| Full text | |
| Author(s): |
Barbosa da Silva Pereira, Heloisa Aparecida
;
Iano, Flavia Godoy
;
da Silva, Thelma Lopes
;
de Oliveira, Rodrigo Cardoso
;
de Menezes, Manoel Lima
[1]
;
Rabelo Buzalaf, Marilia Afonso
[2]
Total Authors: 6
|
| Affiliation: | [1] State Univ Sao Paulo, Sch Sci, Dept Chem, Bauru, SP - Brazil
[2] USP, Fac Odontol Bauru, Dept Ciencias Biol, Bauru Sch Dent, BR-17012901 Bauru, SP - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Journal of Applied Oral Science; v. 18, n. 2, p. 121-126, MAR-APR 2010. |
| Web of Science Citations: | 3 |
| Abstract | |
Dental amalgam residues are probably the most important chemical residues generated from clinical dental practice because of the presence of heavy metals among its constituents, mainly mercury and silver. OBJECTIVE: The purpose of this study was to develop an alternative method for the recovery of silver residues from dental amalgam. MATERIAL AND METHODS: The residue generated after vacuum distillation of dental amalgam for the separation of mercury was initially diluted with 32.5% HNO3, followed by precipitation with 20% NaCl. Sequentially, under constant heating and agitation with NaOH and sucrose, the sample was reduced to metallic silver. However, the processing time was too long, which turned this procedure not viable. In another sequence of experiments, the dilution was accomplished with concentrated HNO3 at 90ºC, followed by precipitation with 20% NaCl. After washing, the pellet was diluted with concentrated NH4OH, water and more NaCl in order to facilitate the reaction with the reducer. RESULTS: Ascorbic acid was efficiently used as reducer, allowing a fast reduction, thus making the procedure viable. CONCLUSIONS: The proposed methodology is of easy application and does not require sophisticated equipment or expensive reagents. (AU) | |
| FAPESP's process: | 06/03164-0 - Silver recovery of dental amalgam waste |
| Grantee: | Heloisa Aparecida Barbosa da Silva Pereira |
| Support Opportunities: | Scholarships in Brazil - Scientific Initiation |