Fig. 1

Mean measured NPOC concentrations of PS samples plotted against the PS concentration: (a) in absence of metal hydroxides, (b) in presence of 10 mg/L Al hydroxide, and (c) in presence of 10 mg/L Fe hydroxide. The error bars represent the standard deviation of the mean. The dashed black line represents the reference NPOC concentration considering the mass percent of C in PS (92.3%). (d) Total recovery in percent for each particle size in presence and absence of Fe or Al hydroxide to the PS samples