Water Treatment The Major Energy Guzzlers in Wastewater Treatment are Identified
Wastewater plants often operate well beyond their defined energy optimum – A recent study shows that only 4 % of the US wastewater treatment plants account for 66 % of national aeration energy consumption from conventional activated sludge. Especially smaller plants could significantly cut costs by adapting a simple technical method...
A report into Low Energy Wastewater Treatment, compiled by Bluetech Research, reveals that in the US municipal wastewater treatment market, two-thirds of the aeration energy consumption associated with conventional activated sludge (CAS) can be attributed to just 4 % of the plants.
The largest WwTPs in the US - those in the 100,000 to 1 million population equivalent (PE) range – comprise just 4 % of the total number of plants, but account for a large proportion of the aeration energy cost - approximately 66 %. This equates to approximately US $ 946 million in annual electricity costs, the analysts say.
US Aeration Energy Guzzlers Identified
The smaller WwTPs - those in the 100 to 100,000 PE range – make up the vast majority of works, but account for a much smaller proportion of the aeration energy consumption. They represent 96 %, by number, of the total 16,000 plants, however the associated estimated electricity aeration costs is approximately US $ 482 million.
Given these numbers, Bluetech analysts see a big potential for low energy treatment technologies worldwide. Paul O’Callaghan, Managing Director of Bluetech Research says, “These larger facilities represent a significant market opportunity for low energy technology implementation. They can also potentially capture the most energy in municipal wastewater in the US for reuse.”
Significant Market Opportunity for Low Energy Technology
Yet there is no ‘silver bullet’ technology available to provide a low energy alternative to CAS at the larger WwTPs, at least in the short-term: One innovative technology that shows promise in terms of offering a complete low energy alternative to CAS for effective biological treatment of municipal wastewater, is the staged anaerobic fluidised bed membrane bioreactor. This technology is currently at the pilot study stage and is unlikely to be commercially available in the next 5-10 years.