A system includes a first fluid inlet and a single reverse osmosis membrane module having a permeate outlet and a first inlet/outlet channel and a second fluid inlet/outlet channel in fluid communication with the first fluid inlet. An energy transfer system has a second fluid inlet, a brine outlet, a first energy exchanging module and a second energy exchanging module. The first and second energy exchanging modules are adapted to reversibly operate in opposite flow phases where a flow direction for the expulsion flow phase in each energy exchanging module is constant and where a flow direction for the energy recover flow phase in each energy exchanging module is constant. The single reverse osmosis membrane module is adapted to reversibly receive a feed flow through one of the first and second fluid inlet/outlet channels and produce a brine outflow through the other of the first and second inlet/outlet channels.

A liquid purification system includes a system raw liquid feed unit and a filtration unit, which includes a liquid concentration device having an internal partition dividing a variable volume collection cavity for raw liquid coming from an initial stage of liquid filtration and for mixing therein concentrate and a raw liquid displacement cavity. The cavity is connected to a secondary line that supplies raw liquid to the cavity to displace concentrate from the collection cavity and to recycle raw liquid from the displacement cavity through the secondary line under pressure exerted by concentrate and raw liquid in the collection cavity. A filtration unit provides long-term contact between raw liquid and concentrate in the variable-volume collection cavity to provide smooth increase in the concentration of liquid supplied to a liquid purification device.

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.

A reverse osmosis system includes a membrane unit, an energy recovery device, high and low pressure inlet lines, and a concentrate line. The membrane unit has a membrane, an inlet for receiving a feed fluid, a permeate outlet for discharging a permeate fluid and a concentrate outlet for discharging a concentrate fluid. The energy recovering device has a turbine portion, a turbine inlet and a turbine outlet, a pump portion, a pump inlet and a pump outlet, a motor, and a motor control unit for controlling the motor. The low pressure inlet line is connected to the pump inlet for supplying the feed fluid at a low pressure. The high pressure inlet line connects the pump outlet with the inlet for supplying the feed fluid at a high pressure. The concentrate line connects the concentrate outlet with the turbine inlet for supplying the concentrate fluid to the turbine portion.

The invention relates to bio-electrochemical systems for the generation of methane from organic material and for reducing chemical oxygen demand and nitrogenous waste through denitrification. The invention further relates to an electrode for use in, and a system for, the adaptive control of bio-electrochemical systems as well as a fuel cell.

A new and innovative power and treated water co-generation system is provided that includes a modified Kalina cycle and a forward osmosis (FO) membrane. The Kalina cycle of the provided system is used for power production, whereas the system's FO process is used for water production. The provided system modifies a typical Kalina cycle to include a more efficient and relatively low-temperature heat source, while still utilizing the same working fluid, which is ammonia-water. The draw solution for the provided system's FO process is also ammonia-water, which is known and efficient for desalination and wastewater treatment. In some aspects, the working fluid of the system may be a specific ammonia-water composition including between 30-95% ammonia. The presently disclosed system combines the Kalina process and the FO process into an improved and innovative heat integration system to minimize energy requirements and enable operation at both small and large scales.

An emitter apparatus is mounted on a marine structure powered by wind or marine hydrokinetic energy to disperse a carbon dioxide sorbent such as sodium hydroxide. The sorbent can be generated by reverse osmosis of seawater with electrolysis of the brine, or delivered from an external supply. Suitable marine structures include offshore wind turbines, marine hydrokinetic generators, offshore oil platforms, merchant vessels, and other fixed and mobile structures. Effective capture is made by dispersing a fine mist or fog of aqueous sorbent from nozzles with a particle size from a nozzle of less than 100 microns. The sorbent reacts with atmospheric carbon dioxide forming carbonates and bicarbonates, which drift and fall to the ocean surface, reducing surface acidity and capturing additional atmospheric carbon dioxide via absorption at the local ocean surface. The resulting carbonates sink to the ocean floor and are there sequestered.

Methods are described for treating aqueous solutions, including wastewater, to remove nitrogen-containing compounds using electrochemical processes. The method may be conducted electrolytically under an applied voltage or using endogenous current in a fuel cell arrangement. In some embodiments, energy is reclaimed in the form of hydrogen, methane, and other hydrocarbons or organic molecules. Microorganisms may be used as the catalyst for oxidation of the nitrogen-containing compound and/or reduction of hydrogen ions, carbon dioxide, or bicarbonate. Anaerobic or low-oxygen conditions may be used in the zone.

A method for quickly converting organic waste into energy, including the following steps of S1, performing anaerobic fermentation on organic waste to convert macromolecular organic matter in the organic waste into soluble small molecular organic matter to obtain fermentation liquid; S2, performing solid-liquid separation on the fermentation liquid to obtain a solid-phase part and a liquid-phase part, respectively; and S3, disposing or reusing the solid-phase part as residues, and enabling the liquid-phase part to enter a flow-catalyzed fuel cell to convert organic matter in the liquid-phase part into electrical energy. The present application can quickly and efficiently convert the organic waste into electrical energy.

An ion exchange system includes an ion exchange column filled with ion exchange media and a passive cooling system. The passive cooling system includes a working fluid that transfers heat away from the ion exchange column. In one embodiment, the working fluid is in a closed system. In another embodiment, the passive cooling system includes a heat pipe. In yet another embodiment, the ion exchange system is used to separate radionuclides, such as Cs-137 from a liquid waste stream.