Effect of vermicomposting process on pesticide sorption capability by agro-industrial wastes

Abstract

The aim of this work was to study the use of organic wastes from olive oil (alperujo), winery, and alcohol industries (vine shoots, spent grape marc, lees cake, and biosolids vinasse) as sorbents for pesticide control. The pesticide sorption capability of these organic wastes and the effect of vermicomposting process was also studied. The insecticide imidacloprid and different herbicides (diuron, metsulfuron-methyl, sulfuron-methyl, and flazasulfuron) were applied. The vermicomposting process was more effective for the agro-industrial wastes with a low lignin content. The sorption capacity of these wastes, natural or previously vermicomposted, was low for the anionic herbicides with respect to hydrophobic pesticides. Adsorption isotherms by the different wastes of confidor (imidacloprid 20% w/v) and diurokey (diuron 80% w/w) fit the Freundlich model (R 2 > 0.933). The larger K f values (231–138 µg1/n−1mL−1g−1) correspond to the spent grape marc, untreated or vermicomposted, due to the high lignin content of this waste.