Gold nanoparticle-aluminum oxide adsorbent for efficient removal of mercury species from natural waters.
We report a new adsorbent for removal of mercury species. By mixing Au nanoparticles (NPs) 13 nm in diameter with aluminum oxide (Al(2)O(3)) particles 50-200 μm in diameter, Au NP-Al(2)O(3) adsorbents are easily prepared. Three adsorbents, Al(2)O(3), Au NPs, and Au NP-Al(2)O(3), were tested for removal of mercury species [Hg(2+), methylmercury (MeHg(+)), ethylmercury (EtHg(+)), and phenylmercury (PhHg(+))]. The Au NP adsorbent has a higher binding affinity (dissociation constant; K(d) = 0.3 nM) for Hg(2+) ions than the Al(2)O(3) adsorbent (K(d) = 52.9 nM). The Au NP-Al(2)O(3) adsorbent has a higher affinity for mercury species and other tested metal ions than the Al(2)O(3) and Au NP adsorbents. The Au NP-Al(2)O(3) adsorbent provides a synergic effect and, thus, is effective for removal of most tested metal ions and organic mercury species. After preconcentration of mercury ions by an Au NP-Al(2)O(3) adsorbent, analysis of mercury ions down to the subppq level in aqueous solution was performed by inductively coupled plasma mass spectrometry (ICP-MS). The Au NP-Al(2)O(3) adsorbent allows effective removal of mercury species spiked in lake water, groundwater, and seawater with efficiencies greater than 97%. We also used Al(2)O(3) and Au NP-Al(2)O(3) adsorbents sequentially for selectively removing Hg(2+) and MeHg(+) ions from water. The low-cost, effective, and stable Au NP-Al(2)O(3) adsorbent shows great potential for economical removal of various mercury species.
Department of Chemistry, National Taiwan University, Taipei, Taiwan.
Sut-I
SI
Lo
Po-Cheng
PC
Chen
Chih-Ching
CC
Huang
Huan-Tsung
HT
Chang
D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D060587:Groundwater / Q000737:chemistry; D007700:Kinetics; D060106:Lakes / Q000737:chemistry; D008628:Mercury / Q000302:isolation & purification*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D059027:Recycling; D012623:Seawater / Q000737:chemistry; D013054:Spectrophotometry, Atomic; D013056:Spectrophotometry, Ultraviolet; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D014874:Water Pollutants, Chemical; D006046:Gold; D008628:Mercury; D000537:Aluminum Oxide