A microbial fuel cell system includes a supply-drain compartment having a supply port and a drain port of an electrolytic solution. The microbial fuel cell system further includes one or more power generation cassettes provided in the supply-drain compartment and each including a microbial fuel cell including: a positive electrode including a first water-repellent layer in contact with a gas phase and a gas diffusion layer attached to the first water-repellent layer; and a negative electrode holding anaerobic microorganisms. The microbial fuel cell system includes one or more purifying cassettes provided in the supply-drain compartment and each including a second water-repellent layer in contact with the gas phase. The power generation cassettes are arranged on the upstream side in a direction in which the electrolytic solution flows from the supply port toward the drain port, and the purifying cassettes are arranged on the downstream side of the power generation cassettes.

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.

A plate structure, such as a plate electrode, comprising two outer layers and an intermediate layer. Both outer layers are provided with a pattern of recesses, such as hexagonal or circular recesses. The recesses on one outer layer are offset with respect to the recesses in the other outer layer. The intermediate layer comprises through-holes, each through-hole connecting a recess at one outer layer with a partially overlapping recess at the opposite outer layer.

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.

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.

A water-processing electrochemical reactor that comprises a cylindrical inner anode (73), an outer tubular cathode (74), an intermediate chamber between the anode (73) and the cathode (74) and being crossed by the water, an outer shell (77) surrounding the cathode (74), a water inlet (71) and a water outlet (78), and a gas inlet (80) and gas outlet (79) connected to the outer shell (77) and to the gas chamber. The cathode surrounds the inner anode (73) and is porous to gas. A gas chamber is defined between the cathode (74) and the outer shell (77). The gas chamber contains a gas comprising oxygen and is at an overpressure that forces the gas through the porous cathode (74).

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.

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.

A method produces hydrogen peroxide in an aqueous solution by electrochemical reduction of oxygen. An oxygen containing gas is supplied to an electrochemically active side of a cathode contained in a cathodic compartment. The cathode contains a porous gas diffusion electrode, one side of which contains a carbon based electrochemically active layer capable of catalyzing the reduction of oxygen to hydrogen peroxide. The cathodic compartment is in fluid communication with an anodic compartment. At least one at least partly water soluble, weak protonic electrolyte is supplied to a catholyte. The weak protonic electrolyte has a pKa which is at least one unit higher than the pH of the catholyte at the onset of the oxygen reduction reaction to hydrogen peroxide. The catholyte is not pH buffered and the pH of the catholyte is let to evolve in course of the reaction.