Abstract: An electrochlorination system comprises a source of feed fluid, a product fluid outlet, and a plurality of electrochemical cells connected fluidically between the source of feed fluid and the product fluid outlet. The system is configured to operate at least one of the plurality of electrochemical cells at one of a first current density or a first flow rate, and to operate another of the plurality of electrochemical cells at a second current density or second flow rate different from the respective first current density or first flow rate.

Abstract: An apparatus and method for prevention and treatment of marine biofouling on a surface to be treated by the apparatus includes a body defining a cavity, the body terminating in a distal open end that is adapted, in use, to be in the vicinity of a surface to be treated such that the surface forms a first end wall of a chamber within the cavity; an acoustic transducer mounted within the cavity to form an opposite second end wall of the chamber, the acoustic transducer being adapted to cause acoustic pressure fluctuations; and a reservoir for a liquid, the reservoir including an inlet passage and a plurality of mutually spaced outlet passages for liquid flow from the reservoir into the chamber, the outlet passages at least partially surrounding the chamber in the vicinity of the distal open end.

Abstract: An apparatus for cleaning a surface, the apparatus including a body defining a chamber, an inlet for liquid flow into the chamber, an outlet for liquid flow from the chamber, a nozzle connected to the outlet for generating an output flow of liquid for cleaning a surface, an acoustic transducer associated with the body to introduce acoustic energy into the liquid within the chamber whereby the acoustic energy is present in the liquid flowing out of the nozzle, and a gas bubble generator for generating gas bubbles within the liquid flowing out of the nozzle.

Abstract: An apparatus for cleaning a surface includes a body defining a cavity and terminating in a distal end that is adapted, in use, to be in the vicinity of a surface to be cleaned such that the surface forms an end wall of a chamber including the cavity; at least one cleaning liquid inlet for flow of a cleaning liquid into the chamber; a divider located in or at the end of the cavity that divides the chamber into first and second portions, the second portion, in use, being in fluid communication with the surface to be cleaned; and an acoustic transducer associated with the first portion to introduce acoustic energy into the chamber; wherein the divider is adapted to permit the passage of acoustic energy therethrough from the first portion to the second portion of the chamber to thereby allow pressure fluctuations to be generated at the surface.

Abstract: An electrochlorination system comprises a source of feed fluid, a product fluid outlet, and a plurality of electrochemical cells connected fluidically between the source of feed fluid and the product fluid outlet. The system is configured to operate at least one of the plurality of electrochemical cells at one of a first current density or a first flow rate, and to operate another of the plurality of electrochemical cells at a second current density or second flow rate different from the respective first current density or first flow rate.

Abstract: A filtration membrane, suitably for water filtration, comprising a porous substrate layer and an active layer arranged over at least a part of the substrate layer. The active layer has a lamellar structure comprising at least two layers of two-dimensional material. The two-dimensional material comprises graphene or a derivative thereof. There is also provided a method for producing filtration membranes and filtration devices containing the filtration membranes.

Abstract: An apparatus and method for cleaning a surface, the apparatus comprising: a body defining a cavity, the body terminating in a distal end that is adapted, in use, to be in the vicinity of a surface to be cleaned such that the surface to be cleaned forms an end wall of a chamber including the cavity; at least one cleaning liquid inlet for flow of a cleaning liquid into the chamber; a divider located in or at the end of the cavity that divides the chamber into a first portion and a second portion, the second portion, in use, being in fluid communication with the surface to be cleaned; and an acoustic transducer associated with the first portion of the chamber to introduce acoustic energy into the chamber; wherein the divider is adapted to permit the passage of acoustic energy therethrough from the first portion of the chamber to the second portion of the chamber to thereby allow pressure fluctuations to be generated at the surface to be cleaned.

Abstract: A method and apparatus for forming an aqueous chlorine dioxide solution is disclosed which includes reacting in a reaction vessel an acid reaction solution containing a hydroxy carboxylic acid and a companion acid with an alkali metal salt of a chlorite ion. In accordance with the process, the hydroxy carboxylic acid serves to temporarily transfer chlorine from and does not form a salt with the alkali metal salt of a chlorite ion. The aqueous chlorine dioxide solution produced is substantially free of chlorous acid and preferably is free of other by-products such as sodium chloride and free chlorine. The method further includes maintaining the reaction vessel at a pH of less than 5 and/or withdrawing at least a portion of the chlorine dioxide from the aqueous chlorine dioxide solution. The method enables rapid, efficient, compact and safe generation of chlorine dioxide. A method of disinfecting water, and apparatus for making chlorine dioxide and for disinfecting water also are provided.

Abstract: A method of forming an aqueous chlorine dioxide solution is disclosed which includes reacting in a reaction vessel an acid reaction solution containing a hydroxy carboxylic acid and a companion acid with an alkali metal salt of a chlorite ion. In accordance with the process, the hydroxy carboxylic acid serves to temporarily transfer chlorine from and does not form a salt with the alkali metal salt of a chlorite ion. The aqueous chlorine dioxide solution produced is substantially free of chlorous acid and preferably is free of other by-products such as sodium chloride and free chlorine. The method further includes maintaining the reaction vessel at a pH of less than 5 and/or withdrawing at least a portion of the chlorine dioxide from the aqueous chlorine dioxide solution. The method enables rapid, efficient, compact and safe generation of chlorine dioxide. A method of disinfecting water, and apparatus for making chlorine dioxide and for disinfecting water also are provided.