A system for an electrochemical process includes an electrochemical reactor, a converter bridge for supplying direct current to electrodes of the electrochemical reactor, and serial inductors connected to alternating voltage terminals of the converter bridge. The converter bridge includes bi-directional controllable switches between the alternating voltage terminals and direct voltage terminals of the converter bridge. Forced commutation of the bi-directional controllable switches enables reduction of current ripple in the direct current supplied to the electrochemical reactor. The forced commutation enables also to control a power factor of an alternating voltage supply of the system.

An unmanned aerial vehicle (“UAV”) system for fluid transport includes a UAV having a fluid chamber configured to transport a fluid, a processor, and a memory. The memory includes instructions which, when executed by the processor, may cause the system to receive a first location for collecting or releasing a fluid, determine a fluid level of the fluid chamber, and transport the fluid by the UAV to the first location based on the determined fluid level.

An unmanned aerial vehicle (“UAV”) system for fluid transport includes a UAV having a fluid chamber configured to transport a fluid, a processor, and a memory. The memory includes instructions which, when executed by the processor, may cause the system to receive a first location for collecting or releasing a fluid, determine a fluid level of the fluid chamber, and transport the fluid by the UAV to the first location based on the determined fluid level.

The invention relates to a method for removing and obtaining carbon dioxide from ambient air, comprising the continuous execution of the following steps: a) bringing ambient air into contact with an aqueous solution of at least one alkali metal or alkaline earth metal for the purpose of absorbing the carbon dioxide into the solution, forming the bicarbonate or carbonate of the at least one metal; b) electrodialysis of the resulting solution using a combination of bipolar ion-exchange membranes and ion-exchange membranes that are selective for mono- and multivalent anions to obtain one solution enriched in (bi-)carbonate anions and one solution depleted in (bi-)carbonate anions, wherein the solution depleted in (bi-)carbonate anions is recycled to step a); c) thermal desorption of the carbon dioxide from the solution, obtained in step b), enriched in (bi-)carbonate anions by means of steam stripping in order to obtain a carbon dioxide-steam mixture and a solution depleted in CO.sub.2 which is recycled to step (b), wherein a pH is set there of between 7 and 8.5 or between 8 and 9.5; and d) removing water from the obtained carbon dioxide-steam mixture by cooling to condense the steam, and possibly further drying of the carbon dioxide.

The invention relates to a method for removing and obtaining carbon dioxide from ambient air, comprising the continuous execution of the following steps: a) bringing ambient air into contact with an aqueous solution of at least one alkali metal or alkaline earth metal for the purpose of absorbing the carbon dioxide into the solution, forming the bicarbonate or carbonate of the at least one metal; b) electrodialysis of the resulting solution using a combination of bipolar ion-exchange membranes and ion-exchange membranes that are selective for mono- and multivalent anions to obtain one solution enriched in (bi-)carbonate anions and one solution depleted in (bi-)carbonate anions, wherein the solution depleted in (bi-)carbonate anions is recycled to step a); c) thermal desorption of the carbon dioxide from the solution, obtained in step b), enriched in (bi-)carbonate anions by means of steam stripping in order to obtain a carbon dioxide-steam mixture and a solution depleted in CO.sub.2 which is recycled to step (b), wherein a pH is set there of between 7 and 8.5 or between 8 and 9.5; and d) removing water from the obtained carbon dioxide-steam mixture by cooling to condense the steam, and possibly further drying of the carbon dioxide.

The present invention provides a device capable of reducing the resistance and increasing the ion exchange rate in an electrodialysis, electro-deionization, or capacitive deionization apparatus and a method for producing said device. More specifically, the device is an electrodialysis spacer designed to have an ionically conductive surface of either cationic nature, anionic nature or a combination of both, which act as conductive pathways for ions as they move towards their respective electrode. The method of producing said spacer involves coating a substrate, such as a woven mesh, expanded netting, extruded netting or non-woven material, with perm-selective ionomer solutions and applying that substrate to an inert spacer material that has undergone chemical or mechanical etching.

The present invention provides a device capable of reducing the resistance and increasing the ion exchange rate in an electrodialysis, electro-deionization, or capacitive deionization apparatus and a method for producing said device. More specifically, the device is an electrodialysis spacer designed to have an ionically conductive surface of either cationic nature, anionic nature or a combination of both, which act as conductive pathways for ions as they move towards their respective electrode. The method of producing said spacer involves coating a substrate, such as a woven mesh, expanded netting, extruded netting or non-woven material, with perm-selective ionomer solutions and applying that substrate to an inert spacer material that has undergone chemical or mechanical etching.

Methods for processing pretreated phosphogypsum wastewater are disclosed. The pretreated wastewater may be subjected to electrodialysis involving at least one monovalent cation selective membrane. Further downstream membrane treatment may be applied. Upstream precipitation and air-stripping techniques may optionally also be employed. Related systems are also disclosed.

Methods for processing pretreated phosphogypsum wastewater are disclosed. The pretreated wastewater may be subjected to electrodialysis involving at least one monovalent cation selective membrane. Further downstream membrane treatment may be applied. Upstream precipitation and air-stripping techniques may optionally also be employed. Related systems are also disclosed.

A device for the electrodeionization of a sample liquid. The device has an anode chamber having two openings and an anode, a cathode chamber having two openings and a cathode, and a treatment chamber, that is arranged between the anode chamber and the cathode chamber and has two openings and ion exchanger. The anode chamber and the cathode chamber are separated from the treatment chamber in each case by a permselective membrane and an energy source is operatively connected to the anode and the cathode. In addition, a method for the electrodeionization of a sample liquid is provided.