| Title |
Recovery of High Concentrated Phosphates using Powdered Converter Slag in Completely Mixed Phosphorus Crystallization Reactor |
| Authors |
김응호 ( Eung Ho Kim ) ; 임수빈 ( Soo Bin Yim ) ; 정호찬 ( Ho Chan Jung ) ; 이억재 ( Eok Jae Lee ) ; 조진규 ( Jin Kyu Cho ) |
| Keywords |
Powdered converter slag; Phosphate recovery; Phosphorus crystallization process; Seeding material; Hydroxyapatite crystallization |
| Abstract |
A phosphate recovery system from artificial wastewater was developed using a completely mixed phosphorus crystallization reactor, in which powdered converter slag was used as a seeding crystal. In preliminary test, the optimal pH range for meta-stable hydroxyapatite crystallization for high phosphorus concentration was observed to be 6.0 to 7.0, which was different from the conventionally known pH range (8.0~9.5) for effective crystallization in relatively low phosphorus concentration less than 5 ㎎/L. The average phosphorus removal efficiency in a lab-scaled completely mixed crystallization system for artificial wastewater with about 100 ㎎/L of average PO₄-P concentration was shown to be 60.9% for 40 days of lapsed time. XRD analysis exhibited that crystalline of hydroxyapatite formed on the surface of seed crystal, which was also observed in SEM analysis. In EDS mapping analysis, composition mole ratio (=Ca/P) of the crystalline was found to be 1.78, indicating the crystalline on the surface of seed crystal is likely to be hydroxyapatite. Particle size distribution analysis showed that average size of seed crystal increased from 28μm up to 50μm, suggesting that phosphorus recycling from wastewater with high phosphorus concentration can be successfully obtained by using the phosphorus crystallization recovery system. |