CDOM dynamics in the presence of inorganic (silica gel) versus polystyrene plastic particles: a laboratory study - oxygen concentrations

The present dataset relates to a study that explored dissolved organic matter dynamics under three scenarios: a particle-free environment, a particle-enriched system with polystyrene microplastics, and a particle-enriched system with inorganic particles (water insoluble SiO₂). In part 1 of the experiment, natural marine organic matter was obtained by culturing a non-axenic strain of Chaetoceros socialis in 2 L flasks under each of three scenarios (1C = control, 2PS = polystyrene, 3S = silica). Dissolved oxygen concentration was used as a proxy for bacterial activity. Oxygen was measured in each cuvette of all of the three scenarios 1C, 2PS and 3S with a FireSting Oxygen needle-type optical probe and temperature sensor, PyroScience® (Aachen, Germany), at the beginning of part 2 (day 7, t7).