The present invention discloses a method and an apparatus for desalination of high-salt and high-concentration organic wastewater by coupling three membrane separation technologies. Wastewater is subjected to diffusion desalination to obtain diffusion desalination wastewater and diffusion desalination circulating water; the diffusion desalination circulating water is subjected to reverse osmosis to obtain pure water and high-concentration salt water; and the diffusion desalination wastewater is subjected to forward osmosis to obtain forward osmosis wastewater and forward osmosis circulating water, where the forward osmosis wastewater is desalted and concentrated wastewater.

A method for treating waste water containing ammonia comprising the steps of: i) passing the waste water as a feed solution through a first RO membrane (24) to produce a first permeate stream (30) and a first reject stream (32), ii) adjusting the pH of the first reject stream (32) to >9, iii) passing the first reject stream (32) through a second RO membrane (26) to produce a second permeate stream (36) containing ammonia and a second reject stream (38), and iv) passing at least a portion of the second permeate stream (36) to a cooling tower (12) to evaporate at least a portion of the ammonia.

Disclosed herein are systems and methods in which an aqueous stream comprising solubilized monovalent ions and solubilized multivalent ions is processed such that multivalent ions are selectively retained and monovalent ions are selectively removed. According to certain embodiments, an aqueous feed stream is transported through an ion-selective separator to produce a multivalent-ion-enriched stream and a monovalent-ion-enriched stream. The monovalent-ion-enriched stream may be transported through a desalination apparatus to produce a substantially pure water stream and a concentrated aqueous stream. In some embodiments, at least a portion of the multivalent-ion-enriched stream produced by the ion-selective separator is combined with at least a portion of the substantially pure water stream produced by the desalination apparatus to produce a combined product stream containing a relatively large percentage of the solubilized multivalent ions from the aqueous feed stream and a relatively small percentage of the solubilized monovalent ions from the aqueous feed stream.

A thermal management loop system may include an accumulator, an evaporator in fluid receiving communication with the accumulator, a condenser in fluid receiving communication with the evaporator, and a membrane separator in fluid receiving communication with the condenser. Gas exiting the membrane separator may recirculate back to the condenser and liquid exiting the membrane separator may flow to the accumulator. The thermal management loop system may be a dual-mode system and thus may be operable in a powered-pump mode or a passive-capillary mode.

The present application provides a switchable forward osmosis system, and processes thereof. In particular, this application provides a process for treating an aqueous feed stream, comprising: forward osmosis using an aqueous draw solution having a draw solute concentration of ?20 wt %, the draw solute comprising ionized trimethylamine and a counter ion; wherein, the feed stream: (i) comprises ?5 wt % total dissolved solids; (ii) is at a temperature of ?20? C.; (iii) is at a temperature between ?30? C.-?60? C.; (iv) has an acidic pH or a basic pH; (v) comprises organic content; (vi) comprises suspended solids; (vii) or any combination of two or more of i)-v). Also provided herein are the related system and draw solution for performing the process, and various uses thereof for treating typically difficult to dewater feed streams.

The present disclosure relates to a hybrid AD-DCMD desalination system, where two subsystems, such as AD and DCMD, are integrated synergistically to maximize freshwater production. The waste heat released from an AD condenser is used to drive the DCMD subsystem in a first configuration of the hybrid AD-DCMD system, while another configuration relies on the heat released due to an exothermic adsorption process in an adsorption bed. The DCMD subsystem is included to exploit the waste heat of the AD subsystem to enhance performance. In both these configurations, seawater is used to release the heat from the AD subsystem, which is then fed into the DCMD subsystem. The hybrid AD-DCMD system configurations demonstrate improved performance in terms of GOR, specific daily water production (SDWP), and freshwater cost reduction.

The present application includes a symbiotic reverse osmosis train system for maximizing desalinated water recovery, meanwhile yielding high salinity brine suitable for osmotic power generation or commercial salt production. The trains comprise a series of cells operating in an interrelated sequential pattern within a salinity field. Each cell forms a closed hydraulic brine loop having pumping means, power recovery means and shared semipermeable membranes between adjacent cells. Used are a semipermeable Flat Sheet or Hollow Fiber Membrane in desalination and osmotic power generation of brackish, seawater and brines of 15% salinity or more. Charging each cell in the train of cells with a formulated brine having a specified ionizable inorganic salt concentration and type, without permitting mixing of the given brines among adjacent cells. Allowing the train to achieve water recovery exceeding 85% with concentrated rejected brine of 28-30% salt content.

A high-magnesium concentrated liquid is disclosed. In a first embodiment, the high-magnesium concentrated liquid comprises magnesium ranged from 60000-70000 ppm, sodium ranged from 1000-3200 ppm, potassium ranged from 300-3000 ppm, calcium ranged from 100-300 ppm, and the balance of water. In a second embodiment, the high-magnesium concentrated liquid comprises magnesium ranged from 40000-50000 ppm, sodium ranged from 8000-18000 ppm, potassium ranged from 8000-17000 ppm, calcium ranged from 15-250 ppm, and the balance of water.

A high-magnesium concentrated liquid is disclosed. In a first embodiment, the high-magnesium concentrated liquid comprises magnesium ranged from 60000-70000 ppm, sodium ranged from 1000-3200 ppm, potassium ranged from 300-3000 ppm, calcium ranged from 100-300 ppm, and the balance of water. In a second embodiment, the high-magnesium concentrated liquid comprises magnesium ranged from 40000-50000 ppm, sodium ranged from 8000-18000 ppm, potassium ranged from 8000-17000 ppm, calcium ranged from 15-250 ppm, and the balance of water.

A filtration system suitable for recovering base stock from used lubricating oil and other applications pass feedstock over nano-filtration membranes assembled as a stack of membranes all experiencing parallel flow. On exiting a first stack of membranes the feedstock passes through an opening in a pressure-sustaining separator plate to flow in the reverse direction past a second stack of membranes and subsequently establish a serpentine flow of feedstock through multiple stacks of membranes. The stacks of membranes all share a common pressure containment vessel. Pressure boosters installed in the flow-through openings of separator plates separating consecutive stacks can serve to restore lost pressure of the feedstock and maintain effective permeation of permeate through the membranes. A pressure control valve at the outlet to the permeate-receiving cavities of a stack can be used to adjust the trans-membrane pressure.