Provided are electrodialysis systems for removing silica from a desalinated water stream and methods for removing silica from a desalinated water stream. For example, described are bipolar membrane electrodialysis devices for removing silica from water comprising one or more anion exchange membranes; one or more bipolar membranes; and a pair of electrodes comprising a positive electrode and a negative electrode. Also described are electrodialysis systems comprising: one or more electrodialysis devices for the removal of dissolved ions and one or more bipolar membrane electrodialysis devices, wherein a product inlet stream of the one or more bipolar membrane electrodialysis devices comprises the product outlet stream of the one or more electrodialysis devices.

The present invention is in the field of a system for gas recovery from wastewater, a method for treating wastewater, and a method wherein ammonia and carbon dioxide are recovered. Typically a wastewater stream is fed into the system, treated and stripped from ammonia and carbon dioxide, and a cleaner stream is released.

A system for electrochemically enhanced water filtration is provided. The system includes: a chamber plug-flow electrochemical cell; a first cathode and anode pair disposed in the cell; and a second cathode and anode pair disposed in the cell. The first and the second pair are collectively operative to apply a 2D electric field in at least one of a horizontal direction and a vertical direction with respect to the chamber plug-flow electrochemical cell.

A bipolar capacitive deionization (CDI) electrode includes a circular current collector having a central hole and inner and outer circumferential surfaces; a nano-carbon coating layer formed on at least top and bottom surfaces of the circular current collector; and a hydrophobic polymer coating layer respectively disposed over the inner and outer circumferential surfaces of the current collector. Maintenance and management is facilitated by a bipolar CDI electrode module configured such that individual parts are formed to be removably attached. A water treatment apparatus including the bipolar CDI electrode module exhibits high water treatment efficiency, superior long-term stability, and easy maintenance and management, while solving terminal corrosion problems due to the formation of a hydrophobic polymer coating layer on the surface of an electrode terminal.

An electrochlorination system includes an electrolyzer fluidically connectable between a source of feed fluid and a product fluid outlet, and a sub-system configured to one of increase a pH of the feed fluid, or increase a ratio of monovalent to divalent ions in the feed fluid, upstream of the electrolyzer.

An electrolytic cell for treating wastewater comprises an anode assembly, a cathode assembly and at least one bipolar electrode assembly placed between the anode and the cathode assembly such that the anodes of the anode assembly and the cathodes of the cathode assembly are interleaved with the bipolar plates of the bipolar electrode assembly. Each bipolar electrode assembly comprises a series of bipolar electrodes which operate as an anode or as a cathode, stacked in a vertical direction along a threaded bolt made of an electrically conductive material such that the bipolar electrodes operating as anodes are oriented in an opposite direction to the bipolar electrodes operating as cathodes and have their ends overlapping over a predetermined portion and being separated by conductive spacers. In preferred embodiments, only the anodes and the bipolar electrodes operating as anodes are coated with catalyst which saves costs and simplifies the manufacturing process.

The invention relates to a system and method for treating wastewater onboard a marine vessel or other limited space application where wastewater treatment is required. In one embodiment of the invention, two polar opposite wastewater treatment processes are incorporated into the same treatment system. The system is a hybrid treatment unit that combines a conventional wastewater treatment using a moving bed biofilm reactor (MBBR) process-based biological treatment unit in combination with a novel electrochemical advanced oxidation process (EAOP) via an in-situ sodium hypochlorite recirculation. The clarified and disinfected effluent from this hybrid treatment unit is filtered to remove residual TSS. The filtered and disinfected effluent is discharged after dechlorination/neutralization. On-site maintenance disinfectant can be produced via the electrochemical/electrochlorination/electro-oxidation process and used for both treatment unit cleaning and disinfection. Additionally, the treatment unit provides a wholly separate stream of electrolysis generated disinfectant for surface disinfection purposes.

The invention relates to a system and method for treating wastewater onboard a marine vessel or other limited space application where wastewater treatment is required. In one embodiment of the invention, two polar opposite wastewater treatment processes are incorporated into the same treatment system. The system is a hybrid treatment unit that combines a conventional wastewater treatment using a moving bed biofilm reactor (MBBR) process-based biological treatment unit in combination with a novel electrochemical advanced oxidation process (EAOP) via an in-situ sodium hypochlorite recirculation. The clarified and disinfected effluent from this hybrid treatment unit is filtered to remove residual TSS. The filtered and disinfected effluent is discharged after dechlorination/neutralization. On-site maintenance disinfectant can be produced via the electrochemical/electrochlorination/electro-oxidation process and used for both treatment unit cleaning and disinfection. Additionally, the treatment unit provides a wholly separate stream of electrolysis generated disinfectant for surface disinfection purposes.

A current conductor for use in an electrochemical device for removing ions from a solution. The current conductor includes a current conductor substrate having a current conductor surface. The current conductor also includes an anti-corrosive, anti-reactive coating coated onto the current conductor surface. The anti-corrosive, anti-reactive coating contains a material with a chemical composition of AO.sub.y, where A= Zr, Nb, Ti, or a combination thereof and 2 < y < 3; M.sub.xAO.sub.y, where M= Ca, Mg, Na, or a combination thereof, A= Zr, Nb, Ti, or a combination thereof, 0 < x < 2, and 2 < y < 3; MgCr.sub.2O.sub.4; or a combination thereof.

A method for removing silica from an aqueous solution is provided. The method includes steps of flowing the aqueous solution into an electro-Fenton reactor, wherein the reactor comprises one or more electrodes in a bipolar arrangement positioned between a monopolar iron anode and a monopolar cathode; applying an electric current to the aqueous solution such that silica aggregates form on ferric hydroxide; and removing the silica aggregates from the aqueous solution.