Abstract: A water treatment system combines a microfiltration or ultrafiltration membrane system with a downstream reverse osmosis membrane system. The MF or UF system has multiple trains of immersed membrane modules. The trains are connected to a common permeate pump. The permeate pump discharges directly into the inlet of an RO feed pump. The membrane trains are each subjected to the same suction. The permeate pumps are operated to provide the required flow to the RO feed pump at or above the minimum inlet pressure of the RO feed pump.

Abstract: A device allows a liquid to flow between two open structures with different liquid surface elevations separated by a wall. The device has a conduit with an inlet on one side of the wall and an outlet on the other side of the wall separated by a high point above the expected liquid surface elevation. The conduit also has two valved openings, one connected to a source of suction that can evacuate air from the conduit and the other connected to a vent. In one example, the conduit is formed between a pair of spaced transverse walls attached to an arched cover. The transverse walls each have a slot allowing the device to be placed on top of a dividing wall between two tanks with surfaces of the dividing wall defining part of the conduit. In an example with multiple conduits, one or more interior walls are provided between a pair of end walls and a cover over the interior and end walls may be provided in segments. To initiate flow, a conduit is evacuated of sufficient air to allow a siphon to develop.

Abstract: A water treatment system combines a microfiltration or ultrafiltration membrane system with a downstream reverse osmosis membrane system. The MF or UF system has multiple trains of immersed membrane modules. The trains are connected to a common permeate pump. The permeate pump discharges directly into the inlet of an RO feed pump. The membrane trains are each subjected to the same suction. The permeate pumps are operated to provide the required flow to the RO feed pump at or above the minimum inlet pressure of the RO feed pump.

Abstract: A device allows a liquid to flow between two open structures with different liquid surface elevations separated by a wall. The device has a conduit with an inlet on one side of the wall and an outlet on the other side of the wall separated by a high point above the expected liquid surface elevation. The conduit also has two valved openings, one connected to a source of suction that can evacuate air from the conduit and the other connected to a vent. In one example, the conduit is formed between a pair of spaced transverse walls attached to an arched cover. The transverse walls each have a slot allowing the device to be placed on top of a dividing wall between two tanks with surfaces of the dividing wall defining part of the conduit. In an example with multiple conduits, one or more interior walls are provided between a pair of end walls and a cover over the interior and end walls may be provided in segments. To initiate flow, a conduit is evacuated of sufficient air to allow a siphon to develop.