A zwitterionic monomer and corresponding cyclopolymerized polyzwitterion () (PZ) (i.e. poly(Z-alt-SO.sub.2). Phosophonate ester hydroloysis in PZ gave a pH-responsive polyzwitterionic acid () (PZA). The PZA under pH-induced transformation was converted into polyzwitterion/anion () (PZAN) and polyzwitterion/dianion (=) (PZDAN).

This filtration treatment system is provided with a membrane filtration device as a prefiltration treatment device for removing insoluble components from the water to be treated containing organic substance, a reverse osmosis membrane treatment device for subjecting the prefiltration-treated water to reverse osmosis membrane treatment, and a chemical agent supply pipe for supplying a chemical agent into the membrane filtration device, wherein the chemical agent contains a sulfamic acid compound, and a bromine-based oxidizing agent or the reaction product of a bromine compound with a chlorine-based oxidizing agent, or, contains the reaction product of a sulfamic acid compound with a bromine-based oxidizing agent or with the reaction product of a bromine compound with a chlorine-based oxidizing agent.

In a method for operating a clarification membrane module the invention, either following steps is conducted after the position of the closed ends in the clarification membrane module is made above the position of the open ends therein: (a) closed-end high-position cleaning step A in which the outer side of the clarification membranes within the clarification membrane module is filled with liquid and air scrubbing is then performed by supplying a gas; (b) closed-end high-position cleaning step B in which air scrubbing is conducted by supplying a gas, while supplying liquid to the outer side of the clarification membranes within the clarification membrane module.

A composition is disclosed for cleaning a membrane. The composition includes: (i) a non-ionic surfactant having the formula: RO(CH.sub.2CH.sub.2O).sub.nH, wherein R is a branched, substituted or unsubstituted, C.sub.11-15 alkyl group, wherein n is an average degree of ethoxylation, and wherein n is in the range of from 3 to 20; and (ii) at least one of an additional non-ionic surfactant, a water soluble solvent, or a hydrotrope. In one version of the composition, an upper limit of a range of molecular weights of the surfactant is 1300 grams or below. In another version of the composition, the composition has a gel point such that it will be in the liquid phase before and after dilution with any amount of water at all temperatures of 40 F. and above. A method of cleaning a membrane using the compositions is also disclosed.

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 zwitterionic monomer and corresponding cyclopolymerized polyzwitterion () (PZ) (i.e. poly(Z-alt-SO.sub.2). Phosophonate ester hydroloysis in PZ gave a pH-responsive polyzwitterionic acid () (PZA). The PZA under pH-induced transformation was converted into polyzwitterion/anion () (PZAN) and polyzwitterion/dianion (=) (PZDAN).

Disclosed are devices, methods and/or systems for use in protecting items and/or structures that are exposed to, submerged and/or partially submerged in aquatic environments from contamination and/or fouling due to the incursion and/or colonization by specific types and/or kinds of biologic organisms and/or plants, including the protection from micro- and/or macro-fouling for extended periods of time of exposure to aquatic environments.

Disclosed are membrane separation cleaning processes and clean in place compositions for such membranes. The cleaning compositions can remove proteins, fats, and other food, beverage, and brewery based soils and offer an environmentally friendly alternative surfactant system to NPE. Branched extended chain PO/EO nonionic surfactants with certain characteristics may be used to provide superior cleaning to membranes. The specific surfactants may be used alone or in combination. In some embodiments, the surfactant package is used as part of a cleaning composition.

An in-situ repair method for the surface of polyamide (PA) membrane after the destruction of oxidizing substances is provided. Lysozyme solution is mixed with tris (2-carboxyethyl) phosphine (TCEP) buffer solution, and the PA membrane to be repaired is immersed in the mixed solution, after being taken out, the PA membrane to be repaired is rinsed, and the nano-protein coating with uniform changes in pore size, charge density and thickness is obtained on the surface of the PA membrane to be repaired. Then the amine solution modification is used, the surface of the nano-protein coating is grafted by amines, and the repaired PA membrane is obtained. The PA membrane to be repaired is immersed in a mixed solution for 1-24 h. The PA membrane repaired by nano-coating has a water permeability of 11.4 Lm.sup.2L.sup.1bar.sup.1 (LMH/bar) and a rejection rate of 98.5% to magnesium chloride for the nanofiltration (NF) membrane after strong chlorine destruction.

Disclosed herein are surfactant booster compositions for filtration membrane cleaning, multi-part detergents comprising the surfactant booster compositions, an enzyme composition, and alkalinity composition. Further disclosed are methods of cleaning filtration membranes with the aforementioned compositions and system. Beneficially, the surfactant booster compositions have low toxicity with high butterfat removal capacity. The compositions and methods are suitable for filtration membranes including microfiltration, ultrafiltration, nanofiltration, and reverse osmosis membranes.