Fig. 4.

Adsorption of HS (quantified as DOC) for the four types of magnetite: a biogenic magnetite, b 13 nm magnetite, c 7 nm magnetite, and d 500 nm magnetite. The orange dashed lines and filled circles correspond to setups with native HS and the grey lines with filled squares correspond to setups with reduced HS. Standard deviations of all experiments were calculated from three independent parallels