Cu fate driven by colloidal polystyrene microplastics with pipe scale destabilization in drinking water distribution...

Area of Science:

• Environmental Science
• Water Quality Research
• Materials Science

Background:

• Microplastics (MPs) and copper (Cu) are contaminants in drinking water distribution systems (DWDSs).
• The impact of MPs on Cu adsorption by pipe scales and pipe scale stability is not well understood.
• Understanding these interactions is crucial for improving water quality.

Purpose of the Study:

• To investigate the effects of polystyrene microplastics (PSMPs) on Cu adsorption by pipe scales.
• To determine how PSMPs influence pipe scale composition and stability.
• To assess the impact of PSMPs on Cu fate and mobility within DWDSs.

Main Methods:

• Batch adsorption experiments were conducted using PSMPs and pipe scales.
• Metal speciation extraction was used to analyze Cu fractions.
• Cu release experiments were performed to evaluate mobility.
• Pipe scale composition was analyzed to assess stabilization.

Main Results:

• PSMPs enhanced Cu adsorption onto pipe scales through complexation and electrostatic interactions.
• PSMPs increased pipe scale negative charges and provided additional adsorption sites.
• The presence of PSMPs decreased iron and manganese oxides while increasing the organic fraction in pipe scales.
• PSMPs demonstrated a higher affinity for Cu than pipe scales, influencing Cu mobility.
• Coexisting PSMPs facilitated Cu release by destabilizing pipe scales.

Conclusions:

• MPs significantly impact Cu fate and pipe scale stabilization in DWDSs.
• PSMPs alter pipe scale composition, favoring organic matter interactions with Cu.
• MPs can increase the mobility and release of Cu from pipe scales.
• This study provides critical new insights into the hazards posed by MPs in drinking water environments.