Related Experiment Videos
Hydroxyapatite crystallization from a highly concentrated phosphate solution using powdered converter slag as a seed
Eung-Ho Kim1, Soo-Bin Yim, Ho-Chan Jung
1School of Urban and Civil Engineering, Hongik University, Sangsu-dong 72-1, Mapo-gu, Seoul 121-791, Republic of Korea.
Journal of Hazardous Materials
|March 1, 2006
Summary
This study presents an effective system for recovering phosphorus from wastewater using a crystallization reactor. The developed method successfully recycled phosphorus from phosphate solutions, demonstrating significant removal efficiency.
Area of Science:
- Environmental Engineering
- Chemical Engineering
- Materials Science
Background:
- Wastewater treatment processes often generate membrane-filtrate with high phosphorus concentrations.
- Efficient phosphorus recovery is crucial for resource recycling and preventing eutrophication.
Purpose of the Study:
- To develop and evaluate a system for recovering phosphorus from membrane-filtrate using a completely mixed phosphorus crystallization reactor.
- To investigate the optimal conditions and efficiency of phosphorus crystallization recovery.
Main Methods:
- Utilized powdered converter slag as seed material in a completely mixed phosphorus crystallization reactor.
- Operated the reactor within a specific pH range (6.8-7.6) for influent containing approximately 72.9 mg/L PO(4)-P.
- Analyzed the crystalline material using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron micrography (SEM), and energy dispersive X-ray spectroscopy (EDS).
Main Results:
- Achieved an average phosphorus removal efficiency of 52.4% over a 30-day experiment.
- Recovered 0.12 kg of PO(4)-P on seed particles from an initial 0.24 kg.
- Identified the recovered crystalline material as hydroxyapatite with a Ca/P molar ratio of 1.84.
- Observed an increase in average particle size from 22 microm to 94 microm after 30 days of crystallization.
Conclusions:
- The developed completely mixed phosphorus crystallization reactor is an effective system for recovering phosphorus from high-concentration phosphate solutions.
- Converter slag is a suitable seed material for phosphorus crystallization.
- The process facilitates phosphorus recycling from wastewater streams.