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KR-20260068084-A - System and method for removing multiple non-biodegradable organic compounds from water

KR20260068084AKR 20260068084 AKR20260068084 AKR 20260068084AKR-20260068084-A

Abstract

The present invention relates to a system and method for increasing the removal of contaminants, such as PFAS and other non-degradable organic compounds, from water, particularly groundwater and drinking water, by using powdered activated carbon of less than 1 micron.

Inventors

  • 리드 테렌스 케이
  • 바우만 피터 지

Assignees

  • 아쿠아-에어로빅 시스템즈, 인코포레이티드

Dates

Publication Date
20260513
Application Date
20240903
Priority Date
20230907

Claims (9)

  1. As a method for removing contaminants from water, A step of adding a plurality of adsorbents to the flow of the water to be treated; A step of combining a plurality of adsorbents with water to be treated; A step of introducing a mixture of adsorbent and water into a single adsorption reactor for treatment; A step of transferring the mixture from the adsorption reactor to a ceramic membrane filter unit operating by cross-flow filtration using a recirculation pump, wherein the treated water is discharged as permeate and the mixture of adsorbents is returned to the adsorption reactor as residue. A method for removing contaminants from water, including
  2. A method for removing contaminants from water according to claim 1, wherein the plurality of adsorbents comprises more adsorbents than the adsorbent type.
  3. A method for removing contaminants from water according to claim 1, wherein the type of adsorbent may include any combination of SPAC, IX resin, and adsorptive clay.
  4. A method for removing contaminants from water according to claim 1, wherein each of the plurality of adsorbents has an average particle diameter of less than 40 microns.
  5. A method for removing contaminants from water according to claim 1, wherein the residence time is 2 minutes to 30 minutes.
  6. A method for removing contaminants from water according to claim 1, wherein a coagulant may be added to the influent flow to improve the performance of the adsorbent and the membrane.
  7. A method for removing contaminants from water according to claim 1, wherein the adsorbent mixture maintained in the reactor is maintained at 500 mg/L to 100,000 mg/L.
  8. A method for removing contaminants from water, wherein, in paragraph 2, the plurality of adsorbents are individually added to the system.
  9. A method for removing contaminants from water, wherein, in paragraph 2, the plurality of adsorbents are pre-mixed and added to the system as a mixture.

Description

System and method for removing multiple non-biodegradable organic compounds from water Claim of priority This application is a partial continuation application, claiming priority to U.S. Application No. 16/293,251, filed on March 5, 2019, which is currently granted, the entire contents of which are incorporated into this specification by reference. Field of invention The present invention relates to a system and method for removing recalcitrant organic compounds, including perfluoroalkyl substances and polyfluoroalkyl substances, from water. In particular, the present invention relates to a system and method for removing the aforementioned contaminants from water using powdered activated carbon of less than 1 micron in size together with ceramic membrane filtration. The present invention also relates to a system and method for concentrating and removing emitted carbon. The present invention also relates to a system and method for removing a number of recalcitrant organic compounds and their co-contaminants from water using a single reactor supporting a number of adsorbents that may include various material combinations of powdered activated carbon of less than 1 micron, ground ion exchange resin, and coagulant. The present invention also relates to a system and method for concentrating and removing one or more of the combinations of adsorbents discharged. Perfluoroalkyl and polyfluoroalkyl substances ("PFAS"), including their precursors and related ranges such as perfluorooctane sulfate ("PFOS") and perfluorooctanoic acid ("PFOA"), are compounds resistant to water and oil. These compounds are artificial compounds that have been used in a wide range of industries, including carpets, upholstery, and fire-fighting foams. However, these compounds are known carcinogens that accumulate in living organisms, and the removal of these compounds from water, particularly groundwater and drinking water, is a significant environmental concern. Due to strong fluorine-carbon bonds, PFAS compounds are resistant to common treatment methods, including biological and chemical oxidation. One of the more common approaches to the removal of PFAS from water is the granular activated carbon ("GAC") treatment system or the powdered activated carbon ("PAC") treatment system. As the name suggests, GAC uses granular activated carbon to remove various contaminants, including recalcitrant organic compounds such as PFAS and other compounds. In a typical GAC system, a tank accommodates the granular activated carbon and is large enough to maintain a flow of water to be treated for a sufficient amount of time for the contaminants to react with the GAC. During the reaction, PFAS and other organic compounds adhere to the surface of the granular activated carbon; that is, the aforementioned substances are adsorbed by the granular activated carbon. However, contaminated water also commonly contains a wide range of PFAS compounds with various sizes and characteristics, and single adsorbents are not optimally designed for this. For example, wood-based SPACs would be able to achieve efficient removal of large PFAS compounds, such as perfluorooctanoic acid (PFOA), which has 8 carbon molecules and a molecular weight of 414 g/mol. However, these wood-based SPACs may not operate efficiently with smaller PFAS molecules, such as perfluorobutanesulfonic acid (PFBS), which has a molecular weight of only 300 g/mol and has only 4 carbon molecules. Conversely, the pore structure of coal-based SPACs may perform better with small compounds like PFBS, but will not provide the same broad PFAS removal as wood-based SPACs. The chemical composition of PFAS species also plays a significant role in their relative adsorption. PFAS compounds can be cationic, anionic, or amphoteric, and in the case of amphoteric compounds, the molecule contains both positively charged and negatively charged functional groups. Perfluoroalkyl substances (PFAAs) are important terminal degradation products that can be further divided into perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids, and their adsorption capacities behave differently, where a single adsorbent may have a limited effect. To address the various compounds present in water, it may be desirable to use more than one type of SPAC material. In some cases, specialized ion exchange (IX) resins can provide a highly efficient means of removing targeted PFAS compounds. Commercial IX resins vary significantly based on their molecular structure and chemical properties, which can be designed to increase contaminant selectivity and provide a dual function of PFAS ion exchange and adsorption. Gel-type IX resins may utilize a continuous polymer composition consisting of polystyrene cross-linked with divinylbenzene. These resins provide high adsorption capacity and can be regenerated by thermal and chemical treatments. Macroporous resins differ in their process by creating larger pores that are beneficial when raw water con