An apparatus (100) for producing an acidic aqueous solution includes: an electrodialyzer (110) that has a monovalent ion perm-selective ion-exchange membrane and separates wastewater containing chloride ions and alkali metal ions into electrodialysis concentrated water and electrodialysis diluted water by an electrodialysis treatment; an electrolyzer (120) includes an anode that that electrolyzes the electrodialysis concentrated water to produce an acidic aqueous solution; and a first circulator (13) that circulates at least some of the acidic aqueous solution to the wastewater supplied to the electrodialyzer (110), and that adjusts a pH of the wastewater supplied to the electrodialyzer to 3 to 9.

Method for treating impurities contained in exhaust gases of ships to reduce sulphur oxide and other emissions. In order for the method to purify wash water exiting from an exhaust gas scrubber sufficiently enough to be directly dischargeable to sea, and in order for a purification unit used to be small enough to be easily placed onboard a ship, exhaust gases are scrubbed in the exhaust gas scrubber and wash water containing impurities and exiting from the scrubber is supplied to the purification unit, circulated in an effluent circuit, and filtered through a semipermeable membrane of a filter to obtain purified effluent and a residue containing impurities, when necessary, the pH value of the purified effluent is adjusted to be at least 6.5, after which it is discharged into the sea or recycled to the scrubber while the residue containing impurities is led back to the effluent circuit.

The present invention is a filtration system and a method for cleaning a filtration system. The filtration system comprising a hydraulic circuit Cp recycling the permeate stream to the feed side of the membrane and/or a hydraulic circuit Cr recycling the retentate stream to the feed side of said membrane. The method injects an amount of a chemical product into the filtration system in the hydraulic circuit Cp or in the hydraulic circuit Cr or upstream of the cross-flow filtration membrane, setting the proportion of recycled permeate stream or recycled retentate stream collected in the hydraulic circuit Cp and/or Cr to enable the recycling of a significant amount of unreacted chemical product having passed through the cross-flow filtration membrane to the feed side of said cross-flow filtration membrane.

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 invention relates to the process for molecular separation of hydrocarbons using nanopore membrane comprising passing the hydrocarbon feedstock with or without separation enhancing additive/additives to produce permeate streams having different refractive indices which resonate with that of naphtha, kerosene and heavier molecules.

A wastewater treatment system is provided for improving the efficiency of existing wastewater treatment plants. In accordance with aspects and embodiments, a wastewater system having a source of wastewater, an effluent, a sludge, a first basin configured to receive the wastewater, and a second basin, in fluid communication with the first basin and configured to receive sludge, may be retrofitted with a closed loop working fluid system. A first membrane system may be arranged in the first basin and a second membrane system may be arranged in the second basin, and a working fluid containing a concentration of at least one solute may be pumped through the first and second membrane systems in a closed loop to enhance overall plant efficiency.

A high recovery variable volume reverse osmosis system where the volume of concentrate cycled through the RO system is reduced in response to recovery levels increasing. By reducing the volume of concentrate cycled through the RO system, this reduces the cycle time of highly saturated concentrate passing through the RO system. Reducing the cycle time of concentrate passing through the RO system tends to minimize or reduce membrane scaling.

Methods for processing pretreated phosphogypsum wastewater are disclosed. Precipitation of select constituents may be promoted to control a hardness level of the pretreated wastewater. Ammonia may then be removed from the process stream via reverse osmosis. A membrane contactor and/or polishing unit(s) may optionally be used. Related systems are also disclosed.

The present teaching relates to method, system, medium, and implementations for storage management. A hash table is constructed, having an index file having one or more slots, each of which includes one or more buckets. Each bucket stores one or more types of records, including a direct record, an indirect record, and a forwarding record. A direct record stores data directly in a bucket of a slot of the index file. When a storage request is received related to some relevant data, the request is handled based on the constructed hash table.

A method, system and composition is described for treating waste generated from manufacturing operations including at least one of Printed Circuit Boards Fabrication (PCB FAB), General Metal Finishing (GMF), semiconductors manufacturing, chemical milling, and Physical Vapour Deposition (PVD). The method, system and composition are used to create zero liquid discharge recycling.