DOI QR코드

DOI QR Code

Treatment of N, P of Auto-Thermal Thermophilic Aerobic Digestion Filtrate with Struvite Crystallization

Struvite 결정화 반응을 이용한 고온 소화 여과액의 N, P 처리 특성

  • Choo, Yeon-Duk (Department of Environmental Engineering, Chungbuk National University) ;
  • Kim, Keum-Yong (Department of Environmental Engineering, Chungbuk National University) ;
  • Ryu, Hong-Duck (Ministry of Environment, Geum River Basin Environmental Office) ;
  • Lee, Sang-Ill (Department of Environmental Engineering, Chungbuk National University)
  • Received : 2011.08.31
  • Accepted : 2011.11.25
  • Published : 2011.11.30

Abstract

Recently, auto-thermal thermophilic aerobic digestion (ATAD) has a great attention for destruction of wasted sludge biomass in wastewater treatment plant. Reduction of sludge concentration has been successfully achieved with pilot scale ATAD and ceramic filtration process in field condition. However, high concentration of COD, total nitrogen (TN) and total phosphorus (TP) was observed in filtrate, which should be treated before recirculation of filtrate to biological wastewater treatment plant. This study was focused on removal of nitrogen and phosphorus contained in the filtrate of ATAD, using struvite crystallization method. The effect of operational and environmental parameters (such as, N, P and Mg ion concentration and molar ratio, pH, reaction time, agitation strength, seed dosage, and reaction temperature) on the treatment of TN and TP with struvite crystallization were evaluated. Magnesium (as $MgCl_26H_2O$) and phosphorus (as $K_2HPO_4$) ions were, if necessary, added to increase nitrogen removal efficiency by the crystal formation. Average concentration of $NH_4^+-N$ and $PO_4^{3-}-P$ of the filtrate were 1716.5 mg/L and 325.5 mg/L, respectively. Relationship between removal efficiencies of nitrogen and phosphorus and molar ratios of $Mg^{2+}$ and $PO_4^{3-}-P$ to $NH_4^+-N$ was examined. Crystal formation and nitrogen removal efficiencies were significantly increased as increasing molar ratios of magnesium and phosphorus to nitrogen. As molar ratio of $Mg^{2+}:PO_4^{3-}-P:NH_4^+-N$ were maintained to 2 : 1 : 1 and 2 : 2 : 1, removal efficiencies of nitrogen and phosphorus were 71.6% and 99.9%, and 93.8% and 98.6%, respectively. However, the effect of reaction time, mixing intensity, seed dose and temperature on the struvite crystallization reaction was not significant, comparing to those of molar ratios. Settled sludge volume after struvite crystallization was observed to be reduced with increase of seed dose and to be increased at high temperature.

Acknowledgement

Supported by : 환경부

References

  1. 원성연, 방승국, 이상일, "Struvite 결정화에 의한 질소 및 인의 제거," 대한환경공학회지, 22(4), 599-607(2009).
  2. 조원실, 윤성준, 라창식, "Struvite 결정화에 의한 축산폐수 로부터 질소, 인 자원의 재생," 동물자원지, 45(5), 875-884 (2003).
  3. 김학균, 김종오, 정종태, "Struvite 결정화를 이용한 혐기성 발효액의 질소 와 인 제거," 한국지반환경공학회지, 7(6), 5- 12(2006).
  4. 류홍덕, 정근욱, 이상일, "축산폐수의 Struvite 전처리가 질산화 과정에 미치는 영향," 대한환경공학회지, 24(10), 1682- 1691(2002a).
  5. 류홍덕, 민경국, 이상일, "Struvite 결정화 반응시 결정핵의 유, 무에 따른 결정화 효율," 대한환경공학회지, 24(12), 2203- 2211(2002b).
  6. 김만수, 류홍덕, 이상일, "침출수의 Struvite 결정화시 결정원의 주입순서가 미치는 영향," 대한환경공학회지, 24(2), 269- 275(2002).
  7. Fujimoto, N., Mizuochi, T. and Togami, Y., "Phosphorus fixation in the sludge treatment system of a biological phosphorus removal process," Water Sci. Technol., 23, 635-640 (1991).
  8. 엄인기, 양창환, 연동석, 이상일, "바닷물을 이용한 질소와 인의 결정화에 의한 처리," 대한환경공학회지, 18(6), 733-741 (1996).
  9. 김진형, 김대근, 강주형, 이상일, "Seeding 및 혼합조건이 Struvite 형성에 미치는 영향," 대한환경공학회지, 29(3), 325- 331(2007).
  10. Ohlinger, K. N., Young, T. M. and Schroeder, E. D., "Kinetics Effects on Preferential Struvite Accumulation in Wastewater," J. Environ. Eng. ASCE, 125(8), 730(1999). https://doi.org/10.1061/(ASCE)0733-9372(1999)125:8(730)
  11. Schulze-Rettmer R., "The simultaneous chemical precipitation of ammonium and phosphate in the form of magne siumammonium- phosphate," Water Sci. Technol., 23, 659-667 (1991).

Cited by

  1. Struvite Crystallization of Anaerobic Digestive Fluid of Swine Manure Containing Highly Concentrated Nitrogen vol.28, pp.7, 2015, https://doi.org/10.5713/ajas.14.0679