Assessment and Comparison of New and Old Carbon Filters for Contaminants Removal: Antwerp Coca Cola plant, Belgium

Abstract

AJOL Abstract: Coca-Cola’s water quality criteria for carbonated beverage process water include an absence of chlorine residual and total trihalomethanes (THMs) below the local drinking water standard or, in the absence of a local standard, the WHO standard is used. Presence of chlorine residual in feed water used for production of carbonated beverage process water is of a concern as chlorine free water is needed for production of carbonated beverages. GAC is used in the bottling industry primarily for de-chlorination of municipal chlorinated water and/or process water subjected to in-plant chlorination at chlorine doses of several mg/L. In addition to de-chlorination GAC is also required for the removal of THMs. This study assessed the proportion of chlorine, TOC and THMs’ before and after the GAC filters. It also compared the removal efficiency of two weeks and four year GAC filters and finally evaluated the effectiveness of steam regeneration of GAC. Samples were taken from before the treatment plant and influent and effluent of the GAC filters for the analysis of TOC, UV and THMs determination. The result showed that 8.8 % TOC removal in the filters and based on the SUVA value. The low removal of TOC was related to non humic substance, relatively low hydrophobicity, less aromatic and of lower molecular weight of the TOC. Comparison of two week and four years in service old GAC reveals THMs breakthrough of 3.8 and 58 % at the end of one steam regeneration cycle for EBCT of 2.41. This suggests that steam regeneration is only partially recovering THMs adsorption capacity