Thesis
Phosphorus removal characteristics on biogenic ferrous iron oxides
Washington State University
Master of Science (MS), Washington State University
2008
Handle:
https://hdl.handle.net/2376/102302
Abstract
Phosphorus is a main aquatic pollutant, which has led to an evolution in treatment technologies. However, it remains a cause of water body degradation. Filters using iron rich or iron oxide containing substrates appear to be an effective method to remove phosphorus from water. A recent study revealed that biogenic iron oxides used within a filter are an improved and more cost effective method (Rentz et al., 2008). Phosphorus resources are depleted, and recovery methods are studied for phosphorus reuse in both agriculture and industry. In order to investigate the characteristics of biogenic iron oxides generated by Leptothrix ochracea and their behavior on phosphorus adsorption and release, we used batch equilibrium experiment methods. Biogenic iron oxides adsorbed 19.02 mg P/g solids on average against 6.27 mg P/g solids for synthetic or chemical substrates. Variations in pH dramatically enhanced phosphorus adsorption. Fresh samples showed an increase in phosphorus by 315% and 307% between low and high pH. Older samples increased by only 50% and 78%. Results suggest that adsorption of phosphorus to biogenic iron oxides is made by weak electronic linkage. Hydroxide sodium was the best chemical to break down these linkages and release phosphorus. Sample released from 159.3% and 295.3% of the initially adsorbed phosphorus. DI water showed the second best phosphorus release potential of 40.60% averaged over the four samples. The KCl solution had an average potential of 30.37% and the saline solution 20.23%. The origin of the released phosphorus is in-situ phosphorus adsorption or cell disruption. Release potential for fresh samples was greater than old samples only using sodium hydroxide. High sorption capacity, adsorption enhancement by lowering the pH, and great phosphorus release capacity should be incorporated to the next step of this project of phosphorus filtration.
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Details
- Title
- Phosphorus removal characteristics on biogenic ferrous iron oxides
- Creators
- Antoine Cordray
- Contributors
- Jeremy A. Rentz (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900524807001842
- Language
- English
- Resource Type
- Thesis