A specially functionalized composite filter material with a high specific surface area is used to adsorb PFAs from potable water. In a preferred embodiment, the base filter material is granular activated carbon (GAC), which is sequentially coated with a thin layer of polydopamine, a thin layer of partially oxidized iron, and a thin coating of octadecylamine. After PFAs are adsorbed onto the coated GAC particles, the PFAs are removed by a rinsing process, and remain in the rinse effluent. GAC particles are recovered and recoated as needed to restore their adsorptive capacity. The PFA-containing effluent is treated using photochemical processes to destroy the PFA molecules. The now PFA-free effluent can be disposed of as a non-hazardous material. The composite filter material works in systems ranging from small passive systems for personal use to large scale, high-flow-rate utility water treatment systems.

Process for the preparation of particles with antibacterial coating, which comprises the following steps: (a) providing an aqueous suspension containing a polyamine, a crosslinker and a porous organic or inorganic carrier material in particle form at a temperature lower than or equal to 10° C. in a mixer for coating the inorganic carrier material with the polyamine; (b) crosslinking the organic polymer in the pores of the inorganic carrier material and simultaneously removing water.

A modular porous swale. The modular porous swale may comprise a porous concrete block and filtration joint. The porous concrete block may snugly fit within a trench having a lower portion filled with an absorption media. The absorption media may include gravel, activated alumina, bone char, or an activated alumina and bone char mixture. The porous concrete block may have a top surface inwardly-sloped to a nadir. The filtration joint may be disposed within the porous concrete block and along the nadir. The liner may cover one or more sides of the porous concrete block. The perforated pipe may be located within the absorption media. The filtration joint may substantially align above a portion of the perforated pipe when the modular porous swale is installed within the trench.

A method of treating water containing arsenic and manganese. Ozone is injected into the water at a concentration in the range of 0.2 to 1.0 mg/L, oxidizing As(III) to As(V) and Mn(II) to Mn(IV). Ferric chloride coagulant is added to the ozonated water, coagulating the As(V) and the Mn(IV). The water is then filtered with a first filter medium selected for removal of the Mn(IV) followed by a second filter medium selected for removal of As(V). This removes the coagulate to produce treated water. The method removes arsenic and manganese to low levels acceptable for drinking water, using low concentrations of ozone as an oxidant. An advantage is that the ozone system can have a relatively small footprint, and use less energy, an important factor for climate change. Further, a quenching agent for removal of residual ozone is not required.

Systems, methods, and filter media for filtering molten aluminum or aluminum alloy are provided. The filter media includes a plurality of porous reticulated filter media pieces composed of at least one type of bonded particle. Each of the plurality of filter media pieces have a porosity between 5 pores per inch (PP) and 90 pores per inch and are between ¾ inches and 6 inches across and between ½ inches and 2 inches thick. The filter media pieces provide a plurality of external tortuous paths between the filter media pieces and a plurality of internal tortuous paths within individual ones of the filter media pieces for the molten aluminum or aluminum alloy to flow through when the filter media pieces are arranged in a filtration vessel. The filter media may be used in an inline deep bed aluminum filtration process to replace existing media.

A method of treating water containing arsenic and manganese. Ozone is injected into the water at a concentration in the range of 0.2 to 1.0 mg/L, oxidizing As(III) to As(V) and Mn(II) to Mn(IV). Ferric chloride coagulant is added to the ozonated water, coagulating the As(V) and the Mn(IV). The water is then filtered with a first filter medium selected for removal of the Mn(IV) followed by a second filter medium selected for removal of As(V). This removes the coagulate to produce treated water. The method removes arsenic and manganese to low levels acceptable for drinking water, using low concentrations of ozone as an oxidant. An advantage is that the ozone system can have a relatively small footprint, and use less energy, an important factor for climate change. Further, a quenching agent for removal of residual ozone is not required.

Air purification apparatus is provided that removes undesirable substances, such as particulate materials, malodors, viruses, bacteria, fungi, and toxins, from the air present within an enclosed environment. The apparatus is switchable between a mode in which air immediately adjacent the apparatus housing is drawn in and purified, and a mode in which air remote from the apparatus housing is drawn in from a specific point within the enclosed environment through use of an elongate duct.

An entrainment-based filtering system for use in connection with a facemask or respirator that includes: a filter housing defining an interior volume comprising at least one airflow pathway having an airflow pathway length that is longer than the length of the interior volume and spaced within the interior volume; and a plurality of entrainment substrates. The plurality of entrainment substrates is positioned within the at least one airflow pathway and the plurality of substrates and the dimensions of the at least one airflow pathway together function to entrain particles on the surface of the chemically coated entrainment substrates and prevent at least 95% of particles traveling through the at least one airflow pathway from exiting the entrainment-based filter.

To provide a titanium-based porous body that has high void fraction to ensure gas permeability and water permeability for practical use as an electrode and a filter, has a large specific surface area to ensure conductivity and sufficient reaction sites with a reaction solution or a reaction gas, thus showing excellent reaction efficiency, and contains less contaminants because of no organic substance used. A titanium-based porous body having a specific void fraction and a high specific surface area is obtained by filling an irregular-shaped titanium powder having an average particle size of 10 to 50 m in a dry system without using any binder or the like into a thickness of 4.010.sup.1 to 1.6 mm, and sintering the irregular-shaped titanium powder at 800 to 1100 C.

The challenge of the present invention is to provide a multilayer filter medium whose deodorizing performance after a long-term storage of the filter medium is suppressed from deteriorating and which is superior in deodorizing performance and exhibits low pressure drop. A multilayer filter medium includes three or more nonwoven fabric layers superposed together and has two or more interlayer regions each formed by two adjacent layers of the nonwoven fabric layers, in which a first interlayer region of the interlayer regions contains functional particles A having an average particle diameter of 50 to 100 m, and a second interlayer region selected from the interlayer regions excluding the first interlayer region contains functional particles B having an average particle diameter of 150 to 500 m.