A water softening device includes an electrolysis device, a first circulation flow path and a second circulation flow path, a first sensor, a second sensor, and a controller, wherein the controller controls the electrolysis device to execute a first mode in which the alkaline water is allowed to flow through the first circulation flow path and the acidic water is allowed to flow through the second circulation flow path, and a second mode in which the acidic water is allowed to flow through the first circulation flow path (8A) and the alkaline water is allowed to flow through the second circulation flow path, and controls to stop electrolysis by the electrolysis device based on a detection value of the first sensor or the second sensor in the first mode and the second mode.

A method for removing a metal from a carbonaceous electrode includes providing a regeneration solution that includes an acid, an oxidizing agent, or a combination thereof. The method further includes applying the regeneration solution to the carbonaceous electrode, and oxidizing the metal on the surface of the carbonaceous electrode. The method also includes collecting the oxidized metal in the regeneration solution.

A plant growing system includes a growth medium preparation unit and a plant growing unit. The growth medium preparation unit includes a supply of water that feeds water through a water treatment unit, a nutrition module, and a reactor sub-system to have the water treated and modified and added with nano-elements and other nutrition components to provide a nutrition formula. The nutrition formula is supplied to the plant growing unit that includes a growing box inside which a tank is provided for receiving and holding the nutrition formula. A plant plate is disposed on the tank and is formed with at least one through opening for receiving and holding a plant. The root of plant is allowed to extend into the nutrition formula inside the tank, while the stem of the plant is growing in a void space above the plant plate and inside the growing box.

A plant growing system includes a growth medium preparation unit and a plant growing unit. The growth medium preparation unit includes a supply of water that feeds water through a water treatment unit, a nutrition module, and a reactor sub-system to have the water treated and modified and added with nano-elements and other nutrition components to provide a nutrition formula. The nutrition formula is supplied to the plant growing unit that includes a growing box inside which a tank is provided for receiving and holding the nutrition formula. A plant plate is disposed on the tank and is formed with at least one through opening for receiving and holding a plant. The root of plant is allowed to extend into the nutrition formula inside the tank, while the stem of the plant is growing in a void space above the plant plate and inside the growing box.

An ocean iron fertilization (OIF) method and system for electrochemically controlled release of iron in an ocean to stimulate growth of phytoplankton to increase CO.sub.2 sequestration by the ocean. The system includes a cathode submerged or floating in the ocean; an iron or iron-producing anode submerged or floating in the ocean spaced apart from the cathode; and a power supply unit connected to the cathode and the anode. The power supply unit drives electric current between the cathode and the anode such the anode generates oxygen (O.sub.2) and ferrous iron through electrolysis to be released in the ocean, and the cathode produces hydrogen (H.sub.2) and hydroxide (OH—) species through an electrochemical reaction at the cathode.

Harmful biological contaminants are treated using plasma fields. The inventive techniques offer improved results over existing devices and methods.

Harmful biological contaminants are treated using plasma fields. The inventive techniques offer improved results over existing devices and methods.

The present invention relates to a carbon-nanotube/nano-adsorption-material-based electrode and an electrochemical valuable-metal recovery device using the same, and more particularly to an environmentally friendly carbon-nanotube/nano-adsorption-material-based electrode and an electrochemical valuable-metal recovery device using the same, in which valuable metals selectively adsorbed from e-waste wastewater are oxidized using, as an anode, an electrode including carbon nanotubes and a nano adsorption material capable of selectively adsorbing valuable metals and are simultaneously reduced at a cathode, thereby separating and recovering valuable metals.

The present invention relates to an electrolyzed water manufacturing device for producing hypochlorous acid water containing hypochlorous acid using hydrochloric acid as an electrolyte, comprising: a hydrochloric acid container for storing the hydrochloric acid as the electrolyte; an electrolytic bath which is connected to the hydrochloric acid container, includes an electrode, and produces slightly weak acidic hypochlorous acid water containing a high-density chlorine solution through electrolysis of the hydrochloric acid; a hydrochloric acid supply pump provided between the hydrochloric acid container and the electrolytic bath so as to supply the hydrochloric acid to the electrolytic bath; and a venturi pipe which is connected to an upper part of the electrolytic bath, is formed between an inlet and an outlet through which dilution water passes, includes a neck part having a smaller pipe diameter in comparison with the inlet and the outlet, and an extraction pipe for connecting the neck part and the electrolytic bath, such that the high-density chlorine solution generated from the electrolytic bath is aspirated through the reduction of the pressure generated from the neck part when the dilution water passes through, and the aspirated high-density chlorine solution is diluted using the dilution solution and the diluted high-density chlorine solution is discharged. The apparatus for producing slightly weak acidic hypochlorous acid water, according to the present invention further, comprises: a discharging pipe connected to the outlet of the venturi pipe; and a screw blade which is inserted into the discharging pipe and accelerates the contact reaction between the high-density chlorine solution discharged from the non-diaphragm type electrolytic bath and the dilution water, wherein the screw blade is preferably composed of flexible plastic material.

A softening apparatus in which resistance applied between electrodes is decreased to reduce power consumption. The softening apparatus includes a regeneration unit and a softening unit. The regeneration unit includes at least one anode and cathode in a first space which generate regeneration water containing hydrogen ions (H+). The softening unit is disposed in a second space partitioned from the first space and includes an ion exchange body regenerated by the regeneration water.