Gradient of suspended particulate matter hastens the multi-interface partition dynamics of atrazine and its degradation products

• Published in: Environmental pollution (1987) 2022-12, Vol.315, p.120432-120432, Article 120432
• Main Authors: Guo, Zewei, Ouyang, Wei, Xavier Supe, Tulcan Roberto, Lin, Chunye, He, Mengchang, Wang, Baodong
• Format: Article
• Language: English
• Subjects: Atrazine; Degradation; Diffuse pollution; Sediment-laden river; Suspended particulate matter
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2022.120432

Herbicides are ubiquitous pollutants in estuaries because of the increased demand for food and the need for intensive agricultural systems worldwide. Multi-interface partitioning processes are inadequate for the degradation products of herbicides, especially in sediment-laden river estuaries with intensive water and sediment partitioning. Therefore, the partition characteristics of atrazine and its degradation products at the surface water-suspended particulate matter (SPM), surface water-surface sediment, and SPM-surface sediment interfaces in a typical sediment-laden river estuary were analyzed, the dominant environmental factors were described, and the related mechanisms were explored. The results showed that the partitioning priority of atrazine and its degradation products was surface water > SPM > surface sediment. The partition coefficients of these three interfaces were significantly correlated. The primary degradation products and desisopropylhydroxyatrazine tended to partition into the SPM, and desethyldesisopropylatrazine tended to partition into the surface sediment. Canonical analysis and structural equation modeling indicated that temperature, salinity, sediment pH, and SPM concentrations were the main influencing factors. In the sediment-laden river estuary, the SPM concentration was the most dominant factor. The partition coefficients increased exponentially when the SPM concentration was