An immersed membrane system or process may use measured or calculated process information to optimize one or more process operating parameters to improve performance or reduce operating costs. An on-line process control system or method may use the resistance in series method in operating an immersed membrane water treatment system. A process control system or process may consider resistance values and adjust operational parameters such as membrane aeration frequency factor, membrane aeration flow, permeate flux, permeation duration, backwash flow and duration, relaxation duration or maintenance or recovery chemical cleaning frequencies in order to reduce the operational costs related to membrane fouling removal.

A sheet filter membrane is arranged on a surface of a filter plate of a thermoplastic resin, and a plurality of projections provided in a hot plate is pressed against the filter plate above a periphery of the filter membrane with different timing for each of the projections to abut on the filter membrane. A plurality of recessed bonding portions with different depths are thus formed in the filter plate, and the filter membrane is bonded to the filter plate by heat welding in each of the recessed bonding portions. Sealing is therefore provided between the filter membrane and the filter plate along the periphery of the filter membrane.

Provided are reverse-osmosis-membrane device capable of treating raw water including a large amount of membrane foulants, such as MBR-treated water, with stability while preventing a reduction in the amount of permeate, and a method for operating the reverse-osmosis-membrane device. The raw water includes a high-molecular organic substance having a molecular weight of 10,000 or more at a concentration of 0.01 ppm or more. The reverse-osmosis-membrane device includes a reverse-osmosis-membrane element including a membrane unit, the membrane unit including a reverse osmosis membrane having a thickness of 0.1 mm or less, a feed spacer disposed on a surface of the reverse osmosis membrane, and a permeate spacer disposed on the other surface of the reverse osmosis membrane. The reverse-osmosis-membrane device is operated at a permeation flux of 0.6 m/d or less.

A spiral wound filtration assembly including: i) a pressure vessel comprising a feed port, concentrate port and permeate port; ii) at least one spiral wound membrane module comprising at least one membrane envelop wound around a permeate tube which forms a permeate pathway to the permeate port; and iii) a bioreactor having a cylindrical outer periphery extending along an axis (Y) from a first end to a second end, an inlet located near the first end, and an outlet located near the second end; wherein the spiral wound membrane module and bioreactor are serially arranged within the pressure vessel.

A wastewater treatment system and a wastewater treatment process, fluidly combining a one or more SBR (sequencing batch reactor) module/s, in which nitrification and denitrification of the wastewater are performed in sequences and one or more MBR (membrane bioreactor) module/s.

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.

There is provided a film separation device 1 equipped with a treatment tank 2 receiving a liquid to be treated, a film unit 3 to be immersed in the liquid to be treated, and a guide mechanism 4. The guide mechanism 4 is composed of holding sections 14 and a guide section 15. The holding sections 14 are provided on a side section of a film cassette 5 constituting the film unit 3, and the guide section 15 is fixed to the treatment tank 2. The guide section 15 has a tank-wall fixed section 15a, an upper extension section 15b, a held section 15c, a lower extension section 15d, and a tank-bottom fixed section 15e. When fixing the film unit 3 to the treatment tank 2, the holding sections 14 are fitted to the held section 15c, thereby guiding the film unit 3 to a predetermined position in the treatment tank 2.

Provided is a water treatment device that suppresses the degradation of electrodes in a capacitive de-ionization treatment section and is capable of maintaining high water treatment capability. The water treatment device includes an activated carbon treatment section that receives an inflow of water having a total organic carbon concentration of 100 mg/l or less and adsorbs and removes organic matters contained in the water; and, on the downstream side of the activated carbon treatment section, a capacitive de-ionization treatment section including a pair of electrodes to which voltages having polarities opposite to each other are applied, a flow path, and ion exchange membranes. Ions contained in the water are adsorbed to the electrodes with voltages applied thereto, and voltages reverse to the voltages at the time of ions adsorption are applied to the electrodes to release the ions from the electrodes.

Provided is a fresh water generation system which filters biotreated water produced by microbiologically treating waste water via a primary semi-permeable membrane (8), and then mixes concentrated water rejected by the filtration with seawater, thereby to filter the mixed water via a secondary semi-permeable membrane (14). This system enables frequencies of chemical cleaning and replacement of the secondary semi-permeable membrane to be reduced. The fresh water generation system comprises: a primary semi-permeable membrane apparatus (9) which separates microorganism treating waste water into permeated water and concentrated water; a secondary semi-permeable membrane apparatus (13) which filters mixed water prepared by mixing the concentrated water into seawater. In the fresh water generation system, the primary semi-permeable membrane (8) has an equal to or a higher microorganism adhesive property than the secondary semi-permeable membrane (14).

The present inventors have developed systems and processes for reducing the overall carbon consumption needed for the generation of low COD treated water. In certain aspects, the systems and processes described herein include an oxidation stage (e.g., one that utilizes ozone, hydrogen peroxide, ultraviolet, or a combination thereof for oxidation) between a first activated carbon stage and a second activated carbon stage to reduce a total carbon consumption within the associated system or process.