Processing of a bulk liquid including particles, including use of a rotating strainer surface with openings disposed on a circumference thereof, the openings allowing an extracted liquid in the bulk liquid to pass through the strainer surface while preventing particles from passing through the strainer surface, such that a concentration of particles in the extracted liquid is less than in the bulk liquid; an extracted liquid outflow port which outputs the extracted liquid from an interior region of the rotating strainer surface; and a motor configured to rotate the strainer surface at a speed sufficient to generate a centrifugal force or turbulence at the openings sufficient to prevent the particles from clogging the openings, wherein the strainer surface is rotated and the extracted liquid is output through the extracted liquid outflow port when the strainer surface is fully submerged in the bulk liquid.