Dynamics of potentially toxic elements in small rivers during high-flow events

Area of Science:

• Environmental Chemistry
• Hydrology
• Geochemistry

Background:

• Potentially toxic elements (PTE) pose environmental risks.
• Understanding PTE transport dynamics is vital for riverine ecosystem health and management.
• Flow events significantly influence the transport of contaminants in river systems.

Purpose of the Study:

• To investigate the concentration dynamics of PTE during river flow events.
• To enhance the understanding of contaminant transport mechanisms.
• To provide insights for improved monitoring and management strategies in river catchments.

Main Methods:

• Sampling of potentially toxic elements (PTE) and suspended particulate matter (SPM) during three to four flow events across three monitoring sites.
• Analysis of total and dissolved concentrations of 29 major and trace elements.
• Collection of riverbed sediment and soil samples using a land-use stratified design.

Main Results:

• PTE transport is primarily driven by SPM, with distinct PTE content dynamics in SPM.
• Early event stages show higher road traffic-related elements (e.g., Antimony) indicating street runoff.
• Dissolved PTE concentrations varied significantly between events, influenced by pre-event low-flow duration.

Conclusions:

• PTE transport is strongly associated with SPM dynamics, requiring consideration of SPM quality.
• Event-driven monitoring strategies are essential for accurate load estimation and source identification.
• The study provides a basis for effective river management and pollution mitigation measures.