Brine recovery from hypersaline wastewaters from table olive processing by combination of biological treatment and membrane technologies

Abstract

The fermentation brines from table olive processing (FTOP) are hypersaline effluents (conductivities higher than 75 mS cm−1) with high organic matter concentrations (COD around 10 g L−1), which also include phenolic compounds (between 700 and 1500 mg TY·L−1). In this work, an integrated process for the FTOP reuse as brine in the table olive processing has been evaluated. This integrated process consisted of a biological treatment followed by a membrane system, which included ultrafiltration (UF) plus nanofiltration (NF). The biological treatment was carried out by 6 L laboratory sequencing batch reactor (SBR). UF and NF were performed in laboratory plants for flat membranes of 0.0125 and 0.0072 m2, respectively. Each stream generated during the FTOP treatment (SBR effluent, and UF and NF permeates) were evaluated. The SBR eliminated around 80% of COD and 71% of total phenols concentration. In the final NF permeate the COD concentration was lower than 125 mg L−1; while the turbidity, colour and phenolic compounds, were completely removed.