Exploring the co-occurrence of microplastics, DOM and DBPs inside PVC pipes undergoing chlorination by correlation...

Area of Science:

• Environmental Science
• Water Chemistry
• Materials Science

Background:

• Drinking water systems face challenges from microplastic (MP) generation, chemical leaching from plastic pipes, and disinfection by-product (DBP) formation.
• Polyvinyl chloride (PVC) pipes are common in water distribution, raising concerns about their contribution to water quality degradation.

Purpose of the Study:

• To investigate the co-release of MPs and chemical leachates from PVC pipes under varying chlorine concentrations.
• To assess the subsequent formation of DBPs and the role of dissolved organic matter (DOM) as an intermediary.

Main Methods:

• Laboratory-scale experiments exposing PVC pipes to different chlorine concentrations.
• Analysis of microplastic (PVC-MP) and dissolved organic matter (PVC-DOM) leaching.
• Quantification of disinfection by-products (DBPs).
• Correlation analysis and unsupervised learning (clustering, dimensionality reduction) to understand relationships between MPs, DOM, and DBPs.

Main Results:

• Significant leaching of PVC-DOM and PVC-MP occurred at higher chlorine concentrations.
• At 1 ppm chlorine, natural organic matter (NOM) dominated, with minimal PVC-DOM and PVC-MP release.
• Dissolved organic matter (DOM), including NOM and PVC-DOM, showed strong correlations with both MPs and DBPs, acting as a key intermediary.

Conclusions:

• DOM plays a critical role in linking microplastic and DBP formation in drinking water distribution systems.
• Chlorine concentration influences the extent of PVC-derived contaminant release.
• Understanding these complex interactions is vital for assessing risks in drinking water.