Abstract: This water treatment system is provided with: a reverse osmosis membrane device; a biofilm treatment device that has a carrier, on a surface of which is formed a biofilm, and that treats water to be treated before the water to be treated is transmitted through the reverse osmosis membrane device; and at least one of a water to be treated stoppage period circulation means and a water to be treated stoppage period supply means that are driven when the intake of new water to be treated is stopped. The water to be treated stoppage circulation means supplies and circulates water to be treated from a water to be treated discharge outlet side of the biofilm treatment device to a water to be treated supply port side. The water to be treated stoppage period supply means supplies new water to be treated to the biofilm treatment device.

Abstract: A suspended-matter removing method and a suspended-matter removing apparatus are disclosed that require no sludge treatment facility, and inexpensively provide filtrate satisfying a water quality standard. The suspended-matter removing method includes: feeding a protrusion element to a filter layer formed by filling a solid filter material, adding a protrusion to a surface of the solid filter material; after feeding protrusion element, determining whether a protrusion has been added to the surface of the solid filter material, and when it is determined that the protrusion has been added, reducing a feeding amount of the protrusion element as compared with when adding the protrusion; forming a biofilm on the surface of the solid filter material; and passing water to be treated containing suspended matters through the filter layer having the solid filter material added with the protrusion in a state in which the feeding amount of the protrusion element is reduced.

Abstract: An object is to provide a pretreatment device of seawater capable of growing and maintaining a biofilm in a good state on each of a plurality of filters connected in series, by supplying nutrients appropriately to the filters. A pretreatment device of seawater is used in removing salt from the seawater to obtain freshwater, and includes: a supply duct (21) through which the seawater is to be supplied; a plurality of filters (16) including a particulate filtering material and a biofilm; connecting tubes (23) which connect the plurality of filters in series; a plurality of bypass tubes (24) each of which connects corresponding one of the plurality of filters to the supply duct; and a plurality of regulating valves (26) each of which is disposed in corresponding one of the plurality of bypass tubes to regulate a flow rate.

Abstract: A reverse osmosis membrane filtering device includes: a water-collecting member including at least one water collecting pipe, and having a plurality of sections each of which has a plurality of water collecting apertures; at least one filter assembly disposed around the plurality of sections, the at least one filter assembly including a filter member including a reverse osmosis membrane; at least one insertion tube disposed inside the water-collecting member and defining a plurality of permeate-water channels corresponding to the plurality of sections inside the water-collecting member in cooperation with at least one seal member; and a pressure adjusting device configured to increase a pressure of at least one of the plurality of permeate-water channels to a pressure higher than that of another one of the plurality of permeate-water channels.

Abstract: Provided is a reverse osmosis membrane cleaning apparatus (10) which includes a membrane module (1) including a reverse osmosis membrane, a cleaning water tank (11) which stores cleaning water, a heater (13) which heats cleaning water supplied from the cleaning water tank (11) to the reverse osmosis membrane, and a temperature control device (17) which controls the heater so that a temperature of the cleaning water heated by the heater (13) is higher than 45° C. and not higher than 60° C.

Abstract: A suspended-matter removing method and a suspended-matter removing apparatus are disclosed which require no sludge treatment facility, and inexpensively provide filtrate satisfying a water quality standard. The method includes: feeding a protrusion element to a filter layer formed by filling a solid filter material, adding a protrusion to a surface of the solid filter material; after feeding of the protrusion element, determining whether or not a protrusion satisfying a preset standard has been added to the surface of the solid filter material, and when it is determined that the protrusion has been added, reducing a feeding amount of the protrusion element as compared with when adding the protrusion; and passing water to be treated containing suspended matters through the filter layer having the solid filter material added with the protrusion in a state in which the feeding amount of the protrusion element is reduced.

Abstract: A suspended-matter removing method and a suspended-matter removing apparatus are disclosed that require no sludge treatment facility, and inexpensively provide filtrate satisfying a water quality standard. The suspended-matter removing method includes: feeding a protrusion element to a filter layer formed by filling a solid filter material, adding a protrusion to a surface of the solid filter material; after feeding protrusion element, determining whether a protrusion has been added to the surface of the solid filter material, and when it is determined that the protrusion has been added, reducing a feeding amount of the protrusion element as compared with when adding the protrusion; forming a biofilm on the surface of the solid filter material; and passing water to be treated containing suspended matters through the filter layer having the solid filter material added with the protrusion in a state in which the feeding amount of the protrusion element is reduced.

Abstract: A water quality monitoring device (111) determines the speed of a wave passing through water present upstream of a reverse osmosis membrane (109). A process for reducing the concentration of organic matter in water present upstream of the reverse osmosis membrane is performed when the determined speed is greater than a predetermined threshold speed.

Abstract: A regeneration method for a filtration apparatus, a filtration apparatus, and a water treatment apparatus are disclosed that shorten a time required until stabilization of water quality of filtrate after backwashing, and stably provide filtrate satisfying a desired water quality standard. The regeneration method for a filtration apparatus according to the invention is a regeneration method for a filtration apparatus that has a filter layer formed by filling a solid filter material formed with a protrusion on a surface, and passes water to be treated containing suspended matters through the filter layer to perform filtration of the suspended matters. The regeneration method for a filtration apparatus includes a step of backwashing the filter layer by passing washing liquid through the filter layer in a direction opposite to a passing direction of the water to be treated such that the protrusion is retained on the surface of the solid filter material.

Abstract: A cleaning method for a water treatment membrane (2) provided with a primary surface (2a) for inflow of untreated water and a secondary' surface (2b) for outflow of treated water, the method including a first cleaning step of bringing a first cleaning fluid containing a metal eluent into contact with at least the primary surface and eliminating metallic scale (11) attached to the water treatment membrane, and then a second cleaning step for bringing a second cleaning fluid containing an oxidizing agent into contact with at least the primary surface and eliminating organic scale (12) attached to the water treatment membrane.

Abstract: Provided are a water treatment apparatus and a water treatment method capable of performing a significant water quality evaluation of treated water before the filtration process, and capable of rapidly responding to a change in water quality of the treated water. A water treatment apparatus of the present invention includes a treated water filtering unit which filters treated water supplied from a treated water line to become filtered water, a filtered water mixing unit which is provided in a treated water extraction line diverging from the treated water line to reduce a turbidity concentration in the treated water of the treated water extraction line to become measured water, and a water quality measuring unit which is provided at a rear stage of the filtered water mixing unit in the treated water extraction line and measures water quality of the measured water to evaluate the water quality of the treated water.

Abstract: A filtration treatment system of raw water includes a raw water supply line to supply raw water, a filtration device provided on the raw water supply line to filter impurities in the raw water, a separation device provided on a rear side of the filtration device and equipped with a separation membrane to separate filtered raw water into permeated water and concentrated water; an organic substance monitoring device provided on either front or rear or both front and rear of the filtration device to monitor an amount of an organic substance in the raw water, and a control device to execute backwashing of the filtration device with the permeated water as backwashing water in a case in which the amount of the organic substance in the raw water exceeds a reference value as a result of monitoring by the organic substance monitoring device.

Abstract: 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.

Abstract: An object is to provide a pretreatment device of seawater capable of growing and maintaining a biofilm in a good state on each of a plurality of filters connected in series, by supplying nutrients appropriately to the filters. A pretreatment device of seawater is used in removing salt from the seawater to obtain freshwater, and includes: a supply duct (21) through which the seawater is to be supplied; a plurality of filters (16) including a particulate filtering material and a biofilm; connecting tubes (23) which connect the plurality of filters in series; a plurality of bypass tubes (24) each of which connects corresponding one of the plurality of filters to the supply duct; and a plurality of regulating valves (26) each of which is disposed in corresponding one of the plurality of bypass tubes to regulate a flow rate.

Abstract: A reverse osmosis membrane filtering device includes: a water-collecting member including at least one water collecting pipe, and having a plurality of sections each of which has a plurality of water collecting apertures: at least one filter assembly disposed around the plurality of sections, the at least one filter assembly including a filter member including a reverse osmosis membrane; at least one insertion tube disposed inside the water-collecting member and defining a plurality of permeate-water channels corresponding to the plurality of sections inside the water-collecting member in cooperation with at least one seal member; and a pressure adjusting device configured to increase a pressure of at least one of the plurality of permeate-water channels to a pressure higher than that of another one of the plurality of permeate-water channels.

Abstract: This water treatment system comprises: a reverse osmosis device (2); a biofilm treatment device (4) that has a media on the surface of which a biofilm is formed and that treats water to be treated (3) before passing through the reverse osmosis device (2); an oxidizing agent addition device (5) that adds an oxidizing agent to the water to be treated (3) at a stage before treatment with the biofilm treatment device (4) or adds an oxidizing agent to the water to be treated (3) at a later stage after treatment with the biofilm treatment device (4) and before treatment with the reverse osmosis device (2); and a reducing agent addition device (6) that neutralizes the oxidizing agent by adding a reducing agent to the early stage water to be treated (3) or the later stage water to be treated (3).

Abstract: This water treatment system is provided with: a reverse osmosis membrane device; a biofilm treatment device that has a carrier, on a surface of which is formed a biofilm, and that treats water to be treated before the water to be treated is transmitted through the reverse osmosis membrane device; and at least one of a water to be treated stoppage period circulation means and a water to be treated stoppage period supply means that are driven when the intake of new water to be treated is stopped. The water to be treated stoppage circulation means supplies and circulates water to be treated from a water to be treated discharge outlet side of the biofilm treatment device to a water to be treated supply port side. The water to be treated stoppage period supply means supplies new water to be treated to the biofilm treatment device.

Abstract: A keyswitch apparatus features a key cap having a stem slidably moveable within a housing of a keyboard frame, to interact with an underlying membrane switch. According to one embodiment, the stem is square and at least two sets of channel-like guides on opposite sides of the stem are configured to be in sliding engagement with corresponding ribs projecting from the housing. Sliding engagement between the ribs and corresponding guides serves to minimize points of contact between the key cap and housing, reducing noise of operation. The rigid ribs and corresponding guides are relatively simple shapes that facilitate their fabrication with precise dimensional tolerances.

Abstract: Conversion of an untreated liquid to a clean harmless treated liquid through microbe removal, characterized in that a mechanical treatment for damaging microbes present in a liquid to thereby effect extinction thereof and sterilization, combined with a chlorination in which a chlorine-containing substance is formed from a liquid and injected into a liquid to thereby effect microbe extinction and sterilization, is applied to a liquid. There is further provided an electrolytic circulation system comprising applying a detoxification treatment for extinction of microbes in seawater and sterilization by means of detoxification facilities on land or on the sea to seawater introduced through a seawater introduction channel and accommodating the seawater having been thus treated in a ballast water tank. As a result, facility and operating costs can be reduced. Extinction of microbes of unlimited size and sterilization can be securely achieved without any strength drop on the side of treated liquid accommodation body.

Abstract: Conversion of an untreated liquid to a clean harmless treated liquid through microbe removal, characterized in that a mechanical treatment for damaging microbes present in a liquid to thereby effect extinction thereof and sterilization, combined with a chlorination in which a chlorine-containing substance is formed from a liquid and injected into a liquid to thereby effect microbe extinction and sterilization, is applied to a liquid. There is further provided an electrolytic circulation system comprising applying a detoxification treatment for extinction of microbes in seawater and sterilization by means of detoxification facilities on land or on the sea to seawater introduced through a seawater introduction channel and accommodating the seawater having been thus treated in a ballast water tank. As a result, facility and operating costs can be reduced. Extinction of microbes of unlimited size and sterilization can be securely achieved without any strength drop on the side of treated liquid accommodation body.