Functional ice slurry enables simultaneous deposit removal and micropollutant control in drinking water distribution pipelines.

During long-term operation, drinking water distribution pipelines develop complex inner-wall deposits composed of corrosion scale, sediments, and biofilm, which can serve as reservoirs and secondary sources of organic micropollutants and heavy metals. Conventional pipe cleaning technologies mainly rely on physical scouring to remove deposits, but offer limited capacity to control micropollutant release during cleaning. Here, a peroxymonosulfate/citric acid (PMS/CA) modified ice slurry was developed to integrate physical cleaning with in situ organic contaminant degradation and heavy metal removal. Results showed that CA complexed with iron species to maintain soluble Fe(II) in the reaction system and accelerate Fe(III)/Fe(II) redox cycling, thereby enabling continuous PMS activation and sustained reactive oxygen species generation. Under optimized conditions, the modified ice slurry achieved 90.88% degradation of carbamazepine within 10 min, accompanied by an overall reduction in predicted product toxicity. Meanwhile, CA enhanced the removal of Cr(VI) and Cd(II) from pipe scale matrices by promoting solubilization, which also lowered the risk of rerelease during subsequent stagnation. Validation under near realistic operating conditions further demonstrated the practical applicability of the modified ice slurry for pipeline cleaning. Life cycle assessment indicated that PMS/CA modified ice slurry imposed the lowest environmental impacts across most categories at an equivalent pollutant removal level among the compared oxidation and cleaning technologies. This study provides an effective and environmentally pipe cleaning strategy for coordinated deposit removal and micropollutant control in drinking water distribution systems.