Fig. 1From: Start-up of a nutrient removal system using Scenedesmus vacuolatus and Chlorella vulgaris biofilmsBiofilm PBR design: a PBR front view, b PBR side view and c PBR photograph. (1) Cotton carrier (for attachment of microalgae), (2) synthetic wastewater, (3) carrier holder, (4) dropper, (5) reservoir of synthetic growth medium, (6) pump, (7) PBR side view and (8) LED lampBack to article page