UV-VIS spectrophotometer. The mean levels (±SE) of As, Pb and Zn were found to be Pb2+ (1.75±0.05 mg/L), Zn2+ (3.86±0.05 mg/L) and As3+ (0.82±0.02 mg/L)] for the detergent unit and Pb2+ (0.98±0.02 mg/L), Zn2+ (2.65±0.02 mg/L) and As3+ (0.74±0.00 mg/L)] for chelating units. Metal ions in the chelating units were found to be completely complexed. The minimum amount of EDTA for complete complexation was consumed at pH 7.0. It was suggested that soft drink manufacturing companies should optimize the conditions at the chelating units to cut down on the consumption rate of EDTA. 

Documentation :