Journal of Korean Society of Environmental Engineers (대한환경공학회지)

Korean Society of Environmental Engineers (대한환경공학회)
권호 표지
DOI QR코드

DOI QR Code

Removal of Hydrogen Fluoride from Waterjet Plasma Wastewater by Electrocoagulation

전해응집법에 의한 불화수소 함유 워터젯 플라즈마 폐수처리

  • 이채홍 (조선대학교 환경공학부) ;
  • 전영남 (BK21 바이오가스기반 수소생산 사업팀)
  • Received : 2010.12.27
  • Accepted : 2012.10.30
  • Published : 2012.10.30
Download PDF
⟨ Previous Next ⟩

Abstract

Tetrafluoromethane ($CF_4$) has been used as etching and Chemical Vapor Deposition (CVD) gases for semiconductor manufacturing processes. These gases need to be removed efficiently because of their strong absorption of infrared radiation and long atmospheric lifetimes which cause the global warming effect. Also, the wastewater including the fluorine is caused by of the ground water pollution. Long-term consumption of water containing excessive fluoride can lead to fluorosis of the teeth and bones. The wastewater including the fluorine among the by-product which is generated by using the waterjet plasma after destroying $CF_4$ by HF is generated. The system which can remove the hydrogen fluoride among the wastewater by using the electrocoagulation using this wastewater the aluminum electrode was developed. The operating condition such as initial pH, electrocoagulation time, wastewater flow rate, current density were investigated experimentally using a electrocoagulation. Through the parametric studies, the highest hydrogen fluoride destruction of 85% was achieved at 3.5 initial pH, 10 min electrocoagulation time, 10 mL/min wastewater flow rate and $159A/m^2$ current density.

사불화탄소($CF_4$)는 반도체 제조공정에서 에칭과 화학기상증착(CVD)에서 사용되어온 가스이다. $CF_4$는 적외선을 강하게 흡수하고 대기 중 잔류시간이 길어서 지구온난화에 영향을 미치기 때문에 고효율의 분해가 필요하다. 또한 불화수소를 포함한 폐수는 지하수 오염의 원인이 된다. 과도한 불소를 포함한 물을 장기간 섭취는 치아와 뼈에 문제를 야기한다. 워터젯 플라즈마를 이용하여 $CF_4$를 분해 후 생성되는 부산물 중 HF에 의하여 폐수가 생성된다. 이 폐수를 알루미늄 전극을 사용한 전해응집을 이용하여 폐수 중 HF를 제거 할 수 있는 시스템을 개발하였다. 실험 변수로는 초기 pH 변화, 반응 시간 변화, 주입유량 변화, 전류 밀도 변화를 실험하였다. 변수 실험을 통하여 초기 pH는 3.5, 반응 시간은 10 min, 주입 유량은 10 mL/min, 전류 밀도는 $159A/m^2$일 때 HF 제거율은 최고 85%까지 도달하였다.

Keywords

Acknowledgement

Supported by : 한국연구재단

References

  1. Sun, J. W. and Park, D. H., "CF4 Decomposition by Thermal Plasma Processing," Korean J. Chem. Eng., 20(3), 476-481 (2003). https://doi.org/10.1007/BF02705551
  2. Chang, M. B. and Lee, H. M., "Abatement of perfluorocarbons with combined plasma catalysis in atmospheric-pressure environment," Catal. Today, 89, 109-115(2004). https://doi.org/10.1016/j.cattod.2003.11.016
  3. Xie, H., Sun, B. and Zhu, X., "Abatement of perfluorocompounds with microwave plasma in atmospheric pressure environment," J. Hazard. Mater., 168, 765-769(2009). https://doi.org/10.1016/j.jhazmat.2009.02.081
  4. Shen, F., Chen, X., Gao, P. and Chen, G., "Electrochemical removal of fluoride ions from industrial wastewater," Chem. Eng. Sci., 58, 987-933(2003). https://doi.org/10.1016/S0009-2509(02)00639-5
  5. Drouiche, N., Ghaffour, N., Lounici, H., Mameri, N., Maallemi, A. and Mahmoudi, H., "Electrochemical treatment of chemical mechanical polishing wastewater: removal of fluoride- sludge characteristics-operating cost," Desalination, 223, 134-142(2008). https://doi.org/10.1016/j.desal.2007.01.191
  6. Ghorai, S. and Pant, K. K., "Equilibrium, kinetics and breakthrough studies for adsorption of fluoride on activated alumina," Sep. Purif. Technol., 42, 265-271(2005). https://doi.org/10.1016/j.seppur.2004.09.001
  7. Miramontes, M. P., Margulis, R. G. B. and Hernandez, A. P., "Removal of arsenic and fluoride from drinking water with cake alum and a polymeric anionic flocculent," Fluoride., 36(2), 122-128(2003).
  8. Ndiaye, P. I., Moulin, P., Dominguez, L., Millet, J. C. and Charbit, F., "Removal of fluoride from electronic industrial effluent by RO membrane separation," Desalination, 173(1), 25-32(2005). https://doi.org/10.1016/j.desal.2004.07.042
  9. Zhu, J., Zhao, H. and Ni, J., "Fluoride distribution in electrocoagulation defluoridation process," Sep. Purif. Technol., 56(2), 184-191(2007). https://doi.org/10.1016/j.seppur.2007.01.030
  10. Yu, S. J. and Chang, M. B., "Oxidative Conversion of PFC via Plasma Processing with Dielectric Barrier Discharges," Plasma Chem. Plasma Proc., 21(3), 311-327(2001). https://doi.org/10.1023/A:1011066208188
  11. Du, C. M. and Yan, J. H., "Electrical and Spectral Characteristics of a Hybrid Gliding Arc Discharge in Air-Water," IEEE T. Plasma Sci., 35(6), 1648-1650(2007). https://doi.org/10.1109/TPS.2007.901941
  12. Hong, Y. C., Kim, H. S. and Uhm, H. S., "Reduction of perfluorocompound emissions by microwave plasma-torch," Thin Solid Films, 435, 329-334(2003). https://doi.org/10.1016/S0040-6090(03)00363-8
  13. Hu, C. Y., Lo, S. L., Kuan, W. H. and Lee, Y. D., "Removal of fluoride from semiconductor wastewater by electrocoagulation- flotation," Water Res., 39(5), 895-901(2005). https://doi.org/10.1016/j.watres.2004.11.034
  14. Hu, C. Y., Lo, S. L., Li, C. M. and Kuan, W. H., "Treating chemical mechanical polishing (CMP) wastewater by electrocoagulation- flotation process with surfactant," J. Hazard. Mater., 120, 15-20(2005). https://doi.org/10.1016/j.jhazmat.2004.12.038
  15. Zuo, Q., Chen, X., Li, W. and Chen, G., "Combined electrocoagulation and electroflotation for removal of fluoride from drinking water," J. Hazard. Mater., 159, 452-457(2008). https://doi.org/10.1016/j.jhazmat.2008.02.039
  16. Emamjomeh, M. and Sivakumar, M., "An empirical model for defluoridation by batch monopolar electrocoagulation/flotation (ECF) process," J. Hazard. Mater., 131, 118-125 (2006). https://doi.org/10.1016/j.jhazmat.2005.09.030
  17. Drouiche, N., Aoudj, S., Hecini, M., Ghaffour, N., Lounici, H. and Mameri, N., "Study on the treatment of photovoltaic wastewater using electrocoagulation: Fluoride removal with aluminium electrodes-Characteristics of products," J. Hazard. Mater., 169, 65-67(2009). https://doi.org/10.1016/j.jhazmat.2009.03.073
  18. Emamjomeh, M. and Sivakumar, M., "Fluoride removal by a continuous flow electrocoagulation reactor," J. Environ. Manage., 90(2), 1204-1212(2009). https://doi.org/10.1016/j.jenvman.2008.06.001