Supplementation strategies to control propionic acid accumulation resulting from ammonia inhibition on dry anaerobic digestion: osmoprotectants, activated carbon and trace elements

In dry anaerobic digestion, when there's too much ammonia, propionic acid can build up. Researchers tested three ways to tackle this problem:Osmoprotectants (like a kind of salt) to help the microbes cope.Trace elements to help produce enzymes.Activated carbon to improve electron transfer between microbes.The results? Activated carbon and a specific salt (MgCl2) were the most effective, increasing methane (a useful gas) production by 28% and reducing unwanted hydrogen gas. Trace elements also boosted methane but didn't stabilize the process. Even with these methods, propionic acid still built up, but the salt delayed it. The carbon and salt also encouraged the growth of specific microbes, which might make the process more reliable.The attached record represents the microbial taxa identified as part of this work.