Assessment and valorization of treated and non‑treated olive mill wastewater (OMW) in the dry region

Abstract

Purpose The quantity of Olive by-products does not stop increasing and a water shortage that threatens the olive tree culture; require a serious valuation of these by-products. A comparative and valorization study of two kinds of OMW; Fresh OMW (FOMW), directly issue from three-phase continuous extraction factory and Disposal Evaporation Ponds OMW (DOMW) were done. Methods Physico-chemical and biological parameters of OMWs and soil irrigated with OMWs, respectively, were determined. An antibacterial activity test of FOMW against Clinic Standard Bacteria was determined. A statistical analysis was performed for all defned parameters. Results A signifcant increase of pH value of 6 and a lower failure of the EC in 8.94 (mS/cm−1) were registered after OMW disposal in evaporation ponds. We registered a fall of BOD5 and COD from 61.05–116.37 (g/L) to 55.67–103.82 (g/L), respectively. A signifcant increment of phenol compound removal was observed after OMW disposal. However, a switch of fatty acids distribution and content was observed, which several fermentation pathways could explain took place. This result suggested by a clear shift in biomass composition. An important soil fertility after DOMW soil irrigated was traduced by an important value of the germination index (170.55%) and efcient organic matter increment of 2.3%. A CMI rate of 32.76 (μg mL−1) was determined by FOMW against diferent clinic standard bacteria. Conclusion A spectacular soil fertility efect was obtained from DOMW soil spreading, that efciently evaluate the OMW biological treatment. In addition, the FOMW was valorized as its powerful antibacterial.