A method for treating wastewater containing fluorine is disclosed. The method for treating wastewater includes applying a vacuum to a membrane unit including a membrane having a hollow, injecting wastewater into the membrane unit so that the wastewater contacts an outer surface of the membrane, recovering hydrofluoric acid gas by evaporating hydrofluoric acid (HF) in the wastewater based on a vacuum applied to the inner surface of the membrane and moving the evaporated hydrofluoric acid (HF) to the inner surface through the membrane, injecting sweep gas into the membrane unit to discharge hydrofluoric acid gas remaining on the inner surface of the membrane, and forming a metal fluoride by reacting the recovered hydrofluoric acid gas with a metal oxide or metal hydroxide using a scrubbing process.

A water distillation system including a reservoir unit configured to reserve a second liquid of higher concentration than the first liquid; a pipe including a first end communicated with the first liquid and a second end communicated with the second liquid in the reservoir unit; a semipermeable membrane fitted on the pipe to separate the first liquid and the second liquid, so that the first liquid is mixed into the second liquid through the semipermeable membrane and led to the reservoir unit by osmotic action; and a distillation unit configured to distill the second liquid in the reservoir unit by solar energy.

Provided are: a dehydration system in which occurrence of damage to a membrane element in a zeolite membrane module can be suppressed; and an operation method of the same. This dehydration system for aqueous organic compounds includes: a zeolite membrane module, inside of which one or plural tubular membrane elements each having a zeolite membrane are arranged and which separates water from an aqueous organic compound supplied thereto; a pressure-reducing means; a condenser, and the dehydration system has at least one of the following configurations (1) and (2). Configuration (1): the dehydration system includes a temperature-maintaining means for maintaining a pipe connecting the membrane module and the condenser to have a temperature at which water does not condense, and Configuration (2): the pipe connecting the membrane module and the condenser is arranged downward from a permeated water outlet of the membrane module toward the condenser.

There is disclosed a process and apparatus for treating urine. Urine is contained in a reservoir and contacted with a liquid side of a separation membrane which also has a gas side. A sweep gas flow is generated on the gas side of the separation membrane. Water in the urine is conducted from the liquid side to the gas flow side of the separation membrane, the separation membrane substantially preventing the passage of other components of urine from the liquid side to the gas flow side of the separation membrane. The water conducted to the gas flow side of the separation membrane is entrained in the sweep gas flow.

A method for the desalination of water, the method comprising flowing salt water through a free-standing single-layer membrane of nanoporous graphene having a first planar side that makes contact with the salt water and an opposing second planar side from which desalinated water exits, wherein said membrane contains nanopores having a size of up to 1 nm, along with a substantial absence of pores above 1 nm in size, wherein said nanopores up to 1 nm in size have pore edges passivated with silicon, wherein salt ions in said salt water are blocked from passing through said membrane while water in said salt water passes through said membrane to result in desalinated water exiting said membrane.

Composite structures composed of inorganic membranes or polymer membranes supported on a multilayered woven wire mesh substrate are provided. Also provided are methods of making the composite structures and methods of using the composite structures as separation membranes. The mesh substrates are composed of a stack of two or more layers of woven wire mesh, wherein the different mesh layers in the stack have different mesh sizes. The multilayered mesh structure can support a defect-free, or substantially defect-free, membrane and has sufficient mechanical strength to allow the supported membranes to be used for chemical separations.

Disclosed are methods for dehydrating a water containing source of formaldehyde in which water is separated from the water containing source of formaldehyde using a zeolite membrane. In certain aspects, the water containing source of formaldehyde includes a separation enhancer having a relative static permittivity ranging from 2.5 to 20, and the water containing source of formaldehyde may further include methanol. In certain aspects, (meth)acrylic acid alkyl ester may be produced using the dehydrated source of formaldehyde.

The present disclosure is directed to a forward osmosis system/process utilized primarily in conjunction with a subsurface irrigation system/process. Saline wastewater or naturally saline water is treated using forward osmosis membranes that draw at least partially purified water from the wastewater into an osmotic draw solution (draw solution). The resulting diluted osmotic draw solution is then circulated through the subsurface irrigation system including one or more tubular membranes that reject the draw solution while permitting water in the diluted draw solution to pass through.

A zeolite membrane complex includes a porous support and a zeolite membrane formed on the support and containing aluminum, silicon, and carbon. In the zeolite membrane, the molar ratio of carbon to the sum of aluminum and silicon is higher than or equal to 0.1. In the zeolite membrane complex, when a mixed solution having a temperature of 60? C. and containing 50 mass % of water and 50 mass % of ethanol is supplied with a permeate pressure of ?94.66 kPaG, the total permeation flux is higher than or equal to 1.0 kg/m.sup.2 h, and a separation factor of water to ethanol is greater than or equal to 1000.

The present disclosure relates to a solvent drying solution and processes therefor. The present disclosure more specifically relates to a solvent drying solution that in use releases water from a solvent mixture. The present disclosure also relates to a process for recovering a solvent drying solution, more specifically to a process for recovering a solvent drying solution by using an osmotic process.