Complexing capacity in a hypereutrophic lake Abstract The mechanism of phosphate release from lake sediments in aerobic condition was investigated fro

Size: px

Start display at page:

Download "Complexing capacity in a hypereutrophic lake Abstract The mechanism of phosphate release from lake sediments in aerobic condition was investigated fro"

しおりしんまつ
4 years ago
Views:

1 Complexing capacity in a hypereutrophic lake Abstract The mechanism of phosphate release from lake sediments in aerobic condition was investigated from the view point of solubilization of Fe(III) through formation of complex with dissolved organic matter. If the formation of Fe(III)-hydroxide which adsorbs phosphate was prevented by complexation of Fe(III), the release of phosphate into water will be possible even in aerobic condition. In this study the complexing capacity of natural waters was measured by the copper(ii) solubilization method. The method gave high recovery for strongly complexing ligand such as EDTA and NTA and low recovery for weakly complexing ligand such as glycollic acid and aspartic acid. The measured complexing capacities of water ranged from 0.54 to 3.15 ƒêm in Lake Teganuma and from 0.58 to ƒêm in the inflowing rivers. The seasonal change of the complexing capacity was exactly similar to those of s-fe and PO4-P. The measured concentrations of s-fe in water were much higher than estimated from the solubility of Fe(III)-hydroxide and almost equal to the levels of complexing capacity of water. It suggests that s-fe is dissolved through complex formation with organic ligands. Key words : phosphate release, aerobic condition, complexing capacity, iron, Lake Teganuma

3 Fig. 1 Sampling locations at Lake Teganuma st.l : Netoshita, st.2: Teganumachuo, st.3 Ohorigawa River, st.4 : Otugawa River Fig. 3 Effect of boiling time in copper(ii) solubilization method Fig. 2 Solubility diagram of copper(ii) oxide Vol.11 No.10(1988)

4 Table 1 Recovery of organic substances by the copper(ii) solubilization method (Initial concentrations of organic substances were all 1 x 10-5M) Fig. Seasonal changes in concentrations of CC, s -Fe and P0 4-P at st.l Fig. 5 Seasonal changes in concentrations of CC, s -Fe and P0 4-P at st.4

5 Fig. 6 Annual changes of monthly concentrations of P04-P at st.123> Fig. 7 Correlation between CC and DOC measured [s-fe(iii)]to,= [Fe] + [FeOH2+] + [Fe(OH)2+] + [Fe(OH)4-] =KI [OH-]-3+l12 [OH-]-2 Fe(OH)3 Fe(OH)3 Fe(OH)3 from January to April in 1983 at st.l-st.4 Fe(OH)~+OH- +K3 [OH ]-r +K4 [OH ] (1) Fe3++3OH- FeOH2++2OH- ± Fe(OH)2++OH- Fe(OH~~logK1 = logk2 = logk3 = logk4= -4.5 Vol.11 No.10(1988)

6 3) C.H. Mortimer (1971) Chemical exchanges between sediments and water in the Great Lakes \speculations on probable regulatory mechanisms \, Limnology and Oceanography, 16 (2), ) J. Fillos and W.R. Swansson (1975) The release rate of nutrients from river and lake sediments, Journal of Water Pollution Control Federation, 47, ) J. Shapiro, V.L. Gilbert and Z.G. Humberto (1967) Anoxically induced release of phosphate in wastewater treatment, Journal of Water Pollution Control Federation, 39 (11), ) R.A. Khalid, W.H. Patrick and R.D. Delaune (1977) Phosphorus sorption characteristics of flooded soils, Soil Science Society of American Journal, 41, ) H. Furumai and S. Ohgaki (1982) Fractional composition of phosphorus forms in sediments related to release, Water Science and Technology, 14, ) T.L. Theis and P.J. McCabe (1978) Phosphorus dynamics in hypereutrophic lake sediments, Water Research, 12, ) W.C. Li, D.E. Armstrong, J.D. Williams, R.F. Harris and J.K. Syers (1972) Rate and extent of inorganic phosphate exchange in lake sediments, Soil Science Society of American Proceeding, 36, ) M.D. Krom and R.A. Berner (1980) Adsorption of phosphate in anoxic marine sediments, raphy, 25 (5), Limnology and Oceanog-

7 17) T.A. Neubecker and H.E. Allen (1983) The measurement of complexation capacity and conditional stability constants for ligands in natural waters, Water Research, 17, ) T.M. Florence and G.E. Batley (1977) Determination of the chemical forms of trace metals in natural waters, with special reference to copper, lead, cadmium and zinc, Talanta, 24, ) R. Kunkel and S.E. Manahan (1973) Atomic absorption analysis of strong heavy metal chelating agents in water and waste water, Analytical Chemistry, 45 (8), ) P.G.C. Campbell, M. Bisson, R. Gagne and A. Tessier (1977) Critical evaluation of the copper(ii) solubilization method for the determination of the complexation capacity of natural waters, Analytical Chemistry, 49 (14), ) W. Stumm and J.J. Morgan 24) J.F. Elder, K.E. Osborn and C.R. Goldman (1976) Iron transport in a Lake Tohoe tribituary and its potential influence upon phytoplankton growth, Water Research, 10, ) EM. Perdue, K.C. Beck and J.H. Reuter (1976) Organic complexes of iron and aluminium in natural water, Nature, 260, ) E.R. Sholkovitz, E.A. Boyle and N.B. Price (1978) The removal of dissolved humic acids and iron during estuarine mixing, Earth and Planetary Science Letters, 40, Vol.11 No.10(1988)

国土技術政策総合研究所　研究資料

国土技術政策総合研究所　研究資料 ISSN TECHNICAL NOTE of National Institute for Land and Infrastructure Management No256 September 2005 Experimental Study on Seismic Behavior of Seawalls for Controlled Waste Disposal Shingo KANO, Katsuya