Selective and efficient removal of fluoride from water by in‐situ engineered amyloid fibrils‐ZrO2 hybrid membranes

Effective and selective removal of fluoride from water systems is a pressing global issue for both drinking water and wastewater purification. Most of the present adsorbents exhibit inferior removal performance and low capacity, due to the intrinsic feature (light halogenide) of fluoride ions, so that developing new materials capable to remove both high and low concentrations of fluoride from water remains a challenge. This work reports a new strategy for efficient removal of fluoride from contaminated water streams, which relies on carbon hybrid membranes made of amyloid fibrils‐ZrO2 nanoparticles (<10 nm) nucleated in‐situ onto the amyloid fibrils surface via a chemical deposition process. These nanoparticles provide the ensued hybrids a remarkable affinity towards fluoride and very efficient removal performance when used in the form of membranes in combination with activated carbon to increase permeability. These hybrid membranes exhibit superior selectivity for fluoride against various competitive ions, with a distribution coefficient Kd as high as 6820 mL/g, exceeding commercial ion‐exchange resins (IRA‐900) by 180 times and outdoing the performance of most commercial carbon‐activated aluminum membranes. In both low (several mg/L) and highly (~200 mg/L) fluoride concentrations, representative of tap‐water and wastewater contamination regimes, the efficiency of the membrane exceeds 99.5% removal. Benchmark on real untreated municipal tap water (~2.8 mg/L) under continuous operating mode, indicates that ~1750 Kg water/m2 membrane can be treated while maintain water quality above WHO drinking threshold, and the saturated membranes can be regenerated and re‐used several times without decrease in performance. The selectivity of the membranes, their simple and affordable manufacturing and their high performance on real water sources, make this technology highly promising for mitigating the problem of fluoride water contamination worldwide

from A via a.sfakia on Inoreader https://ift.tt/2tyxvyz