Ferric Iron-Dosed Anaerobic Biological Wastewater Treatment Technology

Patent metadata

Field	Value
Publication number	US-2022332615-A1
Application number	US-202017753625-A
Country	US
Kind code	A1
Filing date	Sep 24, 2020
Priority date	Sep 25, 2019
Publication date	Oct 20, 2022
Grant date	—

Abstract

A method for treating wastewater comprising subjecting a sulfate containing wastewater to Fe(III) iron dosing in an anaerobic bioreactor containing one or more of an iron reducing bacteria and one or more of a sulfate reducing bacteria, and one or more of a fermentative bacteria, and adjusting a dosage of the Fe(III) iron in the anaerobic bioreactor to achieve a Fe/Sulfate molar ratio that is equal to or greater than 0.50, and removing an effluent from the anaerobic bioreactor that is a treated wastewater. A wastewater treatment system is provided having a wastewater reservoir, a ferric iron solution reservoir, an anaerobic bioreactor, and an effluent reservoir.

First claim

1 . A wastewater treatment system comprising a wastewater reservoir, a ferric iron solution reservoir, an anaerobic bioreactor, and an effluent reservoir, wherein said wastewater reservoir is connected to said anaerobic bioreactor via a first port, wherein said ferric iron solution reservoir is connected to said anaerobic bioreactor via a second port, and wherein said effluent reservoir is connected to said anaerobic bioreactor via a third port, and wherein said anaerobic bioreactor contains one or more of an iron reducing bacteria and one or more of a sulfate reducing bacteria, and a fourth port for providing internal recirculation within said anaerobic bioreactor, a first pump in communication with the first port for feeding a wastewater from the wastewater reservoir to said anaerobic bioreactor, a second pump in communication with said second port for feeding a ferric iron solution from said ferric iron solution reservoir to said anaerobic bioreactor, and a third pump in communication with said fourth port for providing said internal recirculation of the wastewater within the anaerobic bioreactor.

2 . The wastewater treatment system of claim 1 wherein said anaerobic bioreactor contains one or more of a iron reducing bacteria, one or more of a sulfate reducing bacteria, and one or more of a fermentative bacteria.

3 . The wastewater treatment system of claim 2 wherein said iron containing solution is selected from the group consisting of ferric chloride, acid mine drainage, and an electron acceptor for organic oxidation that is not oxygen.

4 . A method for treating wastewater comprising
adding a sulfate containing wastewater and an effective amount of a ferric iron containing solution to an anaerobic bioreactor wherein said anaerobic bioreactor is a vessel that has a top, a bottom, and one or more side walls, and one or more ports for entry of one or more influents and exit of one or more effluents, and providing said anaerobic bioreactor with one or more of an iron reducing bacteria and one or more of a sulfate reducing bacteria, and one or more of a fermentative bacteria, to form a mixture in said anaerobic bioreactor of said sulfate containing wastewater, said ferric iron containing solution, said iron reducing bacteria, said sulfate reducing bacteria, and said fermentative bacteria; maintaining an anaerobic condition in said anaerobic bioreactor; adjusting a dosage of said ferric iron containing solution to said mixture in said anaerobic bioreactor to achieve a Fe/Sulfate molar ratio that is equal to or greater than 0.50; providing an internal recirculation of said mixture in said anaerobic bioreactor; maintaining a neutral pH of said mixture in said anaerobic bioreactor; producing a sludge at said bottom of said anaerobic bioreactor; and removing an effluent from said anaerobic bioreactor that is a treated wastewater.

5 . The method of claim 4 including removing said sludge from said anaerobic bioreactor.

6 . The method of claim 4 including wherein said sulfate containing wastewater is derived from domestic, municipal, and industrial sources.

7 . The method of claim 6 wherein said sulfate containing wastewater includes suspended solids, biodegradable organics, pathogens, nutrients, heavy metals, and pollutants.

8 . The method of claim 4 including increasing said ferric iron dosing of said mixture in said anaerobic bioreactor to affect an enhanced organic component removal and oxidation kinetics.

9 . The method of claim 4 including increasing said ferric iron dosing to affect a lowering of a sulfide level in said effluent through forming iron sulfide precipitates.

10 . The method of claim 4 including increasing a chemical oxygen demand removal.

11 . The method of claim 4 including wherein said iron reducing bacteria is selected from the group consisting of Geobacter sp., Ignavibacteria sp., and Geothrix sp.

12 . The method of claim 4 including wherein said sulfate reducing bacteria is selected from the group of Desulfovibrio sp., Desulfobulbus sp., Desulfatirhabdium sp, Desulforhabdus sp., and Desulfomonile sp.

13 . The method of claim 4 including wherein said ferric iron containing solution is selected from the group consisting of ferric chloride, acid mine drainage, and an electron acceptor for organic oxidation that is not oxygen.

Assignees

• Univ West Virginia

Inventors

• Lin Lian-Shin

Classifications

• C02F2101/101

  Sulfur compounds · CPC title

• C02F2209/40

  Liquid flow rate · CPC title

• C02F3/345

  for biological oxidation or reduction of sulfur compounds · CPC title

• C02F2101/30

  Organic compounds · CPC title

• C02F2209/08

  Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD] · CPC title