Disclosed are methods of treating wastewater using a membrane bioreactor and achieving a target phosphorus concentration for the membrane permeate stream. These methods include the steps of dosing a wastewater stream with a rare earth clarifying agent and passing the dosed wastewater stream through the membrane to obtain a membrane permeate stream with a permeate concentration that is less than the phosphorus concentration of the influent stream. This permeate concentration also can be equal to or less than a target phosphorus concentration. In the methods as disclosed herein, the rare earth clarifying agent can be chloride salts of one or more rare earth elements and in certain embodiments, the rare earth clarifying agent can be CeCl.sub.3 and LaCl.sub.3.

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.

A water purification apparatus (1) comprising a RO-device (2) comprising a RO-membrane (2a). The RO-device (2) is configured to receive inlet water to be purified from an inlet path (19) and produce permeate water into a permeate path (22) and reject water into a reject path (23). The apparatus (1) also comprises a recirculation path (24) arranged to recirculate reject water from the reject path (23) to the inlet water. The apparatus further comprises a cooling arrangement (30) comprising a cooling device (31, 39). The cooling arrangement (30) is configured to cool the recirculated reject water in the recirculation path (24) with the cooling device (31, 39), and a control arrangement (40) configured to control the cooling arrangement (30) to cool the recirculated reject water in the recirculation path (24) in order to cool the RO-membrane (2a).

An automated modular filtration system, particularly for low volume tangential flow filtration processes, comprises a plurality of filtration modules formed as separate assemblies and at least one control unit for jointly controlling filtration processes of individual filtration units. Each filtration module contains at least one individual filtration unit for executing a filtration process independent of the other filtration units, first input ports for receiving a first type of fluids, second input ports for receiving a second type of fluids, and exit ports for outputting unused system fluids. First type fluids are process fluids are specific to the filtration processes executed in individual filtration units. Second type fluids are system fluids not specific to filtration processes executed in the individual filtration units. The second input and exit ports establish inter-module connections so system fluids can be forwarded from one filtration module to an adjacent filtration module of the filtration system.

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 product includes a nanoporous membrane having a plurality of carbon nanotubes and a fill material in interstitial spaces between the carbon nanotubes for limiting or preventing fluidic transfer between opposite sides of the nanoporous membrane except through interiors of the carbon nanotubes. The longitudinal axes of the carbon nanotubes are substantially parallel, an average inner diameter of the carbon nanotubes is about 20 nanometers or less, and both ends of at least some of the carbon nanotubes are open. Moreover, the fill material is impermeable or having an average porosity that is less than the average inner diameter of the carbon nanotubes.

A control system has a water purification module and a control module. The water purification module has a preliminary filter and a reverse osmosis filter. The control module regularly controls the purification and the drainage of the water purification module, and solves the problem that the TDS value of the water on both sides of the reverse osmosis membrane is too high after the water purifier is on standby for a period of time. The control system regularly drains high concentration water on both sides of the reverse osmosis membrane to improve water purification efficiency.

A control system has a water purification module and a control module. The water purification module has a preliminary filter and a reverse osmosis filter. The control module regularly controls the purification and the drainage of the water purification module, and solves the problem that the TDS value of the water on both sides of the reverse osmosis membrane is too high after the water purifier is on standby for a period of time. The control system regularly drains high concentration water on both sides of the reverse osmosis membrane to improve water purification efficiency.

Provided is an apparatus for controlling a seawater desalination plant. The apparatus includes: a dissolved air flotation device configured to provide treated water obtained by treating seawater according to a dissolved air flotation (DAF); an ultrafiltration device including a plurality of ultrafiltration units each having an ultrafiltration membrane, and configured to perform an ultrafiltration (UF) process of filtering impurities remaining in the treated water using the ultrafiltration membranes of the plurality of ultrafiltration units; a reverse osmosis device; an information collection unit; and a state treatment unit.