Pollutant-removal performance and variability of DOM quantity and composition with traditional ecological concrete (TEC) and improved multi-aggregate eco-concrete (IMAEC) revetment treatments

Abstract This study comparatively analyzed the performance of water quality purification on stormwater road runoff, and the changes in the structure and composition of dissolved organic matter (DOM), after traditional ecological concrete (TEC) revetment treatment and a new improved multi-aggregate ecological concrete (IMAEC) revetment treatment. The results showed that the removal rates for chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) reached 14.56%–30.49%, 38.21%–67.96%, and 24.22%–41.14% respectively, in the TEC treatment, and 51.22%–57.90%, 64.61%–81.95%, and 40.29%–53.45% respectively, in the IMAEC treatment, suggesting that the IMAEC revetment treatment showed higher water purification performance than the TEC revetment treatment. The results of SUVA254, a 250/ a 365 and a 253/ a 203 indicated that the IMAEC treatment showed relatively high removal efficiencies of refractory aromatic compounds. Parallel factor (PARAFAC) analysis indicated that the removal rates for three fluorescent components (humic-like Components 1 and 2, and protein-like Component 3) reached 27.94%, 9.69% and 27.86 respectively, in the TEC treatment, and 51.35%, 30.10%, and 52.97% respectively, in the IMAEC treatment. 2D-COS mapping suggested that protein-like materials were more susceptible than humic-like substances, to the addition of metal ions. Protein-like materials can preferentially interact with metal ions, resulting in the effective removal of DOM-metal complexes, and can further influence the migration and transformation of metal ions.