# US 2017/0107137 A1 · Resource reuse-type industrial waste water treatment method and apparatus utilizing oxidizing agent generated by utilizing waste water

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- Number: US 2017/0107137 A1
- Document ID: US20170107137A1
- Status: Published application
- Kind: A1
- Application number: 15/390,444
- Filed: 2016-12-23
- Published: 2017-04-20
- Earliest claimed: 2014-09-24
- Assignees: Techwin Co., Ltd.
- Applicants: Techwin Co, Ltd.
- Inventors: Boong Ik Jung; Jung Sik Kim; Do Won Jung; Chang Bok Lee; Seong Cheol Han; Sung Hwan Jang
- Web page: https://patentgrep.com/patent/US20170107137A1

## CPC

- C02F 9/00: Multistage treatment of water, waste water or sewage
- C25B 1/29: Persulfates
- C25B 9/23: comprising ion-exchange membranes in or on which electrode material is embedded
- C02F 1/20: by degassing, i.e. liberation of dissolved gases (degasification of liquids in general B01D19/00; arrangement of degassing apparatus in boiler feed supply F22D)
- C02F 1/42: by ion-exchange (ion-exchange in general B01J)
- C02F 1/461: by electrolysis
- C02F 1/52: by flocculation or precipitation of suspended impurities {(C02F1/463 takes precedence)}
- C02F 1/5236: {using inorganic agents}
- C02F 1/56: Macromolecular compounds
- C02F 1/66: by neutralisation; pH adjustment (for degassing C02F1/20; using ion-exchange C02F1/42; for flocculation or precipitation of suspended impurities C02F1/52; for removing dissolved compounds C02F1/58)
- C02F 1/72: by oxidation {(C02F1/4672 takes precedence)}
- C02F 1/78: with ozone {(C02F1/4672 takes precedence)}
- C02F 2001/46133: {characterised by the material}
- C02F 2001/46147: {Diamond coating}
- C02F 2101/16: Nitrogen compounds, e.g. ammonia
- C02F 2101/345: {Phenols}
- C02F 2101/38: containing nitrogen
- C02F 2103/28: from the paper or cellulose industry
- C02F 2201/46115: Electrolytic cell with membranes or diaphragms
- C02F 2305/02: Specific form of oxidant
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)

## Abstract

This invention relates to a resource-recycling type method and apparatus for treating industrial wastewater using an oxidizing agent produced from wastewater, wherein, in the treatment of industrial wastewater containing nitrogen compounds and refractory COD-causing pollutants, an oxidizing agent is autonomously produced using ammonia gas stripped from wastewater and is then added back to the wastewater, thus economically treating the wastewater without the need to purchase an expensive oxidizing agent. This wastewater treatment method, suitable for use in decreasing amounts of nitrogen pollutants (T-N), including ethanolamine compounds and ammonia nitrogen (NH3—N), and refractory COD-causing pollutants in industrial wastewater, includes: stripping ammonia from raw wastewater, producing an oxidizing agent via addition of sulfuric acid to the stripped ammonia, electrolysis and addition of sodium hydroxide, and performing chemical treatment by adding the produced oxidizing agent back to the raw wastewater from which ammonia was stripped, thus removing the nitrogen pollutants (T-N) and the refractory COD-causing pollutants, and the apparatus used to perform the wastewater treatment method is also provided.

## Claims

### Claim 1

A resource-recycling-type method of treating industrial wastewater using an oxidizing agent produced from wastewater, suitable for use in decreasing amounts of a nitrogen pollutant (T-N), including an ethanolamine compound and ammonia nitrogen (NH3—N), and a refractory COD (Chemical Oxygen Demand)-causing pollutant in industrial wastewater, comprising:
stripping ammonia from raw wastewater;
producing sodium persulfate in a manner in which the stripped ammonia is placed in a scrubber and added with a sulfuric acid solution diluted to 5 to 50 wt % to thus recover ammonium sulfate concentrated to 5 to 45 wt %, after which the recovered ammonium sulfate and a sulfuric acid solution are fed into an electrochemical conversion unit comprising a diaphragm-type electrical reactor having an ion exchange membrane to produce ammonium persulfate, after which the produced ammonium persulfate is allowed to react with sodium hydroxide in a reaction chamber; and
performing chemical treatment in a manner in which the produced sodium persulfate is added back to the raw wastewater from which ammonia was stripped, thus removing the nitrogen pollutant (T-N) and the refractory COD-causing pollutant.

### Claim 2 (depends on 1)

The resource-recycling-type method of claim 1, wherein the producing the sodium persulfate comprises stripping ammonia generated during a reaction using a gas-stripping unit to thus recover concentrated ammonium sulfate, or further stripping the ammonia so as to be converted into nitrogen.

### Claim 3 (depends on 1)

The resource-recycling-type method of claim 1, wherein the diaphragm-type electrical reactor comprises an anode configured such that a conductive base is coated with at least one selected from among platinum (Pt), iridium (Ir), ruthenium (Ru), tantalum (Ta), tin (Sn) and boron-doped diamond, and a cathode composed of at least one selected from a material used for the anode, titanium (Ti), nickel (Ni), graphite, lead (Pb) and zirconium (Zr), and a surface of the anode or the cathode is in a mesh or plate form.

### Claim 4 (depends on 1)

The resource-recycling-type method of claim 1, wherein the stripping the ammonia from the raw wastewater comprises adding the raw wastewater with a NaOH aqueous solution so that the raw wastewater has a pH of 9 to 13, and then stripping the ammonia using a gas-stripping unit.

### Claim 5 (depends on 1)

The resource-recycling-type method of claim 1, further comprising performing intermediate treatment, which comprises physicochemical treatment using a pH control and coagulation chamber in a manner in which the raw wastewater from which ammonia was stripped is added with at least one selected from among an aluminum sulfate-based flocculant, an iron sulfate-based flocculant, an inorganic flocculant and an organic flocculant and thus a pH of the raw wastewater is adjusted, and the raw wastewater is added with a coagulant, so that an organic material and an SS (Suspended Solid) component in the raw wastewater are coagulated, precipitated and separated, and only a supernatant is discharged, before the performing the chemical treatment.

### Claim 6 (depends on 5)

The resource-recycling-type method of claim 5, wherein the intermediate treatment further comprises electrochemical treatment in a manner in which the raw wastewater composed of the supernatant is electrolyzed through a reaction for 10 to 600 min at a current density of 0.001 to 0.4 A/cm2, after the physicochemical treatment.

### Claim 7 (depends on 5)

The resource-recycling-type method of claim 5, further comprising performing electrochemical treatment in a manner in which the raw wastewater subjected to the physicochemical treatment and the chemical treatment is electrolyzed through a reaction for 10 to 600 min at a current density of 0.001 to 0.4 A/cm2, thus producing a sulfur oxide radical, which is then used to additionally remove a refractory pollutant.

### Claim 8 (depends on 1)

The resource-recycling-type method of claim 1, further comprising subjecting the raw wastewater, from which ammonia was stripped, to intermediate treatment or post-treatment including at least one treatment selected from among physicochemical treatment for pH control and coagulation precipitation using at least one selected from among an aluminum sulfate-based flocculant, an iron sulfate-based flocculant, an inorganic flocculant and an organic flocculant; biological treatment using microorganisms; physical treatment via filtration and reverse osmosis (RO); electrochemical treatment via electrolysis, electro-coagulation and electro-precipitation; and advanced treatment using ozone (O3), reverse electro-osmosis, UV irradiation and sonication, before or after the performing the chemical treatment.

### Claim 9

A resource-recycling-type apparatus for treating industrial wastewater using an oxidizing agent produced from wastewater, suitable for use in decreasing amounts of a nitrogen pollutant (T-N), including an ethanolamine compound and ammonia nitrogen (NH3—N), and a refractory COD-causing pollutant in industrial wastewater, comprising:
a gas-stripping unit for stripping ammonia from raw wastewater;
a sodium persulfate production unit, comprising a scrubber configured such that ammonia stripped from the raw wastewater is allowed to react with a sulfuric acid solution diluted to 5 to 50 wt % to thus recover ammonium sulfate concentrated to 5 to 45 wt %, an electrochemical conversion unit comprising a diaphragm-type electrical reactor having an ion exchange membrane and configured such that the recovered ammonium sulfate is electrochemically reacted and thus converted into ammonium persulfate, and a chemical reaction chamber configured such that the ammonium persulfate thus produced is allowed to react with sodium hydroxide to produce sodium persulfate; and
a chemical reaction unit configured such that the raw wastewater, from which ammonia was stripped using the gas-stripping unit, and the sodium persulfate produced using the sodium persulfate production unit are allowed to react so as to remove a nitrogen pollutant (T-N) and a refractory COD-causing pollutant.

### Claim 10 (depends on 9)

The resource-recycling-type apparatus of claim 9, wherein the sodium persulfate production unit further comprises a gas-stripping unit for stripping ammonia generated upon producing the sodium persulfate.

### Claim 11 (depends on 10)

The resource-recycling-type apparatus of claim 10, wherein the electrochemical conversion unit is a diaphragm-type electrical reactor comprising an anode configured such that a conductive base is coated with at least one selected from among platinum (Pt), iridium (Ir), ruthenium (Ru), tantalum (Ta), tin (Sn) and boron-doped diamond, and a cathode composed of at least one selected from a material used for the anode, titanium (Ti), nickel (Ni), graphite, lead (Pb) and zirconium (Zr), and a surface of the anode or the cathode is in a mesh or plate form.

### Claim 12 (depends on 9)

The resource-recycling-type apparatus of claim 9, further comprising at least one of an intermediate treatment unit and a post-treatment unit disposed before or after the chemical reaction unit.

### Claim 13 (depends on 12)

The resource-recycling-type apparatus of claim 12, wherein the intermediate treatment unit comprises a pH control and coagulation chamber for treating the raw wastewater from which ammonia was stripped, and an electrolysis chamber, which are sequentially disposed.

### Claim 14 (depends on 12)

The resource-recycling-type apparatus of claim 12, wherein the post-treatment unit comprises an electrolysis chamber for electrolyzing the raw wastewater to produce a sulfur oxide radical having high oxidation potential.

### Claim 15 (depends on 12)

The resource-recycling-type apparatus of claim 12, wherein the intermediate treatment unit or the post-treatment unit comprises at least one treatment unit selected from among a pH control and coagulation chamber for physicochemical treatment using at least one selected from among an aluminum sulfate-based flocculant, an iron sulfate-based flocculant, an inorganic flocculant and an organic flocculant; a reaction chamber for biological treatment using microorganisms; a filtration and reverse osmosis chamber for physical treatment through filtration and reverse osmosis (RO); an electrolysis chamber for electrochemical treatment through electrolysis, electro-coagulation and electro-precipitation; and a reaction chamber for advanced treatment using ozone (O3), reverse electro-osmosis, UV irradiation and sonication.