Feeding Microbes the Right Carbon Changed How Much Pollution a Reactor Removed

Researchers at Nankai University paired three carbon additives with three industrial pollutants in bench-scale bioreactors run under an applied electric current, and pollutant removal differed by up to about fourfold depending on which carbon was matched to which pollutant.

These reactors use electricity to help bacteria break down industrial chemicals that ordinary treatment leaves behind, and the extra carbon they are dosed with is chosen largely by experience. The authors say a mismatch between that carbon and the pollutant diverts electrons and carbon into unproductive sinks rather than into breaking down the pollutant, and that the pairings give a basis for matching the dose to what is being treated. The study was published Oct. 6, 2026, in Communications Earth & Environment.

Across the nine pairings, the team reports reproducibly different outcomes. In some combinations the pollutant decided which microbes came to dominate, in others the added carbon did, and in others the two shared control. Removal was most closely associated not with the presence of any single species that eats the pollutant, but with which microbes occupied which roles and how they depended on one another. That association was negative, r = −0.853: removal was lower in the pairings where the measure ran higher.

Nothing in the work was run at the scale of a working treatment plant. The authors describe their result as a shift from dosing aimed at individual pollutant-eating species to dosing aimed at the network those species form, and as support for what they call smart, low-carbon wastewater management.

Ruixiang Li of Nankai University is the paper's first author, and Qixing Zhou, also at Nankai, its senior author. The paper is open access and was posted as an accepted manuscript, ahead of the final published version.