A water-softening system includes a filter device including filter units that are provided in at least some of a plurality of supply channels arranged in parallel to supply raw water to a consumption site and that remove at least part of ionic matter contained in supplied raw water by electro-deionization and discharge soft water containing less ionic matter than the raw water, a plurality of supply valves provided in the plurality of supply channels to open or close the supply channels, and a processor connected to the filter device and the plurality of supply valves. The processor determines whether water is supplied to the consumption site and controls at least one of the plurality of supply valves to remain open to maintain a state in which water is allowed to be supplied to the consumption site, when it is determined that no water is supplied to the consumption site.

Systems and methods for treating produced water and/or flowback water from fracking operations include: an oil water separator; a first filter downstream of the oil water separator; and an electrocoagulation unit downstream of the first filter. Systems and methods can be used for producing a concentrated brine for use in industrial applications and a separate stream of fresh water

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 water savings system and method for reducing the amount of water needed for adiabatic cooling including the use of a softener and a reverse osmosis device, in which tap water, softened if necessary, is delivered to a reverse osmosis device and softened water alone, reverse osmosis reject water, or softened water combined with reverse osmosis reject water is delivered to spray nozzles for cooling, and reverse osmosis pure water is stored and used periodically to flush the coils to inhibit and/or prevent corrosion from dissolved salts and other solids in the spray water.

Methods and systems are provided herein for treating wastewater, such as wastewater from oil and natural gas production. Distilled water may be treated with bacteria and other micro-organisms to remove nitrogen compounds from the distilled water. The distilled water may be produced from pretreating and distilling wastewater. The treatment steps of the distilled water include subjecting the water to microbial action under both anoxic and aerobic conditions and employing a membrane bioreactor to further purify the water. The purified water is still further purified by either reverse osmosis or ion exchange systems.

A wastewater recycling system includes a biological reactor having anaerobic, anoxic, and aerobic chambers. A lift station including a pump is operatively connected to the biological reactor. The lift station receives biologically treated liquid from the biological reactor and pumps the liquid from the lift station. A filtration subsystem is operatively connected to the lift station. The filtration subsystem receives and filters the liquid pumped by the lift station. The filtration subsystem includes a salt-rejecting membrane filter comprising a concentrate recirculation conduit operatively connected to recirculate salt-rejecting membrane filter concentrate to a point along the wastewater recycling system upstream of the salt-rejecting membrane filter, thereby forming a salt concentration loop between said point along the wastewater recycling system and the salt-rejecting membrane filter. A post-filtration subsystem is operatively connected to receive salt-rejecting membrane filter permeate, and comprises a water disinfection system that disinfects the permeate thereby generating potable water.

A purification device for water has a housing with a longitudinal axis, an upper and a lower end and a substantially round cross section. The device includes a first receptacle, arranged parallel to the longitudinal axis of the housing, for a first purification medium, and a second receptacle, which is also arranged parallel to the longitudinal axis of the housing, for a second purification medium. The receptacle for the second purification medium is arranged eccentrically with respect to the longitudinal axis of the housing.

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 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.

Methods of treating a fluid mixture include performing a first treatment on the mixture with electrochemically produced ions to separate an aqueous phase and a hydrophobic phase and performing a second electrochemical treatment on the separated aqueous phase to thereby remove aqueous contaminants from the aqueous phase wherein substantially laminar flow of fluid occurs between electrodes in the second electrochemical treatment.