News from Schwing Bioset

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

Class A Biosolids vs. Class B in Plain English

What’s Class A? What’s Class B?

The EPA provides A Plain English Guide to the EPA Part 503 Biosolids Rule, which is broken into ten chapters. Table 2-5 in Chapter 2 (PDF) summarizes the differences between the pathogen reduction requirements for Class A and Class B biosolids:

 class A biosolids, class B biosolids

Class A

Class B

In addition to meting the requirements in one of the six alternatives listed below, fecal coliform or Salmonella sp. Bacteria levels must meet specific density requirements at the time of biosolids use or disposal or when prepared for sale or give-away (see Chapter Five [PDF] of this guidance).

The requirements in one of the three alternatives below must be met.

Alternative 1: Thermally Treated Biosolids
Use one of four time-temperature regimens.

Alternative 1: Monitoring of Indicator Organisms
Test for fecal coliform density as an indicator for all pathogens at the time of biosolids use or disposal

Alternative 2: Biosolids Treated in a High pH-High Temperature Process
Specifies pH, temperature, and air-drying requirements

Alternative 2: Use of PSRP
Biosolids are treated in one of the Processes to Significantly Reduce Pathogens (PSRP) (see Table 5-7)

Alternative 3: For Biosolids Treated in Other Processes
Demonstrate that the process can reduce enteric viruses and viable helminth ova. Maintain operating conditions used in the demonstration.

Alternative 3: Use of Processes Equivalent to PSRP
Biosolids are treated in a process equivalent to one of the PSRPs, as determined by the permitting authority

Alternative 4: Biosolids Treated in Unknown Process
Demonstration of the process is unnecessary. Instead, test for pathogens—Salmonella sp. or fecal coliform bacteria, enteric viruses, and viable helminth ova—at the time the biosolids are used or disposed of or are prepared for sale or give-away.


Alternative 5: Use of PFRP
Biosolids are treated in one of the Processes to Further Reduce Pathogens (PFRP) (see Table 5-4)

Alternative 6: Use of a Process Equivalent to PFRP
Biosolids are treated in a process equivalent to one of the PFRPs, as determined by the permitting authority


Do you have more questions? CLICK HERE

Tags: Class 'A' Biosolids, Biosolids Process, EPA, Biosolids Handling

The Anatomy of Class A Bisosolids


Wastewater is not considered sludge until it has been de-watered to at least 7% solids content, according to the EPA. To create an end product that is considered Class A grade acceptable, sludge must be used. Acceptable sludge must be free of pollutants, shown below is the EPA specified amount of pollutants allowed:

Pollutant  Must not exceed concentration [Milligrams / kilogram]
Arsenic  41
Cadmium   39
Chromium  1,200
Copper  1,500 
Lead  300
Mercury  17
Nickel  420
Selenium   36

If any of these pollutants are found to be above the ceiling set by the EPA, the sludge is not safe and must be land filled or incinerated. Providing the sludge is acceptable, a range of processes (drying, alkaline stabilization, etc.) can be used to create Class A product. Although no specific process is outlined and approved by the EPA over another, the restrictions for the end product are what sets the bar and defines a Class A product.            

Class A product must have "less than 1000 Most Probable Number per gram of total solids on a dry weight basis" (EPA regulation 503) of fecal coliform & salmonella sp. bacteria. These pathogens can only be tested for in the lab environment where a sample is put into a Petri dish and the bacteria is allowed to grow so it can be accounted for. Then the amount of organisms per gram of material must be below 1000. Meeting this level of pathogen kill is accomplished in most class cases by keeping the sludge in an elevated temperature environment for an extended period of time.

In addition to acceptable levels of pathogen kill the end product must also have "sufficiently reduced vector attraction of the material" (EPA regulation 503). Vectors are bugs such as flies or mosquitoes that carry diseases. Vector reduction can be accomplished in several ways. By increasing material PH or drying the material to greater than 90% the attractiveness of the material to sustain or breed for the bugs is eliminated. At a minimum, each batch needs to be tested and pass these standards before they can be considered Class A biosolids and land applied.                                  

Click here to learn more about Class A technologies

Tags: Biosolids Process, Bisolids Handling, EPA, Sewage Sludge, Biosolids Drying

Natural Fertilizer from Biosolids, reuse to the Nth degree:Part I

Learn more about how we are seeking to make a difference in our communities by beneficialy reusing biosolids, creating jobs and mininmizing the risks associated with Class B Biosolids. By creating a Class A biosolids with a natural process.

Tags: Biosolids Process, Wastewater Treatment, Bioset Class A

Schwing Bioset to be featured on the 21st Century Business TV Series

October 10, 2009, Fox Business Network 

Airing Schedule:     

Boca Raton, FL, --- Multi-Media Productions(USA), Inc. announces that  SchwingBioset, 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: Biosolids Process, Fluid Bed Drying, Wastewater Treatment