A method for reducing nitrates, nitrites, and/or hydroxylamine in water using a homogeneous reduced copper tetra-substituted fluorinated pinacolate ligand catalyst complex. The method includes dissolving a copper(II) tetra-substituted fluorinated pinacolate ligand pre-catalyst complex in water having an excess amount of nitrates, nitrites, and/or hydroxylamine therein. The dissolved copper(II) tetra-substituted fluorinated pinacolate ligand pre-catalyst complex in the water is subjected to electrochemical reduction to form a homogeneous reduced copper tetra-substituted fluorinated pinacolate ligand catalyst complex. The homogeneous reduced copper tetra-substituted fluorinated pinacolate ligand catalyst complex reduces the nitrates, nitrites, and/or hydroxylamine in the water to compounds with nitrogen in a lower oxidation state with the homogeneous reduced copper tetra-substituted fluorinated pinacolate ligand catalyst complex.

This disclosure provides techniques for treatment of aqueous matrices using electrolysis to produce soluble metals. An aqueous matrix of interest is passed through an electrolysis device with at least one consumable electrode, which dissolves under applied current, transferring a desired reagent to the aqueous matrix of interest. In one embodiment, the electrolysis device is used in a water delivery network to passivate hexavalent chromium (Cr6) and/or convert it to trivalent chromium; the electrode can be made of food-grade metal tin, which is electrolyzed to form a stannous reagent, which then reacts with the Cr6. The disclosed techniques provide for Cr6 passivation without requiring the use of concentrated acids or other harmful substances. Long term reagent generation efficiency can be enhanced through the use of cleaning processes which maintain a fresh electrode surface in contact with the aqueous matrix of interest.

The invention relates to a method and a system for purification of water in a water purification system. The water purification system comprises first and second mixing reactors, first and second flotation reactors and first and second filters all serially and fluidly connected in a flow direction of the water as well as an electrolyzer. During the process, electrochemical synthesis of the reagents takes place in the cathode and anode chambers of the electrolyzer, respectively. Moreover, the electrochemically synthesized catholyte and anolyte are dosed into the water kept in the first and second mixing reactors, respectively. Then the mixtures in the first and second mixing reactors are mixed. After that, the flow of the treated water leaving the mixing reactors is passed through the first and second flotation reactors and afterwards through the first and second filters downstream of the first and second mixing reactors.

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 a method for electrochemical purification of an aqueous solution comprising the steps of: providing a cathode and an anode to an aqueous solution, wherein said aqueous solution comprises soluble ions of at least one toxic heavy metal and wherein said cathode comprises an outer surface, which outer surface comprises a noble metal; applying an absolute potential to said cathode and wherein said absolute potential of said cathode drives the formation of an alloy comprising said noble metal and said at least one toxic heavy metal.

The present disclosure relates to processes for treating wastewater such as acid rock drainage. The processes may, for example, comprise subjecting the wastewater to a microbial fuel cell process, neutralizing the acid with a base comprising calcium to produce an aqueous composition comprising calcium ions and subjecting the aqueous composition comprising calcium ions to a biological precipitation process to precipitate the calcium ions as calcium carbonate.

A filtration system for a pet water fountain is provided. The filtration system utilizes a pump placed within or along a watering bowl. The water filtration system also utilizes a multi-stage filtering device. In one aspect, the multi-stage filtering device includes a first filtering stage representing copper zinc alloy particles, and a second filtering stage representing granulated activated carbon particles. Each stage may constitute filtering material that is separated into an array of cells residing along a vertical frame or is separated into stages placed in series within a tubular cartridge. A method for filtering water in a pet fountain is also provided herein.

The present invention concerns a method for reducing the amount of polluting and/or valuable elements through application of electrolysis, in particular of the electrocapturing phenomenon. The electrolysis according to the present invention is applied permanently over time in a polluted water body. The predetermined action area (115bis, 115ter) preferably has a smaller extension than the water body. The at least one phenomenon (125bis, 125ter) is preferably powered electrically through production of electrical energy in loco through at least one renewable energy source (140). The method is suitable for purifying large expanses of water, like seas, lakes, lagoons and rivers, through plants operating permanently, however this does not rule out other applications.

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 provides a novel method for treating soil-contaminated water, the method using a photocatalytic material capable of efficiently removing, by light irradiation alone, volatile organic compounds and heavy metals that give rise to soil contamination. The present invention provides a method for treating soil-contaminated water that detoxifies volatile organic compounds contained in soil-contaminated water using a photocatalytic material, the method being characterized by including the steps of (1) subjecting the soil-contaminated water to a gas-liquid separation to obtain a gas phase, and (2) decomposing the volatile organic compounds contained in the gas phase obtained in step (1) using the photocatalytic material. The present invention further provides a method for treating soil-contaminated water using a photocatalytic material to remove heavy metals contained in the soil-contaminated water, the method being characterized, by including the steps of (1) subjecting the soil-contaminated water to a gas-liquid separation to obtain a liquid phase, and (2) removing the heavy metals contained in the liquid phase obtained in step (1) using the photocatalytic material.