# Fast Adsorption of Short and Long-Chain Per- and Polyfluoroalkyl Substances from Water by Chemically Modified Sawdust

## TL;DR

Researchers developed a low-cost sawdust-based material that effectively removes various PFAS chemicals from water, even in different environmental conditions.

## Contribution

A novel, low-cost, and reusable sawdust-based adsorbent was developed for efficient PFAS removal from water.

## Key findings

- The modified sawdust removed over 90% of nine PFAS and over 80% of GenX in deionized water.
- Environmental factors like pH, organic matter, and ions had minimal impact on long-chain PFAS removal.
- The material was reusable for at least five cycles, enhancing its cost-effectiveness.

## Abstract

To remove per- and polyfluoroalkyl substances (PFAS)
from water,
this study focused on synthesizing a sawdust-based adsorbent through
KMnO4 oxidation and coating m-phenylenediamine (mPD) onto
the sawdust’s surface. The resulting sawdust/MnO2/PmPD was able to remove >90% of nine target PFAS and >80%
of GenX
spiked at 10 ppb in deionized water. When added to river water samples,
the capture of long-chain PFAS remained basically the same. This was
in line with the observations that environmental factors, such as
a change of pH between 4.0 and 11.0, the presence of natural organic
matter in the range of 0 and 100 mg L–1, and the
presence of bicarbonate, nitrate, and chloride, each at 1 mM, did
not affect the removal of long-chain PFAS significantly. The low-cost
nature of this sorbent was further strengthened by its regenerability
and reusability for at least five cycles. To improve the sorption
performance, especially for short-chain PFAS, further modification
of the sawdust/MnO2/PmPD will need to be performed based
on the revealed mechanisms underlying PFAS capture. Overall, at this
stage, the sawdust/MnO2/PmPD material is ready to be used
for removing PFAS from surface water.