A serial filtration system for liquid purification includes a preliminary-stage reverse-osmosis (RO) module and a first-stage, high-permeability, reverse-osmosis (HiRO) module. Both modules include (a) a chamber including an inlet, a retentate outlet, and a permeate outlet, and (b) at least one membrane separating the chamber into a retentate side on an upstream side of the membrane and a permeate side on a downstream side of the membrane. The membrane in the preliminary stage is an RO membrane, while the membrane in the first stage is an oxidized membrane. The first-stage inlet is in fluid communication with the preliminary-stage, retentate outlet; and the oxidized membrane in the first stage, comprises an oxidized polyamide active layer coated on a porous support, wherein the oxidized polyamide active layer has an atomic oxygen/nitrogen ratio of at least 1.5.

A purification system is for purifying a mixture containing a first solvent, a second solvent, and an impurity. The purification system includes a first membrane separation device including a pervaporation membrane and a second membrane separation device including a filtration membrane. The pervaporation membrane separates the mixture into a first permeated fluid and a first concentrated fluid. The first permeated fluid has a lower concentration of the impurity than that in the mixture, and the first concentrated fluid has a higher concentration of the impurity than that in the mixture. The filtration membrane separates the first concentrated fluid into a second permeated fluid and a second concentrated fluid. The second permeated fluid has a lower concentration of the impurity than that in the first concentrated fluid, and the second concentrated fluid has a higher concentration of the impurity than that in the first concentrated fluid.

A water treatment system includes: EDI having deionization chamber that deionizes water that contains boron and concentration chambers in which concentrated water flows; and a cooler to cool the water supplied to deionization chamber or the concentrated water supplied to concentration chambers. Alternatively, water treatment system includes EDI having deionization chamber that deionizes water that contains boron, concentration chambers in which concentrated water flows, and electrode chambers in which electrode water flows; a cooler that adjusts temperature of the water or temperature of the concentrated water supplied to concentration chamber; and a controller that controls the cooler such that the cooler adjusts the temperature of the water supplied to deionization chamber or the temperature of the concentrated water supplied to the concentration chambers within a range of 10-23° C., based on the temperature of the water, temperature of treated water of EDI, the temperature of the concentrated water, or temperature of the electrode water.

Lithium recovery processes are described using concentration and conversion techniques. A vaporizer or membrane can be used to concentrate lithium and precipitate impurities. A conversion process can be used to replace anions in lithium bearing streams by adding a second anion and precipitating lithium in a salt with the second anion. Rotary separation can be used to separate the precipitated lithium salt.

A biogas upgrading system can include a multiple stage membrane system that is configured to remove oxygen so that the biogas is upgraded to have a higher concentration of methane, a pre-selected oxygen (O.sub.2) concentration (e.g. less than or equal to 0.2 mol %, etc.), and a pre-selected carbon dioxide (CO.sub.2) concentration (e.g. less than or equal to 5 mol %, etc.). The membrane system can be configured to reject O.sub.2 by utilizing a low CO.sub.2/O.sub.2 selectivity that is within a pre-determined range (e.g. less than 5 or less than 4.5). In some embodiments, the upgraded biogas that is output from the system can be entirely made up of methane, carbon dioxide, and oxygen. In other embodiments, the biogas can be almost entirely composed of these components along with a small amount of nitrogen and a trace amount (e.g. less than or equal to 0.2%-0.1%, etc.) of other components.

A liquid purification system with purified water mineralization, which uses predominantly water from various resources. The main problem of existing liquid purification systems, particularly membrane systems, is that during purification process not only dangerous debris (residual oil, pesticides, herbicides, heavy metals, bacteria, viruses, mechanical particles and other) are removed, but even minerals necessary for human (calcium, potassium, magnesium, sodium and other), so mineralization step is needed after purification step to normalize mineral composition. In the state of the art are known liquid purification systems with integral mineralization means and also devices for mineralization, which can be connected to liquid purification systems. The working principle of systems, known in the state of the art, is that purified liquid flows through the vessel with mineralization additive, which is partly dissolved, and the liquid becomes mineralized. The main drawback of the systems known in the state of the art is that due to peculiarities of the dissolving process and/or mineralization additive content it is impossible to control mineralization process, so the mineralization level is minor, and the pH is higher than the permitted value. Liquid purification system containing raw liquid line, liquid purification unit, mineralization unit, purified liquid line is characterized in that, mineralization of liquid is done by controlled dispensing of mineralization solution, obtained by selective raw or drainage liquids or their mixture.

An apparatus for producing ultrapure water: first ultrafiltration membrane that is connected to point of use and that supplies ultrapure water to point of use; first concentrated water return line that returns concentrated water of first ultrafiltration membrane to an upstream side of first ultrafiltration membrane; pressure gauge that measures pressure at an outlet of first ultrafiltration membrane; and means for adjusting flow rate of the concentrated water (first valve). Means for adjusting the flow rate of the concentrated water can be operated such that when the flow rate of the concentrated water is changed, a change in the pressure at the outlet of first ultrafiltration membrane that is measured by pressure gauge is kept within a predetermined range.

The present invention provides a process for removing catalyst fine particles from a hydrocarbon product, the process including providing at least one nanofiltration membrane to remove the catalyst fine particles from the hydrocarbon product, the catalyst fine particles comprising a particle size of 0.1 microns or less, contacting the hydrocarbon product at a feed side of the nanofiltration membrane, recovering a catalyst fines-depleted stream at a permeate side of the nanofiltration membrane, recovering a catalyst fines-enriched stream at a retentate side of the nanofiltration membrane, and wherein the catalyst fines-enriched stream comprises the catalyst fine particles removed from the hydrocarbon product, the catalyst fine particles comprising a particle size of 0.1 microns or less.

The invention provides an improvement in terms of control and process technology for a method of continuous removal of a component from a liquid mixture using a membrane unit comprising at least one membrane stage. The improvement is that a portion of the overall permeate stream is recycled to the feed vessel and/or beyond the feed vessel but upstream of the conveying device, and the remainder of the overall permeate stream is removed, with the recycled permeate having a higher concentration of the component to be separated off than the removed permeate. The presently disclosed method can especially be used for separation of a homogeneously dissolved catalyst from a liquid reaction mixture.

A system and method for reclaiming and treating groundwater collected from an underground level of a structure or building site to supply non-potable water to an end use system, such as an irrigation system, a pond, an equipment washing system, a cooling system, or a heating system. Groundwater seeps into such underground levels and has to be pumped out to prevent flooding the structure. Normally, this groundwater is discharged as a waste stream but can be treated for non-potable use using an three-stage treatment system comprising an ultrafiltration system, a water softener system, and a reverse osmosis system. The water softener system may be used or bypassed depending on acceptable TDS levels in the end use system and the TDS level of the reclaimed groundwater. Use of the system and method can save millions of gallons of groundwater per year per building site from being wasted.