A tubular membrane is provided with a vortex generator at an upstream end of the tubular membrane. A spacer with multiple vortex generators may be added to module having a plurality of tubular membranes. A cap over the spacer may have separate inlets for a feed water and gas mixture and recirculating retentate. A system for membrane filtration includes a tubular membrane, a vortex generator, a liquid pump, a gas pump, and a retentate recirculation loop. In a filtration process, a gas is pumped into a flow of a feed liquid to produce a two-phase flow wherein the liquid is the continuous phase. The two-phase flow passes through the vortex generator and through a lumen of the tubular membrane. A continuous gas phase forms in part of the lumen of the tubular membrane. Contaminants in the liquid may be biased towards the continuous gas phase.

According to one embodiment, a working medium is provided. The working medium includes a first amine compound and a second amine compound. The first amine compound is a tertiary amine compound which consists of a carbon atom, a nitrogen atom and a hydrogen atom, and in which a ratio (C/N ratio) of a carbon atom number to a nitrogen atom number included in one molecule is in a range of 7 or more to 9 or less. The second amine compound is a tertiary amine compound which consists of a carbon atom, a nitrogen atom and a hydrogen atom, and in which a ratio (C/N ratio) of a carbon atom number to a nitrogen atom number included in one molecule is in a range of 5 or more to less than 7.

Provided is a method for detecting defects of separation membrane element, and an apparatus for detecting defects of a separation membrane element.

A submerged offshore reverse osmosis desalination apparatus and method uses product water from the apparatus and an onshore cooler or heat exchanger to provide or improve the cooling of a Sea Water Air Conditioning (SWAC) system, power plant, data center, Ocean Thermal Energy Conversion (OTEC) system, or Rankine Cycle heat engine.

A submerged offshore reverse osmosis desalination apparatus and method uses desalinated product water from the apparatus and an onshore cooler or heat exchanger to provide or improve the cooling of an onshore Rankine Cycle heat engine.

A method of treating a fluid comprises introducing a feed fluid stream comprising multiple materials to first side of a semi-permeable membrane. A draw fluid stream having a higher temperature than the feed fluid stream is introduced to second, opposing side of the semi-permeable membrane to form a thermal gradient across the semi-permeable membrane. One or more of the multiple materials of the feed fluid stream is drawn through the semi-permeable membrane and into the draw fluid stream via thermal gradient osmosis. A fluid treatment system and a thermal gradient osmosis apparatus are also described.

Methods, systems, and devices for water treatment or for preventing fouling of components of water treatment systems can include the upstream introduction of nanobubbles in-line and/or in close proximity to a reverse osmosis membrane in the water treatment system. The nanobubbles can bind to and cluster (flocculate) nanoparticles (and possible larger solid particles) so that they can be removed and not foul water purification components such as reverse osmosis membranes. The nanobubbles can also interact with and change some characteristics of nanoparticles and thereby reduce fouling of some system components, such as reverse osmosis membranes, or other components. The systems, methods, and devices disclosed herein can help produce potable water safe for human consumption in a more cost-effective manner, e.g., by reducing maintenance costs and in some cases manufacturing costs.

This publication relates to a method and a system for producing freshwater through a reverse osmosis process in a submerged membrane system requiring a differential pressure over the membrane system. The differential pressure is provided by introducing gas bubbles in the riser device (2) downstream the outlet (7) for fresh water in the riser device (2). The system comprises at least one submerged, reverse osmosis unit (1), with an inlet (4) for water and an outlet (7) for fresh water, a riser device (2) extending from the outlet (7) of the submerged membrane system to at, above or below sea level and a system for providing a low pressure side for the reverse osmosis process.

A water treatment and recirculation system includes means to transport water flows at required pressures, a mechanical filter of approximately 100 microns to capture coarse particles, oxygen production means, autonomous electricity generation means, and variable control means using a PLC that administers parameters such as pressure, oxygen and CO.sub.2 levels, flows, pH, etc. The system also includes means to ultrafilter and remove particles of up to 0.02 microns, the purpose being removing organic material macromolecules, disinfecting bacteria and viruses with mechanical removal, and eliminate harmful contaminants such as ammonia, degasifying means to eliminate CO.sub.2 with a multitubular exchanger with membranes made of hydrophobic materials and micro perforations to take CO.sub.2 away to an extraction gas in atmospheric or vacuum conditions; and means to oxygenate water with a multitubular exchanger having membranes constituted by hydrophobic materials and microperforations that inject O.sub.2 into water of a gas under atmospheric conditions.

A water treatment subsea installation and method are disclosed, adapted for scaling prevention and treatment of raw seawater into process water suitable for use in subsea hydrocarbon production. The water treatment installation comprises a seawater inlet to a primary filtration unit wherein a filtration membrane separates a receiving chamber from a permeate chamber having an outlet for treated water. A pump is installed in fluid flow communication with the treated water outlet, a recirculation loop feeding a portion of the treated water via a subsea electro-chlorinator back to the water stream upstream or downstream of the membrane of the primary filtration unit, and a secondary filtration unit is installed in the treated water stream between the primary filtration unit and the electro-chlorinator.