Published on November 7th, 2009 | by Tina Casey3
Electric Mole Takes a Bite Out of Energy Costs, with Help from Solar Power
November 7th, 2009 by Tina Casey
Veteran solar installer Parkson Corporation is lending its expertise to a new wastewater treatment plant upgrade for the town of Berlin near the Maryland coast. When it’s finished, the new plant will almost eliminate the use of fossil fuels for drying and converting biosolids, also known as sludge, into a lightweight Class A soil amendment or sustainable fuel. The process is pushed along by a stainless steel “Electric Mole” that automaticaly mixes, aerates, and granulates the sludge as it dries.
The $16 million upgrade project is funded by ARRA (American Recovery and Reinvestment Act). Parkson’s Thermo-System Active Solar Sludge Drying Chambers will enable the sludge conversion process to operate under more than 90% solar power rather than using gas or oil. For disposing sludge in landfills, that translates into a significant savings in preparation and transportation costs. Even better, it makes sludge products more cost-competitive with conventional soil amendments and fossil fuels, effectively taking the “waste” out of wastewater.
Parkson will install two of its Thermo-System chambers at the Berlin plant. Using more than 90% solar energy, the chambers will reduce the weight and volume of sludge by up to 75%. Parkson, part of the international Axel Johnson family of businesses, notes that it has installed more than 100 Thermo-System units in a wide variety of climates worldwide including a 40 million gallon-per-day wastewater plant, making it the world’s largest solar drying installation to date. In addition to using solar power, the drying chambers can also use waste heat or digester gas, which is a byproduct of the biodegradation process.
Wastewater as a Marketable Product
Sludge is simply the organic particles that are left over after trash, grit, and most of the water is removed from wastewater. As an organic material, sludge can be biodegraded to result in an inert, non-smelly substance that can be used just like any other manure-based fertilizer or soil amendment. Dewatering, combined with biodegradation, converts the sludge into a final product that is lighter, less expensive to transport, and ready to use on soil or as fuel.
Wastewater Not, Want Not
Graywater recycling has gone a long way toward destigmatizing wastewater, and by integrating alternative energy sources into wastewater treatment operations, companies like Parkson are helping to transform water supply from a consumption-and-disposal model into a process of use and reuse. With the development of more alternative energy to desalinate seawater, that wraps up the global water cycle in one more sustainable package.
Image: zenera on flickr.com.