Olive mill wastewater (OMW), the waste product of olive oil production, typically holds a high concentration of hazardous substances (e.g. phenols) to humans and the environment. OMW is usually disposed of into unregulated, not properly constructed, evaporation ponds in the close vicinity of the olive mil. Efficient, easy to apply, remediation methods are sought to address the impact of uncontrolled OMW in the Mediterranean region. Biochar amended soils could be used to reduce the detrimental effects of OMW since it has been shown to reduce the organic load of impacted soils. We present results from a laboratory experiment designed [a] to treat OMW using biochar, and [b] utilize the spectral induced polarization (SIP) method to monitor the remediation process. Three biochar amended columns (5%, 10%, 25%) and one control were saturated with OMW from the Alikianos waste pond. After 10 day treatment the organic load was reduced on all biochar amended columns, with the 10% showing the highest reduction. Early results indicate aerobic degradation at the initial treatment stages, followed by anaerobic conditions later. SIP monitoring provides some very interesting results, with the real and imaginary components behaving differently. The real conductivity appears to increase significantly only for the 10% biochar column, the one with highest organic load removal. Imaginary conductivity appears to increase with time in all biochar amended columns, and it seems to be affected by the amount of biochar present. Finally, scaning electron microscopy (SEM) showed no alterations on the physical structure of the biochar, potentially allowing for multiple treatments and/or reusing. These early results suggest that biochar is suitable for OMW treatment, and SIP is sensitive to the remediation processes. Overall, the method is simple to setup, run and monitor and does not require any safety precautions. Further geochemical analysis is performed to provide additional insight on OMW and biochar processes, and their links to SIP responses.
|Publication status||Published - Dec 2016|
- Spectral induced polarization
- Olive-mill wasewater