While it may be comforting to think that everything we send down the drain somehow magically disappears without leaving an ecological footprint behind, that is far from what actually happens. In reality, the process involves cleaning the waste at a treatment plant, where water is cleaned and discharged. The remaining toxic sewage sludge — also known as biosolids — is often sent to landfills, where it emits greenhouse gases.
In an effort to find an alternative use for sewage sludge, San Francisco-based company Bioforcetech has figured out a way to transform that organic waste into a grayscale pigment and material additive, called OurCarbon.
As explained by the company, their process first involves diverting organic material, such as food waste and biosolids, from landfills, where they would break down and release methane — a potent contributor to climate change. Next, the diverted materials are dried up with the help of thermophilic bacteria and then subjected to pyrolysis — a thermal decomposition process in the absence of oxygen. The carbon in the resulting materials is then bonded together, preventing it from breaking down and emitting greenhouse gases into the atmosphere.
According to the inventors, the material can be used in a variety of applications, including as a pigment in color paints, 3D print filament, wood stains, and textile dyes. OurCarbon can also be used as a material additive in bio-based resins, in concrete, and even porcelain. As such, the material serves as a sustainable alternative to typically carbon-intensive equivalents like carbon black pigment, mined and shipped concrete aggregates, and Azo dyes used by the fashion industry.
Bioforcetech claims that for every ton of the material produced from landfill-diverted biosolids, they prevent 10 tons of CO2 from entering the atmosphere — the equivalent of taking two cars off the road for an entire year.