A method of concentrating lithium containing solutions includes inputting a feed brine solution to an initial separation stage, the feed brine solution including lithium sulfate and one or more of sodium sulfate, potassium sulfate, calcium sulfate, and sodium chloride dissolved in water. In the initial separation stage, the feed brine solution is introduced to a pre-treatment membrane at a pressure that is less than the osmotic pressure of the feed brine solution. An initial permeate that passes through the pre-treatment membrane becomes the feed to a final separation stage, and an initial retentate that does not pass through the pre-treatment membrane includes a precipitate of at least one of the salts other than lithium sulfate. In the final separation stage, the initial permeate is introduced to a nanofiltration membrane at a pressure that is less than the osmotic pressure of the initial permeate. A final retentate that does not pass through the nanofiltration membrane is combined with the initial retentate to obtain a product solution having a higher concentration of dissolved lithium sulfate than the feed brine solution.

A system for treating a tetraalkylammonium hydroxide-containing liquid having a high-pressure type reverse osmosis membrane device concentrating a liquid to be treated containing tetraalkylammonium hydroxide at a concentration side, and a line for supplying the concentrated liquid to be treated by the reverse osmosis membrane device to an evaporator further concentrating the concentrated liquid to be treated.

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.

Liquid solution concentration methods and related systems involving osmosis units and energy recovery are generally described. In some embodiments, an osmotic system has a pump, a first reverse osmosis unit, a second reverse osmosis unit, and one or more energy recovery devices. Various embodiments are directed to features such as balancing streams, recirculation streams, and/or valving that alone or in combination may afford improved energy efficiency and/or system performance. Some embodiments may improve performance of certain types of energy recovery devices in combination with osmosis units, such as isobaric or turbine energy recovery devices.

A predictive system for monitoring fouling of membranes of a desalination or water softening plant includes ultrafiltration (UF) membranes, reverse osmosis (RO) membranes, and/or nanofiltration (NF) membranes. In addition, the system includes one or more UF skids including a plurality of UF units. Each UF unit contains therein a plurality of UF membranes. Further, the system includes one or more RO/NF skids including one or more RO/NF arrays. Each of the one or more RO/NF arrays includes a plurality of RO units, with each RO unit containing therein a plurality of RO membranes, a plurality of NF units, with each NF unit containing therein a plurality of NF membranes, or a combination thereof. Still further, the system includes UF sensors and/or RO/NF sensors. The system also includes a controller comprising a processor in signal communication with the UF sensors and/or the RO/NF sensors.

A process for purifying a urea-containing aqueous stream, such as the aqueous stream from the recovery section of a urea plant, comprising a step of removing biuret from the urea-containing stream by reverse osmosis in one or more reverse osmosis stages.

A reverse osmosis apparatus for a seawater desalination system is provided. The reverse osmosis apparatus includes: a barrel in which a plurality of reverse osmosis membrane units with a reverse osmosis membrane wrapped in each reverse osmosis membrane unit are arranged; an inflow and outflow portion provided at a first end of the barrel and connected to a seawater inlet a high salinity water outlet; a partition wall configured to partition an inner space of the inflow and outflow portion into a first stage and a second stage; and a transport space portion provided in a second end of the barrel and configured to guide water being moved from a plurality of reverse osmosis membrane units arranged in the first stage to move to a plurality of reverse osmosis membrane units arranged at the second stage, wherein part of seawater fed to the inflow and outflow portion is fed around the tubes in the barrel and insulates the plurality of reverse osmosis membrane units in the barrel from external high temperature while being moved, and flows into the transport space portion.

A reverse osmosis desalination system has a combined displacement pump and displacement pressure recovery motor that propagate feed water with a structurally fixed recovery rate and structurally stabilized volume flow through continuously alternating discharging and recirculation intervals. Thereby enabled is an instantaneous discharge of the entire feed water concentrate and unmixed replacement with low salinity source water that intermittingly and effectively flushes the reverse osmosis membranes. This in turn provides for high recirculation peak salinity and recovery rate that are simple and reliably controlled without impairing membrane longevity.

A filtration apparatus includes a tubular casing having a longitudinal axis and first and second casing ends, a plurality of partition plates positioned in the casing and sealed thereto to thereby define a plurality of axially successive chambers within the casing, including 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 intake and discharge ends and is fluidly connected to the discharge collection chamber, an end of the permeate channel located adjacent the intake end being sealed from the intake collection chamber. The filtration apparatus also includes an intake pipe having a first end fluidly connected to the intake collection chamber and a second end fluidly connected to a first connector located proximate the second casing end; a discharge pipe having a first end fluidly connected to the discharge collection chamber and a second end fluidly connected to a second connector located proximate the first connector; and a reject pipe having a first end fluidly connected to the reject collection chamber and a second end fluidly connected to a third connector located proximate the first and second connectors. Each filtration membrane stack includes a plurality of filtration membranes, and the plurality of filtration membrane stacks together define a plurality of axially successive sets of radially adjacent filtration membranes. Also, each filtration membrane of each of the sets of filtration membranes is sealed to a corresponding hole in a respective one of the partition plates.

Embodiments described herein relate to methods and systems for dewatering alcoholic solutions via forward osmosis, where the concentration of alcohol in the draw stream is equal to or greater than the concentration of the alcohol in the feed stream. As the feed stream is concentrated the alcohol is retained in the feed stream.