Recovery of Cu(II) by chemical reduction using sodium dithionite.
Chemosphere
; 141: 183-8, 2015 Dec.
Article
en En
| MEDLINE
| ID: mdl-26210323
ABSTRACT
Wastewaters containing Cu(II) along with ligands are ubiquitous in various industrial sectors. Efficacy of treatment processes for copper removal, especially precipitation, is greatly debilitated by ligands. Chemical reduction being commonly employed for production of metal nanoparticles has also been used for removing copper. Addition of ammonia was reported to be essential for improving copper reduction efficiency by increasing copper solubility at alkaline pH values. In this study, chemical reduction was employed to treat ligand-containing wastewater, exploiting the fact that ligands and metals are coexisted in many wastewaters. Result shows that copper ions were removed by either reduction or precipitation mechanisms depending on pH, type of ligands, and mixing condition. Complete copper reduction/removal was achieved under optimal condition. The lowest removal efficiency observed at pH 9.0 for ammonia system is due to formation of nano-sized particles, which are readily to pass through 0.45µm filter used for sample pretreatment before copper analysis. Instead of producing metallic copper, cuprous and copper oxide are identified in the samples collected from ammonia system and EDTA system, respectively. Re-oxidation of metallic copper particles by atmospheric oxygen during sample handling or incomplete reduction of Cu(II) ions during reduction process might be the cause. Finally, reduction process was applied to treat real wastewater, achieving complete removal of copper but only 10% of nickel.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Purificación del Agua
/
Cobre
/
Ditionita
/
Aguas Residuales
Idioma:
En
Revista:
Chemosphere
Año:
2015
Tipo del documento:
Article
País de afiliación:
Taiwán