June 2012, Vol. 24, No.6


Lee Kuan Yew Water Prize winner brings to life energy-saving wastewater process

Mark van Loosdrecht, the creator of a biological process that removes pollutants from wastewater, received the 2012 Lee Kuan Yew Water Prize.

The international water award recognizes contributions to solving global water problems by applying technologies or implementing policies and programs, according to a Singapore International Water Week news release.

The professor and group leader of Environment Technology at Delft University of Technology (Netherlands) discovered a unique group of bacteria that removes pollutants from wastewater using less oxygen and no added organic carbon, compared to conventional processes, the news release says. Van Loosdrecht’s patented process, named Anammox, has the ability to reduce overall energy consumption, chemical use, and carbon emissions at wastewater treatment plants.

During the Anammox process, a group of bacteria with a unique set of enzymes converts the ammonia in wastewater to nitrogen gas, bypassing the intermediate steps in traditional treatment in which ammonia is converted to nitrate. This change reduces the overall energy consumption, the news release says.

While this shortened process was hypothesized as early as the 1970s, it wasn’t until the 1990s that Delft University researchers discovered the bacteria that would make it a reality.

Van Loosdrecht devised the engineering tools and systems to harness the bacteria for the process and was instrumental in building the first demonstration plant using the Anammox process in Rotterdam, Netherlands. As of January, there were 16 full-scale Anammox plants implemented by Pagues (Balk, Netherlands), a licensee of the technology, and more than 30 full-scale variant plants in operation in the Netherlands, Austria, China, Japan, and the United States, the news release says.

“Van Loosdrecht’s technology is set to create a paradigm shift in the used water treatment industry,” said Tan Gee Paw, chairman of the Lee Kuan Yew Water Prize nominating committee, in the news release. “The adoption of such energy-saving technology is essential for used water treatment plants seeking complete energy self-sufficiency and will be the future for the used water treatment industry.”

Are plastics that biodegrade in water the next wave?

ReNew Flexible Film Resins produced by DaniMer Scientific (Bainbridge, Ga.) biodegrade in fresh water and during anaerobic digestion, according to DaniMer Scientific news releases.

The water-compostable resins can be made into disposable shopping bags, trash bags, odor-barrier packaging products, compost bags, landscaping weed-barrier films, breathable films for liquid water barriers, hay-bale wraps, and agricultural mulch film, the company website says.

These biodegradable film resins are based on natural, renewable materials that can be composted, the website says. Using these materials would eliminate the time and cost necessary to remove and dispose of such nondegradable films as the petroleum-derived resins polyethylene and polypropylene. The film resins also can be processed at lower temperatures than other resins and, thus, use less energy, the website says.

SSCCP, the Italian Pulp and Paper Research Institute (Milan), granted the resins certification in Fresh Water Biodegradability and Anaerobic Digestion. Vincottee (Vilvoorde, Belgium), which provides inspection, monitoring, and certification services for various applications, granted the resins certification for OK Compost, designating compliance with European standards for industrial composting. Vincottee also is finalizing a backyard composting certification for OK Compost HOME, designating biodegradation in garden composts, the news release says.

The resins degrade in the absence of oxygen during anaerobic digestion and can be used to generate renewable energy during this process, the news release says.

Report shows large potential for harvesting rainwater

Capturing rainfall from roofs remains a largely untapped opportunity to ease water supply shortages and prevent runoff pollution, according to the Natural Resources Defense Council (NRDC; New York) report Capturing Rainwater From Rooftops.

The report analyzes the capability of eight diverse U.S. cities for collecting water on roofs by comparing annual rainfall totals to rooftop coverage. NRDC determined that each city has opportunities to capture hundreds of millions of gallons of rainfall every year for reuse. This water could be used for such purposes as watering yards and flushing toilets, according to NRDC. This onsite reuse would lower energy costs associated with treating and delivering drinkable-quality water, the release says.

The report illustrates opportunities to capture, treat, and supply harvested rainwater for nonpotable use in Atlanta; Austin, Texas; Chicago; Denver; Fort Myers, Fla.; Kansas City, Mo.; Madison, Wis.; and Washington, D.C. If all rooftops in these cities captured rainwater, it would meet the water supply needs of 21% to 75% of each city’s population, the news release says.

Find the report at www.nrdc.org/water/rooftoprainwatercapture.asp.

Minnesota challenges its cities to initiate sustainable best practices

Cities throughout Minnesota are stepping up to take the Minnesota Pollution Control Agency’s sustainability challenge. The Minnesota GreenStep Cities program challenges the state’s 855 cities to achieve sustainability through implementing best practices.

The voluntary program, which began in June 2010, describes 28 best practices tailored to the Minnesota area that focus on cost savings, energy use reduction, and innovation, the GreenStep Cities website says. “Minimize the volume of and pollutants in rainwater runoff” and “assess and improve city drinking water and wastewater facilities” are among the 28 best practices.

To participate in the program, cities must have a GreenStep Cities program coordinator; submit an inventory of completed, planned, and desired best practices; and introduce a city council resolution to work toward GreenStep Cities recognition, the website says.

The program is flexible, depending on the capabilities and size of different cities. At press time, 40 Minnesota cities had earned the title GreenStep Cities. For more information, see http://greenstep.pca.state.mn.us.

Report details benefits of CHP at wastewater treatment facilities

For wastewater treatment facilities looking for a reliable, cost-effective option to generate power, a U.S. Environmental Protection Agency (EPA) report recommends combined heat and power (CHP) applications for those that already have or plan to install anaerobic digesters.

EPA’s Combined Heat and Power Partnership released Opportunities for Combined Heat and Power at Wastewater Treatment Facilities in October. The report presents opportunities for CHP applications in the municipal wastewater treatment sector and documents the experiences of wastewater treatment facility operators who have employed CHP.

Biogas from digesters can be used as fuel to generate electricity and heat in a CHP system, the report says. Benefits of this type of CHP system include producing power at a cost below that of retail electricity, enhancing power reliability, producing more useful energy than using biogas only to heat digesters, and reducing air pollutants.

The report also finds that while many facilities have implemented CHP, the potential exists for more CHP systems, based on technical and economic benefits. For example, the report says that 104 wastewater treatment facilities were using CHP biogas systems in June 2011 but that systems are technically feasible at 1351 additional sites. CHP systems also are economically attractive — with payback periods of 7 years or less — at between 257 and 662 of those sites.

View the report at http://epa.gov/chp/documents/wwtf_opportunities.pdf.


©2012 Water Environment Federation. All rights reserved.