Characterization of brewery wastewater with spectrofluorometry analysis

Abstract

The wastewater treatment systems from the three local breweries consist of upflow anaerobic sludge blanket (UASB) and activated sludge (AS) connected in series for which the influent and effluent from each treatment step were collected and determined for their dissolved organic matter (DOM) surrogate parameters including dissolved organic carbon (DOC), UV 254 and SUVA 254. The analyses suggested that the influent wastewater contained a high level of aromatic organic content classified as humic substances with high average molecular weight. Organic removal mostly occurred in the UASBs where DOC and UV 254 were reduced by 24–58% and 38–50%, respectively. Spectrofluorometry analysis (fluorescent excitation–emission matrix: FEEM) was reasonably accurate in evaluating DOM reduction during the treatment course. A total of eight fluorescent peaks were detected by the FEEM technique comprising (A) 230 nm Ex/315 nm Em, (B) 275 nm Ex/315 nm Em, (C) 230 nm Ex/365 nm Em, (D) 285 nm Ex/365 nm Em, (E) 290 nm Ex/400 nm Em, (F) 335–355 nm Ex/405–465 nm Em, (G) 255 nm Ex/455 nm Em, and (H) 500 nm Ex/525 nm Em. Peaks ‘A and B’ and ‘C and D’ were associated with tyrosine-like, tryptophan-like substances, respectively, whilst each individual peak E, F and G was associated with humic and fulvic acid-like substances. Peaks C, D, F and H were always found in the influent wastewater from all the breweries, whereas the effluents only exhibited Peak F. The origin of Peak H had not been recognized elsewhere and was not identified in this work. This suggested that FEEM could not only be used to monitor the reduction in DOM, but it could also provide details on the organic composition of the wastewater.