A membrane for filtering one or more hydrophobic organic contaminants can include a porous nanostructure that includes one or more of a metal, a metal oxide, and a metal alloy nanostructure component functionalized with one or more amphiphilic ligands.

A filtration apparatus includes a tubular casing having a longitudinal axis and first and second casing ends. A plurality of partition plates are positioned in the casing and sealed thereto to thereby define an intake collection chamber between a first of the partition plates and the first casing end, a discharge collection chamber between a second of the partition plates and the second casing end, and a reject collection chamber opposite the second partition plate from the second casing end. A plurality of elongated filtration membrane stacks are positioned side-by-side in the casing generally parallel to the longitudinal axis. Each filtration membrane stack includes an intake end which is fluidly connected to the intake collection chamber, a discharge end which is fluidly connected to the reject collection chamber, and a permeate channel which extends between the first and second ends and is fluidly connected to the discharge collection chamber.

The purpose of the present invention is to provide a technique whereby it becomes possible to operate for a longer period of time in an aqueous system equipped with a membrane separation apparatus. The present invention can provide a membrane separation method, the method comprising containing a combined-chlorine-based oxidizing agent to water of interest, and allowing the water of interest which contains the combined-chlorine-based oxidizing agent to pass through a membrane separation apparatus, in which the water of interest which contains the combined-chlorine-based oxidizing agent has a Free 300-second value of 0.036 mg/L-Cl.sub.2 or more wherein the Free 300-second value is a result of the measurement of a chlorine concentration after 300 seconds using a free chlorine measurement reagent.

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.

The present invention relates to a composition for treatment of wastewaters in a membrane bioreactor comprising a mixture of inorganic coagulants and organic water soluble polymer(s), wherein the inorganic coagulants are selected from iron and/or aluminium containing compounds and the organic water soluble polymers are selected from the group consisting of anionic, cationic, nonionic polymers, polysaccharides and polyphenolic compounds and any combination thereof. The present invention further relates to a method for treating of wastewaters in a membrane bioreactor, and uses thereof.

Polyethers (A), whose main chain essentially consists of repeating units of the formulae (1) and (2) in alternating order, are useful as an additive to a porous polymer membrane, or as the main polymer constituent of a porous polymer membrane, for stabilizing said membrane against detrimental effects of oxidizing agents and/or for improving the stability of a filtration module comprising said membrane against detrimental effects of oxidizing agents. ##STR00001##

A solution-type water treatment chemical, includes, as one, gluconic acid (salt) and a surfactant having an HLB determined by the following equation (1) satisfying the following equation (2), wherein in a relationship between concentrations of the gluconic acid (salt) and the surfactant and a molecular weight and HLB of the surfactant, the gluconic acid (salt) and the surfactant are contained such that the water treatment chemical does not form a gel or precipitate.

HLB=( inorganic value/ organic value)10(1)

Molecular weight>34.4HLB+1005(2)

An integrated system comprising a closed circuit desalination (CCD) unit with membrane cleaning (MC) means wherein the latter are activated briefly (8 minute) on a frequent basis, once a day or several days, for removal of fouling and/or scaling deposits off membrane surfaces created during the elapsed time interval and thereby, avoiding their accumulation and the need of CIP. MC proceeds in a tie-line sequence with different reagents solution in permeate known to affect the removal of common fouling and/or scaling constituents from membrane surfaces such as organic and/or bioorganic substances and/or inorganic scaling constituents including silica and polymerized silica coatings with either metal hydroxides or organic substances. Removal of silica containing deposits from membrane surfaces proceeds by a brief exposure to diluted hydrofluoric acid solution in permeate in the absence of interfering metal ions (e.g., Ca). The MC sequence incorporate both reverse osmosis (RO) and direct osmosis (DO) principles, the former to enable an effective contact of the cleaning reagents with membrane surfaces and the latter for inside-out backwash of semi-permeable membranes with permeate.

The fully computerized inventive system should enables a near perfect removal of all fouling and/or scaling constituents off membrane surfaces at an early stage on a regular basis before their accumulation and thereby, preventing the need for CIP and avoiding irreversible damage membranes as result of accumulation of irremovable fouling constituents.

Methods of conditioning a membrane utilized for water purification are provided. The methods monitor membrane performance during water purification or membrane conditioning via fluorometric measurement. The monitoring allows for the detection of removal efficiency of the fluorescing substance. A conditioner is introduced in the feed stream to increase the detected removal efficiency of a fluorescing substance by the membrane. The conditioner generally extends the useful life of the membrane being conditioned.

A membrane with rejection properties for mono and divalent-salts, BOD and COD good resistance to cleaning chemicals and maintaining high permeability for water. A polymeric coating prepared from polydopamine or hydroquinone or catechol or mixtures thereof, is deposited. In another embodiment, coating process steps and conditions are taught to achieve thickness control to tune the rejection properties of the membranes.