escape the exiting space and the retentate chamber g an upper adapter for attachment to the preferably tubular filter screen preferably at the upper end of said screen when said screen with its main axis vertically disposed said adapter also attached to a rigid portion of the screen filter module so as to prevent collapse of the filter screen and h a harvest port for removing fluid from the filtrate chamber in the third aspect of the invention it is optional and preferable that the filter screen module further comprise a base adapter for attaching the barrier and or anchoring the filter screen module in the compartmentalized filtration module in a fourth aspect the invention is a compartmentalized filtration module that contains a screen filter module enhanced with an internal barrier such that the screen filter module functions as the filtrate chamber the filtration module comprising a a retentate chamber said retentate chamber comprising a retentate chamber wall and a retentate chamber entrance said entrance permitting fluid containing suspended particulate matter to enter and exit the chamber said retentate chamber wall comprising a filter screen said screen comprising pores such that said screen permits fluid and particles smaller than said pores but not suspended particulate matter larger than said pores to flow through it b a filtrate chamber adjoining said retentate chamber said filtrate chamber comprising a filtrate chamber wall and a filtrate chamber entrance said filtrate chamber wall comprising the filter screen also comprised by the retentate chamber wall said filtrate chamber entrance permitting fluid to enter or exit the filtrate chamber c an alternating pump connected to the filtrate chamber.