Membranes comprising graphene oxide sheets and associated filter media and methods are provided. In some embodiments, a membrane may comprise graphene oxide sheets that have undergone one or more chemical treatments. The chemical treatment(s) may impart beneficial properties to the membrane, such as a relatively small d-spacing, compatibility with a broad range of environments, physical stability, and charge neutrality. For example, the graphene oxide sheets may undergo one or more chemical treatments that form chemical linkages between at least a portion of the graphene oxide sheets in the membrane. Such chemical linkages may impart a small d-spacing, broad compatibility, and/or allow relatively thick membranes to be formed. In certain embodiments, the graphene oxide sheets may undergo one or more chemical treatment that imparts relative charge neutrality to the membrane by altering the ionizability of certain functional groups. Graphene oxide membranes, described herein, can be used for a wide range applications.

A filtration membrane is provided. It comprises a porous support substrate and a porous active layer on top of the support substrate, wherein the active layer is formed of a network of interconnected, randomly arranged ceramic splats with ceramic particles occupying interstices between the splats, and wherein free spaces between the particles define a network of interconnected pores extending through the thickness of the active layer. There are also provided a method of filtering a feed using the membrane and a method of manufacturing the membrane by suspension plasma spraying.

A porous sintered clay mineral matrix that contains aluminum and is doped with 0.1-20 mol %, based on the amount of the aluminum, one or more transition metals, one or more post-transition metals, one or more rare earth metals, or a combination thereof. An example is a kaolinite matrix. The matrix can be made from a calcined clay mineral powder that contains aluminum and is doped with at least one of these metals. Also disclosed are methods of preparing the above-described matrix and powder.

Embodiments provide methods and strictures for purification or volume reduction of a brine by an advanced vacuum distillation process (AVMD) to achieve higher flux by passage of vapors through an AVMD distillation unit. In one example, brine is circulated in a tank. The tank may include one or more membrane pouches that are submerged in the circulating brine or placed above the water level of the hot circulating brine. In other embodiments the membrane pouches are outside of the tank that includes the hot circulating brine but still in communication with it. The circulating brine is heated, allowing creation of water vapor. Using a vacuum, the water vapor is drawn through the membrane, where it may be condensed and subjected to further beneficial use. This process can concentrate to levels to generate crystals or solids, which can be separated and utilized.

Bioartificial ultrafiltration devices comprising a scaffold comprising a population of cells enclosed in a matrix and disposed adjacent a plurality of channels are provided. The population of cells provides molecules such as therapeutic molecules to a subject in need thereof and is supported by the nutrients filtered in an ultrafiltrate from the blood of the subject. The plurality of channels in the scaffold facilitate the transportation of the ultrafiltrate and exchange of molecules between the ultrafiltrate and the population of cells.

Methods and systems for producing urea are provided. Ammonia, carbon dioxide, and a carbamate solution can be combined in a pressurized mixer to produce a carbamate reaction mixture. The carbamate reaction mixture can be transferred from the pressurized mixer to a reactor. The carbamate reaction mixture can be heated in the reactor to produce a urea reaction mixture that can include urea, water, ammonia, carbon dioxide, and ammonium carbamate. The urea reaction mixture can be contacted to a membrane to separate an aqueous filtrate and a urea concentrate that can include urea, ammonia, carbon dioxide, and ammonium carbamate. The urea concentrate can be transferred from the reactor to a urea purification system that can include one or more separators and one or more decomposers. The urea concentrate can flow through the urea purification system to produce one or more urea products and one or more carbamate solutions.

In one embodiment, a separation membrane includes: a porous support structure, wherein the porous support structure comprises a system of continuous pores connecting an inlet of the separation membrane to an outlet of the separation membrane; and at least one alkali metal hydroxide disposed within pores of the porous support structure. Other aspects and embodiments of the disclosed inventive concepts will become apparent from the detailed description, which, when taken in conjunction with the drawings, illustrate by way of example the principles of the invention.

Silicon carbide flat sheet filtration membranes are supported on one piece manifold/end cap structures. Ends of a large number of the parallel flat plate membranes are fitted into elongated end cap slots that are part of a single molded manifold/end cap structure, such a structure being at each end of the series of membranes. In addition, a one piece external frame module can be provided to receive the gang of flat plate membranes with attached manifold/end caps. In the event of a damaged plate, the plate can be removed and replaced along with a special end cap repair section. This provides advantages over prior arrangements with individual end caps for each module or potting of the flat plates into a box or chamber.

The present specification discloses a membrane reactor comprising a reaction region; a permeate region; and a composite membrane disposed at a boundary of the reaction region and the permeate region, wherein the reaction region comprises a bed filled with a catalyst for dehydrogenation reaction, wherein the composite membrane comprises a support layer including a metal with a body-centered-cubic (BCC) crystal structure, and a catalyst layer including a palladium (Pd) or a palladium alloy formed onto the support layer, wherein ammonia (NH.sub.3) is supplied to the reaction region, the ammonia is converted into hydrogen (H.sub.2) by the dehydrogenation reaction in the presence of the catalyst for dehydrogenation reaction, and the hydrogen permeates the composite membrane and is emitted from the membrane reactor through the permeate region.

An improved method for concentrating dispersions of graphene oxide, coating a substrate with a layer of a graphene oxide solution, and producing a supported graphene membrane stabilised by controlled deoxygenation; and graphene-based membranes that demonstrate ultra-fast water transport, precise molecular sieving of gas and solvated molecules, and which show great promise as novel separation platforms.