Removal of aqueous cyanide with strongly basic ion-exchange resin.
Environ Technol
; 36(13-16): 1612-22, 2015.
Article
em En
| MEDLINE
| ID: mdl-25558868
ABSTRACT
The removal of cyanide (CN-) from aqueous solutions using a strongly basic ion-exchange resin, Purolite A-250, was investigated. The effects of contact time, initial CN- concentration, pH, temperature, resin dosage, agitation speed, and particle size distribution on the removal of CN- were examined. The adsorption equilibrium data fitted the Langmuir isotherm very well. The maximum CN- adsorption capacity of Purolite A-250 was found to be 44â
mgâ
CN-â
g(-1) resin. More than 90% CN- adsorption was achieved for most CN- solutions (50, 100, and 200â
mgâ
CN-â
L(-1)) with a resin dose of 2â
gâ
L(-1). The equilibrium time was â¼20â
min, optimum pH was 10.0-10.5, and optimum agitation speed was 150â
rpm. An increase in adsorption of CN- with increasing resin dosage was observed. Adsorption of CN- by the resin was marginally affected (maximum 4% variation) within an environmentally relevant temperature range of 20-50 °C. Fixed-bed column (20.5â
mm internal diameters) experiments were performed to investigate the effects of resin bed depth and influent flow rate on breakthrough behaviour. Breakthrough occurred in 5â
min for 0.60â
cm bed depth while it was 340â
min for 5.40â
cm bed depth. Adsorption capacity was 25.5â
mgâ
CN-â
g(-1) for 5â
mLâ
min(-1) flow rate and 3.9â
mgâ
CN-â
g(-1) for 20â
mLâ
min(-1) flow rate. The research has established that the resin can be effectively used for CN- removal from aqueous solutions.
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Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Purificação da Água
/
Cianetos
/
Resinas de Troca Iônica
/
Modelos Químicos
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article