Solution-phase (e.g., homogeneous) or surface-immobilized (e.g., heterogeneous) electrode-driven oxidation catalysts based on iridium coordination compounds which self-assemble upon chemical or electrochemical oxidation of suitable precursors and methods of making and using thereof are. Iridium species such as {[Ir(LX).sub.x(H.sub.2O).sub.y(μ-O)].sub.z.sup.m+}.sub.n wherein x, y, m are integers from 0-4, z and n from 1-4 and LX is an oxidation-resistant chelate ligand or ligands, such as such as 2(2-pyridyl)-2-propanolate, form upon oxidation of various molecular iridium complexes, for instance [Cp*Ir(LX)OH] or [(cod)Ir(LX)] (Cp*=pentamethylcyclopentadienyl, cod=cis-cis,1,5-cyclooctadiene) when exposed to oxidative conditions, such as sodium periodate (NaIO.sub.4) in aqueous solution at ambient conditions.

A water treatment apparatus using a lamella structure according to an embodiment of the present invention includes a first treatment tank which includes a plurality of inclined plates and is configured to pass water subject to treatment between the inclined plates adjacent to each other and a second treatment tank which is installed at a rear end of the first treatment tank to accommodate the water subject to treatment and into which bubbles are supplied, wherein the plurality of inclined plates include positive electrode plates and negative electrode plates that are alternately arranged, and the water subject to treatment passes between the positive electrode plate and the negative electrode plate.

A process for treating sour water includes combining the sour water with an alkali or alkaline metal hydroxide to produce a sour water mixture, the sour water comprising sulfides, passing an electric current through the sour water mixture, where passing the electric current through the sour water mixture causes at least a portion of the sulfides to react to produce a treated sour water comprising sulfates and having a pH of 7.1 to 9.8, saturating the at least a portion of the sulfates in an aqueous sulfate solution, and separating at least a portion of saturated sulfates from a saturated aqueous sulfate solution.

A system and method for treatment of a wastewater fluid is described. The system includes a gas supply system to provide a process gas into the wastewater fluid, a pulsed electrical-power generator to generate high electrical voltage pulses and a reactor apparatus pneumatically coupled to the gas supply system, and electrically coupled to the pulsed electrical-power generator. The reactor apparatus is configured to produce a plurality of gas microbubbles of the process gas injected into the wastewater fluid supplied into the reactor apparatus for the treatment, and to apply the high electrical voltage pulses generated by the pulsed electrical-power generator to said plurality of the microbubbles. The high electrical voltage pulses have energy sufficient to create a plasma glow discharge within the plurality of the microbubbles, and in an interface of the microbubbles with the wastewater fluid.

A ballast water treatment operating apparatus includes a ballast water treatment unit for performing a certain treatment of ballast water flowing in from the outside for a ballast operation or performing a certain treatment of ballast water discharged into the outside for a de-ballast operation; a positional information receiving unit for receiving positional information; a control unit for confirming a ship's position by using positional information received from the positional information receiving unit and then determining whether to operate the ballast water treatment unit during a ballast operation or during a de-ballast operation, thereby being capable of preventing an unnecessary energy consumption.

A plasma generating method, used in a plasma generating apparatus which includes a container, a first electrode, and a second electrode, includes: supplying a liquid in the container so that the second electrode is in contact with the liquid; in a first period, generating first plasma in a bubble generated in the liquid by applying a first voltage between the first electrode and the second electrode; supplying a first gas in the liquid in a second period after the first period; and generating second plasma in the first gas by applying a second voltage between the first electrode and the second electrode. In generating the first plasma, the first gas is not supplied in the liquid. The bubble contains a second gas.

The present invention discloses an electrocatalytic Fenton oxidation-electrochemical oxidation coupling process and apparatus for efficient treatment of chemical wastewater, and belongs to the field of sewage treatment. The process includes an electrocatalytic Fenton oxidation step, an electrochemical oxidation step, and a pH adjustment step. A spacing between a cathode and an anode in the electrocatalytic Fenton oxidation step is controlled, so that oxygen produced at the anode reacts at the cathode to produce H.sub.2O.sub.2. The treatment requirements can be met without external aeration or external addition of H.sub.2O.sub.2, and meanwhile, the efficiency of COD removal by electro-Fenton oxidation is effectively improved. Further, by connecting a pH adjusting tank with the electrocatalytic Fenton oxidation-electrochemical oxidation coupling apparatus in series, a coupling treatment process with near-zero production of iron sludge is realized

The present disclosure describes methods and systems comprising hydrodynamic cavitation, microwave irradiation, and at least one of oxidative sonoelectrolysis and reductive sonoelectrolysis, providing feedstock purification of at least one of water, fluid and mineral. Contaminants, broken down and chemically degraded into smaller and more volatile substances by hydrodynamic cavitation are ultimately destroyed in the course of one or more sonoelectrolysis steps. In various embodiments, at least one of oxidative sonoelectrolysis and reductive sonoelectrolysis is irradiated with microwaves in order to heat the sonoplasma present within acoustic cavitation bubbles to temperatures sufficient to destroy contaminants therein.

An apparatus has a hub including a water inlet for receiving source water, a water outlet for discharging ozonated water, and an interface between the water inlet and the water outlet. The apparatus also has a cartridge including an electrolytic cell for ozonating the source water. The electrolytic cell has a cathode, an anode comprising diamond, and a membrane between the cathode and the anode. The electrolytic cell is configured to flow source water through both the cathode and the anode. The cartridge further includes at least one cartridge port for removably coupling with the interface on the hub. The at least one cartridge port and the interface are configured to flow source water from the hub into the electrolytic cell and to flow ozonated water from the electrolytic cell into the hub.

The present invention relates to a bio-electrochemical system (BES) and a method of in-situ production and removal of H.sub.2O.sub.2 using such a bio-electrochemical system (BES). Further, the invention relates to a method for in-situ control of H .sub.2O.sub.2 content in an aqueous system of advanced oxidation processes (AOPs) involving in-situ generation of hydroxyl radical (OH) by using such a bio-electrochemical system (BES) and to a method for treatment of wastewater and water disinfection. The bio-electrochemical system (BES) according to the invention comprises:—an aqueous cathode compartment comprising a first cathode and a second cathode,—an aqueous anode compartment comprising an anode at least partly covered in biofilm, wherein the first cathode is connected to a first circuit and the second cathode is connected to a second circuit, wherein the first and the second circuit are connected to the system by an external switch.