STUDY OF IN-FILTER PHOSPHORUS REMOVAL MECHANISMS IN AN AERATED BLAST FURNACE SLAG

Abstract

The removal mechanism of phosphorus in a wastewater treatment system remained uncertain due to their process complexity. Accordingly this study has been conducted to investigate the removal mechanism of phosphorus from domestic wastewater in an aerated blast furnace slag filter. In this study, several blast furnace slag (BFS) samples (fresh, after 2,4 and 6 months treatment period) and particulates (4-5 mm in size) and sediments samples from the BFS filter after one year operation on site from the pilot-scale aerated BFS filter were taken for scanning electron microscopy (SEM) examinations and X-ray diffraction (XRD) analysis to study the changes of the filter media after usage in the ARF system. Scanning electron microscopy and X-ray diffraction spectrometric analyses on the surface of BFS, particulates and sediment samples revealed that the apparent mechanisms of P-removal in the filter are adsorption on the amorphous oxide phase of the BFS surface and precipitation within the filter.