Energy-efficient and cost-effective microalgae dewatering, nutrient recycling and effluent water quality control are some of the major challenges facing industrial — scale microalgae production for commodity feeds and fuels (Benemann 2013; Borowitzka and Moheimani 2013b; Wyman and Goodman 1993a). Irrespective of the cultivation system, the biomass concentration of the algae culture is generally low (a few mg L 1 in open ponds to a few g L 1 in intensive closed photobiore­actors). Dewatering is therefore critical for producing any materials from micro­algae. The objective of harvesting and dewatering is to raise the concentration of the microalgal biomass by more than two orders of magnitude to over 10 % solids, sufficiently concentrated for subsequent processing or drying. It is widely believed that this is best achieved using a combination of technologies in a two-stage process (Benemann et al. 1982; Shelef et al. 1984; Vandamme et al. 2013), such as floc­culation followed by centrifugation. This necessitates that large volumes of water need to be processed to harvest the biomass. This concentration process is typically energy intensive and results in high harvesting, thickening and dewatering costs (Mohn 1988). Available harvesting and dewatering process selection often interacts with both up — and downstream process steps in microalgae production, such as strain selection and medium composition, biomass fractionation (e. g. in a biore­finery) and water or nutrient recycling (de Boer et al. 2012; Wijffels et al. 2010).