Winery wastewater management and treatment in the Niagara Region of Ontario, Canada: A review and analysis of current regional practices and treatment performance

Abstract

The winemaking process produces a large volume of wastewater with highly variable characteristics. Methods in place to manage winery wastewater (WWW) vary, with some wineries treating their WWW on‐site, while others direct the WWW to municipal wastewater treatment plants (WWTPs). Despite the significant presence and growth of the wine industry in the Niagara Region of Ontario, Canada, few data are available regarding the characteristics and treatment of WWW in this geographic region. This work presents a comprehensive review of full‐scale treatment methods currently in place to manage and treat WWW at 53 wineries in the Niagara Region. The most common type of on‐site treatment is the constructed wetland process, providing overall removal rates of >98% for chemical oxygen demand (COD) and >98% for total suspended solids (TSS) for the combined treatment of WWW and site‐generated sanitary sewage. Subsurface effluent discharge is the most widely used disposal strategy, while larger systems treating WWW alone also reuse the effluent for vineyard irrigation. The construction and operation of on‐site treatment systems at wineries does not address all WWW treatment needs, requiring a portion of the WWW to be co‐treated at WWTPs. While full‐scale operating data indicate that anaerobic co‐digestion with municipal sludges is effective (89% COD removal), the co‐digestion capacity is limited. Co‐treatment in the municipal WWTPs' liquid treatment train leads to negative operational and performance impacts. No efficient WWW co‐treatment options, viable in the long‐term, are currently available at municipal WWTPs. Improved co‐treatment strategies are required to address WWW treatment needs in the Niagara Region.

Characterising winery wastewater composition to optimise treatment and reuse

“…As a result, the co-treating municipal WWTPs typically receive high-strength WWW for co-treatment, even during the non-vintage period. A previous analysis of this dataset concluded that, while parameter value ranges are consistent with WWW characteristics reported for other geographic regions, the sample set is not unbiased as it is influenced by the factors noted above (Johnson and Mehrvar 2020). As a result, any conclusions drawn from this dataset may not be directly applicable to WWW characteristics from other geographic regions and/or individual wineries.…”

“…Where possible, the source of the WWW was recorded, and records indicated that the dataset represents WWW from at least 33 local wineries. The hauled WWW originated from holding tanks used by wineries to temporarily store their process wastewaters, loads of highstrength wastewaters that would overload the wineries' onsite treatment systems and pump-down of settling chambers used as part of the on-site treatment processes (Johnson and Mehrvar 2020).…”

“…Because of the nature of regional WWW handling and treatment practices in the Niagara Region, the WWW hauled to municipal WWTPs represents untreated WWW collected from holding tanks at the wineries, settled WWW collected from settling basins (septic tanks) installed as part of the on-site WWW treatment systems and highstrength wastewater diverted from on-site treatment systems to avoid overloading the treatment process (Johnson and Mehrvar 2020). As a result, the co-treating municipal WWTPs typically receive high-strength WWW for co-treatment, even during the non-vintage period.…”

“…Recent investigations into state-of-the-art WWW treatment options have generally focused on advanced treatment technologies, including aerobic and/or anaerobic suspended-growth systems, membrane filtration, advanced oxidation processes (AOPs) and combined biological-AOP systems (Ioannou et al 2015, Lofrano andMeric 2016). In spite of this, full-scale applications at many wineries still consist of simple systems such as lagoons or constructed wetlands (Masi et al 2015, Flores et al 2019, Johnson and Mehrvar 2020.…”

“…The variable characteristics of WWW can affect the performance and effectiveness of co-treatment at municipal WWTPs, with the potential for oxygenation limitations, poor sludge settleability and overloading of the aerobic and anaerobic biological treatment systems (Beck et al 2005, Bolzonella et al 2007, Johnson and Mehrvar 2020. When treated effluent is retained on site and used for vineyard irrigation, a comprehensive understanding of the characteristics of the WWW would allow proactive decision-making regarding chemical conditioning requirements and sludge disposal needs to ensure soil quality is preserved (Bustamante et al 2005).…”