Developments in Winery Wastewater Treatment and Management

Wine processing industries require a substantial amount of water and generate considerable volumes of wastewater. Winery wastewater (WWW) is notable for its high concentrations of biodegradable organic matter, while containing relatively low levels of nutrients. Due to seasonal variability in wastewater generation, treatment processes must be both efficient and adaptable. A range of wastewater treatment technologies are currently implemented at pilot and full scales, and ongoing research continues to yield innovative solutions in laboratory settings. This paper provides a comprehensive review of advancements in WWW treatment technologies, pinpoints gaps, and highlights future research directions. The treatment methods discussed include aerobic reactors, anaerobic systems, constructed wetlands (CWs) and biosand filters (BSFs), as well as advanced oxidation processes (AOPs). The advantages and limitations of these techniques, along with key factors affecting their performance, are examined. CWs are regarded as cost-effective and efficient solutions for small to medium wineries, whereas activated sludge and anaerobic digestion processes, which require a smaller footprint, are suitable for managing higher loads at large wineries. While anaerobic processes offer reduced operating costs, they often produce effluents of lower quality compared to aerobic processes, necessitating subsequent polishing prior to discharge. Advances in AOPs present promising alternatives for pre/post-treatment, facilitating the breakdown of persistent organics and achieving acceptable chemical oxygen demand (COD) levels. Nevertheless, further research is required to address operational optimization and reduce associated costs.