Catalytic water treatment is provided using an active material driven with an optical and/or electrical excitation. The active material is MoS.sub.2, MoSe.sub.2, WS.sub.2, WSe.sub.2, Mo.sub.xW.sub.1-xS.sub.2, Mo.sub.xW.sub.1-xSe.sub.2, MoS.sub.ySe.sub.2-y, WS.sub.ySe.sub.2-y, or Mo.sub.xW.sub.1-xS.sub.ySe.sub.2-y; wherein 0<x<1 and 0<y<2. The active material is configured as one or more layered nanostructures having exposed layer edges. A metal catalyst is disposed on the active material. The combined structure of active material and metal catalyst is disposed in the water to be treated. The excitation is provided to the active material to generate one or more reactive oxygen species by dissociation of water, wherein the reactive oxygen species provide water treatment.

In alternative aspects, the invention provides processes for cyclic electrochemical adsorption of aqueous contaminants using nanocomposites of graphene with tin oxide or antimony doped tin oxide.

A stack of electrochemical cells for wastewater treatment is disclosed comprising at least one electrochemical cell having a solid polymer membrane, an anode catalyst layer and a cathode catalyst layer adjacent to each side of the membrane, an open pore mesh placed next to each of the catalyst layers and a compression frame placed next to each open pore mesh. A cover is placed between the compression frames of two neighbouring electrochemical cells in the stack thereby forming an enclosure which spans the distance between the two neighbouring electrochemical cells thereby isolating the cathode catalyst layer or the anode catalyst layer from the solution in the reactor tank in which the stack is immersed.

An apparatus for capturing CO.sub.2 from flue gas includes (a) an absorber, (b) a stripper, (c) a heat exchanger, (d) an amine absorbent circulating through the absorber, the stripper and the heat exchanger, (e) a water washing unit downstream from the flue gas outlet of the absorber, and (f) an electrochemical cell. The electrochemical cell is connected to the water washing unit and is adapted to adsorb and decompose nitrosamine compounds present in liquid separated by the water washing unit.

The invention of the current application is directed to a wastewater treatment apparatus. The invention includes a divided membrane electrochemical cell including an anode contained within a anode compartment and cathode contained within a cathode compartment. The anode compartment and said cathode compartment are separated by a proton selective membrane. The invention also includes a voltage source, and a liquid-gas separator. The invention is an economically viable electrochemical advanced oxidation system that can cost-effectively treat recalcitrant COD with low energy, without the necessity for chemicals, and reduce or prevent sludge production in a single step.

An electrochemical cell for wastewater treatment comprises a catalyst coated membrane, an open pore mesh placed on each side of the catalyst coated membrane, and a compression frame placed next to each of the open pore meshes. Each compression frame has compression arms spread within the area delimited by the perimeter of the frame to apply a uniform compression force through fasteners which protrude through the compression arms, the open pore meshes and the catalyst coated membrane. Each open pore mesh comprises a flat surface and an embossed surface. The embossed surface can comprise embossed areas around the holes in the open pore mesh, transverse embossed areas which, in the assembled cell, are placed next to the compression arms of the compression frames and peripheral embossed areas along the perimeter of the open pore meshes. The embossed surface provides an improved protection against electro-circuiting.

Apparatus and method for electrolysis of urea is capable of removing urea from waste-water generated by human urine or agricultural run-off while simultaneously producing cleaner water and hydrogen gas. The apparatus and method employ at least one water reduction electrode located close to at least one urea oxidation electrode. The water reduction electrode operates to generate a locally high pH such that the urea oxidation electrode operates in a locally high pH envelope where it can perform its reaction efficiently to break down the urea with little or no impact on the pH of the bulk solution.

There are provided electrooxidation systems and processes which provide an elevated pressure at which components are oxidized in an electrooxidation cell. The elevated pressure reduces power consumption for the cell at least in part by reducing the formation of gas bubbles, which typically leads to increased resistance and an increased power output.

An innovative equipment system comprises a tap water reservoir system, a disinfectant reactor system, a pump system, a disinfection and safety door spraying system, a sewage recycling system and a sewage treatment system, wherein the tap water reservoir system is mainly configured to store tap water in advance according to actual cargo volumes and disinfection requirements, and generally in tons; and the disinfectant reactor system comprises boron-doped diamond electrode modules, a reactor indicating lamp module, a visible reactor, a smart control screen, at least one water tank and a structure protection module. The Innovative disinfection and sterilization equipment system can easily kill bacteria and viruses such as Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, and new coronavirus in a short time and enhance disinfection efficiency. The present invention has no corrosive or irritating effect and is environmental-friendly that would not cause harm to human bodies and would not corrode metal surfaces.

The present invention provides a multi-stage system for treating greywater comprising an electrochemical treatment module configured to carry out electrooxidation and electrocoagulation processes and a filtration module comprising a multistage filtration system for the treatment and removal of chemical and biological contaminants in greywater.