Fig. 4From: A combined experimental and modeling study to evaluate pH-dependent sorption of polar and non-polar compounds to polyethylene and polystyrene microplasticsEquilibrium distribution map for a freshwater system with natural particles (organic carbon) and microplastic particles under two different concentration scenarios. Experimental conditions (plastic LSR = 103 L kg−1, Scenario I) are shown in the top panel and environmental conditions (plastic LSR = 1010 L kg−1, Scenario II) in the bottom panel. Crosses, circles, and pluses show the aqueous equilibrium concentrations at pH 4, pH 7, and pH 10, respectively, in µg L−1 calculated with the experimentally determined DP for PE (black symbols) and for PS (red symbols) and the investigated substances. For both cases, a constant concentration of 10−5 kg L−1 OC was assumed. KOC values were estimated using EPISuite 4.1Back to article page