Pollution control by constructed wetlands: An expanding French industry

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The ability of wetland areas to retain and treat a wide variety of pollutants in urban and rural areas has been known about for a number of years. Understanding how they work has facilitated the creation of biofilters such as constructed wetlands. At Mines Nantes, researcher Florent Chazarenc has studied these systems over lengthy periods and created solutions adapted to different types of wastewater. He aims to improve the French domestic wastewater treatment industry, an area of expertise that is starting to be exported.

 

 

Wastewater treatment tailored to the pollutant

Wastewater can be a by-product of human uses, whether domestic, agricultural or industrial, or can come in the form of surface run-off water. It contains organics, phosphates and nitrates, heavy metals, hydrocarbons and even drugs. “My research consists in developing wastewater treatment solutions adapted to situations which currently don’t have any: it all depends on the nature of the effluent, but the carrier is always water,” explains Florent Chazarenc. The researcher mainly works with a category of treatment processes known as constructed wetlands , which is a wastewater treatment system using macrophyte plants (aquatic plants with underwater or floating organs), substrate materials (sand, gravel etc.) and colonized by micro-organisms. The technique involves creating an artificial wetland that is used as a biofilter, commonly called a reed bed filter or constructed wetland.

In constructeRacines_Florent_Chazarencd wetlands the water is purified through a combination of physical, biological or chemical processes. Plants with a dense root structure offer good physical filtering, while micro-organisms growing on their surface produce biological activity that decomposes pollutants such as nitrates and transforms them into nitrogen gas. “When there’s nothing left to do biologically, we move on to chemicals”, which is the case for phosphates. “This combination of all three is called chameleon technology, Florent continues, “which entails creating biological and chemical-physics reactors adapted to all categories of wastewater”, regardless of climate conditions (temperature, amount of sun) or the liquid pressure and organic load.

Research into all kinds of solutions has been fueled by this variety of wastewater types. Florent Chazarenc and his team work on several projects at the same time, including developing systems to refurbish old extensive wastewater treatment plants built in the 1980s and give them a new lease of life, treating leachate in Africa by getting rid of pollutants through electrolysis and/or photocatalysis in combination with reed bed filters, and protecting natural wetlands with constructed wetlands.

 

Improving the French domestic wastewater treatment industry

“Since the 1980s and the initiative by IRSTEA in Lyon, more than 3,500 reed bed filters have been introduced in France for towns and villages with fewer than 2,000 inhabitants.” Florent Chazarenc has contributed to the sharp rise in these installations since the 1990s. In France, the process is called a “vertical flow filter” because the wastewater is spread out at the surface and filtered down through the bed via percolation. However, the fact that a surface area of 2 to 3 m2 is needed per inhabitant can sometimes hinder the development of the sector. Although improvements do exist to reduce this to 1 m2 or even 0.5 m2 per inhabitant, they have not yet been employed in association with large urban areas or wastewater from the food industry.

 

The double drainage system is only present in the compact channel, limited to the 1st stage, which is deeper.

The double drainage system is only present in the compact channel, limited to the 1st stage, which is deeper.

 

Florent has studied results from more than 150 of these installations over 10 years, looking at systems with two or just one treatment stage. The researcher aims to improve the French domestic wastewater treatment industry, which is now starting to be used abroad. “We are now very good at treating suspended matter or organic matter, but we could do better on nutrients like phosphates or nitrates”, he explains. The idea is to employ the same approach used in process engineering: “intensify the extensive system”.

Two approaches known as semi-extensive are being studied. The first consists in intensifying the pollutant-removal process using chemical techniques. The European project called Slasorb was conducted in this framework, proposing an innovative solution for extensive treatment of phosphates using a co-product of the metallurgic industry as reactive matter. “This project needs its first industrial reference”, added the researcher, who hopes to promote its disruptive technology. The second approach reduces the reaction volume and the surface area taken up by the process. This can be done through forced aeration or by transporting the effluent from the outlet back to the start of the process – recirculation; both these methods require energy, which may be produced from renewable sources (wind turbines or solar energy etc.).

Florent is interested in many other types of wastewater which can be treated with constructed wetlands and specific installations, including industrial wastewater (pastry-making, chocolate manufacturing, fizzy drinks manufacturers etc.) and sludge.

[box type=”shadow” align=”” class=”” width=””]From the lab to on-site testing

Filtres plantés de roseaux, Florent ChazarencIt takes one to two years for a vertical flow reed bed filter to reach its optimum efficiency. These long periods require work on several projects at the same time, in partnership with microstructures, SMEs or large groups. Some projects involve fundamental research, while others, which are greater in number, are focused on applied research with rapid dissemination. In this framework the technology readiness level is an important indicator for the solutions studied, from level 1: “basic principle observed”, to level 9: “real system proved”. Most of Florent Chazarenc’s work is situated between levels 5 and 7, and a few on levels 3 and 4.[/box]

 

Surface run-off water also needs treating

While significant financing is earmarked for wastewater treatment, rainwater treatment has only recently started receiving funding. This water is contaminated through the surface run-off process, washing the ground and coming into contact with contaminated surfaces, for example roads polluted by the car tire wear. “There is still a little atmospheric pollution in certain countries (acid rain)” the researcher explains, “but this is diminishing fairly quickly”. In rural areas, on the other hand, excess fertilizer is washed away by the rain.

Once again “the solution is to use plants as a pollution control factory”. For example, in partnership with highway management companies, the run-off water collected in holding basins can be treated by adding floating wetlands to improve their performance. Another example is processes that encourage sedimentation, with ditches containing plants or grass growing in them. “There is an international policy of no longer discharging this run-off water directly into rivers, but instead treating it first”, Florent is pleased to point out, mentioning among others the Water Framework Directive [2000/60/EEC] in Europe. Nevertheless, there is not as much legislative pressure in this field and potential financial partners, for example, are still few in number.

Although the effectiveness of reed bed filters is widely acknowledged, it is the acceptance of their benefits by the general public that will lead to their use on a large scale.

 

Petit_Portrait_Florent_Chazarenc_jauneAn Associate Professor at Mines Nantes, Florent Chazarenc contributed as early as in the 1990s to the rise in the use of processes for treating wastewater using reed bed filters, through his engineering internship and PhD in Environmental Engineering at the University of Savoie. He carried out his post-graduate research jointly at Polytechnique Montréal and at Institut de recherche en biologie végétale in Montréal, before returning to France in 2007 where he took his Accreditation to Lead Research in 2013.

A marathon-runner and triathlete, he understands what it means to work over the long term and to combine processes. He and his team, “a group which has enabled me to carry out these trials over all these years”, have earned recognition through a large number of projects. Having organized the 5th WETPOL conference (International Symposium on Wetland Pollutant Dynamics and Control) in 2013 in Nantes, he is also strongly involved in specialist groups of the IWA (International Water Association) on the subject of reed bed filters and water pollution control. Through these activities he aims to facilitate the sharing and dissemination of information, help and guide young researchers and promote solutions beyond their initial field, such as the sale of finishing zones at the end of traditional stations.

Augmented Reality, Marius Preda, Télécom SudParis

Augmented Reality: new standards and new tools

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Thanks to their sensors, mobile phones have become powerful platforms for augmented reality. Marius Preda and his team of researchers from Télécom SudParis, GRIN (Graphics and Interactive Media), have developed technologies recently chosen by ISO (International Organization for Standardization) for the production and transmission of augmented reality content.

 

As their capabilities have developed, smartphones and tablets have become powerful platforms for 3D visualization. The integration of sensors (video, photo, position, etc.) has made them platforms for augmented reality. “The idea is to build a bridge between the digital world and the physical world, by enabling the identification of elements in the real world that will trigger a digital action on a smartphone or tablet, and provide a combined view on the screen,” explains Marius Preda, a researcher at Télécom SudParis, in charge of the “graphic content” group for MPEG, a media standardization organization within ISO. His team creates standardized content production and transmission tools for augmented reality, for use with mobile devices.

 

Formal standardized language for augmented reality

Most companies are currently developing integrated augmented reality applications, but another development method is also possible: “We can formalize augmented reality experiences using a standard language that defines the user’s experience and can be interpreted by a browser, just like the web works today.”

Marius Preda and his team therefore developed ARAF technology: an open-source navigator with its own formal standardized language. “Mobile telephone manufacturers will have their own ARAF installed and optimized for their platforms, and content producers will be able to quickly create augmented reality experiences using authoring tools, without going into all the technical details, just like today we can create a website without knowing HTML.”

 

An image recognition cloud platform

At the same time, researchers have developed an image recognition cloud platform within a database. A unique signature, which is specific to each image, makes it possible to compare images and find similar objects in them, such as the Eiffel Tower, for example. To avoid false positives and false negatives, the development of the algorithm must involve a compromise between these two problems.

“One way of doing this is to identify unique characteristic points: we reproduce the human visual system, which focuses its attention on control points with many details,” explains Marius Preda. We obtain a constellation of unique points for an object and we record characteristics, such as the distance between the points, which will be used to compare an image with others in the database. We also work on atypical cases by using contour detection, especially to differentiate cars using images of their tail lights. If the signatures are similar, there’s a big chance the images are similar as well.”

This technology was used in particular by the GOOT application to recommend a similar wine, based on a picture of a wine label.

 

Authoring tools facilitate the creation of augmented reality content

Based on this technology, researchers are also creating authoring tools, like those developed as part of the BRIDGET European project. For users, these tools make it possible to offer quality, interactive and customized content on a second screen while watching television. A signature audio system enables the tool to recognize the program being broadcast, downloads additional content from a server, and displays the content in a synchronized manner.

For content producers, a video on the main screen can be enhanced, either manually using the web, or automatically using a visual search system: “With our huge database of indexed and annotated images, we try to see whether the content is similar to that in the database for each video frame,” explains the researcher. For example, if the Eiffel Tower is recognized in the video, the tool will offer information on the monument that is indexed in the database or retrieved from web. A second phase of the project plans to integrate a connection with social media.

There are many uses for these tools (personalized advertising, interactive cultural content, etc.) and many that have yet to be imagined, which is why companies are encouraged to try the technology and contribute to the database on the cloud platform via APIs.

 

Learn more about MPEG group

Pierre-Antoine Chardel

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Institut Mines-Telecom Business School | #sociology #ethics #DigitalMetamorphosis

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Internet of tomorrow

The Internet of tomorrow: New issues, new challenges

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In just a few years the internet has revolutionized daily life, becoming part of every aspect of society. However, the coming transformations may go much deeper, leading to major changes in the paradigms of vertical markets such as healthcare, energy, the environment etc. Daniel Kofman, a researcher at Télécom ParisTech, has been sketching out the future profile of the internet and examining the challenges of it for several years.

Are we witnessing a turning point in the history of the internet?

There have been three generations in the development of the internet. The first one started with the earliest form of the internet network, included the emergence of the Web 1.0 as a major service infrastructure and finished at the end of the millennium with the development of broadband connectivity. The second generation is that of the interactive web, the explosion of social media and the generalization of cloud computing and mobile internet. We are now entering the third generation, in which digital technology has become the principal conveyor of innovation within most vertical sectors, due in particular to the gradual fusion between the real and digital worlds. This fusion takes place through changes and developments such as the internet of things, Big Data and advances in virtual and augmented reality.

What will the internet of tomorrow offer society?

The merging of the digital and real worlds is taking place through digital technology’s capacity to ‘observe’ the physical world thanks to extensive use of sensors to the infrastructures of the internet of things. This makes many things possible like, for example, medical systems based on real-time monitoring of citizens’ health; optimization of the energy equation through enhanced visibility of consumption, production and storage of energy; integration of diverse transport systems based notably on real-time traffic and demand monitoring, and progression towards Industry 4.0 (self-organized plants and components for efficient mass production of personalized products). This new generation will bring another way of understanding and designing systems, infrastructures and services as well as the underlying technologies, and new societal challenges.

Among the challenges posed by the internet of things is the question of Big Data…

In order for the digital world to ‘understand’ what is happening in the real world, the data captured must be transformed into information, knowledge and cognition: in other words, a learning process that will allow the digital world to make increasingly complex decisions in an autonomous way. This capacity requires advanced digital modeling of the real world for the captured data to be interpreted correctly. Processing this large quantity of data, which is highly varied and most of the time unstructured, relies on a series of approaches that are often encompassed in the term Big Data. Improving Big Data solutions demands new, multidisciplinary working methods: we cannot extract knowledge from the data measured without an understanding of the field that has generated them and without comprehending how they have been captured and filtered.

Lastly, this merging of the digital and real worlds involves action, in other words the digital world’s ability to control connected objects in the real world, and therefore to have an impact on it. The mentioned merge is therefore a process of observing, of analyzing-understanding-learning, then making decisions and acting.

 

LINCS[box type=”shadow” align=”” class=”” width=””]LINCS: bridging the gap between the academic world and industry

The Laboratory of Information, Networking and Communication Science, created in 2010, is a center for industrial and academic research on information and communication technology financed by Institut Mines-Télécom, INRIA (Institut national de recherche en informatique et en automatique), UPMC (Université Pierre et Marie Curie), Alcatel-Lucent, and IRT SystemX (Institut de recherche technologique, whose members include Orange and Thales). It has also established collaborations with various other companies. Its researchers study a wide range of topics such as future architecture for information and communication systems, the forthcoming systems for content distribution, the internet of things, wireless networks and future mobile networks, smart grids, intelligent transport, structural analysis of social networks, etc. Find out more [/box]

 

Does this turning point imply a change in the current infrastructures?

Cars, houses and cities of the future will become service platforms, like our smartphones are today. Instead of statically configuring isolated systems for pre-designed services, these infrastructures will be general and programmable in order to dynamically create new services and applications, meeting users’ needs in real time. These programmable infrastructures, based on paradigms like the virtualization of the entire technology chain, constitute a major challenge that is shaking up industries in the field.

What prospects does the internet of things open up for industry?

While the ‘all-connected’ era is still a few years away, the number of connected objects is already increasing exponentially and industrial firms are undergoing reorganization to be able to take advantage of these structural changes. During the first decade of this century the internet was shaped by big American companies, but the forthcoming turning point may allow France and Europe to catch up: the internet of things will open up multiple opportunities thanks to the merging of digital technology with vertical markets, and France and Europe are very well positioned in fields such energy, transport and healthcare.

What is Institut Mines-Télécom’s positioning in these challenges?

In this context, Institut Mines-Télécom’s academic research and partnership research is already well known. Our strength lies in part in the fact that we have expert knowledge and skills in information and communication technologies, as well as in the fact that we have always built very strong ties with the industrial sector. Our researchers are working on anticipating the challenges raised by connected things, and contributing to the construction of the internet of tomorrow. A good illustration of this is our contribution to the study titled ‘Internet: prospective 2030’ for France Stratégie. However, research continues to advance very quickly.

 

Photo_Daniel_KofmanBorn in Uruguay, Daniel Kofman came to France with a degree in engineering. In 1993 he earned his PHD and in the same year he was taken on as a Research Professor at Télécom ParisTech. Since then he has held various positions of responsibility and carried out high-level missions. They have included consulting for major industry players, acting as an expert for various national and international institutions (he is notably a member of the Scientific Committee of the Parliamentary Office for the evaluation of scientific and technological decisions, OPECST, in the French National Assembly), and presidency of the Management Board and scientific coordination at the Euro-NGI, the European network of excellence, which he co-founded in 2003. He is also a founder of two start-ups as well as LINCS (see insert). For Daniel Kofman, the accumulation of all these roles serves a purpose. “These missions are not independent of each other, but are mutually enriching,” he explained. However, this workload has never prevented him from continuing to give classes at Télécom ParisTech, which he has done for over 20 years. “Transmission has always been my principal aim”, he admits. “Moreover, feedback from high-quality students also provides food for thought”. Simply put, he works to define the communication networks of the future and, of course, to communicate his own knowledge.

Editor: Umaps, Yann Chavance