Harvesting algae by foam aggregation and filtration

摘要

Methods are provided for separating algae from an aqueous environment. An aqueous feed containing algae can be mixed in a turbulent manner in an aerated environment. The turbulent mixing can be sufficient to create a foam within the aqueous feed. The formation of the foam can also result in agglomeration of algae into larger size algae aggregates, which can then be filtered under pressure. Due to the larger size of the algae aggregates, the pressurized filtration can reduce/minimize the tendency to clog the filter, as the algae aggregates can generally be too large to fit within the pores of the filter. The filter can preferably be located at the bottom of the vessel holding the aqueous feed. This can assist in allowing the algae to remain in a cake above the filter, as opposed to having the algae dissolve back into the aqueous feed.

主权项

1. A method for harvesting algae, comprising:
mixing an aqueous feed containing algae under turbulent conditions in an aerated environment, the turbulent conditions being effective for formation of a foam, the foam having a liquid-foam interface; and filtering the aqueous feed through a filter medium at a pressure of about 25 psig (about 170 kPag) to about 1500 psig (about 10.3 MPag) to substantially separate the algae from the aqueous feed, wherein the aqueous feed containing algae is aged after mixing and prior to filtering for about an hour or less.