Brewery wastewater as an alternative external carbon source for full-scale municipal wastewater treatment plants: A performance, cost, and environmental assessment

Abstract

Brewery wastewater, a byproduct of beer production, poses significant challenges for wastewater treatment. However, due to its high organic concentration and substantial volume, it can serve as a valuable carbon source for municipal wastewater treatment plants (WWTPs) where additional carbon is often required for denitrification. This study investigates the collaborative treatment of brewery wastewater and municipal wastewater in full-scale WWTPs using the anaerobic/anoxic/oxic (A²O) process, aiming to achieve mutual benefits in terms of cost savings and carbon emission reductions. Initially, a small amount of brewery wastewater (approximately 0.09 to 0.18 % of the WWTP's influent flow rate) was introduced into the WWTPs. The results indicated that the effluent quality remained stable throughout the experiment. The effluent chemical oxygen demand (COD) and total nitrogen concentrations were approximately 19.97 ± 6.49 mg COD L⁻¹ and 11.02 ± 1.79 mg N L⁻¹ in WWTP Plant-1, and 31.86 ± 5.29 mg COD L⁻¹ and 11.31 ± 1.84 mg N L⁻¹ in WWTP Plant-2, all of which meet discharge standards. This collaborative treatment approach provides both economic and environmental benefits for breweries and municipal WWTPs. Furthermore, increasing the flow rate of brewery wastewater to approximately 7.3 % of the WWTP's influent flow rate also yielded similarly positive results. Specifically, savings of $1.02 to $8.87 per ton of brewery wastewater and a reduction of 0.0014 to 0.0201 tons of CO₂ equivalent per ton of brewery wastewater were achieved. This research offers new insights into brewery wastewater treatment, demonstrating its potential to reduce overall treatment costs and carbon emissions.