著者

臼井 恵次 進藤 晴夫 丸本 卓哉 岸野 拓男

出版者

日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.17, no.9, pp.596-599, 1994

被引用文献数

2 1

---

A release of phosphorus from calcium phosphate, iron(III) phosphate, and aluminum phosphate owing to the complex formation of their metals with fulvic acid was examined. Fulvic acid was extracted from lake sediments and treated with Amberlite XAD-8 resin. The non-adsorbed fraction of fulvic acid on the resin, which has highly Cu2+-complexing capacity, was used in this study, because the adsorbed fraction has only little Cu2+-complexing capacity as reported in our previous paper. The non-adsorbed fraction was able to release phosphorus from calcium phosphate, but not from iron(III) phosphate, and aluminum phosphate. The application of X-ray analysis to the calcium phosphate indicated that the major component is hydroxyapatite. The stability constant of the Cu2+-fractionated fulvic acid was determined to be 2×10(5) (log K=5.3) and the average molecular weight of the fulvic acid was 1,026.

著者

臼井 恵次 岸野 拓男 東 俊雄 進藤 晴夫 丸本 卓哉

出版者

日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.16, no.10, pp.690-695, 1993

被引用文献数

3 3

---

Fulvic acid extracted from lake sediments was treated with Amberlite XAD-2 and XAD-8 resins. The metal complexing ability of the fulvic acid was measured at pH 6.0 with a Cu2+ titration method, in which free Cu2+ was determined with an ion selective electrode. A two binding site model, in which there are two kinds of the molecules having strong and weak complexing ability and they complex with metal ion at the ratio of 1:1, was employed for the determination of the stability constant and complexing capacity of the fulvic acid, because the hyperbolic approxmation could apply to the Scatchard plot of the found values. The stability constants of the fulvic acids having strong complexing ability and weak complexing ability were in the range of 6.33-7.12 and 4.35-4.66, respectively. Both colorless fractions of the fulvic acid which were not adsorbed on XAD-2 and XAD-8 resins had such a high complexing ability as 44 and 32 μmol・g-1, respectively. On the other hand, both colored fractions of the fulvic acid which were adsobed on the resins had only little complexing capacity.

著者

臼井 恵次 進藤 晴夫 丸本 卓哉 岸野 拓男

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.17, no.9, pp.596-599, 1994-09-10 (Released:2008-01-22)

参考文献数

13

被引用文献数

2 1

---

A release of phosphorus from calcium phosphate, iron(III) phosphate, and aluminum phosphate owing to the complex formation of their metals with fulvic acid was examined. Fulvic acid was extracted from lake sediments and treated with Amberlite XAD-8 resin. The non-adsorbed fraction of fulvic acid on the resin, which has highly Cu2+-complexing capacity, was used in this study, because the adsorbed fraction has only little Cu2+-complexing capacity as reported in our previous paper.The non-adsorbed fraction was able to release phosphorus from calcium phosphate, but not from iron(III) phosphate, and aluminum phosphate. The application of X-ray analysis to the calcium phosphate indicated that the major component is hydroxyapatite. The stability constant of the Cu2+-fractionated fulvic acid was determined to be 2×105 (log K=5.3) and the average molecular weight of the fulvic acid was 1,026.

著者

臼井 恵次 岸野 拓男 東 俊雄 進藤 晴夫 丸本 卓哉

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.16, no.10, pp.690-695, 1993-10-10 (Released:2008-04-21)

参考文献数

19

被引用文献数

5 3

---

Fulvic acid extracted from lake sediments was treated with Amberlite XAD-2 and XAD-8 resins. The metal complexing ability of the fulvic acid was measured at pH 6.0 with a Cu2+ titration method, in which free Cu2+ was determined with an ion selective electrode. A two binding site model, in which there are two kinds of the molecules having strong and weak complexing ability and they complex with metal ion at the ratio of 1 : 1, was employed for the determination of the stability constant and complexing capacity of the fulvic acid, because the hyperbolic approxmation could apply to the Scatchard plot of the found values.The stability constants of the fulvic acids having strong complexing ability and weak complexing ability were in the range of 6.33-7.12 and 4.35-4.66, respectively. Both colorless fractions of the fulvic acid which were not adsorbed on XAD-2 and XAD-8 resins had such a high complexing ability as 44 and 32 μmol·g-1, respectively.On the other hand, both colored fractions of the fulvic acid which were adsobed on the resins had only little complexing capacity.