Metal Speciation in the Lagoon Sediment Interstitial Water from the Northeast Coast, Korea

동해안 석호 퇴적물의 간극수에 함유된 금속류의 화학종 분포

  • Kim, Dong-Jin (Ministry of Environment, Republic of Korea) ;
  • Kim, Min-Chul (Department of Environmental Technology, Sangji University) ;
  • Yoo, Jin-Yull (Department of Environmental Technology, Sangji University) ;
  • Kwon, Sang-Yong (Department of Environmental Science, Kangwon National University) ;
  • Seo, Yong-Chan (Department of Environmental Technology, Sangji University) ;
  • Yang, Jae-E. (Division of Biological Environment, Kangwon National University) ;
  • Oh, Seung-Yoon (Ministry of Environment, Republic of Korea) ;
  • Ok, Yong-Sik (Division of Biological Environment, Kangwon National University)
  • Published : 2008.07.31

Abstract

Sediment and interstitial water samples from ten lagoons in the Northeastern coastal part of South Korea were analyzed to obtain the concentrations of metals and inorganic ligand. These data, coupled with pH and ionic strength, were used to compute the aqueous speciation of the metals in the interstitial water using the MINTEQA2 equilibrium program. The K and Na were almost entirely present as the free aqua ions, but Co, Cd, Ni, Pb and Zn were existed as various metal-ligand complexes. Metals such as Al, As, and Cr formed 3$\sim$4 metal-ligand complexes. In the interstitial water with high chloride concentrations, almost all of the metals were dominated by free aqua ions. Metals of Cd, Co, Ni, Pb and Zn were bound as chloride-metal complexes of the type M$^{x+}$ + xCl$^-$, and Fe, Mn and Mg were dominated by sulfate equilibria(M$^{2+}$ + SO$_4{^{2-}}$). Hg(II) was speciated as HgCl$_2$(aq), HgCl$_3{^-}$ and HgCl$_4{^-}$. However, in the interstitial water with low chloride concentrations, Hg(II) and Cd(II) were existed as chloride-metal complexes, metals of Cu, Mg, Mn, Ni, Pb and Zn were dominated by sulfate equilibria, and the speciation of Fe(II) was bound as Fe(OH)$_2{^+}$, Fe(OH)$_3$(aq). However, Al, As and Cr were dominated by hydroxy-metal and oxide-metal species in nearly all of the lagoons.

호소나 하천바닥의 퇴적물에는 많은 양의 미량 금속이 함유되어 있으며, 퇴적물과 간극수 사이에는 미량 금속들의 교환이 일어난다. 간극수로 이동된 미량 금속들은 쉽게 수환경으로 확산되어 수생태계에 독성을 유발한다. 그러나 이러한 미량 금속들은 존재형태에 따라 수생물에 미치는 독성이 다르다. 따라서 본 연구에서는 경포호 등 10개의 동해안 석호에 대한 퇴적물의 간극수를 분석하고 화학종 분포 예측 프로그램(MINTEQA2)을 이용하여 미량 금속들의 존재형태를 예측하여 수환경에서의 독성여부를 확인하였다. 퇴적물에서 추출한 간극수의 미량 금속 분석결과를 예측 결과, K와 Na는 자유이온형태로 존재하고 있었으며, Al, As 및 Cr 등은 자유이온 형태를 비롯한 3$\sim$4개의 착물을 형성하였고 Ca, Co, Cd, Ni, Pb 및 Zn 등은 10개 이상의 다양한 착물을 형성하였다. 염분도가 높은 청초호 등(Group I호소)은 Cd, Co, Ni, Pb, Hg 및 Zn이 주로 염화 착물을 형성하였으며, Fe, Mn 및 Mg는 황산화 착물을 형성하였다. 그러나 염분농도가 낮은 천진호 등(Group II호소)은 Hg와 Cd가 염화 착물을 형성하였으며, Cu, Mg, Mn, Ni, Pb 및 Zn는 황산화 착물을 형성하였다. Fe는 Fe(OH)$_2{^+}$, Fe(OH)$_3$(aq) 등의 수산기 착물을 형성하였다. 또한 염분농도와 상관없이 Al, As 및 Cr은 전체 호소에서 수산기 및 산화형태의 착물을 형성하였다. 대부분 호소의 간극수에 존재하는 미량 금속들은 자유이온(M$^{x+}$)형태로 존재하고 있었으며, 그 외에 M$^{x+}$ + xCl$^-$와 M$^{2+}$ + SO$_4{^{2-}}$의 착물을 형성하고 있어 수환경으로 확산될 경우 생태계 독성 및 축척을 일으킬 것으로 생각된다.

Keywords

References

  1. 원주지방환경관리청, 98 동해안 석호 조사 보고서, pp. 168 (1999)
  2. Kwon, S. Y., Heo, W. M., Lee, S. H., Kim, D. J., and Kim, B. C., 'The limnological survey of a coastal lagoon in Korea(4); Lake Songgj,' Kor J. Lomnol., 38(4), 461-473(2005)
  3. 박석순, '퇴적물 초기 속성작용과 미량 오염물질의 거동,' 대한환경공학회지, 17(9), 825-834(1995)
  4. Cho, Y. G., Lee, C. B., and Choi, M. S., 'Geochemistry of surface sediments off the southern and western coasts of Korea,' Marine Geology, 159, 111-129(1999) https://doi.org/10.1016/S0025-3227(98)00194-7
  5. Landrum, P. F. and Robbins, J. A., 'Bioavailability of sediment-associated contaminants to benthic invertebrates: Sediments,' Chemistry and Toxicity of In-place Pollutants R. Baudo, J. Giesy. and H, muntau.(Eds.), Ann Arbor, Lewis Publishers Inc., pp. 237-263 (1990)
  6. Rhoades, J. D. Soluble salt. In: Method of soil analysis, Part 2. Chemical and microbiological Properties, 2nd ed., Page, A. L. Miller, R. H. and Keeney, D. R.(Eds.), Madison: American society of agronomy, pp. 167-179 (1982)
  7. Sunda, W. G., Tester, P. A., and Huntsman, S. A., 'Effects of cupric and zinc ion activities on the survival and reproduction of marine copepods,' Marine Biology, 94, 203-210(1987) https://doi.org/10.1007/BF00392932
  8. Stauber, J. L., and Florence, T. M., 'Mechanism of toxicity of ionic copper complexes to algae' Marine Biology, 94, 511-519(1984) https://doi.org/10.1007/BF00431397
  9. Schuytema, G. S., Nelson, P. O., Malueg, K. W., Nebeker, A. V., Krawczyk, D. F., RatcliffA, K., and Gakstatter, J. H., 'Toxicity of cadmium in water and sediment slurries to 'Daphnia magna',' Environ. Toxicol. Chem., 3, 293-308(1984) https://doi.org/10.1897/1552-8618(1984)3[293:TOCIWA]2.0.CO;2
  10. Cairns, J. Jr., Nebeker, A. V., Gakstatter, J. H., and Giffis, W., 'Toxicity of Copper-spiked sediments to freshwater invertebrates,' Environ. Toxicol. Chem., 3, 435-446(1984) https://doi.org/10.1897/1552-8618(1984)3[435:TOCSTF]2.0.CO;2
  11. Guchte van de, C., and Mass-Diepeveen, J. L., 'Screening sediments for toxicity: A water-concentration related problem,' Canadian Technical Report of Fisheries and Aquatic Sciences, 1607, pp. 81-91(1988)
  12. Griffin, R. A. and Jurinak, J. J., 'Estimation of activity coefficients from the electrical conductivity of natural aquatic systems and soils extracts,' Soil Sci., 116, 26- 30(1973) https://doi.org/10.1097/00010694-197307000-00005
  13. Farrell, R. E., Yang, J. E., Huang, P. M., and Liaw, W. K., 'Chemical Composition and Metal Speciation in Porewaters from the upper Qu'Appelle River Basin, Saskatchewan,' Water Poll. Res. J. Canada, 28(1), 83- 109(1993)
  14. Allison, J. D., Brown, D. S., and Novo-Gradac., MINTEQA2/ PRODEFA2, A Geochemical Assessment Model for Environmental Systems: Version 3.0 User's Manual. U.S. Environmental Protection Agency, Athens, GA. EPA/600/ 3-91/021(1991)
  15. 김석구, 이미경, 안재환, 강성원, 전상호, '퇴적물 내 입도와 유기물 함량이 영양염 및 중금속 농도에 미치는 영향,' 대한환경공학회지, 27(9), 923-931(2005)
  16. Horne, J. A. & Goldman, R., Limnology, 2nd ed., Mac- Graw-Hill, New York, pp. 576(1994)