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 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 method comprising feeding MF feedstock to a cross-flow microfilter. The MF feedstock includes at least 5% protein solids and has a conductivity of less than 10 mS/cm.

Filter elements for perfusion systems and methods are provided. A filter element sheet includes a microporous membrane having a mean pore size of at least about 0.65 μm and a feed spacer comprising woven fibers and having an open area of at least about 35%. The filter element sheet can be arranged within a filter element, for example, in a spiral-wound format or in a cassette format. A perfusion system includes at least one filter element and a pump configured to control flow of a liquid feed through the at least one filter element.

A circulating water preparation system for cooling plants, a cooling system, in particular a recooling system, and a method for operating such a cooling system. In such a cooling system a surface of a heat exchanger is cooled by wetting with water, the water is collected in a collecting tank and returned by means of a water circuit for the renewed wetting of the surface of the heat exchanger. The method is characterised in that the water is purified by means of a filter, in particular a membrane filter. As a result considerably less biocide is needed to keep the water free of germs, in particular legionella, compared to conventional cooling systems or methods for operating such cooling systems.

The present invention relates to a method for concentrating, with low energy, a solute-containing solution in a state of multiple-no osmotic pressure difference (M(multiple)−Δπ=0 RO), and, more specifically, to a method for concentrating, with low energy, an solute-containing solution intended to be concentrated, as a low pressure in a state of multiple-no osmotic pressure difference. The method for concentrating a solution containing a solute at a low pressure in a state of multiple-no osmotic pressure difference, of the present invention, consumes less energy, enables concentration to be performed until a saturated aqueous solution with a maximum solute concentration is obtained or the concentration of the solute becomes 100% even though an extraction solvent is not used, and does not require the use of an additional osmosis-inducing solution.

Process for upgrading effluent treatment plants for pulp and paper production processes, where salts are removed from the effluent for water reuse and chemical recovery. The process comprises a first dialysis system for salt removal, a second treatment system for recovery or re-concentration, and optionally a post-treatment of the re-concentrate preventing liquid discharges to the environment. In the first system, a reversible electrodialysis or reversible pulsed step is carried out, separating the salts from the effluent, which are sent to the second treatment system to concentrate the salts (re-concentrate) or transform them into useful chemicals for the same process (recovery). Chemical recovery is achieved by electrodialysis with bipolar membranes or metathesis, to reduce the re-concentrate stream, which cannot be reused in the same plant. Lastly, this stream may be treated by spray drying, crystallization or evaporation.

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 at least some of the overall permeate stream obtained is recycled to the feed vessel and/or beyond the feed vessel but upstream of the conveying device. The presently disclosed method can especially be used for separation of a homogeneously dissolved catalyst from a liquid reaction mixture.

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 multiple-loop tangential flow filtration apparatus for concentrating fluids is described herein. The apparatus comprises a plurality of tube loops for receiving fluid therethrough, each tube loop comprising a respective filter, and a common feed pump for driving the fluid across each respective filter. The plurality of tube loops are coupled to the common pump via a common feed line.