Disclosed herein are systems and methods for desalination of salt water based on an engineered acoustic field that causes constructive and destructive interference at precomputed spatial positions. The engineered acoustic field can cause high-pressure and low-pressure regions where desalination membranes are located. The induced pressure from the acoustic field can force pure water through the membranes leaving ionic and dissolved molecular species behind.

A method for purifying a boron nitride nanotube feedstock is disclosed, including an initial step of mixing a boron nitride nanotube (BNNT) feedstock with a solvent to form an initial mixture. This BNNT feedstock is made up of hexagonal boron nitride (h-BN) particles and less than about 50 weight percent BNNTs on a dry basis. This initial mixture is then sonicated within a treatment vessel using an ultrasonic probe. At least a portion of the initial mixture is filtered out of the treatment vessel and across a nanoporous membrane at the same as the sonication. In this manner, the method provides a filtrate which is enriched in h-BN particles relative to the initial mixture and a retentate which is enriched in BNNTs relative to the initial mixture.

An apparatus for reducing concentration polarization and/or membrane fouling on a membrane surface in a filter unit (102) during a membrane separation process and/or a filter cleaning process. The apparatus includes (i) a signal generator (106) that generates electrical signals when there is a fluid flow in the filter unit (102) and (ii) an ultrasonic transducer assembly (108) that receives the electrical signal from the signal generator to generate ultrasonic waves using one or more ultrasonic transducers (604). The ultrasonic waves pass through the filter unit (102) during the membrane separation process and/or the filter cleaning process and generate at least one of a turbulence in the flow of fluid or a vibration on the membrane surface to dislodge particles clogging the membrane surface, thereby reducing the concentration polarization and/or the membrane fouling on the membrane surface of the filter unit (102), which in turn increasing membrane permeability and efficiency.

A method for purifying a boron nitride nanotube feedstock is disclosed, including an initial step of mixing a boron nitride nanotube (BNNT) feedstock with a solvent to form an initial mixture. This BNNT feedstock is made up of hexagonal boron nitride (h-BN) particles and less than about 50 weight percent BNNTs on a dry basis. This initial mixture is then sonicated within a treatment vessel using an ultrasonic probe. At least a portion of the initial mixture is filtered out of the treatment vessel and across a nanoporous membrane at the same as the sonication. In this manner, the method provides a filtrate which is enriched in h-BN particles relative to the initial mixture and a retentate which is enriched in BNNTs relative to the initial mixture.

Rapid evaporation of water for desalination and dewatering using nanobubbles and micro-droplets is disclosed. Warm nanobubbles of air are injected into seawater or another water source to be treated, and the normal stasis of the nanobubbles is disrupted with ultrasonic energy. The nanobubbles implode and violently recombine into microbubbles. Energized by the effects of the nanobubble state change, these energetic, relatively high surface area microbubbles bubbles quickly rise to the surface of the water, creating an aerosol of micro-water droplets above the surface that is drawn into a dry, warm stream of air and rapidly evaporates, precipitating out salt crystals. The air is then cooled with a chiller, condensing the moisture in the air into fresh water.

Rapid evaporation of water for desalination and dewatering using nanobubbles and micro-droplets is disclosed. Warm nanobubbles of air are injected into seawater or another water source to be treated, and the normal stasis of the nanobubbles is disrupted with ultrasonic energy. The nanobubbles implode and violently recombine into microbubbles. Energized by the effects of the nanobubble state change, these energetic, relatively high surface area microbubbles bubbles quickly rise to the surface of the water, creating an aerosol of micro-water droplets above the surface that is drawn into a dry, warm stream of air and rapidly evaporates, precipitating out salt crystals. The air is then cooled with a chiller, condensing the moisture in the air into fresh water.

The invention relates to a method for cleaning a filter element made of a porous material. The method comprises directing ultrasound to the filter element, and directing after a predefined time from starting of the ultrasound an impulse to a filtrate reservoir causing filtrate inside the filtrate reservoir to be forced inside the filter element in order to remove particles from the surface of the filter element. Pressure of the impulse is between 4 to 8 times higher than the forward pressure and also that the reverse flux, measured in volume per area time, caused by the impulse is at the minimum 2 to 8 times the feed flux. The invention also relates to a filtering device comprising a filter element made of a porous material.

A system and method of the purification of drinking water, ethanol and alcohol beverages is based on the action of hydrodynamic cavitation processing of microbiological and chemical contaminants, micro particles and colloidal particles. The fluid flow moves at a high rate through a multi-stage cavitation device and filtration module to generate hydrodynamic cavitation features in the fluid flow. The cavitation features generate changes in the velocity, pressure, temperature, chemical composition and physical properties of the liquid. The cavitation features also prevent the deposition of contaminants upon and remove contaminants from the surface of the filter module, reduce the load on the filter elements and increase the life of the filter module.

A method and apparatus for improved separation and containment of radioactive particulates from liquids by filtration. The improvements are achieved by utilizing more than one stage of filtration to remove radioactive particulates from a fluid. The first stage of filtration is designed for high liquid flowrate, low differential pressure across the filter medium, and reversibility of flow through the medium to facilitate backwashing. The second or more stages of filtration receive the backwash flow and captured particulates from the first stage at a lower flowrate, but at high pressure using a high-pressure pump configured between the stages.

The ultrafiltration system for treatment of coal mine water includes an intermediate water pool, an ultrafiltration membrane pool, an adjustment pool, a water production pool, and a water removal pool; wherein the ultrafiltration membrane pool is connected to the intermediate water pool through a water inlet valve and a water inlet pump, connected to the water production pool through a backwashing valve and a backwashing pump, and connected to the water removal pool through a water production valve and water production pump, and the adjustment pool is connected to the ultrafiltration membrane pool; and an ultrafiltration membrane assembly and a cleaning device are disposed in the ultrafiltration membrane pool, an aeration tube is disposed in the ultrafiltration membrane pool below the ultrafiltration membrane assembly, the aeration tube is connected to a blower, and a water production channel in a ceramic membrane assembly is connected to the water production pool.