A system and method for switching between flows of water solutions passed in groups of blocks of membrane pressure vessels arranged in parallel in a tapered flow system, wherein the system comprises a system inlet feed line, a system outlet flow line, high pressure booster pumps configured to provide a high pressure feed stream to the system; blocks of membrane pressure vessels arrayed in parallel, and a first and second bypass line each parallel to said blocks.

A method of operating a high velocity cross flow dynamic membrane filtration includes feeding a fluid stream into a pressure vessel, in which the vessel defines a treatment chamber containing a disc membrane assembly having a first support shaft and a second support shaft, each support shaft defining a longitudinal axis about which is positioned a plurality of axially spaced membrane discs. The method further includes distributing the fluid stream over at least a portion of the disc membrane assembly. The method also includes discharging a first portion of the fluid stream from the vessel and discharging a second portion of the fluid stream from the vessel. The method additionally includes rotating the first support shaft and the second support shaft in a first direction. The rotating includes modulating a rotation rate in response to the flow rate of the second portion of the fluid stream.

A method for operating a membrane separation device includes (a) setting a flow amount M(t) of permeated water and extracting the permeated water from the membrane separation device by the set flow amount M(t), and (b) temporarily stopping the extracting the permeated water, when a water level of a first water tank in which the membrane separation device is immersed, a water level of a second water tank in communication with the first tank, or a water level of a third water tank receiving overflowing water from the first water tank becomes lower than a predetermined halt water level. M(t), which is the flow amount of the permeated water during a time period t, satisfies a equation M(t)=KQ(t?1), where K is a gain (K>1), and Q(t?1) is an amount of inflow of the water-to-be-treated during a time period t?1 immediately prior to the time period t.

A fluid circulation monitoring system includes a distributed processing system having a first processor located on-premises near a space filled with a circulating fluid and a second processor located off-premises. The first processor and the second processor are in communication with one another. A sensor is operatively connected to the first processor and senses at least one parameter associated with a flow rate of fluid through the circulation system. The distributed processing system is configured to process the at least one parameter and derive a volumetric fluid flow rate through a fluid pump which propels the fluid through the circulation system. Pattern recognition is applied to the at least one parameter to detect maintenance events and predict the need for maintenance events.

A membrane filtration device including a filtration mode for filtrating water to be treated by passing the water to be treated from a primary side to a secondary side of a filtration membrane and a filtration membrane cleaning mode for cleaning the filtration membrane by passing ozone water from the secondary side to the primary side of the filtration membrane, wherein the membrane filtration device includes an inter-membrane differential pressure controller for controlling an inter-membrane differential pressure ?P, and is configured such that in the filtration membrane cleaning mode, the inter-membrane differential pressure controller performs control to gradually lower the inter-membrane differential pressure ?P twin a predetermined initial differential pressure ?P1 to a final differential ?P2, which is a value lower than the ?P1.

A reverse osmosis membrane apparatus has a plurality of high pressure vessels 12a and 12b in parallel with each other with respect to introducing passage 18 of clarified seawater obtained by subjecting raw seawater to sterilization and removal of relatively large foreign substances. The high pressure vessels 12a and 12b have first-stage reverse osmosis membrane elements 14a and 14b, respectively. Concentrated seawater subjected to membrane separation in the high pressure vessels 12a and 12b flows into a high pressure vessel 16. In the high pressure vessel 16, a plurality of reverse osmosis membrane elements 42 are arranged in series. When a detected value obtained by a differential pressure meter 56a or 56b provided for the high pressure vessel 12a or 12b exceeds a threshold value, introduction of the clarified seawater is stopped, and the reverse osmosis membrane element is washed or replaced.

The formation of scale in a reverse osmosis membrane apparatus is reduced at low water temperatures without the necessity of pH adjustment or addition of a scale dispersant to continue a consistent operation for a long period of time. The operation of a reverse osmosis membrane apparatus is controlled on the basis of the concentration of aluminum ions and/or iron ions in the feed to the reverse osmosis membrane apparatus and/or the concentrate from the reverse osmosis membrane apparatus. Not only silica but also aluminum ions and iron ions that are also present in the water significantly affect the reduction in the flux of a reverse osmosis membrane which is caused by silica scale. It is necessary to appropriately control the concentration of aluminum ions and/or iron ions in the feed and/or the concentrate to consistently operate a reverse osmosis membrane apparatus for a long period of time.

Methods include monitoring indicators of blood pH or blood electrolyte levels during a blood fluid removal session and adjusting concentrations of pH buffers or electrolytes in dialysate or replacement fluid used during the session based on the monitored indicators. Blood fluid removal systems may employ sensors that monitor blood pH or electrolyte levels to adjust the fluid parameters during a blood fluid removal session.

A method for operating a filtration apparatus according to an aspect of the present invention is a method for operating a filtration apparatus including three or more filtration modules, the method including a filtration step in which a filtration treatment is performed using the filtration modules and a cleaning step in which some of the filtration modules are stopped from performing the filtration treatment and the filtration modules stopped from performing the filtration treatment are cleaned simultaneously. A filtration apparatus according to another aspect of the present invention is a filtration apparatus including three or more filtration modules, a collection system that collects a filtrate from the filtration modules, and a cleaning system that cleans some of the filtration modules simultaneously.

A method is provided for sanitizing a reverse osmosis system to supply high-purity permeate. Included in the method is supplying raw water to a feed tank and to a filter module using a raw-water inlet line having an inlet valve. A primary circuit is provided, and has a first pump connected to the filter module. A secondary circuit is provided, and has a second pump and a heater, both of which are connected to the filter module. The primary circuit is separated from the secondary circuit using a semipermeable membrane disposed in the filter module. The secondary circuit of the reverse osmosis system is cleaned or disinfected while the raw-water inlet line is in a disconnected state and the inlet valve is in a closed state using the second pump and the heater.