Profiling and monitoring of DOM in brewery wastewater and treated wastewater

Abstract

Dissolved organic matter (DOM) in raw and treated wastewater from two breweries in Thailand was profiled and monitored for the purpose of water reclamation. The wastewater and the effluent from the use of an upflow anaerobic sludge blanket (UASB) and activated sludge (AS) were collected and analyzed through a resin fractionation method using the fluorescent excitation-emission matrix (FEEM) technique. The results revealed that the major organic fractions in the brewery wastewater were hydrophobic acid (HPOA) and hydrophilic base (HPIB), accounting for 65% of total dissolved organic carbon (DOC) mass for brewery A and 56% of total DOC mass for brewery B. The FEEM results indicated that the organic matter in the wastewaters of both breweries were mainly composed of tryptophan-like substances, represented by peaks C (230 nm(Ex)/340-365 nm(Em)) and D (265-295 nm(Ex)/315-390 nm(Em)), and humic-like substances, represented by peaks E (290 nm(Ex)/400 nm(Em)), F (330-335 nm(Ex)/395-410 nm(Em)), and G (255-265 nm(Ex)/435-455 nm(Em)). The analysis revealed that the reduction of DOM occurred mostly during the UASB treatment where most of the DOM reduction resulted from the removal of the HPOA and HPIB fractions. The HPOA fraction, a group of humic-like substances, is of particular concern when reclaiming treated brewery wastewater, and although it was reduced by more than 80% of its initial amount, it was still a dominant DOM fraction in the effluents.