A forward osmosis filtration cell is provided which includes a fluid passageway and a forward osmosis filtration membrane positioned within the passageway. The filtration membrane divides the fluid passageway into two chambers, a first chamber configured to hold a draw solution, and a second chamber configured to hold a feed solution. The filtration cell further includes a first electrode positioned in the first chamber, and a second electrode positioned in the second chamber. The first and second electrodes are configured to apply an electric field across the filtration membrane to prevent fouling on the filtration membrane. A method of using a forward osmosis filtration cell in a water treatment system, and a method of retrofitting a water treatment system with first and second electrodes are also provided.

Methods and circuits for a device for interrupting concentration-related polarisation phenomenon and for self-cleaning of electromembrane processes by application of asymmetric inverse-polarity pulses with high intensity and variable frequency are described. The device, a bipolar switch, is based on the use of solid-state electronics to carry out polarity inversion in a range of frequencies, intensities and pulse widths to prevent or reduce formation of precipitates on the surfaces of the membranes. The inversion protocol, with a frequency that varies as a function of the appearance of dirt on the membranes, as measured by the decrease in voltage or electrical resistance of the membrane cell during electromembrane processes, is also provided. This device and configuration provides application of modulated and stable high-intensity pulses using a second power source. Electromembrane processes can be updated by replacing electrodes, suitable for polarity inversion, and adding a second power source and the bipolar switch described.

Disclosed are systems and processes for the removal and conversion of pollutants in water. A system includes a set of electrodes with at least one electrode having an integrated catalyst material. The system is operatable in a first, electrodialysis mode in which one or more pollutants are separated from a feedwater stream, and a second electrolysis mode in which the separated pollutant(s) are catalytically converted into benign products by way of the catalyst material of the electrode. Electrodialysis and electrolysis are therefore carried out using the same unit.

An electrodialysis desalination device includes a first electrode including a first-stage side; a second electrode including a first-stage side; and a first stage between the first-stage side of the first electrode and the first-stage side of the second electrode. The first stage includes at least one first-stage cell pair positioned between the first-stage side of the first electrode and the first-stage side of the second electrode, and each cell pair includes a pair of first-stage selectively permeable ion-exchange membranes with alternating selectivity that define first-stage channels on opposite sides of each first-stage membrane for respective flows of a first-stage diluate stream and a first-stage concentrate stream. A single pump is configured to pump the diluate streams and the concentrate streams through the first stage.

A biofouling/biofilm removal system includes a filtration module configured to separate a permeate from a feed; a first inert electrode placed at an inlet of the filtration module; a second inert electrode placed at an outlet of the filtration module; and a power source configured to apply a current between the first and second electrodes. The inlet is configured to receive the feed and the outlet is configured to discard a concentrate, and the current applied between the first and second electrodes initiates electrochemical reactions inside the feed and along a biofilm formed in the filtration module, but not into the permeate.

Methods of operating an electrochemical separation device is disclosed. The methods include operating the electrochemical separation device in an active mode until the resistance reaches a predetermined threshold, regenerating the electrochemical separation device in a passive mode until the resistance reaches a predetermined threshold, and resuming operation of the electrochemical separation device in the active mode. The methods also include operating the electrochemical separation device in an active mode for a predetermined period of time, regenerating the electrochemical separation device in a passive mode for a predetermined period of time, and resuming operation of the electrochemical separation device in the active mode. Water treatment systems include the electrochemical separation device and a control module are also disclosed. Methods of facilitating operation of the electrochemical separation device by providing a control sequence are also disclosed.

A fluid treatment apparatus is constructed from at least one electrochemical cell including a bipolar ion exchange membrane and having a single output orifice to deliver treated fluid. The apparatus may employ a power supply transformer featuring a magnetic dispersion bridge to regulate the magnetic flux to secondary coils, thereby limiting the current delivered to the load and protecting the apparatus from over-current damage. The cell includes a membrane assembly which incorporates both the inner and outer electrodes to provide repeatable assembly and service, as well as reliable performance. The apparatus will provide continuous fluid treatment when designed with at least two stages, each stage including at least one cell, in which one stage is treating influent solution and another stage is regenerating. A method to operate these apparatus includes the steps of deionizing influent solution without interruption, halting deionization water flow and removing power from the deionization cells, flushing the liquid between membrane layers to the drain outlet, initiating regeneration power, and initiating regeneration flow.

The water treatment device according to the present disclosure includes: an electrochemical cell having electrodes including a positive electrode and a negative electrode, and a bipolar membrane; a tank; a power supply configured to apply power to the electrodes; a water circulation flow path having at least the tank and the electrochemical cell and through which water circulates; a circulation device configured to circulate water in the water circulation flow path; a raw water supply path configured to supply raw water to the water circulation flow path; and a control device. In performing water softening treatment in the electrochemical cell where power is applied to the electrodes so as to remove ions from raw water and soft water is produced, the control device drives the circulation device so as to circulate water in the water circulation flow path.

Methods and circuits for a device for interrupting concentration-related polarisation phenomenon and for self-cleaning of electromembrane processes by application of asymmetric inverse-polarity pulses with high intensity and variable frequency are described. The device, a bipolar switch, is based on the use of solid-state electronics to carry out polarity inversion in a range of frequencies, intensities and pulse widths to prevent or reduce formation of precipitates on the surfaces of the membranes. The inversion protocol, with a frequency that varies as a function of the appearance of dirt on the membranes, as measured by the decrease in voltage or electrical resistance of the membrane cell during electromembrane processes, is also provided. This device and configuration provides application of modulated and stable high-intensity pulses using a second power source. Electromembrane processes can be updated by replacing electrodes, suitable for polarity inversion, and adding a second power source and the bipolar switch described.

Methods for improving ion flux and energy efficiency in a membrane stack of an electrodialysis unit wherein the membrane stack is disposed between an anode and a cathode each in an electrolyte of a selected concentration. Methods include increasing the concentration of the electrolyte, adding a strong base to the electrolyte and adding buffering anions to the electrolyte. Methods for cleaning the electrodes of such a unit involving involve applying a pulsed polarity reversal to the electrodes. Also provided are methods for improving unit operation by increasing the basicity of the electrolyte to the anode and increasing the acidity of the electrolyte to the cathode or alternatively or in addition, by applying heat to increase the operating temperature of at least one of the electrolyte and the treated water stream.