Investigation of silver recovery from liquid waste during the preparation of silver-containing calcium phosphate
1.What is calcium phosphate?
Calcium phosphate is a compound of phosphoric acid and calcium, and is the main component of bones and teeth.
Calcium phosphate has ion-exchange, biocompatibility, adsorption, and fluorescence properties, and is applied in a wide range of fields.
Fig１ Applications of calcium phosphate[1]
The ion-exchange properties of calcium phosphate can be utilized to add antimicrobial metals to impart an antimicrobial effect and improve the deodorizing effect. In this case, safety and antimicrobial properties are required for antimicrobial metals to be added.Silver has been adopted as an antimicrobial metal that meets these requirements because silver is safe and has long been used in tableware.
FIg２ Antibacterial properties of heavy metal ions[2]
Fig3 Applications of silver-containing calcium phosphate[3]
3．Problem
Silver in the effluent produced during the preparation of silver-containing calcium phosphate may cause adverse effects such as cytotoxicity and discoloration.
In addition, the silver-containing effluent from the manufacturing process has a negative impact on aquatic organisms and the microbial activity of sewage treatment.
4．Purpose of research
There are few reports on methods to recover silver ions generated in the effluent during the preparation of silver-containing calcium phosphate. The purpose is to measure the silver concentration in waste liquid and to investigate methods for recovering it.
[1](Left)Tsuno group Ltd. HP
https://www.tsuno.co.jp/products/fertilizer-feed/dibasic-calcium-phosphate/"
[1](Center)Olympus Biomaterial Ltd. HP
https://www.biomaterial.co.jp/jp/news/2006/nr002.html
[1](Right)Dr.apatite Ltd. HP
https://drapatite.com/?yclid=YSS.EAIaIQobChMImNKJjq7T_wIVAbKWCh0XLAV2EAAYASAAEgJcI_D_BwE
[2]Yoshinobu, M.: Antibacterial properties of silver and copper ions Chemistry and education 53(5) (2005
[3](Left) AG-PROTEX, Kyocera Ltd
https://www.kyocera.co.jp/prdct/medical/ag-protex/
[3]（Right）Finetoday HP
https://brand.finetoday.com/jp/ag/12:18 2024/10/01
