Real-Time LIBD Tracks Nanoplastics Deposition on Nanofiltration Membranes

A new Water Research paper shows how laser-induced breakdown detection (LIBD) can watch nanoplastics land on — and leave — a nanofiltration membrane in real time. The work, issued October 1, 2026 on the University of Basel edoc record (DOI 10.1016/j.watres.2026.126362), comes from Tyler A. Malkoske, Minh N. Nguyen, Susanne Erpel, Marcus Wyss and Andrea I. Schäfer at the Karlsruhe Institute of Technology (KIT) Institute for Advanced Membrane Technology, with University of Basel / Swiss Nanoscience Institute coauthors.

What the researchers did

They coupled LIBD in-line with a bench-scale nanofiltration (NF) system and tracked polystyrene (PS) particles and weathered nanoplastics at environmentally relevant concentrations (1–500 µg/L; about 10⁷–10⁹ particles/mL). The goal was to quantify deposition during filtration and release during backwash, then compare those measurements with theory on hydrodynamic and intermolecular forces.

What they found

Deposition depends strongly on permeate flux. At fluxes higher than 100 L/m²·h, 50–100% of PS particles had deposited by the end of the filtration runs, forming cake layers up to nine particle diameters thick. At fluxes below 50 L/m²·h — just beyond the critical flux — deposition was insignificant.

Backwash release was less sensitive to flux in the range they tested. Backwash fluxes from 15 to 57 L/m²·h showed negligible differences in how many deposited particles came off, because the backwash drag force rose only a little across that range.

Two release patterns. For thin deposits, particles came off completely in small circular patches (diameter ≤2 µm). For thick deposits, the cake layer fractured.

Weathered nanoplastics behaved differently. The authors observed irreversible deposition of weathered NPs on the membrane surface, and they note that aggregation and polydispersity must be accounted for before those results can be treated as fully quantitative.

The authors conclude that LIBD is an effective method for fundamental investigations of nanoplastic transport during membrane filtration.

The caveats

This is a bench-scale laboratory study, not a claim about any consumer product or home drinking-water system. Concentrations and fluxes are experimental settings. Weathered-particle results need care because aggregation and polydispersity can bias counts. The paper discusses NF as a treatment barrier in water-engineering terms; that is the researchers’ framing for membrane process science — not a purity claim and not a product endorsement by Hydrology University.

What it means for readers

The advance is measurement: real-time counting of nanoplastic deposition and release on an NF membrane with LIBD. It helps membrane scientists see when particles stick, when they wash off, and how weathered particles may differ from clean polystyrene standards. It does not set health guidance or drinking-water limits.

A note on scope: this post summarises a peer-reviewed engineering study. It is not medical advice, and Hydrology University was not involved in the research.

Sources

• Malkoske, T.A., Nguyen, M.N., Erpel, S., Wyss, M. & Schäfer, A.I. “Real-time quantification of nanoplastics deposition in nanofiltration using laser-induced breakdown detection (LIBD).” Water Research (2026). DOI: 10.1016/j.watres.2026.126362
• University of Basel edoc record (issued 2026-10-01): edoc.unibas.ch publication 0fd4f38b-476d-49fb-9d03-abf160018f7d
• KIT / KITopen record: publikationen.bibliothek.kit.edu/1000195668

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