Adsorption of chlorpyrifos, penconazole and metalaxyl from aqueous solution by modified clays.
J Environ Sci Health B
; 44(6): 525-32, 2009 Aug.
Article
em En
| MEDLINE
| ID: mdl-20183058
ABSTRACT
Sorption of three pesticides (chlorpyrifos, metalaxyl and penconazole) has been measured on a commercial clay montmorillonite and on the same mineral modified with either of two cationic-surfactant micelles. Both micelle-clay complexes, commercial names Cloisite 20A and Cloisite 30B, showed a good capacity to sorb all three pesticides from water, whereas their sorption on the natural montmorillonite was not described by an isotherm. Modelling sorption on both micelle-clay complexes showed that the Freundlich sorption constant (K(F)) was higher for chlorpyrifos on Cloisite 20A (K(F) = 7.76) than on Cloisite 30B (K(F) = 5.91), whereas the sorption of metalaxyl was stronger on Cloisite 30B (K(F) = 1.07) than on Cloisite 20A (K(F) = 0.57). Moreover the micelle-clay complex Cloisite 20A also showed a good affinity for penconazole, the maximum quantity adsorbed (q(m)) of 6.33 mg g(-1) being 45% more than that on Cloisite 30B. Single-batch adsorption of each pesticide onto both micelle-clay complexes was studied using the Freundlich isotherm for chlorpyrifos and metalaxyl and the Langmuir isotherm for penconazole. The Cloisite 20A micelle-clay complex was predicted to require 23% less adsorbent to treat certain volumes of wastewater containing 30 mg L(-1) chlorpyrifos, 43% more to treat metalaxyl similarly and 57% less to treat penconazole compared with Cloisite 30B.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Praguicidas
/
Tensoativos
/
Bentonita
/
Água
/
Eliminação de Resíduos Líquidos
/
Silicatos de Alumínio
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Environ Sci Health B
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Itália