A substrate for a liquid filter contains a polyolefin microporous membrane. A mean flow pore size d.sub.PP in a pore size distribution of the polyolefin microporous membrane measured by a half dry method according to gas-liquid phase substitution is from 1 nm to 20 nm. A mean flow pore size d.sub.LLP in a pore size distribution of the polyolefin microporous membrane measured by a half dry method according to liquid-liquid phase substitution is from 1 nm to 15 nm. A difference (d.sub.PP?d.sub.LLP) between the mean flow pore size d.sub.PP and the mean flow pore size d.sub.LLP is 12 nm or less, and a thickness of the polyolefin microporous membrane is from 4 to 25 ?m.

This disclosure generally relates to perforated filter media and coalescing filter elements utilizing perforated filter media. One example coalescing filter element is structured to separate a dispersed phase from a continuous phase of a mixture. The filter media includes a first coalescing layer. The first coalescing layer includes a first filter media. The first filter media has a plurality of pores and a first perforation. Each of the plurality of pores is smaller than the first perforation. The first perforation is formed in the first filter media and extends through the first filter media. The plurality of pores are structured to capture a portion of the dispersed phase. The first perforation is structured to facilitate the transmission of coalesced drops of the dispersed phase through the first coalescing layer such that the coalesced drops of the dispersed phase are separated from the portion of the dispersed phase captured in the first coalescing layer.

A fluid filtration assembly (FFA) includes a housing having a thickness defined between an internal surface and an external surface, the housing receiving a filter and defining an outer annular flow passage between an outer surface of the filter and the internal surface of the housing; an inlet pipe communicates with the FFA and injects a fluid into the housing to impart a centrifugal force; an outlet pipe communicates with the FFA and discharges the fluid from the housing; and a collection area disposed towards an end of the outer annular flow passage collects particulate matter from the fluid; wherein a width of the outer annular flow passage increases towards the collection area.

A fluid filtration assembly (FFA) includes a housing having a thickness defined between an internal surface and an external surface, the housing receiving a filter and defining an outer annular flow passage between an outer surface of the filter and the internal surface of the housing; an inlet pipe communicates with the FFA and injects a fluid into the housing to impart a centrifugal force; an outlet pipe communicates with the FFA and discharges the fluid from the housing; and a collection area disposed towards an end of the outer annular flow passage collects particulate matter from the fluid; wherein a width of the outer annular flow passage increases towards the collection area.

A selective catalytic reduction filter (SCRF) including a wall-flow substrate having inlet channels and outlet channels is provided. A first selective catalytic reduction (SCR) catalyst zone is present in the inlet channels, and a second SCR catalyst zone is present in the outlet channels. The first SCR catalyst zone includes an iron-exchanged zeolite catalyst, and the second SCR catalyst zone includes a copper-exchanged zeolite catalyst. Exhaust gas treatment systems including the SCRF and methods of reducing production of nitrous oxide (N.sub.2O) during selective catalytic reduction of an exhaust gas stream using the SCRF are also provided herein.

This disclosure generally relates to perforated filter media and coalescing filter elements utilizing perforated filter media. One example coalescing filter element is structured to separate a dispersed phase from a continuous phase of a mixture. The filter media includes a first coalescing layer. The first coalescing layer includes a first filter media. The first filter media has a plurality of pores and a first perforation. Each of the plurality of pores is smaller than the first perforation. The first perforation is formed in the first filter media and extends through the first filter media. The plurality of pores are structured to capture a portion of the dispersed phase. The first perforation is structured to facilitate the transmission of coalesced drops of the dispersed phase through the first coalescing layer such that the coalesced drops of the dispersed phase are separated from the portion of the dispersed phase captured in the first coalescing layer.

A selective catalytic reduction filter (SCRF) including a wall-flow substrate having inlet channels and outlet channels is provided. A first selective catalytic reduction (SCR) catalyst zone is present in the inlet channels, and a second SCR catalyst zone is present in the outlet channels. The first SCR catalyst zone includes an iron-exchanged zeolite catalyst, and the second SCR catalyst zone includes a copper-exchanged zeolite catalyst. Exhaust gas treatment systems including the SCRF and methods of reducing production of nitrous oxide (N.sub.2O) during selective catalytic reduction of an exhaust gas stream using the SCRF are also provided herein.

This disclosure generally relates to perforated filter media and coalescing filter elements utilizing perforated filter media. One example coalescing filter element is structured to separate a dispersed phase from a continuous phase of a mixture. The filter media includes a first coalescing layer. The first coalescing layer includes a first filter media. The first filter media has a plurality of pores and a first perforation. Each of the plurality of pores is smaller than the first perforation. The first perforation is formed in the first filter media and extends through the first filter media. The plurality of pores are structured to capture a portion of the dispersed phase. The first perforation is structured to facilitate the transmission of coalesced drops of the dispersed phase through the first coalescing layer such that the coalesced drops of the dispersed phase are separated from the portion of the dispersed phase captured in the first coalescing layer.

In some embodiments, the invention provides an apparatus configured to deliver dispersant into the water in a filterwell of a hot tub. Methods for delivering dispersant into the water in a filterwell of a hot tub are also provided.

A tangential flow filtration assembly is provided herein. The tangential flow filtration assembly includes a first and second winding tangential flow channel having an inlet at an endpoint the respective tangential flow channel and an outlet at an opposite endpoint of the respective tangential flow channel, the tangential flow channels further having a first cross-sectional area at the inlet and a second cross-sectional area at the outlet. The tangential flow filtration assembly further includes a filtration membrane positioned between the first and second tangential flow channels. The first cross-sectional area of the first tangential flow channel is greater than the second cross-sectional area of the first tangential flow channel, and the first cross-sectional area of the second tangential flow channel is less than the second cross-sectional area of the second tangential flow channel.