A filtering device for obtaining a chemical liquid by purifying a liquid to be purified has an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path which includes the filter A and the filter B arranged in series between the inlet portion and the outlet portion and extends from the inlet portion to the outlet portion, in which the filter A has a porous base material made of polyfluorocarbon and a coating layer which is disposed to cover the porous base material and contains a first resin having a hydrophilic group.

A filtering device is used for obtaining a chemical liquid by purifying a liquid to be purified and includes an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path that includes the filter A and the filter B arranged in series and extends from the inlet portion to the outlet portion. The filter A has a porous membrane made of ultra-high-molecular-weight polyethylene and a resin layer disposed to cover at least a portion of the surface of the porous membrane, and the resin layer includes a resin having a neutral group or an ion exchange group.

A filtering device is for obtaining a chemical liquid by purifying a liquid to be purified, and has an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path which includes the filter A and the filter B arranged in series between the inlet portion and the outlet portion and extends from the inlet portion to the outlet portion, in which the filter A includes at least one kind of porous membrane selected from the group consisting of a first porous membrane having a porous base material made of polytetrafluoroethylene and a non-crosslinked coating which is formed to cover the porous base material and contains a perfluorosulfonic acid polymer and a second porous membrane containing polytetrafluoroethylene blended with a perfluorosulfonic acid polymer.

A filtering device is for obtaining a chemical liquid by purifying a liquid to be purified, and the filtering device has an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path which includes the filter A and the filter B arranged in series and extends from the inlet portion to the outlet portion, in which the filter A has a porous base material made of polyfluorocarbon and a coating layer which is disposed to cover the porous base material and contains a resin having an adsorptive group.

A water purification apparatus and method for optimizing efficiency of the water purification apparatus comprising a fluid circuit including a Reverse Osmosis, RO, unit (3), providing a permeate flow, and an electrically controlled deionization unit (4) downstream the RO unit (3) receiving at least part of the permeate flow. The method comprises obtaining (S1) a value indicative of power consumption by the electrically controlled deionization unit and determining (S2) whether the obtained value indicative of the power consumption meets at least one criterion. The method further comprises controlling recirculation of reject water produced by the water purification apparatus, based on a result of the determining (S2), in order to optimize efficiency of the water purification apparatus.

A reverse osmosis main plant which may receive non-potable water and discharge out permeate through a permeate out line and concentrate through a concentrate line is disclosed.

A method for treating produced water in a system for treating wastewater is disclosed. The system includes a reverse osmosis unit for removing dissolved solids. The reverse osmosis unit produces a permeate and concentrate. To reduce the fouling potential of the membranes associated with the reverse osmosis unit and/or to increase membrane lifetime and/or to increase system recovery, at least a portion of the concentrate is recycled and mixed with the wastewater stream at a point upstream of the reverse osmosis unit.

Methods and systems are described that produce an ultra-high gravity alcoholic beverage from a high gravity alcoholic beverage stream using an efficient, low waste, combination reverse osmosis and forward osmosis system. Utilizing a reverse osmosis system prior to using a forward osmosis system in removing water content from a high gravity alcoholic beverage stream significantly reduces a draw solution load when compared to a process that utilizes a forward osmosis system alone or prior to using any other dewatering system.

Provided is a novel Nanofiltration-DiaNanofiltration (NF-DiaNF) system and method for extracting divalent ions from saline water (e.g., seawater) to produce solutions rich in divalent ions (in particular Mg2+, Ca2+ and SO42), while minimizing the concentrations of undesirable species (e.g., Cl, Br, B and Na+). The solutions may be added to water (e.g., desalinated, soft, drinking or irrigation water) to enrich the water with divalent ions, thereby improving its quality.

The present inventions are directed to systems and methods to increase the removal of PFAS and other recalcitrant organic compound contaminants from water, and particularly ground and drinking water, using sub-micron powdered activated carbon.