A filter apparatus for treating hydrocarbon contaminated water comprising a housing defining an internal cavity and having an inlet and an outlet; a separating member that separates the internal cavity into a first treatment zone and a second treatment zone, wherein the first treatment zone is in fluid communication with the inlet and the second treatment zone is in fluid communication with the outlet, the separating member having one or more holes therethrough for fluid flow from the first treatment zone to the second treatment zone; at least one distribution tube within the second treatment zone having an end enclosing at least one of the holes to accept liquid flowing through the hole, the distribution tube further having perforations along its length for distributing liquid into the second treatment zone; a filtration barrier within the first treatment zone for removing particulate matter from the liquid flowing therethrough; and a particulate filtration media within the second treatment zone, surrounding the distribution tube, comprising at least one polymer for removing hydrocarbons from the water flowing through the second treatment zone prior to exiting the outlet.

An object of the present invention is to provide a water treatment system in which explosions can be prevented even when filtering water to be treated that is able to generate flammable gas. A water treatment system according to an embodiment of the present invention includes a water-to-be-treated tank which stores water to be treated, a crossflow-type filtration membrane module which filters the water to be treated, a supply passage through which the water to be treated is supplied to the filtration membrane module from the water-to-be-treated tank by using a supply pump, and a recirculation passage through which the water to be treated is recirculated from the filtration membrane module to the water-to-be-treated tank. The supply passage is provided with an aspirator which mixes a gas with the supplied water to be treated, the gas being recirculated through the recirculation passage to the water-to-be-treated tank together with the water to be treated. The water-to-be-treated tank has an upper space provided above the liquid surface of the stored water to be treated, the upper space being hermetically filled with an inert gas. The water-to-be-treated tank is further provided with a gas transport passage through which the inert gas is supplied from the upper space to the aspirator.

The present invention relates to a method for treating an aqueous liquid comprising oil droplets and a surfactant and/or a base. For this method, a pore size threshold of a filter is determined taking into account the interfacial tension between the oil droplets and the water, and a filter is selected whose pore size is less than or equal to this threshold for filtration of the aqueous liquid.

A microfluidic system includes a microfluidic device connected to a bubble trap device whereby fluid flowing to the microfluidic device passes through the bubble trap device to remove gas bubbles prior to entering the microfluidic device. The bubble trap can include a separation chamber and an exhaust chamber separated by a hydrophobic porous membrane and gas bubbles in the fluid entering the separation chamber pass through the hydrophobic porous membrane into the exhaust chamber while the fluid remains in the separation chamber. The bubble trap can be formed by bonding a first body portion to a first side of the hydrophobic porous membrane and bonding a second body portion to a second side of the hydrophobic porous membrane. The exhaust chamber can be connected to an elongated exhaust channel that limits the evaporation losses of the fluid through the hydrophobic porous membrane.

The present invention is directed to methods of treating a hydrocarbon-containing waste stream to form a hydrocarbon-containing retentate and an aqueous permeate which is substantially free of hydrocarbon. The method includes passing the hydrocarbon-containing waste stream through a microporous membrane to yield the hydrocarbon-containing retentate and the aqueous permeate. The membrane comprises a substantially hydrophobic, polymeric matrix and substantially hydrophilic, finely divided, particulate filler distributed throughout the matrix. The polymeric matrix has pores with a volume average diameter less than 1.0 micron, and at least 50 percent of the pores have a mean diameter of less than 0.35 micron.

A polymeric membrane for separating oil from water has a pore size of 0.005 m to 5 m, a thickness of 50 m to 1,000 m, a water contact angle of 0 to 60, an oil contact angle of 40 to 100. The membrane contains a hydrophobic matrix polymer and a functional polymer that contains a hydrophobic backbone and side chains. The side chains each have an oleophobic terminal segment and a hydrophilic internal segment. The weight ratio of the matrix polymer to the functional polymer is 99:1 to 1:9. Also disclosed is a method of making the above described membrane.

A filter structure capable of efficiently separating water and oil using wettability is provided. The filter structure includes a first filter layer including a plurality of openings and a second filter layer including a plurality of openings and positioned so as to be overlapped with the first filter layer at a distance from each other. The first filter layer and the second filter layer include surfaces each having a dual-scale protrusion and depression structure as a combination of a micro-scale structure and a nano-scale structure, and thus have superhydrophilicity and selectively allow water from a water and oil mixture to pass therethrough.

An object of the present invention is to provide a water treatment system in which explosions can be prevented even when filtering water to be treated that is able to generate flammable gas. A water treatment system according to an embodiment of the present invention includes a water-to-be-treated tank which stores water to be treated, a crossflow-type filtration membrane module which filters the water to be treated, a supply passage through which the water to be treated is supplied to the filtration membrane module from the water-to-be-treated tank by using a supply pump, and a recirculation passage through which the water to be treated is recirculated from the filtration membrane module to the water-to-be-treated tank. The supply passage is provided with an aspirator which mixes a gas with the supplied water to be treated, the gas being recirculated through the recirculation passage to the water-to-be-treated tank together with the water to be treated. The water-to-be-treated tank has an upper space provided above the liquid surface of the stored water to be treated, the upper space being hermetically filled with an inert gas. The water-to-be-treated tank is further provided with a gas transport passage through which the inert gas is supplied from the upper space to the aspirator.

The present invention is directed to methods of treating a hydrocarbon-containing waste stream to form a hydrocarbon-containing retentate and an aqueous permeate which is substantially free of hydrocarbon. The method includes passing the hydrocarbon-containing waste stream through a microporous membrane to yield the hydrocarbon-containing retentate and the aqueous permeate. The membrane comprises a substantially hydrophobic, polymeric matrix and substantially hydrophilic, finely divided, particulate filler distributed throughout the matrix. The polymeric matrix has pores with a volume average diameter less than 1.0 micron, and at least 50 percent of the pores have a mean diameter of less than 0.35 micron.

The present invention includes an apparatus and method for removing oil from a oil-containing liquid comprising oil and gas comprising: a source of oil-containing liquid; and a membrane contactor system in fluid communication with the source of oil-containing liquid, the membrane contactor system comprising one or more membrane contactors having a first and a second surface, wherein the first surface coalesces oil and removes gas from the oil-containing liquid, and the oil and gas are collected on the second surface from the oil-containing liquid.