An innovative bioreactor for sustainable industrial wastewater treatment finalized to process water reuse and resource recovery

Many industrial wastewater are characterized by high concentrations of inorganic species and toxic organic molecules, making challenging their biological treatment due to strong inhibition of their constituents on the biocatalysts. Well acclimatized cultures and powerful technologies are required. Two-Phase Partitioning Bioreactors (TPPBs) have been proven to be an effective platform for xenobiotic removal. Main feature of TPPBs is to partition toxic concentrations of xenobiotics from a cell-containing aqueous phase by means of an immiscible phase (organic solvents or granular polymers) and to deliver these substrates back to the cells because of metabolic demand. In this study, we tested a novel configuration of a TPPB operated with a polymeric tubing as an extractive membrane bioreactor (EMB), thus able to achieve, besides the gradual delivery of organic substrates, the additional benefit of separating the "hostile" wastewater from the biomass. Objective of the study is to demonstrate the feasibility of the tubing-TPPB for the treatment of toxic wastewaters: it was applied to the treatment of tannery wastewater and high saline wastewater under severe loading conditions. In the first case, from the biologically treated wastewater valuable metals can be easily recovered and reutilized in the production cycle. Similarly, in the second case the concentrated salt solution can be reused as brine in the production process.