Biocide can be controllably added to a feed stream for a membrane. In some examples, the feed stream is separated into a primary feed stream and a secondary feed stream, for example, with the secondary feed stream having a lower flow rate than the primary feed stream. The secondary feed stream may be used to monitor and control the addition of the biocide, which is then diluted when the secondary feed stream is combined with the primary feed stream to form a combined stream for delivery to the membrane.

Biocide can be controllably added to a feed stream for a membrane. In some examples, the feed stream is separated into a primary feed stream and a secondary feed stream, for example, with the secondary feed stream having a lower flow rate than the primary feed stream. The secondary feed stream may be used to monitor and control the addition of the biocide, which is then diluted when the secondary feed stream is combined with the primary feed stream to form a combined stream for delivery to the membrane.

The present disclosure relates to tangential flow filters, membranes, and ultrafiltration membranes, for various applications, including bioprocessing and pharmaceutical applications, systems employing such filters, and methods of filtration using the same. In an aspect, an alternating tangential flow system for continuous processing may include a feed line containing a fluid. A retentate line may be in fluid communication with the feed line. A first diaphragm may be at an inlet of the retentate line configured to pump fluid toward an outlet of the retentate line. A second diaphragm may be at the outlet of the retentate line configured to pump fluid toward the inlet of the retentate line. A membrane may be in fluid communication with the retentate line between the first diaphragm and the second diaphragm. A retentate pump may be at the retentate outlet configured to pump the fluid out of the retentate line.

The present invention includes: a first sealing portion which has a first entry/exit selectively opened or closed by a first opening/closing valve and a second entry/exit selectively opened or closed by a second opening/closing valve and is configured to seal one end of a housing; a second sealing portion which has a third entry/exit selectively opened or closed by a third opening/closing valve and a fourth entry/exit selectively opened or closed by a fourth opening/closing valve, and is configured to seal the other end of the housing; and a controller which is configured to control the supply of raw water through any one of the first entry/exit and the second entry/exit or control the supply of raw water through any one of the third entry/exit and the fourth entry/exit.

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.

Systems and methods for separating a liquid mixture are disclosed. A membrane is first soaked by the liquid mixture via dynamic soaking to reach steady state. During the soaking process, the flow rate of the liquid mixture is increased at a flow rate ramp, the temperature is increased at a temperature ramp, and the pressure drop is increased at a pressure drop ramp. After the soaking process, the liquid mixture is separated by the membrane under optimized conditions to produce a permeate and a retentate.

A method of predicting membrane fouling in a reverse osmosis process includes collecting information relative to the reverse osmosis process being performed over a predetermined period of time, the collected information including a process factor and a water quality factor, the process factor including a produced water flow rate; calculating a salt removal rate and a pressure drop based on the collected information; normalizing the produced water flow rate, the salt removal rate, and the pressure drop; generating a prediction equation using normalized values of the produced water flow rate, the salt removal rate, and the pressure drop values; and predicting membrane fouling through the generated prediction equation to determine a chemical cleaning time. Process and water quality factors are normalized to temperature and/or flow rate, and the prediction equation uses the normalized factors. Both short-term and long-term predictions are made for chemical cleaning time and membrane module replacement time.

A crossflow filter includes a rigid cylindrical inner wall and a rigid cylindrical outer wall with an inelastic filter membrane positioned therebetween defining a retentate channel inside the filter membrane and a permeate channel outside the filter membrane. Further, the filter includes transition channels shaped and connected to the inner and outer walls to deliver a flow of fluid from an inlet port to the retentate channel and to capture flow flowing longitudinally along the cylindrical inner and outer walls from both the retentate and permeate channels to respective outlet ports.

A drying method for a separation membrane includes supplying a gas for drying to the separation membrane so that a value obtained by dividing the difference between a maximum value and a minimum value of a flow rate of the gas for drying on a membrane surface of the separation membrane by the minimum value of the flow rate is less than or equal to 15%. The gas for drying is less than or equal to 40 degree C. and contains a water-soluble gas that has a solubility in 1 cm.sup.3 of water of greater than or equal to 0.5 cm.sup.3 in conditions of 40 degree C. and 1 atmosphere.

Apparatus and processes for controlling a reverse osmosis system for water desalination to reduce energy consumption. The system has a controller configured to receive information from the sensor array and determine a fouling parameter for each reverse-osmosis stage based on one or more of: an A-Value, a B-value and a normalized differential pressure. The controller is then configured to control the flow through each of the reverse-osmosis assemblies based on the determined fouling parameters to meet a predetermined criterion for total permeate production for the reverse-osmosis system.