Winning Wastewater Treatment Technologies Use Passive Aeration, Process Control

New technologies using passive aeration and process control dramatically improve wastewater treatment, according to Lux Research.

Traditional options for secondary wastewater treatment burn up huge amounts of 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.

Advances in Secondary Wastewater Treatment says winning technologies harness passive aeration to reduce energy costs and fine-tune the microbial population to significantly reduce sludge production.

Among the findings:

Growing population and climate pressure force capacity expansions. The frequency of extreme storm events has increased about 30 percent 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.

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 fertilizer.

Winners have 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.

Applied CleanTech’s sewage recycling technology for wastewater has helped a UK wastewater treatment plant lower its carbon footprint and emissions and is expected to reduce operating costs between 20 percent and 30 percent the company announced last month.