From Tuesday 29th of June until 1st of July 2021 the ESRs attended the Liverpool Summer School organized by Xin Tu and Timo Gans. The training focused not only on plasma catalysis with lectures like Plasma catalytic experiment design, data analysis & energy efficiency by Xin Tu and Olivier Guaitella but also on the development of soft skills e.g. Communication skills by Dr. Dale Heywood or on commercialization issues like Understand IP by Howard Read and Richard Bray. This diversity was very much appreciated by the students. The only to make the school even better would have been to meet in person rather than online. We are looking forward for the next event…
We would like to thank the Sorbonne University Library service for providing our ESRs with a cycle of workshops about Open Access and bibliographic Search and Watch on May 5th and 6th, 2021 . It was very useful and informative, looking forward to use the tips learned for our future publications within the PIONEER consortium.
On March 17, 2021 Brigitte Attal-Tretout (member of the advisory board) and Richard Engeln were joined by quite a few ESRs as well as supervisors to discuss in situ analysis of trace species in plasma by Raman and LIF (Laser induced fluorescence ) diagnostics while enjoying a cup of coffee. This really shined light on the possible challenges.
In the last sixty years, the freshwater demand has more than doubled and as many as 3.5 billion people could experience water scarcity by 2025. Agriculture is the largest global user of freshwater and its consumption has increased by a 100 % in the last century while industrial water demand has more than tripled, due to an increasing requirement of electricity, fuel and water-intensive goods like textiles. During the same period, domestic water use has quickly risen by 600 %1. As the world population is still growing fast, finding suitable technologies to achieve a smarter water reuse and reduce our water footprint is urgent and of vital importance.
Hard time for conventional water treatment processes
According to the WHO, 500 million people die each year because of poisoning or disorders associated to water contamination by biological or chemical agents3. The need to tackle water scarcity together with health issues related to pollution calls for the introduction of treatment capability beyond conventional water treatments methods. Water contaminants may include organic and inorganic substances, which can be toxic, and pathogens. Conventional water treatment processes are not always very effective in their removal. For instance, coagulation, sedimentation and filtration units are unable to effectively remove trace organic compounds such as pharmaceuticals, personal care products and endocrine disrupting chemicals4. Moreover, chlorination can lead to the formation of by-products such as trihalomethanes (e.g. chloroform), haloacetic acids and chloramines, which can be even more toxic than the parental molecules and thus requiring further depuration steps5. In order to meet the modern requirements for water quality, a combination of reverse osmosis and advanced oxidation processes (AOPs) has been often proposed. Moreover, UV irradiation is typically added as an additional layer of protection against pathogens and some chemicals. However, treatment costs are typically higher than conventional methods6.
Advanced oxidation processes (AOPs)
AOPs refer to those processes that generate large amounts of OH radicals, which have proven to be effective in the decomposition of a wide range of organic contaminants, toxins and pathogens. Conventional AOPs generally involve the addition of chemical precursors on site as well as adequate infrastructure to accommodate storage. Therefore, treatment costs exceed that of conventional water treatment methods, making them less attractive for the commercial scale and poorly accessible to the underdeveloped regions of the world, where the water scarcity is more severe6.
Plasma is here to help
At this purpose, plasma technologies are attracting more and more interest as a source of advanced oxidation species. Plasma-liquid interactions can offer a number of features that conventional treatment cannot provide at all and conventional AOPs can only provide at high cost. In particular, Foster6 points out that plasma can be generated in regular air or in the liquid itself, without the requirement of consumables. Moreover, plasma can combine the effects of different reactive species simultaneously, leading to faster decomposition rates. In addition, its application is inherently modular and therefore can be easily suited in a conventional water treatment system to substitute and reduce the number of depuration steps6.
Plasma for organic contaminant reduction
The reliability of plasma treatment to decontaminate water from organic pollutants has been deeply investigated in the past years. Magureanu et al.7 reviewed numerous studies on the removal of harmful pollutants such as phenols, organic dyes, pharmaceuticals and pesticides. While the potential of plasma to remove these contaminants is widely accepted, many efforts are still required to improve the energy efficiency of their decomposition and mineralization. In this respect, reactor design stands out as a major critical point. Besides the intrinsic characteristics of the pollutants and the aqueous medium, faster and efficient removal rates depend on the mass transfer of reactive species from the plasma to the liquid. At this purpose, maximizing the contact area between the plasma and the treated solution is of crucial importance. This could be achieved by generating a foam on the liquid surface or spraying the solution through the discharge area7,8. Magureanu et al.7 also points out that the combination of plasma treatment with other AOPs can enhance the removal efficiency by the generation of additional OH radicals. This can be realized either by recycling the effluent gas from plasma, rich in ozone, or by adding a catalyst to promote Fenton oxidation with the plasma-generated hydrogen peroxide. Indeed, additional ozone gas bubbling could improve removal rate of alachlor, an aromatic pesticide, and energy cost by more than 50 %9. Nevertheless, as much efficient as it is considered compared to conventional processes, plasma is energy consuming. At this purpose, Jiang et al.10 suggested that biological treatment should be coupled with plasma into integrated technologies for water treatment. Here, the AOP treatment step should be minimize as much as possible in favor of the biological stage, which is almost energy free. Therefore, the role of plasma should be limited to the breakdown of non-biodegradable molecules into biodegradable byproducts, leaving the task of completing the decomposition and mineralization processes to the biological treatments.
Perfluoroalkyl substances: a new threat to water quality
Unfortunately, there are some extreme situations where most of the work cannot be delegated the biological treatment step and almost all the mineralization process needs to be completed beforehand. This is the case of perfluoroalkyl substances (PFAS), whose degradation byproducts are still harmful and non-biodegradable. PFAS are a group of more than 4700 chemicals and are used in a wide variety of consumer products and industrial applications because of their unique chemical and physical properties, including oil and water repellence, temperature and chemical resistance and surfactant properties. Those outstanding features are deriving from the fluoro-carbon bonds, which are extremely stable and thus unreactive. Their extraordinary characteristics turn out to be very undesirable when it comes to remove PFAS from water. The high hydrophobicity of the perfluorinated tails makes PFAS very prone to bioaccumulation and therefore potentially dangerous even at very low concentrations. On the other hand, their surfactant behavior and persistency bring those molecules far away from the source of contamination. Detection of PFAS in water is still very challenging and requires advanced analytical methods such as high-resolution mass spectrometry. To face this new challenge, water treatment plants are often equipped with activated carbon beds and ion exchange resins to adsorb PFAS. However, these techniques are affected by short breakthrough times and generate waste products, which require further treatments13. Moreover, most of the AOPs, based on oxidation by OH radicals, have proven to be inefficient against PFAS14. At this purpose, plasma technologies can be helpful to handle the issues related to the removal of these hazardous molecules by featuring a wide range of reactive species beyond OH radicals. Of particular interest are aqueous and free electrons, which are able to attack and remove fluorine from the long perfluorinated tails protruding from the solution surface into the gas phase. When the plasma feed gas is argon and a positive voltage polarity is applied, argon ions may also initiate reactions of charge transfer and trigger the decomposition of PFAS15. Moving from air to argon as feed gas can indeed improve the energy efficiency and lead to a faster mineralization without producing nitric acid and thus maintaining almost unaltered the characteristics of the aqueous medium11. Moreover, argon allows recirculation of argon through the reactor, reducing its consumption and eventually leading to decomposition of gaseous by-products which otherwise would be introduced in the atmosphere. Here, reactor design is extremely important and should focus on increasing the contact area between plasma and solution. In addition, bubbling should be introduced in order to increase the concentration of PFAS in the plasma-liquid interface11,15.
New challenges for plasma: micro- and nanoplastics
After disposal, up to 70 % of plastics is lost to the environment. Most of plastic materials are hardly degradable through weathering and ageing, thereby accumulating in the aquatic system for decades. Their slow degradation leads to the formation of plastic debris of different size. Particles with a diameter between 1 and 5 µm are defined microplastics (MPs), while particles with lower diameters are categorized as nanoplastics (NPs). Water and wastewater treatment plants are considered as an important pathway for the release of NPs/MPs since fragmentation and ageing of plastics can be accelerated by photo-oxidation by UV light, hydrolysis and mechanical fracture17. MPs are also contained in some commercial products such as face cleaners, drilling fluids, 3D printing products, pharmaceutical vectors and industrial abrasives and thus are directly introduced in the environment18. Detection of NPs/MPs is still very challenging and, due to their small particle size, only a few techniques can give a reliable quantification. Those techniques would be Raman and micro-Raman spectroscopy dynamic light scattering (DLS) and nanoparticles tracking analysis (NTA) which are quite expensive and sensitive to impurities in real water and wastewater samples17. AOPs, such as photo-degradation by UV light and chemical oxidation, have been proposed as suitable way to reduce the concentration of NPs/MPs in water but they are limited by long process periods, making them disadvantageous for scaling up18. However, ozonation led to formation of carbonyl groups on the surface of polystyrene plastic making its mineralization by microorganisms faster. Moreover, the generation of reactive oxygen species and strong UV irradiation in plasma systems could work together to induce the dissociation of C-C and C-H bonds in the PVC MPs19. In recent years, a few studies to simulate the artificially-accelerated aging of MPs have been carried out and those are reviewed by Liu et al.20 The aging potential of plasma treatment compared to the other processes tested is outstanding and very promising. However, no studies have been conducted on the possibility to decompose and/or make NPs/MPs more biodegradable by plasma treatment so far.
Plasma is a very promising and versatile tool, which can help to tackle water scarcity and reduce the disparity on the access to high quality drinking water. The wide range of reactive species produced can simultaneously decontaminate water by organic and inorganic compounds, pathogens and perhaps even by micro and nanoplastics, with a low energy demand and cost. Studies on the upscaling of such technologies must be prioritized as the stress on the water resources is constantly increasing.
This text was written by Omar Biondo.
1World Resources Institute. (2021, March 9). Retrieved from https://www.wri.org/
2Aerial view of a wastewater facility in California, US [online]. Available at: [https://unsplash.com//][Accessed 11 March 2021]
3World Health Organization (WHO). (2018). Retrieved from http://www.who.int/
4Huerta-Fontela, M., Galceran, M. T., & Ventura, F. (2011). Occurrence and removal of pharmaceuticals and hormones through drinking water treatment. Water Research 45, 3, 1432-1442.
5Gopal, K., Tripathy, S. S., Bersillon, J. L., & Dubey, S. P. (2007). Chlorination byproducts, their toxicodynamics and removal from drinking water. Journal of Hazardous Materials 140, 1-6.
6Foster, J. E. (2017). Plasma-based water purification: Challenges and prospects for the future. Phys. Plasmas 24, 055501.
7Magureanu, M., Bradu, C., & Parvulescu, V. I. (2018). Plasma processes for the treatment of water contaminated with harmful organic compounds. J. Phys. D: Appl. Phys. 51, 313002 (23pp).
8Stratton, G. R., Bellona, C. L., Dai, F., Holsen, T. M., & Mededovic Thagard, S. (2015). Plasma-based water treatment: Conception and application of a new general principle for reactor design. Chemical Engineering Journal 273, 543-550.
9Wardenier, N., Gorbanev, Y., Van Moer, I., Nikiforov, A., Van Hulle, S. W., Surmont, P., . . . Vanraes, P. (2019). Removal of alachlor in water by non-thermal plasma: Reactive species and pathways in batch and continuous process. Water Research 161, 549-559.
10Jiang, B., Zheng, J., Qiu, S., Wu, M., Z. Q., Yan, Z., & Xue, Q. (2014). Review on electrical discharge plasma technology for wastewater remediation. Chemical Engineering Journal 236, 348-368.
11Saleem, M., Biondo, O., Sretenović, G., Tomei, G., Magarotto, M., Pavarin, D., . . . Paradisi, C. (2020). Comparative performance assessment of plasma reactors for the treatment of PFOA; reactor design, kinetics, mineralization and energy yield. Chemical Engineering Journal 382, 123031.
12Tomei, G. (2019). Plasma non-termico per la degradazione di acido perfluoroottanoico (PFOA) in acqua (Master’s thesis). Università degli studi di Padova, Italy.
13Woodard, S., Berry, J., & Newman, B. (2017). Ion exchange resin for PFAS removal and pilot test comparison to GAC. Remediation 27, 19-27.
14Trojanowicz, M., Bojanowska-Czajka, A., Bartosiewicz, I., & Kulisa, K. (2018). Advanced Oxidation/Reduction Processes treatment for aqueous perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) – A review of recent advances. Chemical Engineering Journal 336, 170-199.
15Stratton, G. R., Dai, F., Bellona, C. L., Holsen, T. M., Dickenson, E. R., & Mededovic Thagard, S. (2017). Plasma-Based Water Treatment: Efficient Transformation of Perfluoroalkyl Substances in Prepared Solutions and Contaminated Groundwater. Environ. Sci. Technol. 51, 1643-1648.
16Collected plastic during Community Cleanup at the shoreline and harbourfront in Hamilton, Canada [online]. Available at: [https://unsplash.com//][Accessed 11 March 2021]
17Enfrin, M., Dumee, L. F., & Lee, J. (2019). Nano/microplastics in water and wastewater treatment processes – Origin, impact and potential solutions. Water Research 161, 621-638.
18Rodríguez-Narvaez, O. M., Goonetilleke, A., Perez, L., & Bandala, E. R. (2021). Engineered technologies for the separation and degradation of microplastics in water: A review. Chemical Engineering Journal, 128692.
19Zhou, L., Wang, T., Qu, G., Jia, H., & Zhu, L. (2020). Probing the aging processes and mechanisms of microplastic under simulated multiple actions generated by discharge plasma. Journal of Hazardous Materials 398, 122956.
20Liu, P., Shi, Y., Wu, X., Wang, H., Huang, H., Guo, X., & Gao, S. (2021). Review of the artificially-accelerated aging technology and ecological risk of microplastics. Science of the Total Environment 768, 144969.
Sometimes there is nothing more helpful than a casual discussion with your colleagues over a hot cup of coffee to overcome obstacles in your work. Even before Corona forced us to maintain some distance between each other it was not always easy to realize these discussions because the people (and therefore the knowledge) is distributed all over Europe. According to the targeted objective of this year, namely stepping up efforts to cooperate within the consortium we introduced the “Coffee with …” sessions.
These are online meetings with multiple experts in a certain field of Pioneer present and all ESRs are invited to join to discuss their questions and problems with the experts but also among each other. In contrast to the trainings, that are mainly lecture-based, the “Coffee with … ” is really about the interaction of the people.
So far two sessions took place. On January 27, 2021 Fédérico Azzolina Jury, Frédéric Thibault Starzyk (member of the Advisory board), and Olivier Guaitella offered their expertise when discussing in situ (or “operando”) infrared absorption measurements. And on February 22, 2021 Annemie Bogaerts and Vasco Guerro took the ESRs’ questions regarding modelling.
In a one day online workshop organized by Sorbonne University on March 4th, 2021 the ESRs got a nice overview over methods to find research literature. Even the “old stagers” in literature search among the ESRs could learn a few new tricks to improve and accelerate the process.
As part of the celebration of women in science we are encouraged to talk about our experience as women in STEM. With an early career in chemistry, it seemed to me that chemistry is very comfortable in the presence of women actively working in the field. More than half of my classmates were females and the same proportion applied to the professors. I always counted on female role models during my studies that inspired me to be curious, to work hard, and to aspire for the best. However, life as a student is very different from the struggles of a scientist in modern times such as postulating for a permanent position or getting funding for a project. Given our short experience in academia, the best is to ask women who have already passed through all these things and currently work as full-time researchers. For this article, we have interviewed Maria Victoria Navarro from the Instituto de Carboquimica (ICB) in Spain and Ana Sobota from the Eindhoven University of Technology (TU/e) in The Netherlands, two of the PIONEER supervisors who were invited to share their personal experiences.
- Why did you choose to become a scientist? What moment in your youth made you choose a career in science?
Ana: This is just what I always wanted to be. It never occurred to me that I had enough schooling or enough knowledge and that I wanted to do something else. Becoming a scientist wasn’t a conscious decision, the curiosity to learn more and to understand never died.
Maria Victoria: In my case, the science career was always there. From school, the science, mathematics and natural sciences subjects were the ones that interested me the most and also I obtained the best qualifications. As the science topics became more specialized (physics, chemistry, biology and more complex mathematics), they continued to attract me a lot and the image of the laboratory and the research in chemistry began to appear. However, it seemed to me a job that only extraordinarily intelligent people like Santiago Ramón y Cajal or Marie Curie could access.
Lately, I began my training in chemistry at the university that allowed me to acquire knowledge about the transformation of the matter from which we are made and the world that surrounds us, the reason for different natural and production processes, the change of some compounds into others and the behaviour of the materials. I thought to graduate in Technical Chemistry specialty that joined chemistry and mathematics, very close to Chemical Engineering. At that moment, I was focused to follow my career in the industry.
However, when I was finishing my studies at the University, the possibility arose to do a PhD in chemical engineering, that is, to take up the idea of research in a laboratory applying the studies I had carried out. I did not hesitate.
- Why did you choose plasma physics? What impact do you expect make in the scientific world by working in plasma physics?
A: I chose plasma physics because I had to pick a mentor for my diploma thesis, and the professor doing plasma was the nicest one around. Afterwards I really found it beautiful.
You create impact as you go along. As a scientist, you always stand on the shoulders of people who came before you. Maybe they’re not extremely visible as individuals, but every discovery is a building block that supports someone else’s later work. The new knowledge I created will be the shoulder someone else stands on. In addition, I educate the next generation of engineers and scientists. If you want to measure impact, I think that is much more valuable. My own scientific discoveries cannot be compared with the sum total of the future scientific discoveries of the people I helped educate. Actually, seeing your student succeed based on something you taught him/her is one of the best feelings in this job.
- In ten years, what do you hope to have accomplished in terms of your work? What is your goal as a scientist?
A: My goal as a scientist is to create good science – reliable new knowledge. About 10 years in advance… my plan in terms of science is always the same: find a niche in your own field which you can advance significantly beyond the state of the art. Currently this is developing diagnostics for plasma-surface interactions, which are suitable for the specificities of non-thermal atmospheric pressure plasmas. There is a lot to discover in this field.
MV: My goal as a scientist is to reduce the production of wastes by using them to produce energy without polluting. In this way, I would like to contribute to preserving the environment by helping to improve the progress and future of people.
In 10 years I would like to have developed the necessary technology for a process that allows the use of CO2 to generate methane with high energy efficiency. I would like to develop it at all levels, from the concept development to the proof of concept, the process validation at different scales and the development of the production prototype.
- What were the biggest obstacles or challenges you had to overcome? Did you ever have the impression that it would be easier or harder if you were male?
A: The hardest time I had in terms of career was in securing tenure. Switching gears between the wonderful world of scientific discovery during my PhD and postdoc projects and the world of management and especially funding is something I had some trouble with. Getting that first funding was stressful. I think the biggest challenge were cultural differences. I don’t live and work in the culture I was brought up in. During the PhD project everyone is friends with everyone else and cultural differences are fun. When you have to start competing for money in a culture that is not yours, you start noticing that your system of values is unusable. (For example, in my own view the biggest sin you can commit in The Netherlands is to be inefficient. That means that long explanations annoy your audience, because you’re wasting their time. That means that a project proposal which explains things in minute detail is not even going to get read, even though it might be a great scientific idea. This is in complete contrast to my own culture.) This was a bigger deal for me than the gender issue. I don’t think it would have been easier for me if I was male.
MV: There have been several challenges that I have faced in my scientific career such as defending the PhD, doing postdoctoral stays in foreign institutions or passing exams to obtain a research position. Currently, the biggest difficulty I find is obtaining funding for research and PhD students. All these challenges have to be faced by men and women in the same way and the success is based on presenting interesting scientific developments.
In my opinion, nowadays the Spanish public research system is equally opened to the participation of men and women. From my personal experience, one of my supervisors was a brilliant woman scientist that reached the highest research level in the organisation. Actually, the research permanent staff in my research institute has a balanced representation of women and men.
- What kind of prejudices, if any, did you have to face? How did that make you feel? Were you able to overcome these?
A: There are always prejudices, everyone has them. However, it is really difficult to say with certainty that someone’s decisions are being influenced by prejudice. When I feel unfairly judged or unfairly treated because of cultural or gender differences, I try to get a strong foothold on something else and not waste too much time on the prejudiced person. Of course, being treated unfairly hurts, but staying hurt and stuck in that situation hurts more.
MV: I do not remember myself facing any kind of general prejudices. Most of the people involved in science usually will wait to see your actions before creating themselves an idea of you.
- What have you seen as changes (major or minor) that have happened in terms of women in science? For example, opportunities for advancement, funding, tenure, salary differentials, etc.?
A: The Netherlands is one of those countries with a very low percentage of women in physics and the number gets miniscule if you look at the positions at the top, which would be the position of full professor. However, this is changing very quickly in the last years. This is a side of the Dutch culture that I admire. Once they managed to recognize the problem, they put immediate efforts on several levels to rectify it. Just to give you an example, at my own department I believe that the number of female scientific staff has more than tripled in the last few years.
On a larger scale, both in space and in time, the gender issue is progressing slowly, but it is getting better. I don’t think we’re all on equal grounds regarding any of the criteria from the question, however we’re doing better than before. For example, my grandmother would never have been able to be a scientist, even though she was a very clever woman, but I am perfectly able to be an associate professor at a university. I think it’s important to accept that gender inequality is in many cases a cultural matter and should be addressed on all levels, from family to top managerial positions. For example, while there are people telling (young) women that science is not for them, that it’s not feminine, that they aren’t smart enough and that they should be pretty, timid and agreeable instead of making up their own minds, the problem won’t be solved.
MV: In my work environment in the public National Research Council, opportunities for improvement are the same for men and women, obtained through the recognition of scientific merit and I don’t know direct salary differences between women and men in the same working scales. During my years in the Instituto de Carboquímica, I have seen the participation of scientist women in managing positions like four Institute directors. In addition, I have seen other managing positions actually occupied by women like Regional delegate, Area coordinator or President of CSIC. There are also examples of women scientist dedicating part of their time to apply their knowledge of the science system and its needs into politics, trying to improve the government management of the science field.
However, I know it could be different in other scientific environments. The recognition of merits may have a factor estimated by evaluators that can be influenced by their personal conception of the different qualities of men and women. To reduce the influence of this point, I have seen many initiatives regarding the inclusion of qualified women in evaluation boards for thesis PhD, staff selection or project selection.
- In your opinion, which changes, if any, are needed in the scientific system to be more attractive to women in science and possible future scientists?
A: Maybe it’s just a matter of critical mass. As soon as there is enough diversity in an environment, this diversity tends to sustain itself, whether it concerns women or internationals or people with background in poor social class. In short, we’re on a good route. The present female role models are in the position to attract more female scientists and the system will change itself. Perhaps the next frontier are indeed students whose families are rooted in the poorer social class. They have to overcome a large barrier just to invest time into studying instead of getting a full-time job as soon as possible.
MV: One of the aspects of the Scientific System that could make it more attractive to women is to increase the visibility of the actual participation of women at all research and managing levels. As I said, the scientific system is open to the participation of women and to have this knowledge from the school to the general society could make it more attractive to women. I want to highlight that there are also women scientist who are actively participating in actions to increase the visibility of the women in science, for instance AMIT (Asociación de Mujeres Investigadoras y Tecnólogas) There is important work to do in social, educational or cultural aspects that could provide more general information on the participation of women in the scientific system.
- Thinking in terms of careers, what words of wisdom would you offer to young women considering entering the field of science?
MV: The sciences careers offer fields of work that maintain and improve the quality of life, directly in industrial production processes or in research to solve health, food, energy or environmental problems. It is a wide range of possibilities in constant evolution in which the most personal interests can easily be included.
A: Don’t worry about prejudice. Spend as little time as you can on people who treat you unfairly and find a way around them. Life is too short.
This initiative for the International Day of Women and Girls in Science has brought us ESRs to start a discussion, with sharing of ideas, opinions and experiences. We have just scratched the surface of the theme we are touching, therefore please wait for one more insightful perspective on the matter of inclusivity and representation in research and science. Coming soon!
Worth having a look: Pioneer Universities Gender Equality webpages
AGH Krakow – no gender equality webpage
University of Bucharest – National Gender studies ban (https://www.euronews.com/2020/06/17/romania-gender-studies-ban-students-slam-new-law-as-going-back-to-the-middle-ages)
University of Trento
University of Antwerp – Master in Gender studies but no committees for gender equality
University of Liverpool
University of Caen – no webpage dedicated
University of Zaragoza
University of Paris-Saclay
Several figures have been used to describe the gender gap in academia and research, from “leaky pipeline” to “glass ceiling”. But what are the experiences of girls and women in the scientific community? We have tried to gather together our perspectives as young women starting our careers in the science, technology, engineering and mathematics (STEM) field, reflecting on the past formative years and wondering about our future prospects.
It is undeniable that our childhood and school years have a great influence on our interests and on the person that we become as adults. There is still a considerable disparity between the education provided to male and female children around the world. Patriarchal and obsolete gender roles are still engraved in the way society teaches young boys and girls: from the toys that we are given to the life lessons we are told. This lack of equal education is leaving women in a skills crisis when it comes to STEM and high responsibility jobs . Another issue is the under-representation of successful female role models in science. Let’s be honest, at most people would be able to name Madame Marie Sklodowska Curie if asked on the street to name a famous female scientist. Young girls do not have a mirror to seem themselves in when it comes to dreaming of becoming a researcher. As a consequence, women are unmotivated to try a career in STEM, feeling ashamed to speak up about their passion and discriminated against in case they do.
One of us had a strong model growing up: her grandmother who, in the mid-1900s, chose a career in physics, facing a world that was encouraging women even less to pick their own path. We recognize now the importance of representation: it makes everything you imagine obtainable and possible.
With our short experience as PhD students, we would like to send out a few words of encouragement to girls who are interested in science and research. But first, let’s have an idea of the situation we are delving into.
More than 500 000 people were studying Science (Biology, Chemistry, Physics and Mathematics) in the European Union (EU) in 2018 at a Bachelor or Master level (or equivalent). Overall, women were under-represented, accounting for roughly 46% of all Science students in the EU. However, this number is not representative as there is a strong disparity amongst the subjects of study. Indeed, less than 30% are female students in Physics against more than 60% in the field of Biology.
In Figure 1, the share of female students in different fields of Science in 2016 and 2018 is represented for the countries that are part of the Pioneer consortium. Among the EU Member States, Romania and Poland stand out with more than 50% of female students in the four fields considered. In contrast, the share of female Physics students is less than one fifth in Belgium (18.5%) and the Netherlands (15.7%). Excluding Romania and Poland, the highest shares of female students in Mathematics were recorded in Italy (>50%) and Portugal (>40%).
Concerning the evolution between 2016 and 2018, the general trend would suggest an increase of the number of female students in Science. The field mostly concerned by this increase is the field of Physics, with a growth in all the countries considered except Ireland, Italy, and Poland.
When discussing the gender gap the term STEM is mostly used and refers to subjects such as Astronomy, Biochemistry, Biology, Chemical engineering, Chemistry, Computer science Electrical engineering, Mathematics, Physics, Statistics… the issue of female underrepresentation and lack of female role models in STEM subjects has been discussed extensively and is often blamed for steering women away from studying these subjects. Indeed, it reinforces the perception that women will feel isolated and excluded in these typically male-dominated environments. In order to encourage more female students to choose a STEM degree, universities, employers and governments have also introduced policies aimed at increasing the proportion of women but the effects of these policy instruments are difficult to assess and there is still a long way to go before equality is reached. Universities can also fight the gender gap by creating new interdisciplinary scientific fields as it was shown that women would be more drawn to this type of research. Finally, efforts should be made to increase the exposure of positive female role models both in schools and in universities.
We have discussed the disproportion between men and women in STEM at BSc and MSc levels. These numbers remain below 40% at doctoral level, where we find 37% and 39% of female PhD students and graduates, respectively . If we compare these data to the corresponding shares in all fields, we see that European early stage researchers are almost reaching parity on a gender basis, while women in science and technology suffer from a drop of 11 and 9 percentage points respectively, in the same positions.
There are however differences between all EU Countries, with some doing better than others, as well as more marked disparities depending on the discipline within the broad STEM category. For instance, physics and engineering have the worst female participation, while the number of women in natural sciences, biology and chemistry is increasing at a faster rate, mirroring the same trends we saw for undergraduate and postgraduate students.
How are universities and institutions tackling this problem? Gender equality has been included among the 17 Sustainable Development Goals in the 2030 EU Agenda. We have examined the websites of the 15 Universities taking part in our Consortium, to have a general picture of the situation in Europe. The majority of them has a dedicated webpage on gender equality and diversity, where its policies and resolutions are listed. Only two Universities (U. of Trento and U. of Zaragoza) have an actual Monitoring Center that provides public progress stats on a yearly basis, confirming the need to fill huge data gaps. We strongly encourage all universities to take a leaf from them, to be more effective in their actions for the achievement of equality. A special mention goes to the University of Liverpool for its LivWiSE project (Liverpool Women in Science and Engineering society) , for their outstanding work on promotion, networking and event organization. We really recommend you to visit their webpage and youtube channel.
Across all the EU Marie Sklodowska-Curie Actions (MSCAs) funded between 2014 and 2018, the average presence of women accounted for 40,9%. Specifically, the Doctoral programmes MSCA-ITN (Innovative Training Networks) registered 42,5% presence of female researchers. In the frame of Pioneer, only 1 out of 3 ESR is female, which is way below the general share.
To conclude, a doctorate is a period of intensive training and the beginning of a research career in an elective field. Women must not be cut out from the technological and scientific advancement and from shaping tomorrow’s world. Finally, “there is overwhelming evidence that diverse teams are more creative and productive”, as Frank Baaijens, Rector of Eindhoven TU, declared, speaking about the University’s resolutions to increase women’s and minorities’ representation in academia. 
With this overview of the current situation of gender gap in university, we are looking ahead at the future scenarios and prospects for our professional careers. Nowadays, it can be said that finding a proper job and becoming a successful professional is one of the biggest challenges in one’s life. In today’s society, based on living cost, usually in each family both parents are employed. With progress in education and industry, unlike the previous generations, the last two generations are well educated and the competition for employment has increased. But the question is: are all these opportunities equal for women and men? Statistics show that in EU (Schengen Area) the employment rate of men is 11.8 percentage points higher than for women, despite the fact that the population of women in working age is 51% and for men is 49% . Moreover, women are generally paid less with hourly earnings on average 14.8 % below those of men . It seems that even in developed countries, there is still gender inequality in the workplace.
Compared to men, especially in technical positions, women are still not considered as experts. For example, imagine there is a job opportunity as an engineer in a company, there are two candidates: one woman and one man with exactly same credentials. Most likely, the man is going to be chosen based on prejudices that picture male professionals as more suitable and more educated in STEM field. Of course, with such point of view coming from society, women are less confident and usually underestimate themselves. Just imagine in such environment how women are under pressure to prove their perfection. Even if they are selected for a job, they always have these thoughts in mind that they should prove themselves to their peers. A study showed that, in the same workplace if you ask a man and a woman what they are mostly thinking about during their work is that the man thinks about improve his work because he is sure of his perfection in the work and the woman thinks about to compete with other colleagues just because of lack of confidence.
Just being a woman is a big challenge to face inequalities, so you can imagine how much harder is to be a successful woman. It’s still long way to show the societies that being a successful woman is not just being a good mother or wife. Women’s share in science and industry is much bigger than what we think. We have to rely on our set of skills, our solid preparation and our passion to show the world that these gender biases are outdated and a new generation of girls in STEM is ready to tackle the challenges of tomorrow.
Stay tuned for the second part of the blogpost in honor of the International Day of Women and Girls in, we will be reflecting on these important topics with some of the PIONEER supervisors.
 “https://www.unicef.org/media/84046/file/Reimagining-girls-education-through-stem-2020.pdf,” [Online].
 Dataset ‘Pupils and students enrolled by education level, sex and field of education’ “https://ec.europa.eu/eurostat/web/products-datasets/-/educ_uoe_enra03” (Accessed on 31/01/2021)
Extra references: Pioneer Universities Gender Equality webpages
AGH Krakow – no gender equality webpage
University of Bucharest – National Gender studies ban (https://www.euronews.com/2020/06/17/romania-gender-studies-ban-students-slam-new-law-as-going-back-to-the-middle-ages)
University of Trento
University of Antwerp – Master in Gender studies but no committees for gender equality
University of Liverpool
University of Caen – no webpage dedicated
University of Zaragoza
University of Paris-Saclay
Nowadays, agriculture is facing numerous problems due to the continuous world population growth, the environmental pollution, and climate change. In particular, the global population growth leads to an increased food demand and climate change has caused significant reductions in crop yield. According to the United Nations Food and Agriculture Organization (FAO), the main reasons for the global food shortages would be climate change, fast development of industrialization and urbanization. Due to the lack of cultivable land, the only course of action to address the food shortage is to increase the crop yield in an economically viable way ensuring the quality of the agricultural products and the preservation of resources and habitats. The current situation calls for agricultural research to ensure food security while keeping detrimental effects of agriculture on the environment to a minimum.
By improving the seed germination and plant growth we could meet the world population food needs. Indeed, the major cause of low germination of seeds of various plant is often connected to the seed surface and soil contamination with microorganisms and fungi. Until now, conventional techniques such as irrigation, fertilization, and crop protection have been implemented in order to increase the production. However, these methods present economic and environmental disadvantages. Increasing agricultural productivity, taking into account protection of the environment, must therefore be addressed with novel approaches. One such approach is to use Low Temperature Plasmas (LTPs) in agriculture (“Plasma Agriculture”), whereby plasma can increase the yield without demanding more water and/or more chemicals.
LTPs are ionized gas containing charged species and neutrals, in different excited states, in strong non-equilibrium due to electromagnetic and/or collisional interactions. They can be generated in different gas mixtures using microwaves, radio frequency, continuous, pulsed, or alternative current in various configurations like dielectric barrier discharge (DBD), atmospheric pressure plasma jet (APPJ), and corona discharges. LTPs are non-equilibrium plasmas that have high kinetic energy electrons, but low kinetic energy atomic and molecular species. On the one hand, the terms “low temperature” refer to the electron temperature being in the range of electron volts which is high enough to produce a variety of reactive species and UV radiation. On the other hand, the heavy particles (ions, molecules) remain at low temperature which prevent LTPs from damaging organic materials.
In the White paper on the future of plasma science in environment, for gas conversion and agriculture2 Ronny Brandenburg et al showed how plasma technology including plasma agriculture can contribute to address the different challenges that our society is currently facing, namely, climate change, environmental pollution control, and resource utilization efficiency, as well as food security, sustainable agriculture, and water supply. A review3 by Nevena Puač et al reports the state‐of‐the‐art of LTPs applications in the complete food cycle, that is, in treatments of seeds, plants, and food. This work is an overview of the wide variety of applications of LTPs in agriculture and food processing and presents promising results published in many studies. Finally, Bhawana Adhikari et al4 summarized prior experimental studies showing the activation effects of cold atmospheric or low-pressure plasmas effects on seed germination, plant growth and development, and plant sustainability including flowering and fruit production.
II. Soil and plant treatment
A key parameter for productivity in agriculture is the remediation of soil. Indeed, an important issue is the overuse of chemicals used in agriculture for fertilization or plant protection from various insects and viruses. Plasmas could provide an alternative ecological and low‐cost technology for decontamination and modification of soil thanks to its radicals, being very reactive with less effects in the long term than conventional chemicals. The challenge in soil remediation is to enable a selective treatment to reduce fungi and detrimental bacteria while preserving or enhancing the activity of nitrogen‐fixing bacteria. In fact, plasma can meet these challenges and can as well protect from detrimental outcomes of continuous cropping. The effects of plasmas are moisture and soil material dependent.
Plant treatment is also a possibility and the earliest studies on the effects of electricity on plants date back to the XVIIIth century. Moreover, non-equilibrium atmospheric-pressure plasma sources have been applied to actual agricultural crops for the inactivation of microorganisms (disinfection) and some of these sources are reviewed in an article from Masafumi Ito et al5.
I. Plasma treated Water
The use of plasma‐activated water (PAW) rather than direct plasma treatment is, also, a possible approach. Generally, PAW is produced by arc or gliding arc discharge (usually in air) on water surface. It is widely agreed that the antimicrobial properties of PAW derive from the combined effect of a high positive oxidation reduction potential (presence of H2O2) and a low pH, affecting the seed germination and plant growth. Several studies showed that PAW captures atmospheric nitrogen and acts as a fertilizer with similar effects to a conventional one. Nitrogen, especially in the ionic form NO3−, is indispensable for plant growth. According to K Takaki et al6, PAW could double the nitrogen content in the leaves of plants, increase the leaf area and dry weight, and reduce the bacterial density by five orders of magnitude in hydroponic water. Indeed, the growth rate of the plants increased with the plasma irradiation time and the nitrate and nitrous nitrogen ions were produced by the application of plasma irradiation to the drainage water improving the plant growth rate. Finally, PAW is an environmentally friendly and cost-effective disinfectant. It was also suggested that the active species could be produced by the discharge in the liquid phase through photolysis by plasma emitted UV photons.
II. LTP in seed treatment
Low and atmospheric pressure plasmas such as DBDs, RF‐ and MW‐sustained plasmas, and gliding arcs under different conditions (mostly operating in air, but also in other gases) have been applied, either directly to the seeds or by remotely using the products of the gas discharge. The effects of plasma treatment in seeds are assumed to be induced by the plasma‐generated reactive oxygen and nitrogen species. The decontamination of seeds, e.g., the removal of pathogenic fungi, and bacteria as well as the insecticidal activity against larval and pupal stages of pests and the enhancement of their germination by treatment with nonthermal plasmas have been demonstrated in several studies. Plasma treatment can have a variety of effects on the morphology of seeds due to its complex interaction with organic materials and living cells.
Plasma treatment generates UV radiation, radicals and chemical reactions, which can play a role in dormancy breaking. Dormancy is the inhibition of germination under conditions (temperature, humidity, oxygen, and light) that are favorable to germination. It is a natural seed property enabling the species to reproduce and thus to survive. This can be caused by various factors such as temperature, light, water, impermeability of the seed coat, lack of supply and activity of enzymes and external inhibitors.
Another consequence of the plasma treatment is the modification of surface properties. The change of wetting properties and structure of the coat increases the water uptake and the permeability of nutrients, and it can accelerate the development of the roots. Many studies have suggested that a plasma-induced faster seed germination and increased seedling growth rates might be associated with the water uptake of seeds. Seeds in contact with cold plasmas are exposed to an attack by oxygen radicals and are bombarded by ions resulting in seed coat erosion. The altered seed coat could increase the hydrophilic ability of the seed and the oxidation of the seed surface changes its wettability eventually improving the water uptake of the seed. For instance, Jiang J. et al8 showed that cold helium plasma treatment, at atmospheric pressure, improved seed germination, growth, and yield of wheat. On the contrary, Volin J. et al9 reported that fluorocarbon plasma treatments at low pressure inhibited corn and bean seed germination. The most plausible explanation is the modification of seed coats via plasma-deposition of hydrophobic materials that reduces the water uptake, and thus leads to delayed seeds germination. The seed plasma treatment (exposure time, gas carrier, plasma input power, etc…) must be optimized for each type of seed.
III. Experiment on seed treatment and Plasma Activated Water
In their work Enhanced seed germination and plant growth by atmospheric pressure cold air plasma: combined effect of seed and water treatment10, L. Sivachandiran and A. Khacef studied the combined effect of non-thermal plasma treatment of water and seeds on the rate of germination and plants growth. For this purpose, they used a dielectric barrier discharge in air under atmospheric pressure, at room temperature.
As can be seen in Figure 3, the results show a positive effect of the seeds and water plasma treatment for tomato and pepper plants. We can note that in the case of untreated tomato seeds, there is no significant difference in plant growth when watered with Tap Water (TW) or Plasma Activated (30min) Water (PAW-30) whereas for untreated pepper seeds a significant growth is observed when watered with PAW-30 as compared to TW. Therefore, they concluded that the effect of plasma treatment of seeds and water on plant growth probably depends on the nature of the seeds. Finally, for longer exposure times of seeds and water to the plasma a detrimental effect was observed therefore the plasma treatment time must be optimized for each seed.
LTPs potentially offer novel ways to enhance seeds germination, plants growth, crop yields, to protect crops thus increasing the production with less impacts on the environment. The effects of cold atmospheric or low pressure plasma on plant growth, development, and sustainability have been verified by abundant experimental data. Indeed, many papers have reported promising results in this wide variety of applications. However, available experimental data are biased toward laboratory conditions and evidence for the applied usage of plasma in agricultural fields and facilities is still lacking. Besides, more information about the modes of plasma action on plant production and sustainability is necessary to optimize and upgrade the plasma systems and applications. For this purpose, collaborations between plasma research scientists, plant biologists, agricultural experts, and food technologists will be needed to clarify the key mechanisms underlying plasma‐agricultural applications, and with the aims to understand, control, and scale up these new processes.
This text was written by Chloé Fromentin
1 Sunset over the corn field. [online]. Available at: [https://unsplash.com//][Accessed 27 January 2021].
2 Brandenburg, R., Bogaerts, A., Bongers, W., Fridman, A., Fridman, G., Locke, B., Miller, V., Reuter, S., Schiorlin, M., Verreycken, T. and Ostrikov, K., 2018. White paper on the future of plasma science in environment, for gas conversion and agriculture. Plasma Processes and Polymers, 16(1), p.1700238.
3 Puač, N., Gherardi, M. and Shiratani, M., 2017. Plasma agriculture: A rapidly emerging field. Plasma Processes and Polymers, 15(2), p.1700174.
4 Sivachandiran, L. and Khacef, A., 2017. Enhanced seed germination and plant growth by atmospheric pressure cold air plasma: combined effect of seed and water treatment. RSC Advances, 7(4), pp.1822-1832.
5 Masafumi Ito, Takayuki Ohta, and Masaru Hori, 2012. Plasma Agriculture. Journal of the Korean Physical Society, Vol. 60, No. 6, pp. 937∼943.
6 Takaki K., Takahata J., Watanabe S., Satta N., Yamada O., Fujio T., and Sasaki Y., 2013. Improvements in plant growth rate using underwater discharge. J. Phys.: Conf. Ser. 418 012140.
7 Schnabel U., Andrasch M., Stachowiak J., Weihe T., Ehlbeck J., Schlüter O., 2017. Non‐thermal atmospheric pressure plasmas for post‐harvest application of fruit and vegetable sanitation. [http://publicaciones.poscosecha.com/es/sanidad-vegetal/359-non-thermal-atmospheric-pressure-plasmas-for-post-harvest-application-of-fruit-and-vegetable-sanitation.html] (Accessed on 27 January 2021).
8 Jiang, J., He, X., Li, L., Li, J., Shao, H., Xu, Q., Ye, R. and Dong, Y., 2014. Effect of Cold Plasma Treatment on Seed Germination and Growth of Wheat. Plasma Science and Technology, 16(1), pp.54-58.
9 Volin, J. C., Denes, F. S., Young, R. A. & Park, S. M. T., 2000. Modification of seed germination performance through cold plasma chemistry technology. Crop Sci. 40, 1706–1718.
10 Bhawana Adhikari, Manish Adhikari, and Gyungsoon Park, 2020. The Effects of Plasma on Plant Growth, Development, and Sustainability. Appl. Sci., 10(17), 6045.