Disclosed herein are Fenton filters comprising a porous substrate and a catalyst coating the porous substrate, wherein the catalyst includes a matrix and single metal atoms incorporated in the matrix. Also disclosed herein are methods of generating radicals from an oxidant, electrolyzers, methods of generating hydrogen peroxide, and water treatment systems.

The present invention includes a method including providing an anode and a cathode; providing a desalination device operably coupled to establish an electrical potential between the anode and the cathode when the desalination device is operating; providing water containing dissolved solids; thereby establishing the electrical potential; reducing a salinity of the water by supplying the water to the desalination device; and generating electrical power by reducing the salinity of the water.

Disclosed is a method of removal of an organic pollutant from an aqueous solution, comprising: a) contacting the solution with an anode and a cathode comprising a carbon material; b) applying electrical current to the anode, thereby generating reactive oxygen species; b) oxidizing the organic pollutant with the reactive oxygen species; and c) regenerating the carbon material. Also disclosed is a method of producing reactive oxygen species, comprising: a) flowing an aqeous solution through a reactor comprising at least one cathode and at least one anode; b) applying electrical current to the at least one anode; and c) collecting a product solution comprising reactive oxygen species.

The present invention provides methods for removing arsenic from an aqueous solution containing dissolved arsenic using a continuous-flow air-cathode iron electrocoagulation device and current densities of from at least 30 mA.Math.cm.sup.2 to about 250 mA.Math.cm.sup.2. The present invention also provides continuous-flow air-cathode iron electrocoagulation devices having barriers for reducing electrode fouling and maintaining faradaic efficiency for longer periods of time.

A purification unit includes a first electric conductor, a second electric conductor, and a third electric conductor. At least a part of the first electric conductor is electrically connected to one surface of the third electric conductor, and at least a part of the second electric conductor is electrically connected to the other surface of the third electric conductor. At least a part of the first electric conductor contacts a gas phase including oxygen, and at least a part of the second electric conductor contacts a treatment target. A purification device includes the purification unit, and a treatment tank for holding, in an inside, the purification unit and wastewater to be purified by the purification unit. The purification unit is installed so at least a part of the first electric conductor contacts the gas phase, and at least a part of the second electric conductor contacts the wastewater.

A purification unit includes a first electric conductor and a second electric conductor that contacts the first electric conductor. The first electric conductor includes a junction composed of a contact surface with the second electric conductor and an electronic connection section that conducts electrons from the junction to a catalyst. The second electric conductor includes a junction composed of a contact surface with the first electric conductor and an electronic connection section that conducts electrons, which moves from microorganisms to the second electric conductor, to the junction. The electronic connection section of the first electric conductor has higher electrical resistivity than the junction of the first electric conductor, and/or the electronic connection section of the second electric conductor has higher electrical resistivity than the junction of the second electric conductor. The first electric conductor contacts a gas phase including oxygen, and the second electric conductor contacts a treatment target.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

Disclosed are modular microbial fuel cell (MFC) devices, systems and methods for treating wastewater and generating electrical energy through a bioelectrochemical waste-to-energy conversion process. In some aspects, a modular MFC system includes a wastewater pretreatment system to receive and pre-treat raw wastewater for feeding pre-treated wastewater for bioelectrochemical processing; one or more modular MFC devices to bioelectrochemically process the pre-treated wastewater by concurrently generating electrical energy and digesting organic contaminants and particulates in the wastewater to yield treated, cleaner water; and a water collection module to receive the treated water from the one or more modular MFC devices and store the treated water and/or route the treated water from the system.

The present invention provides a strong polymer electrolyte membrane which can provide a water electrolyzer operable at low electrolysis voltage. The polymer electrolyte membrane of the present invention comprises a fluorinated polymer and a woven fabric, wherein the weight of the woven fabric is from 20 to 95 g/m.sup.2, and the warp and weft of the woven fabric independently have a denier of from 30 to 100.

Provided is a microbial fuel cell including a cathode and an anode, wherein the cathode includes a waterproof gas diffusion layer including a siloxane and a catalyst layer including a binder, wherein a surface of the gas diffusion layer opposite the catalyst layer contacts air, and the anode includes electrogenic bacteria. Also provided is a method for making a microbial fuel cell, including fabricating a cathode, wherein fabricating includes disposing a siloxane solution onto a surface of a substrate, wherein the siloxane solution includes a siloxane and a solvent, drying the siloxane solution to form a waterproof gas diffusion layer, and placing the gas diffusion layer on a catalyst layer including a binder, and facing an anode with the cathode whereby the gas diffusion layer faces away from the anode and contacts air.