Eliminating toxic compounds by composting olive mill wastewater-straw mixtures.
The present work studies the changes occurring in organic matter, phenols and biotoxicity on composting olive mill wastewater with barley straw. The total organic matter decreased, a drop of 25% was reached after the stabilization phase and 52% at the end of the maturation phase. Degradation of the phenols reached 54% and 95%, respectively, after these periods. The toxicity of the water extract, evaluated by the Photobacterium phosphoreum fluorescence, decreased to disappear after only 2 months of composting. This trend was confirmed by the tight correlation between the physico-chemical and toxicity parameters, indicating that the degradation of organic matter leads to a strong reduction of the C/N ratio and of toxicity. The results obtained indicate a normal process of humification occurring during the composting of the formerly highly toxic olive mill wastewater-straw mixture and resulting in a product, which has good agricultural properties as organic fertilizer.
Zenjari
B
B
Laboratoire d'Ecotoxicologie, Faculté des Sciences Semlalia, Université Cadi Ayyad, BP 2390, Marrakech, Morocco.
El Hajjouji
H
H
Ait Baddi
G
G
Bailly
J-R
JR
Revel
J-C
JC
Nejmeddine
A
A
Hafidi
M
M
D005308:Fertilizers; D005419:Flavonoids / Q000032:analysis / Q000302:isolation & purification / Q000633:toxicity; D015386:Hazardous Substances / Q000302:isolation & purification* / Q000633:toxicity*; D001467:Hordeum / Q000737:chemistry*; D031658:Olea / Q000737:chemistry*; D010636:Phenols / Q000032:analysis / Q000302:isolation & purification / Q000633:toxicity; D059808:Polyphenols; D012987:Soil; D014865:Waste Disposal, Fluid / Q000379:methods*
D005308:Fertilizers; D005419:Flavonoids; D015386:Hazardous Substances; D010636:Phenols; D059808:Polyphenols; D012987:Soil