A TOUR OF SLUDGE TREATMENT INNOVATION

I recently had the opportunity to join PC Construction Senior Estimator Andy Seaton on a trip to England and Ireland to tour several facilities and learn about a new sludge treatment process being used in Europe and that is expected to be introduced in the United States soon. A Norwegian company, Cambi, developed a Thermal Hydrolysis Process (THP) that takes primary sludge and heats it to approximately 165 degrees Celsius (330 degrees Fahrenheit), resulting in hydrolysed sludge. This process kills all of the pathogens that are found in sludge which makes it suitable for creating a Class “A” Sludge that can be land applied as a commercially saleable fertilizer. It also increases the amount of Volatile Organic Compounds that are released during the digestion process (which increases the amount of biogas that can be produced and used to generate electricity and steam that is used in the THP –while reducing the amount of sludge to be handled) and reduces the mesophilic digestion time (which reduces the size of the anaerobic digesters from those that would be required in a conventional process).  Utilization of this process has gradually increased in Europe as many of the technical issues associated with the extreme heat, pressure and caustic environment that are created in the process have been resolved. Engineers are now beginning to recommend the use of the THP at U.S. facilities.

In short, the following benefits can be achieved:

• Increased biogas production
• Biosolids mass reduction (less solids and less water in final product)
• Enhanced digester capacity due to much higher solids loading rates
• Stable digester operations
• A safe product that is easy to store and has little odor
• A compact and flexible waste treatment plant

Customer Service is one of PC Construction’s core values and we have always believed that to best serve our clients we need to understand their needs and how to best meet them. To accomplish this goal we feel it is important to understand the technology available to make treatment facilities more efficient and effective with their processes. As a result, Andy and I spent four days reviewing the process, learning the equipment, and gaining greater knowledge of the challenges and opportunities associated with this new technology. We are excited to learn more about this technology as it becomes accepted in the U.S. and for the promise it brings to the sludge treatment facilities of the future.

Bran Sands Facility – Manchester U.K. – Andy Seaton and Ben Astbury (Cambi) on the mid-level walk between the reactor trains