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Recycled Steel Slag as a Porous Adsorbent to Filter Phosphorus-Rich Water with 8 Filtration Circles
- Source :
- Materials, Vol 14, Iss 12, p 3187 (2021)
- Publication Year :
- 2021
- Publisher :
- MDPI AG, 2021.
-
Abstract
- Steel slag is a secondary product from steelmaking process through alkaline oxygen furnace or electric arc furnace (EAF). The disposal of steel slag has become a thorny environmental protection issue, and it is mainly used as unbound aggregates, e.g., as a secondary component of asphalt concrete used for road paving. In this study, the characteristics of compacted porous steel slag disc (SSD) and its application in phosphorous (P)-rich water filtration are discussed. The SSD with an optimal porosity of 10 wt% and annealing temperature of 900 °C, denoted as SSD-P (10, 900) meets a compressive strength required by ASTM C159-06, which has the capability of much higher than 90% P removal (with the effluent standard < 4 mg P/L) within 3 h, even after eight filtration times. No harmful substances from SSD have been detected in the filtered water, which complies with the effluent standard ISO 14001. The reaction mechanism for P-rich water filtration is mediated by water, followed by two reaction steps—CaO in SSD hydrolyzed from the matrix of SSD to Ca2+ and reacting with PO43−. However, the microenvironment of water is influenced by the pH value of the P-rich water at different filtration times and the kind of P-rich water with different free positive ion that interferes the reactions of the release of Ca2+. This study demonstrates the application of circular economy in reducing steel slag deposits, filtering P-rich water, and collecting Ca3(PO4)2 precipitate into fertilizers.
- Subjects :
- porous steel slag disc
phosphorus-rich water
phosphorus removal
filtration times
circular economy
Technology
Electrical engineering. Electronics. Nuclear engineering
TK1-9971
Engineering (General). Civil engineering (General)
TA1-2040
Microscopy
QH201-278.5
Descriptive and experimental mechanics
QC120-168.85
Subjects
Details
- Language :
- English
- ISSN :
- 19961944
- Volume :
- 14
- Issue :
- 12
- Database :
- Directory of Open Access Journals
- Journal :
- Materials
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.7fefd633f74b60a94f276867d2aace
- Document Type :
- article
- Full Text :
- https://doi.org/10.3390/ma14123187