Work

Combined UV/H2O2 and biochar processes for enhanced removal of contaminants of emerging concern in dry wells

Year: 2025

Type: article

Abstract: UV dose degraded all CECs by >50 %, except dicamba, with direct photolysis as the dominant mechanism due to strong hydroxyl radical scavenging by dissolved organic carbon (DOC). Combining UV and biochar reduced CEC breakthrough concentration by 4 - 92 %. Based on the results, a contaminant transport model was calibrated and used to estimate the system lifespan in dry wells in Los Angeles. Findings showed that the insecticide, imidacloprid, is the limiting contaminant for the system's lifespan. Without UV/H₂O₂ pre-treatment, the system could last about four years with 10 wt% biochar in the filter. With pre-treatment, the lifespan will be determined by other operational factors rather than CEC removal. This study developed effective stormwater treatment systems for dry wells, supporting future local stormwater capture projects while safeguarding groundwater quality.

Source: Water Research