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

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 ۶ and a lower failure of the EC in ۸.۹۴ (mS/cm−۱) were registered after OMW disposal in evaporation ponds. We registered a fall of BOD۵ and COD from ۶۱.۰۵–۱۱۶.۳۷ (g/L) to ۵۵.۶۷–۱۰۳.۸۲ (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 (۱۷۰.۵۵%) and efcient organic matter increment of ۲.۳%. A CMI rate of ۳۲.۷۶ (μg mL−۱) 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.

Keywords:

Olive mill water valorization  , Ponds evaporation  , OMW compounds  , Soil treatment  , Soil fertility  , OMW antibacterial activity