Removal of organophosphorus insecticides from aqueous solution by adsorption on microporous pillared clays and mesoporous alumina aluminum phosphates

Citation
Tm. Sakellarides et al., Removal of organophosphorus insecticides from aqueous solution by adsorption on microporous pillared clays and mesoporous alumina aluminum phosphates, ENV TECHNOL, 20(10), 1999, pp. 1033-1044
Citations number
33
Categorie Soggetti
Environment/Ecology
Journal title
ENVIRONMENTAL TECHNOLOGY
ISSN journal
09593330 → ACNP
Volume
20
Issue
10
Year of publication
1999
Pages
1033 - 1044
Database
ISI
SICI code
0959-3330(199910)20:10<1033:ROOIFA>2.0.ZU;2-7
Abstract
Al-pillared montmorillonite (ecaza), Fe-Al-pillared montmorillonite (ecfaza ) and mesoporous alumina aluminum phosphates (AAPs) were contacted with aqu eous solutions of organophosphorus insecticides, ethyl parathion, methyl pa rathion, fenitrothion and fenthion, at a concentration ranging between 1 an d 10 mg l(-1), in batch equilibrium experiments, in order to determine thei r adsorption properties. The removal of organophosphorus compounds by the a dsorbents increased in the following order: methyl parathion<fenitrothion<f enthion<ethyl parathion. In the case of ethyl parathion, the more lipophili c insecticide, the increased affinity allowed adsorption to occur much more efficiently than in the case of other compounds. At equilibrium ecaza mont morillonite adsorbed 96.4% of ethyl parathion, 92.3% of fenthion, 92.3% of fenitrothion and 87.6% of methyl parathion. The adsorption of selected orga nophosphorus insecticides on mesoporous AAPs was much less pronounced compa red to the two clays but increased with the ratio of P/A1, as the surface a cidity of those solids also increased. The AAP mixture with a ratio P/Al=0. 6 adsorbed 81% of ethyl parathion, 83.1% of fenthion, 39.8% of fenitrothion and 61.4% of methyl parathion. The amounts of insecticides decomposed duri ng the treatment increased in AAPs after 24 hours and especially in those w ith a higher P/Al ratio (=0.6) and reach 70.5% for ethyl parathion, 59.2% f or fenthion, 32.5% for fenitrothion and 54.8% for methyl parathion.