Assessment and valorization of treated and non‑treated olive millwastewater (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 defined parameters.
Results A significant 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 significant 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 efficient organic matter increment of 2.3%. A CMI rate of
32.76 (μg mL−1) was determined by FOMW against different clinic standard bacteria.
Conclusion A spectacular soil fertility effect was obtained from DOMW soil spreading, that efficiently evaluate the OMW
biological treatment. In addition, the FOMW was valorized as its powerful antibacterial.