Uses of electro-coagulation-flocculation (ECF) for the pre-concentration of microalgae biomass

• DOI: 10.1016/j.procbio.2022.09.012
• Publication Date: 2022-09-15T16:24:58Z
• Authors: Cristian Inostroza; Naoufel El Bahraoui; Rodrigo Rivera-Ti...; F. Gabriel Acién
• Keywords: Settling; Electrocoagulation; Sedimentation

The separation of microalgae biomass from diluted cultures found in large-scale production systems is a major challenge for microalgae-related processes. Conventional methods use centrifugation but it requires too much energy (1 kWh/m3), the combination with previous pre-concentration operations such as settling or flotation needed to reduce this consumption. However, both and require addition chemical coagulants/flocculants, thus contaminating biomass. This work explores potential Electro-Coagulation-Flocculation (ECF) method Thus, recovery freshwater Scenedesmus almeriensis was studied, batch continuous mode, using technique optimize operating conditions. Data experiments show minimum conductivity 5 mS∙cm−1 required, electrical 12 V current density 18 mA∙cm−2 allowing 90 % biomass, while increases up 99 when increasing 23 mA∙cm−2. efficiency process concentration, consumption reduces by half 1.0 0.5 kWh∙Kg−1 concentration 2.8 5.0 g∙L−1. To performance system were performed mode maintaining voltage at 47 respectively, modifying flow rate provided electrocoagulation chamber. shows optimal residence time 15 s whereas 3.2 0.58 0.75 4.20 Results confirm reliability being fast consuming reasonable energy. Further optimization chamber conditions will improve further commercial processes keeping its advantages non-contaminating achieve high values short times.