US-20260125294-A1 - PLASMA ACTIVATED WATER PRODUCTION WITH MEMBRANE CONCENTRATION

US20260125294A1US 20260125294 A1US20260125294 A1US 20260125294A1US-20260125294-A1

Abstract

A plasma activated water production system includes a plasma reactor and a membrane concentrator. The plasma reactor includes an internal cavity, at least one electrically-conductive inlet capillary and outlet capillary. A mixing chamber has a feed gas inlet, a liquid inlet, and a mixed gas and liquid outlet. A power source is provided. The plasma reactor propagates a plasma discharge between the inlet capillary and the outlet capillary. A membrane concentrator includes a water flow channel with a water inlet and a water outlet, a dry gas inlet and a humidified gas outlet. An ion selective membrane is provided, and water will pass through the membrane into the dry gas, and the water leaving the membrane concentrator will have increased concentrations of nitrates, nitrites and hydrogen peroxide. An electrodialysis embodiment and a method of generating plasma activated with increased concentration of nitrates, nitrites and hydrogen peroxide are also disclosed.

Inventors

Bruce R. Locke

Assignees

FLORIDA STATE UNIVERSITY RESEARCH FOUNDATION, INC.

Dates

Publication Date: 20260507
Application Date: 20251231

Claims (6)

1 . A plasma activated water production system, comprising: a plasma reactor, comprising: a tubular reactor body portion having one or more internal walls that define an internal cavity; at least one electrically-conductive inlet capillary having an inlet capillary body extending between a fluid-receiving tip and a fluid-injecting tip, wherein the fluid-receiving tip is positioned outside the internal cavity, and wherein the fluid-injecting tip is positioned inside the internal cavity; at least one electrically-conductive outlet capillary having an outlet capillary body extending between a fluid-collecting tip and a fluid-ejecting tip, wherein the fluid-collecting tip is positioned inside the internal cavity, and wherein the fluid-ejecting tip is positioned outside the internal cavity, the inlet capillary being aligned with the outlet capillary; a mixing chamber outside of the tubular reactor body having a feed gas inlet, a liquid inlet, and a mixed gas and liquid outlet, the mixed gas and liquid outlet being in fluid communication with the fluid-receiving tip of the electrically conductive inlet capillary; a power source supplying a voltage across the at least one electrically-conductive inlet capillary and the at least one electrically-conductive outlet capillary; wherein the fluid injecting tip is disposed relative to the fluid collecting tip to generate a flowing liquid film region on the one or more internal walls and a gas stream flowing through the flowing liquid film region, when a fluid is injected into the internal cavity via the at least one electrically conductive inlet capillary; wherein the fluid injecting tip is disposed relative to the fluid collecting tip to propagate a plasma discharge along the flowing liquid film region between the at least one electrically-conductive inlet capillary and the at least one electrically-conductive outlet capillary; and, an electrodialysis membrane concentrator comprising concentrate and diluate plasma activated water flow channels separated by an ion exchange membrane, the plasma activated water flow channels communicating with one of an anode and a cathode, the anode and cathode being connected to a voltage source for creating a potential difference across the ion exchange membrane, wherein ions in the plasma activated water streams flowing through the plasma activated water flow channels will pass through the ion exchange membrane to form a concentrate flow stream and a diluate flow stream in the plasma activated water flow channels.
2 . The plasma activated water production system of claim 1 , wherein the ion exchange membrane is an anion exchange membrane and comprises at least one selected from the group consisting of polymer binders, anion exchange resins and additives.
3 . The plasma activated water production system of claim 2 , wherein the polymer binders comprise chlorinated polypropylene.
4 . The plasma activated water production system of claim 1 , wherein the anion exchange resins comprise styrene-divinyl benzene cross-linked copolymers.
5 . The plasma activated water production system of claim 1 , wherein the additives comprise activated carbon particles.
6 . The plasma activated water production system of claim 1 , further comprising a recycle conduit for recycling a portion of the concentrated flow stream to an inlet side of the concentrate plasma activated water flow channel.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 19/087,002 filed on Mar. 21, 2025 which is a divisional of U.S. patent application Ser. No. 17/711,798 filed Apr. 1, 2022, now U.S. Pat. No. 12,291,470, issued on May 6, 2025, which claims priority to U.S. Provisional Patent Application No. 63/170,836 “PLASMA ACTIVATED WATER PRODUCTION WITH MEMBRANE CONCENTRATION,” filed Apr. 5, 2021, the contents of which are incorporated herein by reference their entireties. FIELD OF THE INVENTION The present invention relates generally to plasma activated water production. BACKGROUND OF THE INVENTION Plasma reactors take a gas stream (typically air) and a pure liquid water stream and produce a mixture, called plasma activated water, which consists of ionic species such as nitrate and nitrite and neutral species including hydrogen peroxide. Such reactors and uses for such reactors are described in Method for Reacting Flowing Liquid and Gas in a Plasma Discharge Reactor, U.S. Pat. No. 9,861,950; Simultaneous On-Site Production of Hydrogen Peroxide and Nitrogen Oxides from Air and Water in a Low Power Flowing Liquid Film Plasma Discharge for Use in Agriculture, U.S. Pat. No. 10,350,572; Gas-Liquid Plasma and Bioreactor System and Method for Remediation of Liquids and Gases, U.S. Pat. No. 10,556,817; and Simultaneous On-Site Production of Hydrogen Peroxide and Nitrogen Oxides from Air and Water in a Low Power Flowing Liquid Film Plasma Discharge for Use in Agriculture, U.S. Pat. No. 10,589,252. The disclosures of these patents are hereby incorporated fully by reference. SUMMARY OF INVENTION A plasma activated water production system includes a plasma reactor and a membrane concentrator. The plasma reactor includes a tubular reactor body portion having one or more internal walls that define an internal cavity. At least one electrically-conductive inlet capillary has an inlet capillary body extending between a fluid-receiving tip and a fluid-injecting tip, wherein the fluid-receiving tip is positioned outside the internal cavity, and wherein the fluid-injecting tip is positioned inside the internal cavity. At least one electrically-conductive outlet capillary has an outlet capillary body extending between a fluid-collecting tip and a fluid-ejecting tip, wherein the fluid-collecting tip is positioned inside the internal cavity, and wherein the fluid-ejecting tip is positioned outside the internal cavity, the inlet capillary being aligned with the outlet capillary. A mixing chamber outside of the tubular reactor body has a feed gas inlet, a liquid inlet, and a mixed gas and liquid outlet, the mixed gas and liquid outlet being in fluid communication with the fluid-receiving tip of the electrically conductive inlet capillary. A power source is provided for supplying a voltage across the at least one electrically-conductive inlet capillary and the at least one electrically-conductive outlet capillary. The fluid injecting tip is disposed relative to the fluid collecting tip to generate a flowing liquid film region on the one or more internal walls and a gas stream flowing through the flowing liquid film region, when a fluid is injected into the internal cavity via the at least one electrically conductive inlet capillary. The fluid injecting tip is disposed relative to the fluid collecting tip to propagate a plasma discharge along the flowing liquid film region between the at least one electrically-conductive inlet capillary and the at least one electrically-conductive outlet capillary. The membrane concentrator includes a plasma activated water flow channel with a plasma activated water inlet and a plasma activated water outlet, a dry gas inlet and a humidified gas outlet. The plasma activated water flow channel includes an ion selective membrane, the membrane concentrator receiving liquid from the plasma reactor, whereby the plasma activated water will contact the ion selective membrane, water will pass through the membrane into the dry gas, and the plasma activated water in the plasma activated water flow channel leaving the membrane concentrator will have increased concentrations of nitrates, nitrites and hydrogen peroxide. The electrically-conductive inlet capillary can have a first internal diameter, the tubular reactor body can have a second internal diameter, and the electrically conductive outlet capillary can have a third internal diameter. The third internal diameter can be larger than the first internal diameter and smaller than the second internal diameter. The ion selective membrane can be Nafion®. The ion selective membrane can include polymeric membranes. The polymeric membranes can include at least one selected from the group consisting of polyamides, polyurethanes, poly (bio-amides), polyanilines, polyesters, polyimides, cellulose, and sulfonated polyethersulfone. The ion selective membrane can include a nanofiltration membrane for nitrate removal. The nanofi