Device for purifying liquid wastewater, and method for cleaning liquid wastewater using said device

Patent metadata

Field	Value
Publication number	US-9758412-B2
Application number	US-201314371793-A
Country	US
Kind code	B2
Filing date	Jan 8, 2013
Priority date	Jan 12, 2012
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A device for purifying liquid wastewater, includes: a container suitable for retaining a granulate consisting of solid particles, and for enabling the contact between the solid particles of the granulate and the liquid wastewater flowing in the container between: an inlet for the liquid wastewater to flow into the container, and an outlet for substantially decontaminated water to flow out of the container; a community of microorganisms extending so as to be in contact with the solid particles of the granulate; at least one live benthic invertebrate whose mean size is greater than 250 μm and which is distributed in the granulate; and at least one live benthic invertebrate whose mean size is from 50 μm to 250 μm and which is distributed in the granulate, characterized in that the community of macrobenthic organism and meiobenthic organism species includes a proportion of 60% to 80% of invertebrate detrivorous organisms.

First claim

The invention claimed is:

1. A device for sanitizing liquid wastewater, comprising:
a container holding an aggregate of solid particles and permitting contact between the solid particles of the aggregate and liquid wastewater flowing in said container between an inlet for said liquid wastewater into said container, and an outlet for substantially decontaminated water from the container;
a community of at least one species of microorganism growing on the surface of and in contact with the solid particles of the aggregate and forming a matrix, wherein said community of microorganisms develops;
at least one live benthic invertebrate selected from the group consisting of invertebrate macrobenthic organisms, having an average size greater than 250 μm, said macrobenthic organism(s) being distributed in the aggregate; and
at least one live benthic invertebrate selected from the group consisting of invertebrate meiobenthic organisms, having an average size of from 50 μm to 250 μm, said meiobenthic organism(s) being distributed in the aggregate,
wherein the macrobenthic organisms and the meiobenthic organisms form a community of species of benthic invertebrate organisms comprising a proportion of detritivorous invertebrate organisms, expressed as a percentage of the dry weight of the detritivorous invertebrate organisms and of the dry weight of the benthic invertebrate organisms of said community, of from 60% to 80%.

2. The device according to claim 1 , wherein the aggregate presents a ratio between the void volume capable of being occupied by water in the aggregate and the volume of said aggregate in the container of from 20% to 40%.

3. The device according to claim 1 , wherein the macrobenthic organisms are selected from the group consisting of: organisms of the phylum of hirudineans, organisms of the phylum of oligochaetes, organisms of the phylum of arthropods, and Ere organisms of the phylum of mollusks.

4. The device according to claim 1 , wherein the meiobenthic organisms are selected from the group consisting of: organisms of the phylum of nemathelminths, organisms of the phylum of cladocerans, organisms of the phylum of ire rotifers, organisms of the phylum of copepods, organisms of the phylum of gastrotrichs and organisms of the phylum of foraminifers, and organisms of the phylum of tardigrades.

5. The device according to claim 1 , wherein the community of microorganisms comprises unicellular microorganisms selected from the group consisting of bacteria, algae, fungi and protozoans.

6. The device according to claim 1 , wherein the macrobenthic organisms are from a community of at least one species of live benthic invertebrate selected from the group consisting of: communities of one or more species of live benthic invertebrate(s) collected from a bed of a natural watercourse, communities of one or more species of live benthic invertebrate(s) collected from a bed of a modified watercourse, communities of one or more species of live benthic invertebrate(s) collected from a bed of an artificial watercourse, and communities of one or more species of live benthic invertebrate(s) collected from a rearing pond.

7. The device according to claim 1 , wherein the meiobenthic organisms are from a community of at least one species of live benthic invertebrate selected from the group consisting of: communities of one or more species of live benthic invertebrate(s) collected from a bed of a natural watercourse, communities of one or more species of live benthic invertebrate(s) collected from a bed of a modified watercourse, communities of one or more species of live benthic invertebrate(s) collected from a bed of an artificial watercourse, and communities of one or more species of live benthic invertebrates collected from a rearing pond.

8. The device according to claim 1 , wherein the ratio of the dry weight of the live benthic invertebrate organisms contained in the container and the volume of the aggregate contained in the container is greater than 5 mg/dm 3 .

9. The device according to claim 1 , comprising a tank configured for containing a quantity of liquid wastewater, said tank belonging to a circuit for circulating said liquid wastewater between said tank and the inlet of the container and for returning the substantially decontaminated water between the outlet of the container towards the fluid inlet of said container via the tank.

10. The device according to claim 1 , comprising means of oxygenating the substantially decontaminated water with a gaseous fluid.

11. The device according to claim 9 , further comprising a circulator configured for collecting the substantially decontaminated water at the outlet of the container and reintroducing said substantially decontaminated water at the inlet of the container via the tank.

12. A method for treating liquid wastewater for the purpose of its decontamination, the method comprising:
selecting an aggregate made up of solid particles,
placing said aggregate within a container configured to maintain contact between said aggregate and a flow of percolating liquid water flowing in said container,
forming a flow of the percolating liquid water in contact with the aggregate between a liquid water inlet of the container, and a liquid water outlet of the container,
maintaining said flow for a specified period of time, together with conditions suitable to establish a community of at least one species of microorganism(s) on the surface of and in contact with the particles of the aggregate, and to form a matrix wherein said community of at least one species of microorganism(s) develops,
selecting the following:
at least one live benthic invertebrate selected from the group consisting of the live invertebrate macrobenthic organisms, having an average size greater than 250 μm, and said macrobenthic organism(s) is/are distributed in the aggregate, and
at least one live benthic invertebrate selected from the group consisting of the live invertebrate meiobenthic organisms, having an average size of from 50 μm to 250 μm, and said meiobenthic organism(s) is/are distributed in the aggregate,
the macrobenthic organisms and meiobenthic organisms forming a community of benthic invertebrate organisms comprising a proportion of detritivorous invertebrate organisms, expressed as a percentage of the dry weight of the detritivorous invertebrate organisms and of the dry weight of the benthic invertebrate organisms of said community of one or more species, of from 60% to 80%, and
introducing a flow of the liquid wastewater into the container in such a way as to permit its decontamination and formation of a flow of substantially decontaminated water at the liquid water outlet of the container.

13. The method according to claim 12 , wherein the community of species of live benthic invertebrate(s) is collected by filtration from a sediment selected from the group consisting of: sediments of a bed of a natural watercourse, sediments of a bed of a modified watercourse, sediments of a bed of an artificial watercourse, and sediments of a rearing pond.

14. The method according to claim 12 , wherein said method permits a treatment of the liquid wastewater and prevents clogging of said container.

15. The method according to claim 12 , wherein the level of nitrogen in the substantially decontaminated water is reduced from that of the contaminated wastewater.

16. The method according to claim 12 , wherein a level of plant protection agent in the contaminated wastewater is reduced.

Assignees

• Gerino Magali
• Vervier Philippe
• Sanchez Perez Jose Miguel
• Gauthier Laury
• Centre Nat De La Rech Scient (C N R S )
• Inst Nat Polytechnique Toulouse
• Université Paul Sabatier (Toulouse III)

Inventors

• Gerino Magali
• Vervier Philippe
• Sanchez Perez Jose Miguel
• Gauthier Laury

Classifications

• C02F2305/06

  Nutrients for stimulating the growth of microorganisms · CPC title

• C02F3/104

  Granular carriers · CPC title

• Y02W10/15

  Cross-Sectional Technologies · mapped topic

• C02F3/10

  Packings; Fillings; Grids (packing elements in general B01J19/30, B01J19/32) · CPC title

• C02F2103/007

  Contaminated open waterways, rivers, lakes or ponds · CPC title