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Research article - Peer-reviewed, 2015

Phosphorus removal performance and speciation in virgin and modified argon oxygen decarburisation slag designed for wastewater treatment

Zuo, Minyu; Renman, Gunno; Gustafsson, Jon Petter; Gustafsson, Jon-Petter; Renman, Agnieszka

Abstract

Argon oxygen decarburisation (ADD) slag may be used for phosphorus (P) removal, as its high pH and weatherable calcium (Ca) minerals provide sufficient Ca2+ and OH- for calcium phosphate (Ca-PO4) precipitation. This study examined the P removal performance of AOD slag for use as wastewater treatment material. Batch experiments were carried out using both synthetic P solution and real wastewater, followed by chemical modelling and X-ray absorption near edge structure (XANES) spectroscopy. The influences of initial P concentration, slag dose and modification by polyethylene glycol (PEG), an effective agent for generation of porous materials, were investigated to determine the optimal conditions for P removal by AOD slag. It was found that virgin AOD slag removed 94.8% of P from a synthetic P solution in 4 h and 97.8% in 10 h. This high P removal was accompanied by a rapid increase in pH from 7.0 to 10.74. The maximum P removal capacity (PRC) from synthetic P solution ranged from 1.3 to 27.5 mg P g(-1). The optimal AOD dose for P removal from wastewater, determined in 8-h batch experiments, was 25 g L-1. PEG modification increased the reaction rate and resulted in higher final pH, increasing PRC by 47.9%. Combined Visual MINTEQ and XANES analysis for detailed examination of P removal mechanisms revealed that the main P removal mechanism was precipitation of calcium phosphate. According to the XANES analysis, the main Ca-PO4 precipitate formed on virgin AOD slag under low initial P concentration and high pH was apatite, while brushite was the dominant product at high initial P concentration and low pH. (C) 2015 Elsevier Ltd. All rights reserved.

Keywords

Phosphorus; Slag; Apatite; Brushite; Visual MINTEQ; XANES

Published in

Water Research
2015, volume: 87, pages: 271-281
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

Authors' information

Zuo, Minyu
Royal Institute of Technology (KTH)
Renman, Gunno
Royal Institute of Technology (KTH)
Gustafsson, Jon Petter (Gustafsson, Jon-Petter)
Royal Institute of Technology (KTH)
Swedish University of Agricultural Sciences, Department of Soil and Environment
Renman, Agnieszka
Royal Institute of Technology (KTH)

Sustainable Development Goals

SDG6 Clean water
SDG3 Good health and wellbeing

UKÄ Subject classification

Environmental Management
Oceanography, Hydrology, Water Resources
Water Engineering

Publication Identifiers

DOI: https://doi.org/10.1016/j.watres.2015.09.035

URI (permanent link to this page)

https://res.slu.se/id/publ/69478