Transport model-based method for estimating micropollutant removal efficiency in riverbank filtration

Area of Science:

• Environmental Science
• Water Treatment Technologies
• Environmental Chemistry

Background:

• Riverbank filtration is a cost-effective drinking water production method utilizing natural gravel bed filtration.
• Traditional removal efficiency calculations for organic micropollutants (OMPs) fail to account for surface water variability and aquifer travel times.
• Accurate OMP removal assessment is crucial for ensuring safe drinking water.

Purpose of the Study:

• To develop and validate a novel numerical transport model for estimating OMP removal during riverbank filtration.
• To assess the impact of travel time distribution on OMP removal efficiency.
• To identify environmental factors influencing OMP removal in riverbank filtration systems.

Main Methods:

• A numerical transport model was developed and applied to two Danube River production sites.
• River and well water samples were collected over one year and analyzed for 41 OMPs.
• Model-based travel time distribution was used to calculate OMP removal efficiencies.

Main Results:

• The model-based method provided more consistent OMP removal estimates than traditional approaches.
• Median removal rates for detected OMPs ranged from 4-97%, with some compounds increasing in concentration.
• Removal efficiency correlated with redox potential, travel time, and distance from the shore; background contamination impacted pesticide levels.

Conclusions:

• The proposed model-based approach offers a more reliable method for assessing OMP removal in riverbank filtration.
• Environmental factors significantly influence the removal efficiency of various OMPs.
• This study provides valuable insights for optimizing riverbank filtration for safe drinking water production.