News from Schwing Bioset

Case Study: Stewartstown, PA

piston pumpsThe Stewartstown Sewage Treatment Plant (STP) is owned by the Stewartstown Borough Authority of Stewartstown, PA. The plant experiences flow at an average rate of 0.625 MGD (millions of gallons per day) plant with MBR (membrane bioreactor) treatment. Sludge is dewatered with a 1.5m belt filter press that produces 16-17% solids. Before working with the Bioset process, the Stewartstown Sewage Treatment Plant's disposal strategy typically consisted of processing liquid sludge at a neighboring facility. Alternatively, dewatered sludge was hauled to a landfill.

Upon recommendation of their consulting engineer, the Borough investigated Class A technology to take advantage of more disposal options. A thermophilic digestion process was considered. However, given the relatively small size of the plant, this option was rejected for requiring the investment of too much capital and manpower. The Bioset process offered a low-cost Class A option that could be integrated into the plant operation. Alkaline stabilization was designed into an overall plant upgrade and put out for tender in 2007.

The layout flexibility of the process was again crucial as the mixer, pump, power unit, and reactor were engineered to fit into a single garage bay, with reactor discharge pumping to an adjacent garage bay to load the truck. The process was operational by the end of 2007.

Today, using the Bioset process, the Class A biosolids are disposed of at two agricultural sites. The farmers are responsible for spreading the product. The farmers have reported positive results with their crop yields and have not had any odor-related complaints. Pennsylvania regulations permit spreading Class A biosolids year-round, so there is no need for material storage through the winter.

Tags: Class 'A' Biosolids, Bioset Process, Sludge Pumps, Wastewater Treatment

Generating "Revinu"

Lime stabilization is a proven, EPA-approved method for treating sewage sludge. In the capable hands of Schwing Bioset, the technique of lime addition has gone from effective to exceptional.

Bioset's process optimizes the chemical requirements and system efficiencies of lime stabilization. The end product, called Revinu, is safe and has many uses including fertilizer and as a soil stabilizer. Revinu is inexpensive and reliable, and produces a readily usable and valuable Class AA product.

affordable fertilizer-Revinu

Compared to other methods of producing Class AA material, the Bioset process is affordable from both initial capital expenditures and ongoing operation and maintenance costs. The equipment is fully automated and requires very little operator time. As a Class AA biosolid, the end product can be widely used and handled without many of the restrictions imposed on a Class B product.

Revinu's nutrient composition is a strong selling point. First, Revinu's low phosphorus content means it can be applied in phosphorus-sensitive areas. Second, Revinu provides a slow-release alternative to commercial nitrogen, which gives consumers three times the amount of nitrogen breakdown for prolonged plant nutrition. Third, Revinu provides sufficient potassium-a nutrient that is often prohibitively expensive-to support root growth and proper seed germination for a fraction of the market price of potassium.

Finally, Revinu is made up of 35% to 55% organic humus. The humus in the material acts as a topsoil, replenishing the natural bacteria that are essential for optimal plant growth and root strength. Until Revinu arrived on the market, landowners were often unable to replace eroded topsoil due to the astronomical cost associated with the process. Revinu makes topsoil replenishment accessible and affordable.

In short, the Bioset process is the most versatile and attractive method for biosolids treatment on the market today.

Tags: Bioset Process, Class AA/EQ Biosolids, Biosolids, Wastewater Treatment, Fertilizer, Lime Stabilization

Wastewater Treatment: London, Ontario

The London Greenway Pollution Control Centre ("Greenway" for short) is the main wastewater treatment facility for the city of London, Ontario. Greenway is an activated sludge plant that also receives liquid sludge trucked in from the city's other five wastewater plants. 

new Greenway small

Greenway dewaters the sludge and relies on a fluid bed incinerator. In 2008, the incinerator required shutdown for major overhaul that would last over three months. The city's Wastewater and Solid Waste departments are separate entities and are required to charge each other for services rendered. After determining that a prolonged incinerator shutdown would have a prohibitive cost, the Wastewater Department sought alternatives.

Schwing Bioset piston pumps were previously installed at the Greenway plant to feed the dewatered sludge to the incinerator, so plant personnel were knowledgeable about Schwing Bioset capabilities. The Bioset process was proposed to treat the dewatered sludge to beneficially reuse the biosolids as landfill cover. Representatives from the Wastewater and Solid Waste departments visited Bioset installations in Florida to observe the process and it was determined the end product would be acceptable as landfill cover at a preferable cost.

A change order was issued to the incinerator rehabilitation contractor to install the Bioset process equipment as a back-up sludge treatment train to the incinerator. The component equipment permits flexibility in the layout design that allowed the plant to use distinct idle spaces so that no new structures were needed to accommodate the installation.

The plant processed 25,000 metric tons of Bioset product between August and December 2008 while incinerator rehabilitation work was completed. The city has since returned to incinerating the biosolids, but maintains the Bioset equipment as a back-up for annual shut-down/rehabilitation work.

Tags: Bioset Process, Piston Pumps, Wastewater Treatment

Managing Cost, Air Quality and Odor Control with Schwing

Case Study: Ellsworth, WI

The West Central Wisconsin Biosolids Facility (WCWBF) is a regional biosolids processing facility in Ellsworth, Wisconsin, serving Ellsworth and over 20 neighboring communities. The biosolids are dewatered by centrifuges to 20-24% total solids. The dewatered sludge enters an alkaline stabilization system that mixes the sludge with lime and fly ash to yield a Class A product. The treated biosolids are stockpiled in a 37,000-square-foot covered storage building, and beneficially reused semi-annually by local farmers.

In 2008, WCWBF decided to upgrade the lime stabilization process, with the main goals being to contain cost and maintain air quality and odor control. The existing mixer used open hoppers; between that and the fly ash, the system generated a lot of dust. Furthermore, the facility received periodic complaints from neighbors about the odor.

WCWBF chose a Schwing-Bioset system employing a closed hopper, screw conveyors, and pressurized piping system to contain dust and odors. To avoid costly contract hauling charges, WCWBF had to achieve demolition of the old system and installation of the new Schwing-Bioset system within 10 days of shutting down the old system. Demolition and preparation took three days; Schwing Bioset's team installed the new equipment, including the electrical, within the remaining seven days.

With a few minor modifications to adapt it to the winter weather, the Schwing-Bioset system has performed within expectations since commissioning, achieving its goals of managing cost, dust, and odors.

Tags: Class 'A' Biosolids, Bioset Process, Alkaline Stabilization, Biosolids, Dewatering

Lime Stabilization-Fact vs. Fiction(myth-busted)

As you can imagine, working with sludges and biosolids brings up a number of concerns, from the basic to the technical. At the very basic, there’s “does it have an awful smell?” It’s a natural enough concern—we’re working with human waste, after all. But is there a terrible smell?

Class A Biosolids
Not at all, thanks to the Schwing Bioset process. A pinch valve flattens the sludge flowing out of the reactor, creating additional surface area to allow the ammonia and other compounds to be released and subsequently captured and scrubbed under the collection hood. The smell, overall, is akin to wet concrete (because of the lime content). In fact, in many instances the Class AA product produced by the Schwing Bioset process is stored outdoors on the edge of town with residential homes within sight.
At the more technical end, other lime stabilization systems are plagued by poorly mixed lime and sludge. Schwing Bioset solves this with a twin auger mixer that ensures the lime and sludge are thoroughly combined.
Another common concern is that the lime/sludge dust will make for a tough work environment. But the Schwing Bioset process is a closed system with a sealed mixing hopper—and that ensures the dust stays inside the machine, and not your lungs.


Tags: Biosolids Process, Bioset Process, Bioset Class A, Fertilizer Replacement, Biosolids Handling

Schwing featured on 21st Century Business TV Series

21st Century Business


November 12, 2009 - CNBC                                           

Click Link for Airing Schedule - 

Boca Raton, FL, --- Multi-Media Productions (USA), Inc. announces that Schwing Bioset, Inc. will be featured on 21st Century Business.

Schwing Bioset, Inc. (SBI) was created in 2006 by spinning off the Material Handling Division of Schwing America into its own company. The new company was created to better focus on meeting the unique needs of the wastewater treatment industry. In addition, the spin off afforded Schwing Bioset, Inc. the ability to leverage its two-decades of successful wastewater treatment installations at Schwing America into an aggressive pursuit of alternative "green" solutions in the wastewater treatment industry.

In 2006, SBI opened a new 20,000 square foot engineering and manufacturing facility in Somerset, WI in order to rapidly expand its service offerings. The "Bioset Process" and Fluid Bed Drying technology are two examples of Schwing Bioset's commitment to delivering innovative and environmentally friendly solutions to the wastewater treatment industry.

SBI's Project Management and Fluid Bed Drying teams remain in their respective locations of Danbury, CT and Houston, TX. Schwing Bioset's mission is simple, to become the market leader in the biosolids  and beneficial reuse industry.

For more information, visit

JL Haber, Vice President of Programming at Multi Media Productions, adds, "Schwing Bioset is an exciting company with a unique mission. We are excited to have them as a guest on our program."

About 21st Century Business

21st Century Business airs on CNBC and the Fox Business Network as paid programming. 21st Century Business may also be viewed through video on demand via The 21CBTV Series is also available at more than 90 prestigious universities, including Carnegie Mellon University, Howard University, Dartmouth College, and Georgetown University.

For specific market-by-market air dates and times, please e-mail For more information, please visit

Tags: Bioset Process, Fluid Bed Drying, Beneficial Reuse, Biosolids, Schwing Bioset