Further Insights into Metal-DOM Interaction: Consideration of Both Fluorescent and Non-Fluorescent Substances
Figure 4
The 2D infrared correlation maps generated from 1300 to 1700 cm−1 region for NOM and EPS matrix with increasing Cu(II) addition.
(a) synchronous map for NOM; (b) asynchronous for NOM; (c) synchronous map for LB–EPS; (d) asynchronous for LB–EPS; (e) synchronous map for TB–EPS; (f) asynchronous for TB–EPS. Red represents positive correlations and blue represents negative correlations; higher color intensity indicates a stronger positive or negative correlation.