Copyright : Daniel Garcia/CEA
Wash station. The effluents are collected through the metal grating and transported toward the treatment basins.

A process for treating phytopharmaceutical effluents
The plan consists of a station for the washing and recovery of phytopharmaceutical effluents, which supplies a series of three lagooning basins. The basins are unventilated and cascading, and are seeded with a bacterial collection that degrades the active molecules of effluents.

A plan that has completed its proof of concept
A first analysis was conducted in a farm located in the southwest of France (Lot-et-Garonne) that grows wheat, soybean, sunflower, alfalfa and stone fruits. The initial results indicate an almost complete degradation (> 90%) of most of the active molecules discharged into the ponds.

To further characterize the process, the project intends to:

– diversify the nature of the molecules to be degraded by expanding the types of crops (viticulture, market gardening, arable crops, etc.)
– assess the functionality of the process according to the climatic conditions (such as a mountainous climate)
– compare two paired demonstrators, with and without seeding, so as to compare the efficiency of the process with a control that does not contain the added bacteria.

Copyright : Daniel Garcia/CEA
The lagooning system consist of three covered basins, wich are unventilated ans cascading. On the right, the basins take on the color of the bacteria with wich they were seeded.

Bacteria for use in decontamination
The process is based on the bio-decontamination ability that some microorganisms have to degrade active molecules. For the “Phytobarre” process, the laboratory of cellular bioenergetics (CEA/LBC) selected a collection of photosynthetic* bacteria that are able to adapt to the established lagooning system (i.e. polluted and unventilated waters). The laboratory will be responsible for producing this non-transformed and non-pathogenic collection of environmental bacterial strains. The laboratory will also establish the type of conservation and the most suitable packaging for a simple and easy manipulation by non-specialist users.

Study of the degradation of phytopharmaceutical products
Throughout the project, the content of phytopharmaceutical products in the basins will be regularly analyzed by an approved laboratory. A more specific monitoring will be performed at the paired demonstrator located at the partner “La Pugère”. This will allow comparing the degradation of products in the presence and absence of the bacterial collection.

*Photosynthetic organisms: organisms that use light as an energy source to produce their own organic matter. Plants and certain bacteria are able to carry out the photosynthesis reaction.

Experimentations took place in the 4 treatment stations of phytosanitary effluents, which were set up in 2014 in the farms of the project participants.  Effluents were collected in washing areas and treated by a biological process using selected photosynthetic bacteria, added to the storage tanks.

Samples of storage tanks content have been regularly collected since 2014  :

1. -before the beginning of phytosanitary treatment period : january to march
2. -during the treatment period  : june to november
3. -after the treatment period  :  november to january

Samples were collected monthly in each prototype and each storage tank. The laboratory tests allowed to :

1. -quantify the active substances from phytopharmaceutic products;
2. -monitor volume fluctuations  (balance beetwen inputs and water evaporation)
3. -verify the bacterial content

Copyright : Guy LAMBERT/LESA
Bacteria’s identification in the Laboratory of Cellular and Pathological Bioenergetics – CEA Cadarache

Samples were quantitatively analysed for about 400 active substances.

Futhermore AMPA, the highly toxic product from glyphosate degradation, was tested and quantify.

Year 2015

from january 2015 to february 2016

In 2015, 9,5 kg of active substances from phytosanitary effluents were collected in the PhytoBarre prototypes. Results showed a reduction of polluant load about 82 % on average. The bacteria consortium activity was tested on the 82 different active substances used in the 4 farms.

Copper content, polluant concentration and outdoor conditions had no effect on the biological process of biodegradation.

Thanks to an accurate preliminary diagnosis, effluent volumes in storage tanks were efficiently controled, and no environmental release occured.

[i] Arrêté du 11 janvier 2007 du Ministère de la Santé et des Solidarités

[ii] Observatoire des services publics d’eau et d’assainissement – Panorama des services et de leur performance en 2012, ONEMA, 2015