Fig. 5. Distribution of binding site strengths for Cd at pH 7 determined using the normal distribution approach. The upper diagram displays data for humic acid (HA) and fulvic acid after dialysis with a molecular weight cutoff of 1000 Da (FA > 1000) and the lower, for dissolved organic matter (DOM) fractions (HoA, HoN, HiA, HiN, and HiB) from municipal solid waste (MSW) compost. The term µ is the average,
is the standard deviation, and s is skewness.