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.
Department of Water Quality Control, Technical University Berlin, Sekr. KF 4, Strasse des 17. Juni 135, 10623 Berlin, Germany. arne.genz@tu-berlin.de
Arne
A
Genz
Anja
A
Kornmüller
Martin
M
Jekel
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