1:45 PM - 3:15 PM
[O06-P85] How to use Starfish Skeleton and its structural and compositional analysis
Keywords:Sea
We have data from the Hokkaido Kushiro Fisheries Research Center and the Tottori Prefecture Aquaculture Center showing that there has been damage to bivalves by starfish, as well as high levels of starfish contamination in bottom trawl nets and crab traps. As a result, efforts have been made to control starfish populations, and many of the starfish that have been removed are disposed of as general waste. Therefore, we attempted to find effective ways to utilize starfish in order to promote their removal, reduce damage to fisheries, and decrease predation on scallops and other shellfish.
In previous research, we attempted to make chalk using the calcium carbonate found in starfish, but we abandoned this idea due to difficulties in differentiating it from scallops, which are already in commercial use, as well as the low absolute amount of calcium obtained from starfish and the low density of starfish skeletons. In this study, our main focus is to explore new applications for starfish-derived calcium, taking into consideration a comparison with scallops, which are already in practical use.
In this study, with the cooperation of Mr. Takashi Toyofuku, a senior researcher at JAMSTEC X-star, we conducted analysis of the three-dimensional structure of starfish skeletons using Hitachi's desktop SEM Miniscope 3000 and compositional analysis of starfish skeletons using Bruker's QUANTAX EDS.
Based on the information obtained from these analyses, we conducted experiments to consider how starfish can be utilized as a resource. SEM analysis revealed that starfish skeletons have a three-dimensional porous structure with many holes (a three-dimensional interconnected pore structure). In addition, compositional analysis by EDS revealed the presence of magnesium in addition to calcium, carbon, and oxygen derived from calcium carbonate (CaCO3). Due to the high porosity (=large surface area) and the high reactivity of magnesium with water, we considered the possibility of using starfish as a raw material for producing calcium oxide through calcination and utilizing it in dehumidifiers and other applications that utilize the reaction with water.
Based on this consideration, we conducted the following experiments to investigate how the structure of starfish skeletons and the presence of magnesium influence their reaction with water.
In this experiment, we used starfish and scallop shells, as well as commercially available calcium oxide, as materials. After removing impurities such as organic matter from starfish and scallop shells, and converting the main component, calcium carbonate, to calcium oxide through calcination at 950 degrees Celsius for 30 minutes using an electric furnace, we then powdered the commercially available calcium oxide, as well as the calcined starfish and scallop shells using a coffee mill. We measured the heat generation of each material and considered the differences in reactivity with water.
I express my gratitude to Mr. Toyofuku Takashi, a senior research fellow at JAMSTEC and X-star, for his invaluable assistance and cooperation, as well as for allowing us to use the electron microscope in the progress of this research, as mentioned above.
In previous research, we attempted to make chalk using the calcium carbonate found in starfish, but we abandoned this idea due to difficulties in differentiating it from scallops, which are already in commercial use, as well as the low absolute amount of calcium obtained from starfish and the low density of starfish skeletons. In this study, our main focus is to explore new applications for starfish-derived calcium, taking into consideration a comparison with scallops, which are already in practical use.
In this study, with the cooperation of Mr. Takashi Toyofuku, a senior researcher at JAMSTEC X-star, we conducted analysis of the three-dimensional structure of starfish skeletons using Hitachi's desktop SEM Miniscope 3000 and compositional analysis of starfish skeletons using Bruker's QUANTAX EDS.
Based on the information obtained from these analyses, we conducted experiments to consider how starfish can be utilized as a resource. SEM analysis revealed that starfish skeletons have a three-dimensional porous structure with many holes (a three-dimensional interconnected pore structure). In addition, compositional analysis by EDS revealed the presence of magnesium in addition to calcium, carbon, and oxygen derived from calcium carbonate (CaCO3). Due to the high porosity (=large surface area) and the high reactivity of magnesium with water, we considered the possibility of using starfish as a raw material for producing calcium oxide through calcination and utilizing it in dehumidifiers and other applications that utilize the reaction with water.
Based on this consideration, we conducted the following experiments to investigate how the structure of starfish skeletons and the presence of magnesium influence their reaction with water.
In this experiment, we used starfish and scallop shells, as well as commercially available calcium oxide, as materials. After removing impurities such as organic matter from starfish and scallop shells, and converting the main component, calcium carbonate, to calcium oxide through calcination at 950 degrees Celsius for 30 minutes using an electric furnace, we then powdered the commercially available calcium oxide, as well as the calcined starfish and scallop shells using a coffee mill. We measured the heat generation of each material and considered the differences in reactivity with water.
I express my gratitude to Mr. Toyofuku Takashi, a senior research fellow at JAMSTEC and X-star, for his invaluable assistance and cooperation, as well as for allowing us to use the electron microscope in the progress of this research, as mentioned above.