Systems and methods for reducing total dissolved solids (TDS) in wastewater by an algal biofilm treatment

Patent metadata

Field	Value
Publication number	US-12054411-B2
Application number	US-202318199051-A
Country	US
Kind code	B2
Filing date	May 18, 2023
Priority date	Jan 22, 2019
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

A system for reducing total dissolved solids in wastewater can include a vertical reactor that can include a flexible sheet material, where the flexible sheet material can be configured to facilitate the growth and attachment of an algal biofilm. The vertical reactor can include a shaft, where the shaft can be associated with and can support the flexible sheet material, and a drive motor, where the drive motor can be coupled with the shaft such that the flexible sheet material can be selectively actuated. The system can include a fluid reservoir containing a portion of wastewater through which the flexible sheet material is configured to pass as well as a stressor operably configured to stimulate the algae to produce an extracellular polymeric substance. A method of reducing total dissolved solids in wastewater includes moving an algal biofilm through the wastewater and moving the algal biofilm through a gas.

First claim

We claim:

1. A method of reducing total dissolved solids in wastewater comprising:
providing an algal biofilm, the algal biofilm comprising a material configured for growth and attachment of a defined mass of algae;
providing a fluid reservoir containing a portion of wastewater fluid;
moving the algal biofilm through the portion of wastewater fluid in the fluid reservoir;
providing a stressor to algae in the algal biofilm to trigger a defense mechanism of the defined mass of algae such that a first amount of an extracellular polymeric substance is produced, wherein the stressor comprises exposing the algal biofilm to a first liquid phase and a second gas phase, and wherein the second gas phase comprises rotating the algal biofilm out of the first liquid phase to expose the algal biofilm to ambient air; and
removing a portion of total dissolved solids in the portion of wastewater fluid with the extracellular polymeric substance.

2. The method of claim 1 , wherein the stressor is biotic or abiotic.

3. The method of claim 1 , wherein the stressor is selected from the group consisting of increasing the pH of the algal biofilm, decreasing the pH of the algal biofilm, increasing the temperature of the algal biofilm, decreasing the temperature of the algal biofilm, modulating the temperature of the algal biofilm, adjusting an amount of light applied to the algal biofilm, adjusting a wavelength of the light applied to the algal biofilm, and combinations thereof.

4. The method of claim 1 , wherein the extracellular polymeric substance comprises proteins and polysaccharides.

5. The method of claim 1 , further comprising an algal growth system, the algal growth system comprising:
(a) a vertical reactor configured to retain the algal biofilm;
(b) a shaft, wherein the shaft is associated with and supports the algal biofilm; and
(c) a drive motor, the drive motor being coupled with the shaft such that the algal biofilm is selectively actuated.

6. The method of claim 1 , further comprising harvesting the algae from the algal biofilm.

7. The method of claim 1 , further comprising precipitating salts from the portion of wastewater fluid in the fluid reservoir, wherein removing a portion of total dissolved solids in the portion of wastewater fluid further comprises removing at least a portion of precipitated salts.

8. The method of claim 1 , further comprising providing a second amount of extracellular polymeric substance created by the defined mass of algae.

9. A method of reducing total dissolved solids in wastewater comprising the steps of:
providing an algal growth system comprising:
(a) a vertical reactor comprising;
(i) a flexible sheet material, the flexible sheet material being configured to facilitate growth and attachment of algae;
(ii) a shaft, wherein the shaft is associated with and supports the flexible sheet material; and
(iii) a drive motor, the drive motor being coupled with the shaft such that the flexible sheet material is selectively actuated;

(b) a fluid reservoir, wherein the flexible sheet material is configured to pass through the fluid reservoir during operation of the algal growth system, the vertical reactor being positioned at least partially within the fluid reservoir; and
(c) a portion of wastewater, wherein the portion of wastewater is retained within the fluid reservoir and includes an amount of total dissolved solids;

rotating the flexible sheet material of the algal growth system through the portion of wastewater retained in the fluid reservoir in a first liquid phase;
rotating the flexible sheet material of the algal growth system through a gas in a second gas phase, wherein the second gas phase comprises rotating the flexible sheet material out of the first liquid phase to expose the flexible sheet material to ambient air to trigger a defense mechanism of the defined mass of algae such that a first amount of an extracellular polymeric substance is produced; and
harvesting the algae from the flexible sheet material; and
wherein stimulating the production of the extracellular polymeric substance reduces the amount of total dissolved solids in the portion of wastewater.

10. The method of claim 9 , wherein rotation of the flexible sheet material of the algal growth system through the gas is a first stressor, and wherein the method further comprises providing a second stressor.

11. The method of claim 9 , further comprising providing a plurality of algal growth systems to decrease the amount of total dissolved solids in a water system.

12. The method of claim 9 , further comprising precipitating salts from the portion of wastewater fluid in the fluid reservoir, wherein removing a portion of total dissolved solids in the portion of wastewater fluid further comprises removing at least a portion of precipitated salts.

13. A method of reducing total dissolved solids in wastewater comprising:
providing an algal biofilm, the algal biofilm comprising a material configured for the growth and attachment of a defined mass of algae;
providing a fluid reservoir containing a portion of wastewater fluid;
moving the algal biofilm including the defined mass of algae through the portion of wastewater fluid in the fluid reservoir;
providing a stressor to the defined mass of algae in the algal biofilm to affect the defined mass of algae such that a first amount of extracellular polymeric substance is created by the defined mass of algae, wherein the stressor comprises exposing the algal biofilm to a first liquid phase and a second gas phase, wherein the second gas phase comprises rotating the algal biofilm out of the first liquid phase to expose the algal biofilm to ambient air; and
removing a portion of total dissolved solids in the portion of the wastewater fluid.

14. The method of claim 13 , wherein the stressor is biotic or abiotic.

15. The method of claim 13 , wherein the stressor is selected from the group consisting of increasing the pH of the algal biofilm, decreasing the pH of the algal biofilm, increasing the temperature of the algal biofilm, decreasing the temperature of the algal biofilm, modulating the temperature of the algal biofilm, adjusting an amount of light applied to the algal biofilm, adjusting a wavelength of the light applied to the algal biofilm, and combinations thereof.

16. The method of claim 13 , wherein the extracellular polymeric substance comprises proteins and polysaccharides.

17. The method of claim 13 , further comprising an algal growth system, the algal growth system comprising:
(a) a vertical reactor configured to retain the algal biofilm;
(b) a shaft, wherein the shaft is associated with and supports the algal biofilm; and
(c) a drive motor, the drive motor being coupled with the shaft such that the algal biofilm is selectively actuated.

18. The method of claim 13 , further comprising harvesting the algae from the algal biofilm.

Assignees

• Univ Iowa State Res Found Inc
• Metropolitan Water Reclamation Distr Of Greater Chicago

Inventors

• Wen Zhiyou
• Peng Juan
• Gross Martin A
• Kumar Kuldip
• Kunetz Thomas

Classifications

• C12M35/08

  Chemical, biochemical or biological means, e.g. plasma jet, co-culture · CPC title

• C12M35/02

  Electrical or electromagnetic means, e.g. for electroporation or for cell fusion · CPC title

• C12M29/18

  External loop; Means for reintroduction of fermented biomass or liquid percolate (loop type reactors for chemical or physical processes B01J19/2435) · CPC title

• C12M27/20

  Baffles; Ribs; Ribbons; Auger vanes · CPC title

• C12M25/14

  Scaffolds; Matrices (in general C12N5/0068) · CPC title