A review of winery wastewater treatment: A focus on UASB biotechnology optimisation and recovery strategies

The upflow anaerobic sludge blanket (UASB) bioreactor was reviewed in search of a sustainable biotechnology solution for the management of winery wastewater (WWW) accumulation. Aerobic wastewater treatment systems are notorious for heavily exploiting energy and water resources, wasting residual materials, and depending on commercialised chemicals for winery wastewater treatment (WWWT). In comparison, anaerobic digestion (AD) and accelerated anaerobic bioprocesses, such as the UASB bioreactor, holds the potential to save electric kWh (kWh-e), water, sludge waste, and chemical residue generated during WWWT. The successful implementation of the UASB bioreactor at the wineries and wastewater treatment plants (WWTPs) is dependent on the preparedness of the biotechnology to manage the fluctuating discharge of raw WWW and meet the legislative demands for high product quality at a low cost. A rapid analysis approach and post-treatment options are proposed in the literature as a possible aid for inexpensive WWW quality control and hence effective WWW management. The conditions for optimum biogas production and the removal of chemical oxygen demand (COD) in the UASB bioreactor were also reviewed. Optimal COD removal and biogas production for reactors operating under mesophilic bioreactors (30-35 degrees C) were observed when OLR and HRT were 6 kg/m(3)/d and 22 h, respectively, while submesophilic bioreactors (19-21 degrees C) required an OLR and HRT of 7 kg/m(3)/d and 16 h, respectively.