Bacteria absorb DOC and are actively removed by protein skimmers as a nutrient export mechanism. You are right about this Felderman article did not detail DOC, my bad. He does in other articles. However, let me provide this link which is specific to activated carbon. While somewhat dated at 20 years there are ample footnotes to glean what you wish.
https://melevsreef.com/articles/carb...-part-1-repost
In a more recent article, Hovanec (1998) states flatly that “the best carbon for use in water filtration for removing dissolved organic carbons is bituminous coal-based carbon.” He also comments about the decline in use of coconut carbon, stating that “coconut carbons have the wrong pore size for filtering the target materials from water.”