Biocide can be controllably added to a feed stream for a membrane. The membrane can separate the feed stream into a purified permeate stream and a concentrate stream containing contaminants from the feed stream. In some examples, a charge neutral biocide is introduced into the feed stream at a first addition rate. The concentration of the charge neutral biocide in the permeate stream is measured to provide a measured concentration of the charge neutral biocide in the permeate stream. The addition rate of the charge neutral biocide can be adjusted based on the measured concentration of the charge neutral biocide in the permeate stream to introduce charge neutral biocide into the feed stream at a second addition rate different than the first addition rate.

The present invention relates to a water extraction system for up-concentration of organic solutes comprising a flow cell comprising a membrane; said membrane comprising an active layer comprising immobilized aquaporin water channels and a support layer, and said membrane having a feed side and a non-feed side; and an aqueous source solution in fluid communication with the feed side of the membrane. The system also includes an aqueous source solution in fluid communication with the feed side of the membrane and an aqueous draw solution in fluid communication with the draw side of the membrane. The aqueous source solution comprises the organic solutes. The membrane module comprises an inlet and an outlet for the aqueous draw solution. The aquaporin vesicles are formed by self-assembly of block copolymers in the presence of an aquaporin protein suspension.

A solution-type water treatment chemical, includes, as one, gluconic acid (salt) and a surfactant having an HLB determined by the following equation (1) satisfying the following equation (2), wherein in a relationship between concentrations of the gluconic acid (salt) and the surfactant and a molecular weight and HLB of the surfactant, the gluconic acid (salt) and the surfactant are contained such that the water treatment chemical does not form a gel or precipitate.
HLB=(Σinorganic value/Σorganic value)×10  (1)
Molecular weight>−34.4×HLB+1005  (2)

Provided is a method for cleaning a filtration membrane provided in a membrane filtration device that is immersed in a liquid to be treated and performs solid-liquid separation on the liquid to be treated. When a transmembrane pressure difference exceeds a first predetermined pressure difference P1, a first cleaning step W1 for cleaning a filtration membrane is performed using a first chemical solution; when the transmembrane pressure difference immediately after performing the first cleaning step W1 exceeds a second predetermined pressure difference P2 that is lower than the first predetermined pressure difference, a second cleaning step W2 for cleaning the filtration membrane is performed using a second chemical solution having a concentration higher than the first chemical solution; and when the second cleaning step W2 is performed, the concentration of the second chemical solution and/or the cleaning time is changed according to the temperature of the liquid to be treated.

Method for treating impurities contained in exhaust gases of ships to reduce sulphur oxide and other emissions. In order for the method to purify wash water exiting from an exhaust gas scrubber sufficiently enough to be directly dischargeable to sea, and in order for a purification unit used to be small enough to be easily placed onboard a ship, exhaust gases are scrubbed in the exhaust gas scrubber and wash water containing impurities and exiting from the scrubber is supplied to the purification unit, circulated in an effluent circuit, and filtered through a semipermeable membrane of a filter to obtain purified effluent and a residue containing impurities, when necessary, the pH value of the purified effluent is adjusted to be at least 6.5, after which it is discharged into the sea or recycled to the scrubber while the residue containing impurities is led back to the effluent circuit.

The present invention is a filtration system and a method for cleaning a filtration system. The filtration system comprising a hydraulic circuit Cp recycling the permeate stream to the feed side of the membrane and/or a hydraulic circuit Cr recycling the retentate stream to the feed side of said membrane. The method injects an amount of a chemical product into the filtration system in the hydraulic circuit Cp or in the hydraulic circuit Cr or upstream of the cross-flow filtration membrane, setting the proportion of recycled permeate stream or recycled retentate stream collected in the hydraulic circuit Cp and/or Cr to enable the recycling of a significant amount of unreacted chemical product having passed through the cross-flow filtration membrane to the feed side of said cross-flow filtration membrane.

Biocide can be controllably added to a feed stream for a membrane. The membrane can separate the feed stream into a purified permeate stream and a concentrate stream containing contaminants from the feed stream. In some examples, a charge neutral biocide is introduced into the feed stream at a first addition rate. The concentration of the charge neutral biocide in the permeate stream is measured to provide a measured concentration of the charge neutral biocide in the permeate stream. The addition rate of the charge neutral biocide can be adjusted based on the measured concentration of the charge neutral biocide in the permeate stream to introduce charge neutral biocide into the feed stream at a second addition rate different than the first addition rate.

A treatment system for removing hardness, silicon, and turbidity from wastewater having a high salt concentration, comprising an integrated reaction apparatus comprising a reaction box and a chemical drug adding device, and a membrane separation apparatus comprising a membrane pool and a membrane component. The wastewater having the high salt concentration enters the reaction box; a required chemical drug is added to the wastewater by means of the chemical drug adding device; the chemical drug and the wastewater are fully mixed and reacted to produce different kinds of sludge particles; a sludge particle mixed liquid directly enters the membrane pool; under the action of an aeration device, the sludge particle mixed liquid is in a suspension state and uniform in concentration, and is screened and filtered by the membrane component; and produced water is discharged from the membrane pool, and intercepted sludge particles are discharged from the membrane pool.

The present disclosure relates to biocide compositions, formulations and methods for using formulations. In particular the present disclosure relates to biocide compositions and their use in treating reverse osmosis membranes.

The present invention relates to a method for removing metal ions from an aqueous system comprising a step of filtering the aqueous system through a loaded membrane which contains a carrier membrane based on a polyarylene ethersulfone which carries anionic groups, and a cationic polymer which is a polymer comprising primary and/or secondary amino groups. The invention further relates to a loaded membrane which contains a carrier membrane based on a polyarylene ethersulfone which carries anionic groups, and a cationic polymer which is a polymer comprising primary and/or secondary amino groups.