Patent ID: 7052610

Claim:
A process of filtering water comprising the steps of, a) providing one or more modules of filtering membranes immersed in water in a tank open to the atmosphere; b) providing one or more open channels connected to a retentate outlet, the one or more open channels spanning a portion of the tank above the one or more modules; c) permeating filtered water by (i) adding a selected volume of feed water to the tank and (ii) withdrawing substantially the selected volume of water through the one or more modules as permeate; d) periodically stopping permeation to perform a deconcentration step, the deconcentration step further comprising at least one of (I) backwashing or (II) providing a flow of feed water into the tank from below the modules or both (I) and (II); and, e) flowing excess water containing retained solids out of the retentate outlet via the one or more open channels during the deconcentration step.