Investigation of the usage of olive black water cake (pomace) as a bio fertilizer

Turkey is one of the world's leading countries in olive production. We can say that most of the olives produced are used in olive oil production. During the production of olive oil, high amounts of olive black water prina and pomace are released. Consisted black water, consists of a mixture of olive juice, olive washing water, water used during the process and water leaking from olive pomace after processing the olives. Due to the presence of toxic compounds in the composition of olive black water, it causes a large pollution that cannot be ignored in the environment. Olive black water contains high amounts of phenol, lipid and organic substance. Efforts are made to ensure that the resulting olive black water is generally disposed of by evaporation in the lagoons. If olive black water is discharged to the environment without being subjected to any treatment or if it is kept in lagoons without appropriate conditions, olive black water causes underground and surface water pollution, soil pollution and bad odors in the environment. Approximately more than thirty phenolic components, namely; phenolic alcohols, phenolic acids, lignans, flavonoids and secoiridoids. When we look at the composition of olive black water, we see that phenolic compounds are the most important source of toxicity in olive black water. These phenolic compounds in black water also limit the microbial degradation in olive black water. In short, we can say that the phenolic compounds in olive black water are the most difficult by-products to be treated in black water. In this study, the lowest total phenolic compound amount was determined with 578.48 mg/kg in ethyl acetate extraction, and the highest total phenolic compound amount was determined in ethanol+methanol extraction with 950.10 mg/kg. When the quality parameters of raw and biofertilizers are examined; The highest ammonium nitrogen concentration was found in methanol extraction with 0.83 mg/L. In the study, nitrite nitrogen concentration was not found in the biofertilizer obtained as a result of crude and solvent extraction. The lowest nitrate nitrogen concentration was 6.35 mg/L in raw olive pomace, and the highest nitrate nitrogen concentration was 14.12 mg/L in ethyl acetate extraction. High phosphate phosphorus concentration was determined as 11.97 mg/L in the biofertilizer obtained as a result of ethyl acetate extraction. In addition, the characterization of the biofertilizer was determined by FT-IR analysis.