Passive aeration and new technologies improve secondary wastewater treatment

Traditional options for secondary wastewater treatment burn up way too much energy - 68 GWh annually in the US alone - and still leave behind excessive amounts of sludge. With increasing pressure from growing populations and more frequent severe storm events, there is a dire need to improve this secondary wastewater treatment, according to Lux Research. 
 
As a result, a new crop of technologies is looking to transform wastewater treatment. Successful systems dramatically simplify the wastewater process and scale down easily to serve the hordes of small facilities in the market. Winning technologies harness passive aeration to reduce energy costs and fine tune the microbial population to significantly reduce sludge production.
 
“Technologies like membrane bioreactors emerged to improve the quality of wastewater treatment, but don’t address the energy and sludge concerns, and the smallest facilities struggle to implement them effectively,” said Tess Murray, Lux Research associate and the lead author of the report titled, ‘Advances in secondary wastewater treatment’.
 
She added, “Now, new start-ups are fundamentally rethinking wastewater treatment and effectively addressing energy consumption and sludge generation, which together account for nearly half of the operating costs at today’s plants.”
 
Growing population and climate pressure are forcing capacity expansions of wastewater treatment facilities. The frequency of extreme storm events has increased about 30% in the US over the past 67 years, with states in the Northeast hardest hit. The resulting increase in stormwater, combined with a growing population, puts pressure on treatment facilities.
 
According to Lux Research, electricity and sludge management are almost half of a plant’s operating costs. Sludge transport and disposal accounts for about a quarter of wastewater treatment plant operating costs, and only about 40 percent of leftover sludge is put to beneficial use in the US – for example, spread on land as a low-grade crop fertiliser.
 
New start-ups offer a variety of ideas for implementing passive aeration. The best alternative systems offered by companies such as Baswood and Aquarius Technologies find new ways to provide the oxygen that microbes need, reducing energy consumption by as much as 50 percent and sludge production by as much as 90 percent. “The combination of savings adds up, and could save the average wastewater treatment plant as much as $1.1 million in operating expenses per year,” added Lux Research press release.