Analysis of Hypoxia Dynamics Using Pelagic and Benthic Biogeochemical Model: Focus on the Formation and Release of Hydrogen Sulfide Masayasu IRIE, Shuzo NISHIDA, Kyosuke TERANAKA, Yohei TSUJI Mitsunari HIRASAWA, Toshiharu FUJIWARA and Miyuki NAKASUJI A field survey and laboratory analyses of sediment quality in the eastern part of Osaka Bay are carried out to clarify their characteristics and influence on the dynamics of hypoxia. Nitrogen, phosphorus and sulfur cycling in the coastal water and sediment are modeled with a focus on the formation of hydrogen sulfide in hypertrophic sediment and its release to the bottom water. In the calculated results the oxygen consumption in the bottom water by the release of sulfide is much larger than the direct oxygen consumption by the sediment in the northern port of the bay. Without the release of sulfide, the hypoxic water area would be estimated to be limited in and near the port area of the head of the bay. The wide spreading of hypoxia in the eastern part of the bay would be contributed largely by the sulfide release. 1. a DO ΣH 2 S 1997b ph ORPΣH 2 S 2008 2009 2008 ΣH 2 S 2008 ΣH 2 S ΣH 2 S COD 2009 2010 Fossing2004 3
2 1 1 2. 1 a 2009 9 24 10 22 1 7 111 CTD AAQ1183 DOHydrolab QuantaG a DO b 2009 10 11 4 20051999 2000 S1 S2 S3 S4 11cm 10.6cm 25 30cm 0 2cm 2 5cm 5 10cm 10 15cm 15 20cm 20 25cm 6 5 1 1988 1987 2010 2 3 POM Princeton Ocean Modelσ 20 1km500m 2 32 COD DO 8 ΣH 2 S 2004 Fossing2004 Soetaert1996 Wijsman2002 Soetaert1996 Mn 2+ Fe 2+ ΣH 2 S CH 4 Fossing2004 Wijsman2002 Anggara Kasih2009Fossing 2008 2009 2010 2
2 O 2 NO - 3 SO 2-4 NH + 4 Mn 2+ Fe 2+ ΣH 2 S CH 4 PO 3-4 3MnO 2 Fe OH 3 FeS FeS 2 HS - ΣH 2 S Fe 2+ FeS 1 R SO4red R m 1/day MM Ks SO4 SO 4 µmol/l K inm M µmol/l SO 4 2- H 2 S 12 1cm 25 2 x y N/P C/P Wijsman2004 2008 2008 0.5cm 1cm 2009910 10 1 20 7 1 6 1800 MnO 2 Fe OH 3 FeS FeS 2 7 1 4 4 3. 1 3NH 4 - N S1 S3 S2 S4T-N PO 4 -PNH 4 -N NP 2005 S3 ΣH 2 S S1 S3 S1 S1 S35 10cm 10 15cm
4. 3 mg/l SO 2-4 SO 2-4 S1 2 15cm S4 S1NH 4 -N PO 4 -P ΣH 2 S SO 2-4 S1 NH 4 -N PO 4 -P S2 ΣH 2 S SO 2-4 S3 ΣH 2 S Fe OH 3 FeS 2 DO 4 10 50cm DO DO 3mg/l 10 7 0918 1DO DO 10 310 9 DO 5mg/l 10 22 DO ΣH 2 S 2009 8 7DO5 ΣH 2 S ΣH 2 S 6 6 4 5 DO ΣH 2 S
S1 ΣH 2 S S1 S3 ΣH 2 S S10918 10 15 S4 ΣH 2 S S2 ΣH 2 S FeS ΣH 2 S 2004 5. 3 1 NH 4 -N ΣH 2 S 3 2 3 S1 S3 ΣH 2 S S2S4 S2 S4 2008 Vol. 24 pp. 669-674 2009 B2 Vol. B2-65 No. 1 pp. 1041-1045 2004 51pp. 926-930 2009 56pp. 1061-1065 2010 54pp. 1639-1644 1988 175p. 2008 - -55pp. 1206-1210 Arjen Markus1997 44 pp. 1096-1100 2008 55pp. 1191-1195 2008 pp. 128-164 http://www.jrtt.go.jp/business/ research/project/05d-saitaku/data/2005-04s1.pdf. 2005 52pp. 966-970 2004 51 pp. 931-935 1987 199p. Anggara Kasih, G.A., S. Chiba, Y. Yamagata, Y. Shimizu, K. Haraguchi(2009): Numerical model on the material circulation for coastal sediment in Ago Bay, Japan, Journal of Marine Systems, 77, pp. 45-60. Fossing, H., P. Berg, B. Thamdrup, S. Rysgaard, H.M. Sorensen and K.A. Nielsen(2004): Model set-up for an oxygen and nutrient flux for Aarhus Bay(Denmark), National Environmental Research Institute (NERI) Technical Report No. 483, Ministry of the Environment, Denmark. 65 pp. Soetaert, K., Herman, P. M. J. & Middelburg, J. J. (1996) : A model of early diagenetic processes from the shelf to abyssal depths, Geochimica et Cosmochimica Acta 60, 1019-1040. Wijsman, J. W. M., P. M. J. Herman, J. J. Middelburg and K. Soetaert (2002): A Model for Early Diagenetic Processes in Sediments of the Continental Shelf of the Black Sea Estuarine, Coastal and Shelf Science, 54, pp. 403-421