Phosphorus removal from municipal wastewater by hydrous ferric oxide reactive filtration and coupled chemically enhanced secondary treatment: part II--mechanism. |
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Authors: | R L Newcombe D G Strawn T M Grant S E Childers G M?ller |
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Institution: | University of Idaho, Moscow 83844-1052, USA. |
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Abstract: | The removal mechanism of a hydrous ferric oxide (HFO) reactive filtration (RF) process with coupled chemically enhanced secondary treatment (RECYCLE) for phosphorus removal from municipal wastewater (HFO-RF-RECYCLE) was examined. A 0.95-ML/d (0.25-mgd) demonstration of HFO-RF-RECYCLE was performed at a municipal wastewater treatment plant equipped with oxidation ditches and secondary clarifiers. Influent to the plant averaged 6.0 mg/L phosphorus, with a 3-month tertiary effluent average of 0.011 mg/L phosphorus. In addition to aqueous geochemical modeling, experiments with surface charge, scanning electron microscopy, adsorptive capacity, thermal desorption, and most probable number of iron(III)-reducing bacteria were performed on samples from the system, to determine the major phosphorus-removal pathways. Results suggest that, in addition to filtration of particulate phosphorus, the low tertiary effluent total phosphorus result was achieved by adsorption. |
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