A water purification cartridge, and water permeate tubes and end caps for use therewith, are provided. An exemplary water purification cartridge has a central core with at least a first pair of permeate water tubes disposed about a central channel and a membrane assembly wrapped around and covering the central core. The membrane assembly includes at least a first membrane structure wrapped around a first permeate water tube, thereby creating a first permeate water tube assembly, and a second membrane structure wrapped around a second permeate water tube, thereby creating a second permeate water tube assembly. The first and second membrane structures are different. In another embodiment, a water purification cartridge comprises a central core with at least a first pair of permeate water tubes and a membrane assembly wrapped around and covering the central core, with each of the permeate water tubes having a generally tear-drop cross-sectional shape.

A method of operating a dual reverse osmosis/pressure retarded osmosis plant, including when electricity costs less than a first predetermined price, moderate salinity water is pumped into the first portion of a pressure vessel having first and second portions separated by a water permeable/salt impermeable osmotic membrane to yield desalinated permeate in the second portion and brine in the first portion. Further, when electricity costs greater than the first predetermined price, low salinity water is pumped into the second portion and brine is pumped into the first portion to yield pressurized moderate salinity water in the second portion which is run through an energy recovery device to generate electricity. The salinity of the low salinity water is lower than the salinity of the moderate salinity water, and the salinity of the moderate salinity water is lower than the salinity of the brine.

Described are porous, sintered metal bodies that include multiple layers made from different metal particles and that may be useful as porous filter membranes, as well as methods of making and using the porous, sintered metal bodies.

The present invention refers to a process for the purification of levulinic acid, an aqueous solution comprising levulinic acid and a process for the production of levulinic acid.

The present invention refers to a process for the purification of levulinic acid, an aqueous solution comprising levulinic acid and a process for the production of levulinic acid.

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 process for reducing injector deposits in an internal combustion engine fuelled with a fuel composition, the process comprising contacting a fuel composition with a metal-selective membrane situated in the fuel delivery system. The reduction of such deposits provides an increase in fuel efficiency, fuel thermal stability, boost in engine cleanliness, improves fuel economy and enables the possibility of using a reduced amount of expensive detergent in the fuel composition.

A process for producing a liquid coffee concentrate that has a reduced acrylamide content. The process involves contacting a low aromatic aqueous coffee extract with a selectively-permeable membrane to reduce the acrylamide content of the extract, prior to combining the treated extract with a high aromatic aqueous coffee extract. In particular, the process comprises the steps of: a) providing a low aromatic aqueous coffee extract having a first acrylamide content; b) providing a high aromatic aqueous coffee extract; c) contacting the low aromatic aqueous coffee extract with a selectively-permeable membrane to provide a low aromatic aqueous coffee extract having a second acrylamide content; and d) combining the low aromatic aqueous coffee extract having a second acrylamide content and the high aromatic aqueous coffee extract to provide a liquid coffee concentrate, wherein the second acrylamide content is lower than the first acrylamide content.

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.

Methods and systems of lowering a concentration of divalent cations in lithium-containing brines are described. A method includes diluting saturated salar brine such that sodium chloride concentration is at most about 80% of saturation. The method also includes feeding the diluted salar brine to a high pressure nanofiltration system operating at pressure above about 60 bar effective to form a permeate and a concentrate. The method also includes collecting the permeate having a lower concentration of divalent cations relative to the saturated salar brine.