MicroalgCurrent algal cultivation has been mainly performed in open ponds or closed
photobioreactors in which algal cells are suspended in liquid and harvested through
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sedimentation, flocculation, filtration and/or centrifugation devices. Due to the issue with
separating large volumes of water from algae, there is a growing interest in developing biofilmbased
cultivation methods that allow algae to attach to a substrate and form a biofilm.
Attachment-based cultivation systems have been less studied than suspended algae systems even
though they have received increased interest in the past five years. Examples of these
attachment-based systems are outlined in Table 1. One major benefit of these attachment-based
systems is that harvested biomass typically contain 80-95% of water, much higher than that in
suspension culture systems (Johnson and Wen, 2010).