- Author: Michael Cohen
Biosolids, the nutrient-rich organic materials resulting from the treatment of sewage sludge, have long posed a challenge for waste management. Recent regulatory changes have complicated the issue, discouraging the once-common practice of using biosolids for landfill cover. This shift has made landfill disposal more expensive for municipalities. However, innovative technologies are now transforming these materials into valuable resources, reducing greenhouse gas emissions and landfill usage while creating sustainable products. Two notable Bay Area companies are leading the charge:
Bioforcetech: From Biosolids to Carbon-Negative Materials
In Redwood City, Bioforcetech is revolutionizing biosolids management through an innovative drying and pyrolysis process. This method transforms municipal biosolids into a clean, stable material called OurCarbon®
Key features of the Bioforcetech process:
- Carbon sequestration: The process effectively “fixes” carbon, preventing its breakdown into greenhouse gases for centuries.
- Concrete decarbonization: Approximately 90% of the OurCarbon® is used as a partial substitute for sand in concrete, storing over 1 pound of CO2 equivalents for every pound used.
- Petroleum-based pigment replacement: The material also serves as a sustainable alternative to carbon black in inks, coatings, and polymers.
The environmental impact is significant. For every ton of OurCarbon® produced, 24 tons of CO2 emissions are avoided through landfill diversion, and 1.02 tons of CO2 are directly sequestered within the material.
Left photo: Bioforcetech Co-Founder & COO Valentino Villa explaining the workings of the patented biosolids dryers to UCCE Advisor Natalie Levy and Santa Clara County UCCE Compost Education Program Coordinator Victoria Roberts at the Silicon Valley Clean Water, Wastewater Treatment Plant in Redwood City. Right photo: Mr. Villa demonstrating the properties of the odorless OurCarbon® powdered product of pyrolysis.
Lystek: Transforming Biosolids into a Safe Liquid Fertilizer
At their Fairfield Organic Material Recovery Center (OMRC), Lystek uses an innovative approach that not only diverts biosolids from landfills but also creates a valuable agricultural product. Biosolids from around the Bay Area are transformed using heat and high pH into a pathogen-free Class A liquid fertilizer called LysteGro.
Photo: Lystek GM/Business Development Manager Jim Dunbar (right) leading a recent tour of the OMRC facility in Fairfield.
Compared to burial in a landfill, application of biosolids to agricultural land greatly reduces greenhouse gas emissions. Furthermore, by using the nutrients in the biosolids as fertilizer, we can avoid the energy-intensive greenhouse gas emitting process of synthetic fertilizer production, such as extracting nitrogen from air through the Haber-Bosch process or mining phosphorous from finite mineral deposits.
These innovative technologies in the Bay Area demonstrate ways that waste management challenges can be transformed into opportunities for sustainability and resource recovery. By turning biosolids into valuable products like carbon-negative materials and high-quality fertilizers, these processes are paving the way for a more circular and environmentally friendly approach to organics waste management.
- Author: Michael Cohen
Biochar, the product of charring wood under low oxygen conditions, shares many properties with activated charcoal, a common component of at-home water purifiers. Similarly, water purification in built environments can be accomplished by engineered basins with plants and rich porous soil, called bioswales. Several recent studies worldwide have shown that incorporating biochar into bioswale soils can improve their capacity to bind and detoxify water contaminants.
Building on these studies, a bioswale containing biochar on one side and no biochar on the other was engineered into the stormwater drainage area of Veggielution Community Farm in San Jose. This side-by-side setup will allow for a controlled comparison of biochar's impact on bioswale activity. Members of the project team, including Earth Foundries, Sonoma Ecology Center, ReScape, and the North Santa Clara Resource Conservation District, attended an inaugural ceremony at Veggielution on October 5th.
To prepare the foundation for the bioswales, Lyngso Garden Materials of San Carlos donated 70 cubic yards of Biotreatment Mix (60% sand and 40% compost) and 26 cubic yards of composted mulch. On the biochar side, approximately 4 inches of biochar was blended into the mix.
The next step for the project is to wait for the rains to come. Regular water and soil testing will be conducted to monitor the performance of the two sides. The project managers expect the performance of the biochar side to improve over time as the biochar particles become colonized by a microbial community capable of breaking down pollutants.
One way to prime the biochar with such a microbial community is to include it when starting a compost pile. However, as co-composted biochar is not yet available on a commercial scale, the compost and biochar were added separately. Project leaders Raymond Baltar and Roger Smullens (pictured below) have previously worked on a test of biochar co-composting at Napa Recycling that demonstrated biochar's ability to speed the rate of composting, increase the nitrogen retention of the compost, and substantially lower its emissions of volatile organic compounds (VOCs), which are highly regulated by Air Quality Management Districts. Studies elsewhere have found similar benefits, including large reductions in methane emissions. Thus, co-composting with biochar not only makes a better product but also improves the bottom line for composters.
With increasing forest thinning across California, such as the clearing of urban eucalyptus stands for fire control in the East Bay, producing biochar from the cut material presents a way to generate higher-value downstream products and environmental benefits.
Pictured left to right: Raymond Baltar, Climate and Biochar Project Manager, Sonoma Ecology Center; and on the biochar-side of the bioswale, Roger Smullens, CEO, Earth Foundries; and Arun Jani, Assistant Professor of Crop Management, California State University, Monterey Bay.
