A process for treating sour water includes combining the sour water with an alkali or alkaline metal hydroxide to produce a sour water mixture, the sour water comprising sulfides, passing an electric current through the sour water mixture, where passing the electric current through the sour water mixture causes at least a portion of the sulfides to react to produce a treated sour water comprising sulfates and having a pH of 7.1 to 9.8, saturating the at least a portion of the sulfates in an aqueous sulfate solution, and separating at least a portion of saturated sulfates from a saturated aqueous sulfate solution.

An integrated, membrane-based process to produce purified water and conversion of salt to high value chemicals from oil and gas well produced water is described. A liquid stream including water and dissolved salt is flowed through pretreatment units and one or more desalination and concentration units which remove at least a portion of the water to form a brine enriched in dissolved salt. The purified high-density brine may be subjected to electrically-enforced salt dissociation techniques to produce chemicals from oil and gas produced water.

A system and method for producing high quality potable water by re-mineralization of desalinated water is provided. The retentate rejected from a nanofiltration unit becomes a source of mineral-rich divalent ions for mixing with the desalinated water being produced by a desalination unit, thereby reducing or eliminating the need for separate supply from outside sources of chemicals needed to obtain potable water that meets various drinking water standards. The nanofiltration unit may be located in a desalination upstream and/or downstream of the desalination unit, and the amount of flow of the nanofiltration retentate supplied to the re-mineralization unit relative to the amount of desalinated water flow may be adjusted to achieve the desired potable water quality.

Embodiments of the present disclosure provide for systems for removing contaminants from a leachate, methods of removing contaminants from a leachate, and the like.

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.

Lithium brine is treated with a multiple pass nanofiltration (NF) membrane system. Sulfate is added to permeate from an upstream pass before it flows through a downstream pass. Optionally the sulfate may be added to the permeate by dosing it with sulfuric acid or a slat such as sodium sulfate. The softened brine may then be processed further, for example by a combination of solvent extraction, electrolysis, crystallization and drying, to produce a lithium hydroxide product that can be used to make batteries.

A filtration apparatus includes a tubular casing having a longitudinal axis and first and second casing ends. A plurality of partition plates are positioned in the casing and sealed thereto to thereby define an intake collection chamber between a first of the partition plates and the first casing end, a discharge collection chamber between a second of the partition plates and the second casing end, and a reject collection chamber opposite the second partition plate from the second casing end. A plurality of elongated filtration membrane stacks are positioned side-by-side in the casing generally parallel to the longitudinal axis. Each filtration membrane stack includes an intake end which is fluidly connected to the intake collection chamber, a discharge end which is fluidly connected to the reject collection chamber, and a permeate channel which extends between the first and second ends and is fluidly connected to the discharge collection chamber.

This specification describes a method for lowering the content of monovalent ions in a final concentrate of a nanofiltration system relative to a brine and a corresponding nanofiltration system. The nanofiltration system comprises at least three stages of nanofiltration, wherein the concentrate from each segment flows into the next segment. A feed stream is sent into one stage to generate a concentrate stream, and a first portion of the concentrate stream is recirculated to the one stage. The pH of the feed stream is controlled in a range of 2-7. The temperature of the feed stream is in a range of 20-60 C. The feed stream includes the recirculated concentrate stream and at least part of a concentrate generated from an upstream stage. The method and the system described herein can reduce the concentration of monovalent ions in the final concentrate during a nanofiltration separation process.

The invention relates to pre-treating an oil derived from a renewable feedstock to remove at least a portion of one or more contaminants by filtering the oil with a nanofiltration membrane. The resulting permeate oil has a reduced concentration of the contaminant relative to the feed stream to the nanofiltration membrane.

A novel reverse osmosis or nanofiltration system (RO/NF) capable of detecting and responding to onset of fouling within the system utilizing uniquely configured membrane permeate flow path within the system which generates a time-sensitive data. Membrane performance data in real-time operating conditions is then utilized for rapid detection of membrane fouling, fouling rate, and cause of fouling, followed by controller-based system generated actions to stop, and recover from fouling or slow-down fouling, and, if required, to predict, plan, and schedule operator intervention steps to recover optimum system operating conditions. The end-result is a novel energy-efficient and fouling-managed advanced (machine learning) reverse osmosis system for brackish water desalination.