Sunday, February 19, 2023

Can Charcoal Save the Bay?

No, but it might help a little. Bay Journal, Can the age-old use of biochar help solve modern pollution problems?

Biochar, created from an ancient practice that turns organic waste into a charcoal-like substance, is getting a closer look for its potential to help address modern-day problems such as climate change and nutrient-laden runoff.

The material has been lauded over the past decade, with advocates calling it a simple and important tool to capture carbon from the air, soak up stormwater runoff and build up healthier soils in agricultural and urban settings.

But it has not become widespread in either production or use.

That may be changing. A major push by government agencies and other organizations seeks to close research gaps, set quality standards, scale up production — likely with federal aid — and better promote biochar through demonstrations sites in Chesapeake Bay states and beyond.

Advocates hope to see its widespread use within a decade.

In simple terms, biochar is created by turning plant and animal waste into a carbon-rich product by heating them at high temperatures without oxygen. The process is called pyrolysis.

Biochar has been used as a soil amendment in some places around the world for more than a thousand years. Recent research shows that it can suck carbon from the air and store it in the ground, where it can enrich soil for hundreds of years — some call it a biological carbon battery.

The latest Intergovernmental Panel on Climate Change report praises biochar as an important climate change mitigation technique.

It also retains nutrients in the soil, keeping them close to plant roots where they can stimulate both crop growth and the production of microbes that improve soil health.

Farmers in the Bay states could add biochar to not only crop fields, but also to feedlots where it would absorb nutrients and other contaminants, as well as to passtures to improve productivity.

But except for scattered experimental uses, biochar is not widely used in the Bay states. Pennsylvania only has three biochar suppliers or manufacturers. New York has two, while Maryland and Virginia each have one.

In large part, this is because questions remain about its effectiveness, which can change with various soil types and the climate of the application site, as well as the application methods.

To answer those questions, the bipartisan Biochar Research Network Act has been introduced in both houses of Congress. If passed as part of the next Farm Bill, it would allocate $50 million annually to establish a network of up to 20 research facilities across the nation to test the effectiveness of biochar.

Those research gaps are the biggest obstacles to greater use of biochar, according to the December findings from a summit of government agencies, nonprofits organizations, conservation groups and biochar producers.

A paper generated from the gathering seeks to have sustainable and widespread commercial production of biochar available in the next five years.

Biochar “is not a silver bullet, but it is part of a natural climate solution and a tool in soil health,” said Rachel Seman-Varner, senior soil health and biochar scientist in the American Farmland Trust’s climate initiative. The Trust organized the summit, along with the Foundation for Food & Agriculture Research and the National Center for Appropriate Technology.

Georgia and I were involved in a study of whether or not biochar could be used to inhibit the formation of methylmercury in anaerobic wetland soils. Methylmercury is the form that is primarily accumulated by fish, and presents the greatest threat of mercury poisoning to man for widespread mercury pollution from coal burning and concrete production. As far as I can remember, (and this was not really my project) the biochar strongly inhibited the formation of methylmercury from inorganic mercury. 

The ancient Amazonian natives used charcoal (among other things) to improve the jungle soils for farming, forming a black soil called "terra preta" which persist to this day.

1 comment:

  1. Not to worry, most of the mercury from coal-fired power plants gets scrubbed out in the acid gas removal stage and ends up in the caustic scrubber solids, which then get turned into drywall. So it ends up in the walls of new construction.