Managed ecosystems, methods for producing managed ecosystems and methods for using managed ecosystems for sequestering carbon dioxide are described herein. Produced water is obtained and purified to sustain a managed ecosystem with saline-tolerant vegetation. The managed ecosystem biologically sequesters carbon dioxide by photosynthetically absorbing carbon dioxide from the atmosphere and by decomposition into a layer of sediment on the ecosystem floor.

A flexible electrocatalytic membrane for removing nitrate from water, a preparation method and use thereof are provided. The method of the present invention includes dropwise adding an aramid fiber solution into deionized water to prepare an aramid nanofiber sol, then reacting an ethanol solution containing 3,4-ethylenedioxythiophene and ferric nitrate with the aramid nanofiber sol to prepare a conductive aramid nanofiber sol, and finally dropwise adding MXene nanosheets ultrasonically pretreated by a tetramethylammonium hydroxide solution into the conductive aramid nanofiber sol to prepare the flexible electrocatalytic membrane. The prepared flexible electrocatalytic membrane possesses good mechanical strength and flexibility, and can not only effectively remove nitrate but also avoid failure of electrocatalytic materials due to surface fouling in the process of electrocatalytic reduction of nitrate, and thus has a long service life.

A system for an efficient and sustainable electrochemical treatment of wastewater comprises a reactor tank, a first electrolyzer with a stack of electrolytic cells, each electrolytic cell comprising an anode of a first composition, and a second electrolyzer with a stack of electrolytic cells, each electrolytic cell comprising an anode of a second composition, and a contaminant concentration measuring device for monitoring the contaminant concentration in the reactor tank to the first or to the second electrolyzer. Wastewater to be treated is supplied from the reactor tank to the first electrolyzer until the contaminant concentration becomes substantially constant as measured by the contaminant removal rate being around 0 mg/h, which indicates the buildup of byproducts generated in the first electrolyzer, at which time the wastewater is supplied from the reactor tank to the second electrolyzer with anodes which can efficiently treat the byproducts of the reaction in the first electrolyzer.

A method of destroying a fluorocarbon compound includes regenerating an adsorbent to remove the fluorocarbon compound and to produce a regeneration fluid having a concentration of the fluorocarbon compound and directing the regeneration fluid to an electro-oxidation system. The method also includes applying a current to the electro-oxidation system to oxidize the fluorocarbon compound within the regeneration fluid and measuring a quantity of fluorides in the regeneration fluid to determine the progress of the removal of the fluorocarbon compound from the regeneration fluid.

An electrolyte solution production device includes: an electrolysis unit that includes a stacked body having conductive film stacked and interposed between electrodes adjacent to each other and is configured to electrolyze a liquid; and housing having the electrolysis unit disposed in an inside of the housing. In addition, housing includes inflow port into which the liquid supplied to the electrolysis unit flows and outlet port from which an electrolyte solution produced in the electrolysis unit flows out. Conductive film has protrusion that protrudes toward the inner surface of housing and is provided to position conductive film with respect to housing. This can provide the electrolyte solution production device in which conductive film can be downsized and easily positioned with respect to housing.

A system and a method for separation of ions from ions-containing medium is disclosed herein, that utilizes capacitive-faradaic fuel cells (CFFC) particles coated at least partially with catalysts capable of catalyzing redox reactions provided a reductant (fuel) and/or an oxidant, thereby polarizing the particles to more effectively absorb charged species (ions) from the water upon introducing, e.g., H.sub.2 gas or O.sub.2 gas, in the medium during the adsorption or regeneration. The same concept is utilized in a hybrid electrochemical cell for providing a system and a method for generating and converting electrochemical energy.

There is provided a method of preparing a photoelectrochemical and electrochemical electrode catalyst, the method including preparing a metal oxide-based electrode, introducing a phosphate layer on a surface of the metal oxide-based electrode; and converting the phosphate layer into an oxyhydroxide layer by performing electrochemical activation on the phosphate layer.

The efficiency of selective oxidation reaction of ammonia in wastewater may be improved.

A humidifier includes a storage water tank configured to accommodate a predetermined amount of water; a circulation water tank having a smaller capacity than the storage water tank and including a circulation low water level sensor; a supply pump configured to supply water from the storage water tank to the circulation water tank; a circulation pump configured to supply water from the circulation water tank to a humidifying member; a residual water tank configured to accommodate water discharged from the circulation water tank; a drainage member disposed between the circulation water tank and the residual water tank selectively to discharge water from the circulation water tank to the residual water tank and a processor configured to control the drainage member to discharge water from the circulation water tank to the residual water tank when a low water level signal is received from the circulation low water level sensor.

A humidifier includes a storage water tank configured to accommodate a predetermined amount of water; a circulation water tank having a smaller capacity than the storage water tank and including a circulation low water level sensor; a supply pump configured to supply water from the storage water tank to the circulation water tank; a circulation pump configured to supply water from the circulation water tank to a humidifying member; a residual water tank configured to accommodate water discharged from the circulation water tank; a drainage member disposed between the circulation water tank and the residual water tank selectively to discharge water from the circulation water tank to the residual water tank and a processor configured to control the drainage member to discharge water from the circulation water tank to the residual water tank when a low water level signal is received from the circulation low water level sensor.

A water treatment system comprises an actinic radiation reactor, an electrochemical cell configured to produce hydrogen peroxide and having an outlet in fluid communication between a source of electrolyte and the actinic radiation reactor, and a source of oxygen in communication with an inlet of the electrochemical cell.