This article first appeared in Waste Management Review where CDE Regional Manager for Australasia, Daniel Webber shared his thoughts with the team at Waste Management Review.
LOOKING BEYOND THE SURFACE OF CONTAMINATED SOIL IS PROVING TO BE A VALUABLE TOOL IN RESOURCE RECOVERY. CDE GROUP’S SEPARATION TECHNOLOGY IS AT THE FOREFRONT OF CHANGE.
Increasing landfill levies and stringent government regulation is driving a demand to find better ways to deal with contaminated soils. At the same time, higher density urban development is revealing new layers of contamination. Daniel Webber, Regional Manager Australasia for CDE Group explains that, as land is rezoned and old buildings and roads are demolished in urban areas, PFAS (per- and poly-fluoroalkyl substances), hydro carbons and heavy metals are being unearthed.
CDE Group has engineered turnkey projects around the world for processing plants that remove naturally occurring and man-made contaminants from the ground, or those that have leached from previous land use. Daniel believes there is growing appetite to process contaminated soil, either on-site or at a treatment plant, rather than send it to landfill.
“Rather than just treating soil, and it becoming inert fill or going to landfill, which has a huge price tag, companies are looking to screen, scrub and wash materials to recover valuable stone and sands,” he says.
“When you tear down an old service station or rip up an old road for resurfacing, we’re now not just banishing those valuable raw materials.
There are small volumes of highly contaminated soil, and there are experts that deal with that, but with some of these lowly-contaminated materials, processing it is a more practical and sustainable thing to do.”
Unlocking The Value In Waste
Daniel says that waste processing accounts for 50 per cent of CDE Group’s business, 30 per cent of that waste has contaminated soil. Treatment can include chemicals, where appropriate, and thermal desorption.
However wet process solutions are a growing area, driven by “entrepreneurial customers” who see the added value of reusing products.
“Seeing a source and finding a home for the end product is where we’re headed,” he says.
CDE’s bespoke processing solutions can be designed as full-scale plants for sustainable mining operations or tailored to smaller applications. Smart design and technology allows treatment plants to be more versatile. To that end, a recently commissioned CDE build, which was primarily a road sweepings processing plant, was also designed to treat contaminated soil. A new build for Enviropacific, Melbourne has combined wet processing and thermal desorption.
“Other people have seen wet processing and thermal desorption as a choice of one or the other,” Daniel says. He says the Enviropacific project has used two technologies to solve a problem.”
The NDD mud recycling plant includes two HYDRO:TIP tanker reception bays where material is screened, rinsed and dewatered to remove coarse material. The CDE EvoWash recovers reusable washed sand while the EvoWash hydrocycle recovers fine sand which is dewatered and removed from the process.
Cleared water is pumped to a wastewater treatment plant for reuse. Coarse material and liquids produced by the process are sampled for contaminant loading and any contaminated aggregates are moved to a thermal plant for destruction.
Second Generation Soil Treatment
Daniel describes the plant as the “second generation” in soil treatment.
CDE Group has designed and built a number of flagship plants, including a PFAS removal plant in Edinburgh in 2018 and a category C processing plant for resource recovery business Repurpose It.
“These guys have shown there is an alternative to sending waste to expensive landfill,” Daniel says. “The market mechanism is working. It’s encouraging people to look at these materials and say ‘we can do better’. This isn’t science fiction, it’s doable today.”
Get in touch with our team today to learn more about our range of waste recycling solutions including our NDD mud solutions.