Potential upgrading of bio-refinery streams by electrodialysis

Modern bio-refineries generate considerable volumes of wastewater that are highly coloured (5600-572,000 PtCo) as well as being concentrated in both salts (conductivities up 72.4 mS cm− 1) and organics (up to 380 g COD L− 1). In this study, bench-scale batch electrodialysis was performed to examine the feasibility of separating salts from organics for a range of industrial biorefinery streams. High levels of salt removal (up to 96% for a lignocellulosic effluent) were possible with minimal organic losses (0.3-6.3%), while key performance parameters were highly encouraging (current efficiencies = 69-104%; specific power consumption = 0.44-1.59 kWh kg− 1 of salt recovered). Collectively, the experimental results obtained here showed the cost-effective potential of electrodialysis to separate salts from organics in complex bio-refinery streams at the industrial scale.