입상활성탄을 이용한 이온성 및 비이온성 의약품의 제거

Removal of Ionic and Non-ionic Pharmaceuticals Using Granular Activated Carbon

  • Oh, Hee-Kyong (Department of civil engineering, Tokyo Institute of Technology) ;
  • Kagawa, Chie (Department of civil engineering, Tokyo Institute of Technology) ;
  • Urase, Taro (Department of civil engineering, Tokyo Institute of Technology) ;
  • Simazaki, Dai (Department of water supply engineering, National Institute of Public Health) ;
  • Kunikane, Shoichi (Department of water supply engineering, National Institute of Public Health)
  • 발행 : 2006.11.30

초록

입상 활성탄을 이용한 회분식 흡착실험과 연속식 흡착 컬럼 실험을 통해 이온성 및 비이온성 의약품의 제거특성을 평가하였다. 초기 혼합 의약품을 10 ${\mu}g/L$로 주입한 회분식 흡착실험의 경우 입상 활성탄을 500 mg/L로 하였을 때 대상 의약품은 $94{\sim}98%$ 이상의 높은 제거율을 보였다. 이온성 의약품은 pH가 감소할수록 흡착능이 증가하였으나 비이온성 의약품의 흡착능은 pH변화에 큰 영향을 받지 않았다. 이온성 의약품은 pH가 이온화 상수(pKa) 이하로 낮아짐에 따라 COOH형태로 비이온화되어 흡착이 용이하게 되지만 pH가 pKa 이상에서는 이온 상태의 $COO^-$로 존재하게 되어 흡착이 저하되기 때문이다. 또한 pH저하는 액상내 $H^+$ 증가 및 활성탄 표면에 양하전을 증가시켜 용액으로부터 이온성 의약품을 이온 결합에 의해 제거시킬 수 있기 때문이다. 40일간 흡착 컬럼을 연속 운전한 결과 15분의 공탑체류시간(EBCT)에서는 활성탄과 의약품의 충분한 접촉시간으로 대상 의약품에 대해 $93{\sim}99%$의 제거율을 얻었다. 짧은 EBCT의 운전조건에서는 이온성 의약품 가운데 CA, IBP 및 GFZ가 다른 이온성 및 비이온성 의약품에 비해 빠르게 파과에 도달했고 EBCT의 변화에 따른 흡착특성의 변화는 비이온성 의약품에서 더 크게 나타났다. 본 연구를 통해 기존 정수 처리공정을 통해 제거되기 어려운 의약품을 입상 활성탄 흡착공정을 통해 효과적으로 제어할 수 있음을 알 수 있었다.

Adsorbability of ionic and nonionic pharmaceuticals was studied using granular activated carbon(GAC). In a batch adsorption test of muticomponent solution, 500 mg/L of GAC dose removed all target compounds between 94 and 98% at initial concentration of 10 ${\mu}g/L$. Adsorption of ionic pharmaceuticals increased as pH was lowered toward to pKa, however adsorption capacity of nonionic pharmaceuticals showed insignificant variation with the changing pH. The enhanced adsorption capacity of ionic pharmaceuticals at lower pH was attributed to the corresponding increase in the molecular form of ionic pharmaceuticals with carboxylic group at low pH. In addition, decrease of pH increased hydrogen ion concentration in the bulk solution and the protons bound to the available sites on the carbon enhanced the removal of the ionic pharmaceuticals from solution. After 40 days of continuous operation, GAC column showed the removal of target compounds were removed by $93{\sim}99%$ at 15 min of EBCT mainly due to adsorption mechanism of GAC. At shorter EBCT than 15 min, breakthrough of CA, IBP and GFZ occurred earlier than the other ionic and nonionic pharmaceuticals. effect of EBCT on adsorption of nonionic pharmaceuticals was greater than ionic ones. This study showed that persitent pharmaceuticals found in drinking water treatment could be effectively controlled by adsorption in GAC process.

키워드

참고문헌

  1. Halling-Sorensen, B., Nors Nielsen, S., Lanzky, P. F., Ingerslev, F., Holten Lutzheft H. C., and Jorgensen S. E., 'Occurrence, fate and effects of pharmaceutical substances in the environment- A review,' Chemosphere, 36(2), 357 - 393(1998) https://doi.org/10.1016/S0045-6535(97)00354-8
  2. Vieno, N. M., Tuhkanen, T., and Kronberg, L., 'Seasonal variation in the occurrence of pharmaceuticals in effluents from a sewage treatment plant and in the recipient water,' Environ. Sci. Technol., 39, 8220-8226 (2005) https://doi.org/10.1021/es051124k
  3. Castiglioni, S., Bagnati, R., Fanelli, R., Pomati, F., Calamari, D., and Zuccato, E., 'Removal of pharmaceuticals in sewage treatment plants in Italy,' Environ. Sci. Technol., 40(1), 357 - 363(2006) https://doi.org/10.1021/es050991m
  4. Loraine, G. A. and Pettigrove, M. E., 'Seasonal Variations in Concentrations of Pharmaceuticals and Personal Care Products in Drinking Water and Reclaimed Wastewater in Southern California,' Environ. Sci. Technol., 40(3), 687-695(2006) https://doi.org/10.1021/es051380x
  5. Ternes, T. A., Meisenheimer, M., Mcdowell, D., Sacher, F., Brauch, H.J., Haist-Guide, B., Preuss, G., Wilme, U., and Zulei-Seibert, N., 'Removal of pharmaceuticals during drinking water treatment,' Environ. Sci. Technol., 36, 3855 - 3863(2002) https://doi.org/10.1021/es015757k
  6. Koutsouba, V., Heberer, Th., Fuhrmann, B., SchmidtBaumler, K., Tsipi, D., and Hiskia, A., 'Determination of polar pharmaceuticals in sewage water of Greece by gas chromatography-mass spectrometry,' Chemosphere, 51, 69 - 75(2003) https://doi.org/10.1016/S0045-6535(02)00819-6
  7. Lin, W. C., Chen, H. C, and Ding, W. H., 'Determination of pharmaceutical residues in waters by solid-phase extraction and large-volume on-line derivatization with gas chromatography-mass spectrometry,' J. of Chromatography A, 1065, 279-285(2005) https://doi.org/10.1016/j.chroma.2004.12.081
  8. Kummerer, K., Pharmaceuticals in the Environment, Springer, 2nd Eds., pp. 3 - 90(2004)
  9. 한국화, 김상돈, '방류수 내 잔류 의약품의 위해성 평가: 수서생물에 의한 독성평가와 GC/MS를 이용한 수질시료 분석,' 대한환경공학회 춘계학술연구발표회, 389-393 (2004)
  10. Westerhoff, P., Yoon, Y. M., Snyder, S., and Wert, E., 'Fate of endocrine-disruptor, pharmaceutical, and personal care product chemicals during simulated drinking water treatment processes,' Environ. Sci. Technol., 39, 6649 - 6663(2005) https://doi.org/10.1021/es0484799
  11. AWWA Research Foundation, 'Endocrine disruptors and pharmaceuticals in drinking water,' AwwaRF 90849(2002)