A method of removing chemical contaminants from a composition comprising an active, a solvent, and a contaminant can include providing an initial feed supply, wherein the initial feed supply comprises the active, the solvent, and the contaminant, wherein the contaminant can include 1,4 dioxane, dimethyl dioxane, or a combination thereof; including filtering the initial feed stock through a nanofilter.

A method for controlling water purification, and a water purification apparatus (1). The apparatus (1) comprises a reverse osmosis membrane (3a) configured to receive feed water from a feed pump (5), and to produce permeate water and reject water. The method comprises measuring (S1) a property indicative of an inlet water quality C.sub.inlet of inlet water to the feed pump (5), and determining (S2) a target recovery for the water purification based on the property indicative of the inlet water quality. The method further comprises controlling (S3) a feed pump speed to a predetermined speed, or to a speed determined based on a relation between the feed pump speed, the inlet water quality C.sub.inlet and a target permeate water quality C.sub.per, based on the inlet water quality. The method comprises measuring (S4) a property indicative of a product water flow rate Q.sub.prod, wherein the product water is permeate water that is delivered for consumption, recirculating (S5) a first portion of the reject water, and controlling (S6) a drain flow rate Q.sub.drain to drain, from a second portion of the reject water, to accomplish the target recovery based on the product water flow rate Q.sub.prod.

A process including converting, in one or more cross-flow filtration separation units, a slurry catalyst containing solid particles and a petroleum-based oil liquid carrier to a slurry catalyst comprising solid particles and a renewable-based liquid carrier. The slurry catalyst containing solid particles and the renewable-based liquid carrier includes less than about 5 wt. % of the petroleum-based oil liquid carrier.

The present disclosure relates to a carbon dioxide capture apparatus and process combined with biogas upgrading, and there is provided the carbon dioxide capture apparatus combined with biogas upgrading for simultaneously obtaining high purity methane and carbon dioxide, and improving separation efficiency without an additional process by making use of gas streams after a liquefaction process, and recovering cold heat in the process.

A method for separating and recovering carbon dioxide from ambient air includes continuously bringing ambient air into contact with a basic aqueous solution; electrodialysis of the solution using bipolar and anion-selective ion exchange membranes as well as recycling the depleted solution; separating CO.sub.2 from the enriched solution and recycling the solution depleted of CO.sub.2. The absorption is performed in an absorber, open basin, or a combination thereof. Separation is achieved by thermal desorption of CO.sub.2 by steam stripping to obtain a carbon dioxide/steam mixture; and/or by chemical reaction of the (hydrogen-) carbonate ions, in which the CO.sub.2 contained is converted into a water-insoluble salt or a gas and simultaneously removed from the solution. The pH of either obtained solution is measured before the recycling or before the separation, and is adjusted to a predetermined value. pH is measured and adjusted based on how absorption and separation are performed.

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.

Processes and systems for recovering hydrogen include feeding a gas stream, comprising hydrogen and additional gases, to a pressure swing adsorption (PSA) system and feeding a membrane permeate stream comprising hydrogen to the PSA system. In the PSA system, a portion of the hydrogen is separated from the additional gases to recover a hydrogen product stream and a PSA tail gas stream comprising unseparated hydrogen and the additional gases. The PSA tail gas stream is fed to a membrane separation unit for separating hydrogen from the additional gases and to recover (i) the membrane permeate stream comprising hydrogen fed to the PSA system and (ii) a membrane tail gas stream comprising the additional gases. Processes and systems herein may additionally include a refrigeration system for partially condensing one or both of the feed gas stream and the PSA tail gas stream, enhancing the efficiency of the membrane separation unit.

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.

The present disclosure relates to a water purification apparatus that comprises a reverse osmosis device, RO-device, producing a purified water flow and to a corresponding method. The proposed method comprises detecting at least one fluid property of purified water in the purified water path and regulating a flow rate of water in the recirculation path to fulfil one or more predetermined criteria of the purified water in the purified water path, based on the at least one detected fluid property. The present disclosure also relates to a computer program and a computer program product implementing the method.

A method for controlling water purification is disclosed. The method comprises measuring a property indicative of an inlet water quality of inlet water to a feed pump and determining a target recovery for the water purification based on the property. The method further comprises controlling a feed pump speed to a predetermined speed, or to a speed determined based on a relation between the feed pump speed, the inlet water quality, and a target permeate water quality, based on the inlet water quality. The method further comprises measuring a property indicative of a product water flow rate, where the product water is permeate water that is delivered for consumption. The method also comprises recirculating a first portion of the reject water and controlling a drain flow rate to drain, from a second portion of the reject water, to accomplish the target recovery based on the product water flow rate.