The controlled spreading on agricultural soil, allowed by Italian regulations, seems at the moment, especially in marginal lands, the best method for olive mill waste water (AV) disposal. The decrease of phenolic substances, with antimicrobial and phytotoxic properties, could reduce potential negative effects on environment and crops. A possible easy way of reducing these substances in the AV could be the addition of ashes obtained by combustion of plants. In order to check this possibility, laboratory tests were made by using a solution obtained from frozen olives treated in a way like the processing for oil extraction. To samples of this solution ashes were added; then, after standing, phenols were periodically determined. For phenols analysis by the use of Folin–Ciocalteu reagent a simplified method was used. These compounds were also separated into two groups: mono-phenols and orto-diphenols by a non destructive method by using strong cation exchanger resins saturated with ferric ions, where orto-diphenols (or similar compounds), but not simple monophenols, were adsorbed. The analyses shoved that ashes caused an appreciable decrease of the content of the total phenols in the tested solutions and, especially, of orto-diphenols, which are those having bigger phytotoxic activity. This means that the biodegradation of the AV could be improved by the controlled addition of ashes. If these do not contain toxic elements and if they are obtained from plants grown in the same soils where the spreading is made, the AV treated with this by-product could be seen as a resource because of the return to soil of nutritive elements absorbed by plants.
Effetti della aggiunta di cenere alle acque di vegetazione delle olive destinate allo spargimento su suolo agrario
ANDREONI, NARCISO
2005-01-01
Abstract
The controlled spreading on agricultural soil, allowed by Italian regulations, seems at the moment, especially in marginal lands, the best method for olive mill waste water (AV) disposal. The decrease of phenolic substances, with antimicrobial and phytotoxic properties, could reduce potential negative effects on environment and crops. A possible easy way of reducing these substances in the AV could be the addition of ashes obtained by combustion of plants. In order to check this possibility, laboratory tests were made by using a solution obtained from frozen olives treated in a way like the processing for oil extraction. To samples of this solution ashes were added; then, after standing, phenols were periodically determined. For phenols analysis by the use of Folin–Ciocalteu reagent a simplified method was used. These compounds were also separated into two groups: mono-phenols and orto-diphenols by a non destructive method by using strong cation exchanger resins saturated with ferric ions, where orto-diphenols (or similar compounds), but not simple monophenols, were adsorbed. The analyses shoved that ashes caused an appreciable decrease of the content of the total phenols in the tested solutions and, especially, of orto-diphenols, which are those having bigger phytotoxic activity. This means that the biodegradation of the AV could be improved by the controlled addition of ashes. If these do not contain toxic elements and if they are obtained from plants grown in the same soils where the spreading is made, the AV treated with this by-product could be seen as a resource because of the return to soil of nutritive elements absorbed by plants.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
