A resource recovery method includes: feeding raw water to a first-stage raw water tank; supplying high-temperature vapor to a first-stage heat exchanger; performing heat exchange between the supplied high-temperature vapor and the raw water in the first-stage raw water tank, changing a portion of the water into vapor and supplying the changed vapor to a subsequent-stage heat exchanger; repeatedly performing the performing step for each of the raw water tanks sequentially in the order from a second state to a n-th stage; being feed to a crystallizer from the n-th stage raw water tank; detecting a turbidity of the raw water fed to the crystallizer from the n-th-stage raw water tank; and extracting crystals of valuable resources contained in the raw water fed to the crystallizer from the n-th-stage raw water tank when the turbidity of the raw water becomes a predetermined value.

A multi-stage submerged membrane distillation water treatment apparatus including: a plurality of raw water tanks arranged in multiple stages ranging from a first stage to an n-th stage and storing raw water, the raw water flowing sequentially from the first stage to the n-th stage; membrane distillation (MD) modules submerged in the respective raw water tanks and discharging a portion of the raw water as vapor; heat exchangers submerged in the respective raw water tanks and maintaining the raw water at a predetermined temperature by performing heat exchange between the raw water and vapor supplied from the respective previous-stage MD modules; a vapor generator generating and supplying high-temperature vapor to the first-stage heat exchanger; a condenser condensing vapor supplied by the n-th-stage MD module; and a raw water feeder feeding low-temperature raw water to the first-stage raw water tank via the condenser.

A reverse osmosis desalination system for treating feed water, the feed water containing minerals, the system comprising a reverse osmosis unit comprising a first reverse osmosis stage (21) and a second reverse osmosis stage (22), each of the reverse osmosis stages (21, 22) having a feed water input, a product water outlet and a brine outlet, and a fluidized bed crystallizer (30), configured to remove minerals from the water, wherein the fluidized bed crystallizer (30) receives brine from the first reverse osmosis stage (21) and passes treated water to the feed water input of the second reverse osmosis stage (22).

An aqueous solution flows through a desalination system that separates the aqueous solution into purified water and concentrated brine. The concentrated brine is directed into an electrodialysis system that includes an anode and a cathode and at least two monovalent selective ion exchange membranes between the anode and the cathode. At least one of the monovalent selective ion exchange membranes separates at least one diluate channel from at least one concentrate channel in the electrodialysis system, and this membrane selectively allows at least one monovalent ion to pass through the membrane while blocking or inhibiting the transport therethrough of multi-valent ions. The concentrated brine flows through at least the concentrate channel while a voltage is applied to the anode and cathode; and additional aqueous solution flows through the diluate channel.

A method for treating produced water stream from a production well of an oil and gas field including a first step of ultrafiltration or microfiltration and a second step of removing the alkalinity in produced water.

A water treatment process (10) includes, in a crystallisation stage (12), passing a saline water feed (16) through an elongate conduit kept in a cold environment at a temperature below the equilibrium freezing temperature of the saline water, forming a slurry of brine and ice crystals inside the conduit, and, in a separation stage (14), separating the ice crystals from a bulk of the brine, producing a brine stream (22) and an ice stream (26). The elongate conduit is of a material, or has an inner material layer in contact with the saline water and with the slurry of brine and ice crystals, with a thermal conductivity of less than 5 W/m.Math.K and has a length configured to ensure formation of the slurry of brine and ice crystals in the conduit at the flow rate of the saline water feed through the elongate conduit.

The present disclosure provides methods of controlling the size of cellulose crystals by mixing a first composition comprising cellulose and coagulating this mixture with varying concentrations of hydrogen peroxide.

A wastewater treatment equipment and a treatment method of a wastewater are provided. The wastewater treatment equipment includes: a microfiltration unit, configured to receive and filter a wastewater to obtain a solution; a membrane salt separation unit, configured to receive the solution and separate monovalent ions and multivalent ions from the solution to obtain a first solution including the monovalent ions and a second solution including the multivalent ions; a first evaporative crystallization unit, configured to crystallize the first solution to form a monovalent salt; and a second evaporative crystallization unit, configured to crystallize the second solution to form a mixed salt; the microfiltration unit is connected to the membrane salt separation unit, and the first evaporative crystallization unit and the second evaporative crystallization unit are both directly connected to the membrane salt separation unit, the wastewater treatment equipment can achieve the standard discharge of wastewater.

A process for preparing metal oxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum. The process comprising: reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum with lithium hydroxide and optionally a chelating agent to obtain a solid comprising a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum, and a liquid comprising lithium sulfate, the metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum; separating the liquid and the solid from one another to obtain the metal hydroxide; submitting the liquid comprising lithium sulfate to an electromembrane process for converting the lithium sulfate into lithium hydroxide; and reusing at least a first portion of said lithium hydroxide obtained by the electromembrane process for reacting with the metal sulfate; reacting at least a second portion of said lithium hydroxide obtained by the electromembrane process with the obtained metal hydroxide to obtain a mixture of metal hydroxides; and roasting said mixture of metal hydroxides to obtain the metal oxide.

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.