Advanced phosphorus removal from membrane filtrates by adsorption on activated aluminium oxide and granulated ferric hydroxide.
The advanced phosphorus (P) removal by adsorption was studied for its suitability as a post-treatment step for membrane bioreactor (MBR) effluents low in P concentration and particle content. Two commercial adsorbents, granulated ferric hydroxide (GFH) and activated aluminium oxide (AA), were studied in batch tests and lab-scale filter tests for P adsorption in MBR filtrates. GFH showed a higher maximum capacity for phosphate and a higher affinity at low P concentrations compared to AA. Competition by inorganic ions was negligible for both adsorbents at the original pH (8.2). When equilibrium P concentrations exceeded 2 mg L(-1) in the spiked MBR filtrates, a precipitation of calcium phosphates occurred additionally to adsorption. During column studies the effluent criteria of 50 microgL(-1) P was reached after a throughput of 8000 bed volumes for GFH and 4000 for AA. Dissolved organic carbon appears to be the strongest competitor for adsorption sites. A partial regeneration and reloading of both adsorbents could be achieved by the use of sodium hydroxide.
Genz
Arne
A
Department of Water Quality Control, Technical University Berlin, Sekr. KF 4, Strasse des 17. Juni 135, 10623 Berlin, Germany. arne.genz@tu-berlin.de
Kornmüller
Anja
A
Jekel
Martin
M
D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D005374:Filtration; D008567:Membranes, Artificial; D010758:Phosphorus / Q000302:isolation & purification*; D013696:Temperature; D014865:Waste Disposal, Fluid; D018508:Water Purification / Q000379:methods*
D005290:Ferric Compounds; D008567:Membranes, Artificial; D010758:Phosphorus; C021024:ferric hydroxide; D000537:Aluminum Oxide