Could the water sector become carbon neutral?
The Australian water sector could become carbon neutral within a decade, according to an expert.
Jurgen Thiele, Business Unit Leader – Waste Value Recovery at Calibre Professional Services said the technology already exists, it’s just the will to reduce emissions that is needed.
“There is a resistance to change because things have been done a certain way in the past and the urgency is often not as clear [to the industry] as it is to some of the scientists who have done the climate modelling,” he said.
“Getting that sense of urgency into the industry is a hurdle that we should address quickly, because 2030 [the target year to achieve the United Nations’ Sustainable Development Goals] is just around the corner.
“Assuming the will is there, zero emissions could be achieved within a decade.”
Thiele said there is a range of waste-to-energy solutions that can make wastewater treatment plants energy self-sufficient.
The key lies in optimising the anaerobic digestion process to maximise the amount of biogas a wastewater treatment plant is able to produce. The energy generated by the gas can then be used to run the plant.
Rather than using new technology, Thiele said conventional anaerobic digesters can be upgraded by adding a recuperative thickening process. This not only doubles the amount of sludge that can be treated and the amount of biogas produced – it also leads to a 50% reduction in biogas production costs.
“I’m a biotechnologist, and we’re using biotechnology know-how to make the bacteria in these anaerobic digesters perform more efficiently and more robustly,” Thiele said.
“Therefore, you can load and challenge them with more waste than you traditionally could. At the same time, these resilient, robust bacteria are more concentrated. To use a military analogy: you have an army three times the size, so it’s much easier to win.”
But the benefits aren’t limited to a reduction in greenhouse gas emissions. As anaerobic digestion can accept different feedstocks (biosolids, trade waste, food waste, etc.), water authorities can also turn a profit by charging a gate fee to companies to deliver their waste to the plant.
“Using a common tool to process a wide range of organic waste and wastewater makes it cost effective,” Thiele said.
“Over a period of three to four years, a water authority could recover its initial outlay, and then over the next 10 to 15 years it would generate a very substantial profit.”