NOM removal by adsorption and membrane filtration using heated aluminum oxide particles.
Heated aluminum oxide particles (HAOPs) are a newly synthesized adsorbent with attractive properties for use in hybrid adsorption/membrane filtration systems. This study compared removal of natural organic matter (NOM) from water by adsorption onto HAOPs with that by adsorption onto powdered activated carbon (PAC) or coagulation with alum or ferric chloride (FeCl3); explored the overlap between the NOM molecules that preferentially adsorb to HAOPs and those that are removed by the more conventional approaches; and evaluated NOM removal and fouling in hybrid adsorbent/membrane systems. For equivalent molar doses of the trivalent metals, HAOPs remove more NOM, and NOM with higher SUVA254, than alum or FeCl3. Most of the HAOPs-nonadsorbable fraction of the NOM can be adsorbed by PAC; in fact, that fraction appears to be preferentially adsorbed compared to the average NOM in untreated water. Predeposition of the adsorbents on a microfiltration membrane improves system performance. For the water tested, at a flux of 100 L/m2-hr, predeposition of 11 mg/L PAC and 5 mg/L HAOPs (as Al3+) allowed the system to operate 5 times as long before the transmembrane pressure increased by 1 psi and to remove 10-20 times as much NOM as when no adsorbents were added.
Cai
Zhenxiao
Z
Department of Civil and Environmental Engineering, University of Washington, Seattle 98195-2700, USA.
Kim
Jaeshin
J
Benjamin
Mark M
MM
D000327:Adsorption; D000534:Alum Compounds / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D002712:Chlorides; D005290:Ferric Compounds / Q000737:chemistry; D005374:Filtration; D006358:Hot Temperature; D014873:Water Pollutants / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
D000534:Alum Compounds; D002712:Chlorides; D005290:Ferric Compounds; D014873:Water Pollutants; C041524:aluminum sulfate; D002244:Carbon; D000537:Aluminum Oxide; C024555:ferric chloride