Pine posts and poly problems

Most winegrowers are well aware of the challenges especially around posts and poly.

The copper and arsenic in CCA posts act as fungicides and insecticides, while the chromium fixes the chemicals into the wood to prolong the useful life of the as the most frequently chosen supporting structure for vine trellis. There are almost 21,000 hectares of vineyards in the Riverland of which at least 85% would have CCA timber trellis posts. It has long been known that treated timber poses a danger to both humans and the environment mostly due to the seepage of arsenic and chromium into nearby soil or surrounding water – both of which are human carcinogens. Stockpiles of used and broken posts have grown for many years throughout the industry and a method to deal with them in an environmentally responsible manner does not currently exist for the wine industry.

Similarly, since drip irrigation was introduced widely in the 1980s polypipe has been used extensively for irrigation in vineyards. In recent years much of that poly tubing has been replaced and stockpiles of replaced poly have grown alongside the broken CCA posts. These piles of waste products create a haven for pests and are a real blight on the region’s landscape.

But there is a glimmer of hope. Following the June visit of the team of senior academics to Riverland Wine, from the School of Chemical Engineering and Mathematical and Computer Sciences at the University of Adelaide, Dr Philip van Eyk and colleagues have drafted a proposal for a project to be carried out in collaboration with Riverland Wine to investigate the issues around these waste products. The team is hoping to develop an affordable, sustainable solution for the region’s growers, using what is known as an hydrothermal carbonisation (HTC) process, for the CCA posts, converting this waste into a valuable product.

For the poly tubing the process is known as HTL (hydrothermal liquefaction). HTL is one of the leading candidates for crude oil production from waste streams (especially plastics) due to the excellent properties of the produced oil comparable to conventional crude oil.

Stay posted for updates as this project develops interest in this region and indeed throughout the industry.

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