A normal flow filtration system having a housing with one or more filters contained within a bowl and attached to the outlet of the system. Liquid enters the bowl, contacts the surfaces of the one or more filters. Impurities are trapped in the filter and the filtered liquid flows through to the outlet. Parameter(s) such as flow rate, transmembrane pressure drop and/or time are measured and when met, filtration ceases. A backflushing occurs through the filter(s) so as to remove the impurities from the filter. This backwashed material is directed to an outlet of the bowl that is connected to a drain. Additionally a port formed in the side of the housing adjacent an outer surface of the filter(s) can be used to provide a lateral washing of the filter(s). The system is then recirculated in a downstream manner to reestablish equilibrium and filtration is then restarted.

A water purification device, including a first pressure cylinder, a second pressure cylinder, a first connecting piece and a second cylinder block arranged successively from bottom to top, and further comprising a first cylinder block arranged inside the second cylinder block. The first pressure cylinder and the second pressure cylinder both are open at one end and formed with a first through-hole at the other end; the first cylinder block and the second cylinder block both are open at two ends and arranged in a hollow shape. A water inlet, which is communicated with first flow passages formed between the first cylinder block and the second cylinder block, is formed on the second cylinder block, and a water outlet pipe, communicated with the first cylinder block, is inserted into an outer wall of the water purification device.

A natural water treatment control apparatus (190) controls a treatment device configured to perform treatment used to contribute to purification of drawn natural water. The natural water treatment control apparatus (190) includes: a tide information acquiring unit (191) configured to acquire tide information serving as information associated with tides of a body of water from which the natural water is drawn; and a treatment mode determining unit (193) configured to determine a treatment mode of the treatment device on the basis of the tide information.

The present invention relates to a water treatment method including: a filtration step of feeding water to be treated to a membrane filtration device having loaded therein a porous separation membrane and performing filtration treatment to obtain filtrate; a discharging step of discharging the water to be treated in the membrane filtration device, which has been separated and concentrated by the porous separation membrane; and a cleaning step of cleaning the porous separation membrane by at least one treatment of physical cleaning and chemical cleaning, in which a cycle including a combination of the filtration step, the discharging step and the cleaning step is repeated multiple times, thereby obtaining filtrate. In each cycle, the filtration step and the discharging step are repeated multiple times, and the cleaning step is then carried out.

A water treatment assembly (10) and method for its operation, comprising a spiral wound hyperfiltration membrane module (12) connected to: i) a feed line (14) adapted for connection to a source of pressurized feed water, ii) a permeate line (16) adapted for connection to a dispenser of treated water and iii) a concentrate line (18) adapted for connection with a drain; wherein the assembly includes a pressurizable reservoir (22) containing weak acid cation exchange resin (25) and further includes at least one valve for selectively diverting flow of pressurized feed water along the feed line (14), through the reservoir (22) and returning to the feed line (14) prior to passing through the hyperfiltration membrane module (12).

A control method is provided for a filter system, which includes at least one filter element (2). The method includes continuously recording a total energy consumption (E.sub.G) during a filtration cycle (22) of the filter system. The total energy consumption (E.sub.G) includes at least of the energy consumption (E.sub.B) for a physical cleaning (24) and the energy consumption (E.sub.P) for the subsequent production cycle (23) up to a predefined, in particular current point in time. The method further includes computing a relative energy consumption (E.sub.rel) by way of division of the recorded total energy consumption (E.sub.G) by a net permeate volume (Q.sub.N) which has been produced during the filtration cycle (22) up to the predefined point in time and starting a physical cleaning (24) in dependence on the relative energy consumption or of a characteristic value derived from this.

The present invention is concerned with the treatment of produced water, obtained from a chemically enhanced oil recovery process using viscosity-increasing polymeric compounds. Said treatment comprises particularly the steps of obtaining a produced water, from an oil-water mixture recovered from an oil-bearing formation, wherein the produced water comprises the viscosity-increasing polymeric compounds; and, of directing the produced water to a specific filtration device, and subjecting the produced water to filtration, for obtaining a retentate stream and a permeate stream. Said process allows particularly obtaining a permeate comprising the viscosity-increasing polymeric compounds, said permeate being substantially free of suspended solids, free oil and emulsified oil.

The present invention relates to a method of operating a membrane filtration unit including plural hollow fiber membrane modules connected to each other in parallel, the method including: a filtration step; a collection step; and a recovery step, in which a relation of n.sub.1≥n.sub.2>n.sub.3 is satisfied, where n.sub.1 is the number of the hollow fiber membrane modules simultaneously used in executing the filtration step, n.sub.2 is the number of the hollow fiber membrane modules simultaneously used in executing the collection step, and n.sub.3 is the number of the hollow fiber membrane modules simultaneously used in executing the recovery step.

Apparatus and method for semi-permeable membrane cleaning in particular, applying series of pulsed water stroke, made simultaneously with osmosis backward flow causing superposed membrane directional shaking and fouling detachment. Pulsed water stroke provided by water stroke generator as several momentum sharp changes in gauge pressure and induce velocity pulse of residual brine flow. The pulsed water strokes ideally induce resonance in the membrane. Osmosis backward wash may be provided either by injection for predetermined injection time, additional solution selected in such way that net driving pressure becomes opposite to normal osmotic operation thereby providing a backward flow of permeate towards to the side opposite to normal operation mode, so as to lift said foulant, or by throttling permeate exiting from the permeate enclosure, until the net driving pressure value become equal to zero, during application of precise synchronized and opposing brine and permeate pressure strokes thereby providing a plurality of quick RO-FO-RO process changes. These procedures allow a membrane to be kept continuously clean and operate at higher recovery.

A method for cleaning a filter membrane in which at least 2 types of cleaning water containing oxidizing agents are prepared, and the filter membrane is cleaned using the cleaning water in an ascending order of the oxidizabilities of the oxidizing agents. Moreover, an apparatus for cleaning a filter membrane of the present invention comprises a means for cleaning the filter membrane using at least 2 types of cleaning water containing oxidizing agents, and the filter membrane is cleaned using the cleaning water in an ascending order of the oxidizabilities of the oxidizing agents. The method and the apparatus for cleaning a filter membrane can efficiently remove polluting substances adhered to a filter membrane while reducing the amounts of oxidizing agents and water to be used, and can maintain the filtration performance for a long period of time.