Monitoring of organic load reduction in olive-mill wastewater by biochar using the spectral induced polarization (SIP) method

Olive oil production process creates a large volume of organic waste rich in phenols and other substances hazardous for human health and the environment. The olive-mill wastewater (OMW) is usually disposed of into unprotected and uncontrolled evaporation ponds nearby the main olive oil production facility. OMW disposal often leads to soil and groundwater degradation and is a direct threat to the flora and fauna of the area. A holistic strategic approach for the management of OMW is required. One promising method for organic load removal is the use of biochar. Lately, rice husk and corncob biochar have shown high sorption capacity towards phenolic compounds (Mohan et al., 2014). Essential to the success of any organic load removal approach is the accurate monitoring of the process. The spectral induced polarization (SIP) method is a prime candidate for a monitoring tool in OWM remediation processes using biochar. Previous work has established the sensitivity of induced polarization on OMW (Ntarlagiannis et al., 2016); as part of this work we established the dependence of electrical parameters on OMW concentration in porous media. Furthermore, the links between SIP and a variety of biochar materials have been established (Haegel et al., 2013). With this work we present early results on the use of spectral induced polarization (SIP) method as a monitoring aid in a controlled laboratory experiment with biochar used as a tool for countering land degradation (Barrow, 2012).