A gas diffusion electrode includes a carbon fiber tube, a support layer, and a catalyst layer. The carbon fiber tube is straight and functions as a substrate. The support layer includes a carbon black-polytetrafluoroethylene (PTFE) coating, and is disposed on the substrate. The catalyst layer includes carbon black, anhydrous ethanol, and PTFE, and is disposed on the support layer. The gas diffusion electrode has a diameter of 3-20 mm and a length of 50-500 mm.

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.

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.

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.

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.

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.

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.

An apparatus (100) for producing an acidic aqueous solution includes: an electrodialyzer (110) that has a monovalent ion perm-selective ion-exchange membrane and separates wastewater containing chloride ions and alkali metal ions into electrodialysis concentrated water and electrodialysis diluted water by an electrodialysis treatment; an electrolyzer (120) includes an anode that that electrolyzes the electrodialysis concentrated water to produce an acidic aqueous solution; and a first circulator (13) that circulates at least some of the acidic aqueous solution to the wastewater supplied to the electrodialyzer (110), and that adjusts a pH of the wastewater supplied to the electrodialyzer to 3 to 9.

A three-dimensional electrode-ozone oxidation-electrocatalytic membrane coupled wastewater treatment device, including a circulating fluidized bed reactor. The circulating fluidized bed reactor includes a funnel-shaped internal, a truncated cone, a fiber ball filter, a gas-liquid distribution plate, an inner cylinder, an intermediate cylinder and an outer cylinder. The inner cylinder, the intermediate cylinder and the outer cylinder are coaxial. The inner cylinder is an electrocatalytic membrane assembly; the intermediate cylinder is a gas diffusion electrode; and the outer cylinder is a stainless-steel mesh. A particle electrode is filled between the intermediate cylinder and the outer cylinder, and between the intermediate cylinder and the inner cylinder. The intermediate cylinder is connected to a negative electrode. The inner cylinder and the outer cylinder are connected to a positive electrode. A wastewater treatment method using the device is also provided herein.

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.