Environmentally and economically sustainable management of winery waste and wastewater is a high priority for the industry. Each winery generates wastewater with a unique quality, and seasonal variation pattern. Winery wastewater is often of high strength and is highly variable in quantity and quality making it a difficult effluent to manage.
This project was undertaken in order to better understand the best practices available to minimize wastewater volume and reduce the production of poor quality effluent. The ways in which wastewater can be treated and disposed of were investigated and appraised against their environmental impact. Key outputs from the project were a comprehensive review of winery wastewater management across the industry and a detailed breakdown of wastewater quality and volumes from different winery processes. This information has been summarized into reports and has been communicated to the industry via popular press articles, reports and workshops. The information has also been packaged into software tools that identify the contribution of components of the waste stream arising from various processes in the winery, quantify the environmental footprint and provide a costing of the wastewater treatment.
Operators need rapid and reliable quantitative indicators to tell them if their effluent falls within the allowable thresholds and if not, to diagnose, optimise and troubleshoot the plant processes. The suggested suite of key indicators includes pH, electrical conductivity (EC), dissolved oxygen (DO), turbidity and chemical oxygen demand, COD. Biological oxygen demand, BOD, while a useful indicator, is both expensive and has too large a lag time to assist with day-to-day management, so COD is suggested as a surrogate. The sodium adsorption ratio (SAR) of irrigation water is a good indicator of the potential damage that will occur to soil structure through repeated application of the wastewater.