“Every Waste Water Treatment Plant produces Sludge. A third of the total waste volume going to a landfill site is sludge. About half a million tonnes per year just for the lower North Island of New Zealand and the problem just keeps on getting bigger.
Wetox addresses one of today’s biggest pollution problems, with the potential to clean-up New Zealand’s rivers and waterways that have become polluted from run-off from our dairy farms, wineries and meat works.
The basis of Wetox is catalysed wet air oxidation. This is a well-established technique for the removal of organics from water and has been around since the 1920s. However in the past it was always seen to be an expensive process and reserved for only the most hazardous wastes or toxic compounds where traditional Waste Water Treatment techniques were ineffective.
Innovative research at Victoria University of Wellington, New Zealand has made this process more affordable. In addition the new process is able to deconstruct the sludge in such as manner that it produces useful chemical by-products and recovers valuable minerals and metals.
What is Sludge?
Sludge is a by-product of a Waste Water Treatment process and just about every Waste Water Treatment Plant makes it. It needs to be disposed of and Wetox is the scientific solution, that not only eliminates the sludge but produces clean water and other useful chemical products from the waste as well as recovering valuable mineral resources.
Under high pressure and temperatures Wetox deconstructs the sludge to base components such as water and carboxylic acids. Carboxylic acid, mainly acetic acid – vinegar are valuable industrial chemicals. In addition minerals such as phosphates and metals bound to the sludge, which would otherwise be lost with the sludge, are released. Phosphate is an important fertiliser, that can be recovered and reused.
The Up Side
Waste disposed of by industry to land fill (or even worse land-spreading) is almost eliminated. This means protection of the pristine New Zealand environment and business savings in both landfill charges and transportation costs.”