Ik. Konstantinou et al., Removal of herbicides from aqueous solutions by adsorption on Al-pillared clays, Fe-Al pillared clays and mesoporous alumina aluminum phosphates, WATER RES, 34(12), 2000, pp. 3123-3136
Fractionated Al-pillared (code name AZA) and Fe-Al-pillared (code name FAZA
) clays and mesoporous alumina aluminum phosphates (AAPs) were contacted wi
th aqueous, atrazine, propazine, prometryne, propachlor, propanil and molin
ate solutions at a concentration range of between 1 and 20 mg/l, in batch e
quilibrium experiments in order to determine their adsorption properties. T
he pillared clays showed an improved affinity which allowed the adsorption
of the studied herbicides to occur much more efficiently than in the case o
f AAPs. The removed amounts of the studied herbicides by using the pillared
clay materials reached 95.3% for atrazine, 92.2% for propazine, 98.5% for
prometryne, 60.9% for propachlor, 86.8% for propanil and 70.2% for molinate
. The iron substitution in FAZA pillared clay did not show great difference
s in adsorption capacity. The adsorption of s-triazines on mesoporous AAPs
decreased with the alkyl substitution of the lateral chains, thus atrazine
was the most adsorbed compound. The removal of propachlor by AAPs decreased
with the increase of P/Al ratio. The material with P/Al = 0.4 ratio was mo
re efficient for the removal of molinate and propanil. The amounts of herbi
cides decomposed during the treatment were higher for AAPs in comparison wi
th those for AZA and FAZA. (C) 2000 Elsevier Science Ltd. All rights reserv
ed.