A polyamide (PA) nanofiltration (NF) membrane and a preparation method thereof by regeneration from a scrapped microfiltration (MF) membrane are provided. The method adopts a cleaning-repairing-interfacial polymerization upgrading strategy, where, sodium hypochlorite and oxalic acid are used for deeply cleaning a scrapped MF membrane. PDA is used as a repairing agent to construct a reaction platform on the membrane surface, and finally a reaction system of piperazine and trimesoyl chloride (TMC) are used to form a PA NF membrane with a PA active layer. The repairing can construct a coating with a given thickness and prominent hydrophilicity on the membrane surface, which provides favorable base membrane conditions for upgrading and preparing an NF membrane.

A solvent extraction process for desalination of seawater. The process uses a special class of polar organic solvents to preferentially dissolve salt-free water from salty water, which exhibits a reverse solubility-temperature behavior (i.e., the solubility of water in the solvent is high at room temperature but significantly lower at higher temperatures). The desalination process includes adding these special class of solvents to sea or salty water at room temperature, separating the solvent-water phase (organic phase) from the remaining mass of salt-rich water (aqueous phase), heating the solvent-water phase to a higher temperature and recovering the relatively salt-free water that separates out. The process is simple, fast, ecologically safe and energy efficient.

A method and device for removing chloride ions in desulfurized wastewater by electrochemical coupling in which the device comprises: an electrolyte tank having a top and a bottom wherein the tank is used as a separator in a separation process and as an electrode regenerator in an electrode regeneration process; two electrodes comprising a hydrogen evolution electrocatalysis function electrode and an electrochemically switched ion exchange (ESIX) function electrode respectively, wherein the electrodes are connected with each other by a wire; two DC circuits having opposite electric field directions and used alternately in the separation process and the electrode regeneration process respectively; the bottom of the electrolyte tank is provided with a purified high-concentration chloride ion wastewater inlet and a flocculation product outlet; the top of the tank is provided with a dechlorination treatment water outlet and a hydrogen collecting port; and, in the electrode regeneration process, the electrolyte tank is connected to an electrode regeneration liquid storage tank through a pump and a pipeline.

A filter assembly and method of filtering wastewater from a washing machine. The filter has a framework for supporting a first filter stage and a second filter stage, a connection on a top of the filter assembly for connecting to a wastewater stream, a diffuser positioned to extend into the first filter stage and configured to rotate about a vertical axis of installation within the first filter stage, and a second filter stage below the first filter stage and configured to receive overflow from the first filter stage. The filter assembly does not include a motor or motorized parts and wherein the diffuser is rotatable by way of the force of the wastewater stream fed into the first filter stage to diffuse the wastewater stream and to spray the wastewater onto and through the filter media allowing the filter media to catch debris within the first filter stage.

Purification devices and methods remove perfluorinated compounds (PFCs) from PFC-contaminated water using temperature swing adsorption and desorption.

A liquid cleaning and watering system for living plants rests on a surface covered by a non-porous material. A plate layer covering the non-porous layer has two or more layers, each layer having runners arranged in a grid. The grid of each successive layer is offset at an angle with respect to the grid of a previous layer. An upper layer covers the plate layer and has a plurality of holes for the passage of liquids into the liquid cleaning system. As the living plants are watered or cleaned, excess liquids containing water and oils that were excreted by the living plants enter the liquid cleaning system through the holes, the liquid traverses the grid layers, flowing towards a drain. Contaminants within the liquid collect within the grid of the layers of the plate layer for later disposal.

A system for membrane fouling control configured to run one or more filter cycles, wherein each filter cycle of the one or more filter cycles includes an operation mode and a cleaning mode. The system includes: a first conduct portion; a second conduct portion; a membrane arranged between the first conduct portion and the second conduct portion. The membrane is configured in the operation mode to filter a liquid to be filtered by conducting it from the first conduct portion to the second conduct portion. A fouling control means filled with fouling control particles is added in the operation mode in the first conduct portion so that a dynamic protective layer is formed on the membrane. The fouling control particles are mineral particles based on calcium and/or magnesium.

The invention relates to a system for reducing the hardness of a water body. According to the system, the acidic water body near a filter element anode is continuously extracted in the electrolytic process, the effect of acid-alkali separation can be achieved without internally disposing an ion exchange membrane, acid-alkali mixing generated by electrodes slows down, the alkaline atmosphere of a cathode chamber is kept, and a good environment is provided for generation of calcium carbonate seed crystals; and meanwhile, the acidic water body extracted near the anode of an electrochemical electrolysis unit can be used for regenerating ion exchange resin in an ion exchange column, so that resources are fully utilized.

Methods and systems for the extraction of metals from an aqueous feed solution containing the metal ions. The aqueous feed solution is contacted with one side of a hydrophilic membrane support while an organic liquid is contacted with an opposite side of the hydrophilic membrane support. Metal ions migrate from the aqueous feed solution through the membrane support and into the organic liquid. The metal ions may be re-extracted from the organic liquid using a strip solution. The steps of extraction and reextraction may be carried out in a system including two hollow fiber membrane modules that each include a plurality of hydrophilic polymer hollow fibers.

This disclosure relates to new filtration systems, granular substrates, granular media and processes that are highly effective for removing suspended oil, particulates and oily particulates from an oil-water mixture. The new filtration media comprises a microporous granular substrate having a combination of specified micro-porosity, hardness and additional characteristics, the substrate being modified by an infused or coated absorption composition. This resulting filtration media displays excellent filtration performance, including outstanding durability and robustness to sustain its excellent performance over a large number of backwash cycles.