Tarac Environment Future Fund:	2005
Project:	Minimising potassium content of winery wastewater
Fund recipient:	JJC Engineering Pty Ltd

The reuse of winery wastewater for vineyard irrigation is a key environmental objective of the Australian Wine Industry. Current wastewater treatment technologies successfully remove the biological oxygen demand (BOD), however the dissolved salts, in particular sodium and potassium, pass through the treatment processes and are inhibitors to reuse because of their potential impact on soil health and wine quality.

The project was funded by the Tarac Environmental Future Fund (TEFF) and the Grape and Wine Research and Development Council (GWRDC) to identify and quantify the potential removal of potassium by segregation of water of high strength salt from specific cleaning processes during wine making.

Trials were conducted in collaboration with two premier South Australian wineries, Yalumba’s winery at Moppa in the Barossa Valley and Rosemount Ryecroft (Foster’s) in McLaren Vale.

A prior study conducted at Rosemount in 2003-4 had established that the tank sludges (lees plus potassium hydrogen tartrate (KHT)) contributed most to the potassium found in wastewater. The work of the current research therefore focussed on quantifying the amount of potassium lost at each stage of the tank washing process.

The key findings of the investigations demonstrated that tank wash water discharged from tanks used to process wine immediately after fermentation contributed:

• 110 mg/L potassium into wastewater during vintage, compared to typical levels of 150 mg/L found in winery wastewater and also
• 13% of site wastewater chemical oxygen demand (COD) load in 1.4% of the total wastewater flow during vintage.

Segregation of these streams would therefore significantly improve the quality of waste water and allow the recovery of potassium and tartrate for reuse.

Spent caustic from the caustic wash, which followed the tank wash process, was found to contain relatively low levels of potassium, offering little incentive for recovery. However the reduction of sodium in the wastewater at the winery is encouraged. This could be achieved through the replacement and/or more efficient use of caustic cleaning agents. Based on trials undertaken during the project personnel at Ryecroft were successful in developing equipment and procedures that reduced sodium-based cleaner use and reuse increased by an impressive 60%. Analysis of the spent caustic suggested that there is potential to further concentrate this stream and facilitate removal of an even greater load from the treatment plant.

The current trials have enhanced the understanding of the impact that the wine making process has on the potassium content of wastewater streams and provided quantifiable benefits in support of changing practices to improve outcomes for the environment.

Tarac Environment Future Fund:	2005
Project:	Viability of establishing a micro wave carbonisation facility to process CCA and Creosote treated posts
Fund recipient:	Fibrecell (Aust) Pty Ltd

The project was funded under TEFF and investigated the potential feasibility of establishing a microwave carbonization (MC) facility to process Copper, Chromium and Arsenic (CCA) and Creosote treated posts to solve a significant problem faced by the Wine Industry. No effective disposal process currently exists for these materials and with the high levels of the current stockpile there is an imperative to find an environmentally feasible disposal solution.

The Unique Planet Pty. Ltd. Microwave Carbonisation process provides a unique waste disposal solution which produces outputs of potentially commercially viable products. In addition this process is able to process feedstock of differing quantity and quality and demonstrates suitability for differing waste types and locations.

Information was collated from a range of sources in order to identify current and predicted level of CCA and Creosote treated post waste. Discussions were held with a range of industry and Government bodies.

Though the financial viability of the proposed plant was prepared there were several areas that required further investigation:

• Very high levels of investment
• Evidence that the technology will work with different feedstocks
• Environmental issues with disposal of residuals some of which were quite toxic
• Further market analysis for use of process by-products
• High risk technology
• Location of plant