1.

論文

論文
Miki, Osamu ; Ueki, Chika ; Kato, Toshiaki
出版情報: Journal of Water and Environment Technology.  11  pp.101-110,  2013-01-01.  Japan Society on Water Environment = 日本水環境学会
URL: http://hdl.handle.net/2297/36943
概要: There are many borrow pits caused by sand mining at the bottom of the coastal sea in Japan. Borrow pits have been identified as a source of oxygen-deficient water with hydrogen sulfide. It has become increasingly important to restore borrow pits to improve the marine environment. However, large quantities of sand materials are needed to restore borrow pits. Recently, dredged materials generated by sea route maintenance have been adopted instead of sand materials. However, one problem of dredged materials is that they can be weak ground materials. Therefore, slag-mixed material made from the dredged material and steelmaking slag has been proposed. In this study, control of hydrogen sulfide release resulting from changing the hardness of the slag-mixed materials has been examined. Hydrogen sulfide release strongly depends on the hardness of the slag-mixed material. Microbial analysis indicated fewer living bacteria and the relative abundance of sulfate-reducing bacteria in the slag-mixed material compared with the dredged material. The solidification of the dredged material using steelmaking slag decreased not only hydrogen sulfide release but also dissolved iron and manganese release. It is considered that controlling the hardness of the dredged material mixed with steelmaking slag provides an effective means of sulfide release control. 続きを見る
2.

論文

論文
小杉, 知佳 ; 加藤, 敏朗 ; 三木, 理
出版情報: Journal of Advanced Marine Science and Technology Society = 海洋理工学会誌.  20  pp.1-9,  2014-12-27.  海洋理工学会 = Marine Science and Technology Society
URL: http://hdl.handle.net/2297/46796
概要: The use of steelmaking slag as a material is being advanced as a means of improving the marine environment in coastal waters. Recently, mixing steelmaking slag with dredged material has been developed for restoring tidal flat estuaries. In this study, the control of microalgae outgrowth from dredged material by steelmaking slag was examined in a batch experiment and mesocosm experiment. The dredged material in artificial seawater showed both the release of nutrients (PO4-P, D-Inorganic N, D-Si) and the outgrowth of planktonic microalgae. Also, it was found that the predominant species of planktonic microalgae in the artificial seawater was Haptophyta, Coccolithophorids. On the other hand, when steelmaking slag was added to the dredged material, the hardness of the resulting mixture increased, and the outgrowth of microalgae from the dredged material was inhibited. The mechanism for this is follows. The application of steelmaking slag to the dredged material improved the hardness of the dredged material by forming calcium-silicate-hydrooxide (CSH), which strongly affected the microalgae outgrowth from the dredged material. 続きを見る
3.

論文

論文
植木, 知佳 ; 加藤, 敏朗 ; 三木, 理 ; Ueki, Chika ; Kato, Toshiaki ; Miki, Osamu
出版情報: 海洋理工学会誌 = Journal of Advanced Marine Science and Technology Society.  17  pp.49-55,  2011.  海洋理工学会 Advanced Marine Science and Technology Society
URL: http://hdl.handle.net/2297/00064522
概要: 金沢大学理工研究域機械工学系<br />Discoloration of nori, Porphyrayezoensis, is a terrible economic problem for the fisheries. One of t he reasons for the discoloration of nori is suggested the decreasing concentrations of nutrients, nitrogen and phosphorus. The red tide by some diatom, rainfall, and so on cause the bad balance of water quality. Recently, it was showed that iron is important for the color maintenance of nori. Sea desertification, isoyake. can be seen in some Japanese coastlines. It is suggested that one of the reasons for this phenomenon is the decreasing concentrations of nutrients and iron. Against this backdrop, the fertilizer has been produced using steel-making slag and humus soil, which can stably supply iron and some nutrients. We have demonstrated the effect of the fertilizer on algal growth in Japan. In this study, we studied the effect of the fertilizer to the growth of nori by the mesocosm experiment Both of experimental tanks for the mesocosm were set up nori-meshes. and 60 kg fertilizer in one side, while the other tank was no fertilizer as a control. We surveyed the concentration of nutrients and trace metals, and the growth of nori. As a result, in the fertilizer containig tank the concentration of nitrogen, phosphorus and iron were raised, in brief the nutrients and iron eluted from the fertilizer. And only in the fertilizer containig tank, nori grew up over 10 cm in length. On the other hand, we could not identify the growth of nori by visual observation in the control tank, fertilizer not containing tank. 続きを見る
4.

論文

論文
三木, 理 ; 植木, 知佳 ; 赤司, 有三 ; 中川, 雅夫 ; 畑, 恭子 ; 永尾, 譲太郎 ; 笠原, 勉 ; 鈴木, 輝明 ; Miki, Osamu ; Ueki, Chika ; Akashi, Yuzoh ; Nakagawa, Masao ; Hata, Kyoko ; Nagao, Kentaro ; Kasahara, Tsutomu ; Suzuki, Teruaki
出版情報: 海洋理工学会誌 = Journal of Advanced Marine Science and Technology Society.  17  pp.37-48,  2011.  海洋理工学会
URL: http://hdl.handle.net/2297/00064524
概要: 金沢大学理工研究域機械工学系<br />There are many borrow pits, caused by the sand mining at the bottom of the coastal sea in Japan. Bor row pits have been identified as a source of oxygen-deficient water killing benthic fauna by hydrogen sulfide. And, much nutrients such as nitrogen or phosphorus tend to release from the bottom of borrow pits, which is attributed to red tide. From these reasons, it has become more important to restore borrow pits for marine environment improvement. But, a large amount of earth and sand materials are needed to restore borrow pits. Then, we have examined the restoring borrow pits process by ”slag mixture material” mixing the steelmaking slag that is the by-product of the steel industry with the dredged material generated by the sea route maintenance. In this study, firstly, by the experiment using ”slag mixture material”, we examined the sulfide generation control effect and the microalgae generation control effect by phosphorus release control. Then, by the developed ”biogeochemical model” based on the experiment, we predicted the improvement effect when ”slag mixture material” are applied to a borrow pit of Osaki area in Mikawa Bay. As a result of that, ”slag mixture material” decreased 92% of the reduction material release such as hydrogen sulfide. And. compared with dredged material, ”slag mixture material” decreased 26% of the reduction material release. The prediction shows the ”slag mixture material” bring larger improvement effects. The restoring borrow pits process by ”slag mixture material” mixing the steelmaking slag is more effective for marine environment improvement. 続きを見る
5.

論文

論文
三木, 理 ; 加藤, 敏朗 ; 楠井, 隆史 ; Miki, Osamu ; Kato, Toshiaki ; Kusui, Takashi
出版情報: 水環境学会誌 = Journal of Japan Society on Water Environment.  33  pp.141-146,  2010.  日本水環境学会 Japan Society on Water Environment
URL: http://hdl.handle.net/2297/00064533
概要: 金沢大学理工研究域機械工学系<br />The use of steelmaking slag as a recycled material is being progressed in coastal waters for marine environment improvement, by exploiting the characteristics of steelmaking slag. However, regarding its use in coastal waters, there are as yet no criteria for determining which bioassay should be used for assessing its effect on marine organisms. As a method of voluntary quality control of steelmaking slag, we selected a suitable battery of bioassays. The acute toxicity of steelmaking slag leachate on a copepod (Tigriopus japonicus) and a luminescent bacterium (Vibrio fischeri) was evaluated. As a result of the bioassay tests on some types of steelmaking slag, the leachate from the steelmaking slag with the pH preadjustment carbonation process showed smaller pH increases and no inhibitory effect on the marine organisms evaluated. On the other hand, the leachate from the steelmaking slag without carbonation showed an inhibitory effect on both organisms, as shown by an increase in its pH up to 12. This inhibitory effect was observed only in T. japonicus even when the pH was reduced to 8. The inhibitory factors of such leachate on T. japonicus and luminescent V. fischeri were examined. No hazardous substances were detected in the leachate. However, the calcium and magnesium concentrations of the leachate markedly changed compared with those of seawater. When the calcium concentration of the leachate was adjusted to that of seawater, the inhibitory effect on T. japonicus almost disappeared. Therefore, calcium concentration changes brought about by pH changes were considered to be the main inhibitory factors in the leachate. When bioassays with marine organisms are used to evaluate a recycled material such as steelmaking slag, the calcium and magnesium concentrations of the leachate should be carefully considered. 続きを見る
6.

論文

論文
三木, 理 ; 加藤, 敏朗 ; 堤, 直人 ; Miki, Osamu ; Kato, Toshiaki ; Tsutsumi, Naoto
出版情報: 水環境学会誌 = Journal of Japan Society on Water Environment.  32  pp.33-39,  2009.  日本水環境学会
URL: http://hdl.handle.net/2297/00064537
概要: 金沢大学理工研究域機械工学系<br />The control of phosphorus release from eutropHicated coastal sediment by a carbonated steelmaking sl ag was examined. Batch experiments showed the following. Without slag addition, the pH, DO and ORP of seawater easily decreased with the progress of coastal sediment corruption. Moreover, phosphorus release from coastal sediment occurred rapidly. On the other hand, with steelmaking slag addition, the decreases in pH and DO were inhibited and the high ORP values of seawater were maintained. Phosphorus release from coastal sediment was clearly inhibited by slag addition. Even when the carbonated steelmaking slag was compared with sand, phosphorus release from coastal sediment was further improved. In the mechanism of phosphorus release control through steelmaking slag addition, it was considered that a carbonated steelmaking slag promotes calcium hydroxyapatite (HAP) generation induced by the high Ca2+ concentration of seawater. Furthermore, continuous experiments for more than 300 days showed that pH control and phosphorus release control from coastal sediment by carbonated steelmaking slag addition were maintained for a long term. 続きを見る