Tag Archives: arsenic

We made the news in Nature, MRS Bulletin and Business Inside

Last year we had three articles on the news regarding the activities we do in our lab. One of the highlights without a doubt was an article in Nature (Young, talented and fed-up). To be blunt I wasn´t particularly happy with the word “fed-up” when I first saw the title, however after reading all the comments of other young scientist I understood the origin and the purpose of such article. Like many others, prior to my permanent position I had to live with the uncertainty of where to go and what to do after my temporary contract finishes, not a happy feeling considering that I had a family with me. Like it was mentioned in the article, we were not really whining but putting our life and struggle into context considering that our chances of success got slimmer from the time senior colleagues started their career. I feel honoured from being chosen to participate in the discussion and being featured in that article.

Another article about our work was focused on the out-reach activities we do with kids of low-income and rural schools. With the support of the MRS Foundation we have been working with a few schools and performing outreach activities as part of Cinvesniños-Saltillo. Our project finishes this year, the funding that is, but I am certain that we will keep working in these activities and those schools for a long period of time. I hope we will be able to see the effect of working with kids from an early stage and see them progress in their lives.

Finally, Business Inside Latinoamerica made an article of the work we currently do on arsenic removal using graphene oxide. We are on an early stage of our work but preliminary results show adsorption capacities already of 30 mg/g despite early reports in the literature of much lower adsorption capacity. We are showing that by controlling the production route and even functionalising its surface we can considerably increase the arsenic adsorption capacity of graphene oxide without the use of other nanoparticles as it is commonly used.


Nanoarquitecture of nanomaterials/molecules for the elimination of arsenic in drinking water.

Arsenic ranks the 20th most abundant element in nature. It can have a valency of −3, 0, +3, or +5, depending on water chemistry. In natural waters, it exists as arsenate (AsO4)-3 and/or arsenite (AsO3)-3, also referred to as arsenic(V) and arsenic(III). The toxicity and mobility of arsenic are affected by its oxidation states. Arsenite is more toxic and mobile than arsenate in the aqueous environment. Arsenate primary exists in surface water, whereas arsenite dominates in ground water. The presence of arsenic in water is a serious threat to more than 100 million people in the world. There have been many documented incidents of arsenic contamination in ground water around the world, most notably in countries such as Taiwan, Chile, Argentina, Hungary, Bangladesh, India, Pakistan, Thailand, Vietnam, China, México (Zacatecas, San Luis Potosi, Chihuahua, Torreón, Durango) and the United States. In Mexico alone, it is estimated that 13 of the 31 states in Mexico suffer of arsenic contamination. It is known that Arsenic ingestion can lead to many adverse health effects, including skin lesions, diabetes mellitus, chronic bronchitis, cardiovascular disease, peripheral neuropathy, adverse reproductive outcomes, and hematological effects. Prolonged exposure to arsenic damages the central nervous system and results in diverse types of cancer in liver, lungs, bladder and skin. Arsenic poisoning has a great social cost since it affects children and adults alike. Due to these reasons is of great importance to provide cost-effective technologies capable of eliminating or reduce the levels of concentration of arsenic in drinking water, especially in rural and poor communities where access to costly or complex filtering systems is limited.

Arsenic removal from water is possible through different physicochemical processes which include coagulation, precipitation, ion exchange, membrane filtration, and sorption. Among them, sorption can have a good performance, ease in operation, and lower cost, which makes it attractive for its utilization.

Adsorption is limited by the surface area, active sites and lack of selectivity of the material used, however the arrival of nanomaterials has opened the opportunity to considerably increase the absorption capacity of materials. Furthermore, the possibility to carry out multiscale modeling of chemical systems (topic of research of this year Nobel laureates in Chemistry) can also be used to design molecules or materials with specific properties, for example the selectivity towards a specific chemical molecule or element.

At the CenERgy group in CINVESTAV-SALTILLO (Mexico), in collaboration with Dr. Joaquín Barroso Flores from the National Autonomous University of Mexico, we are combining computer modeling and experimentation to design and synthesize molecules and nanomaterials capable of eliminating arsenic more efficiently. For example, Figure 1 shows some computer models where the interaction between arsenic oxide and calix[n]arenos is being studied.

calix[n]arenos and arsenic modeling top and side view

Figure 1. Top and side view of different calix[n]arenos obtained by computer modelling showing their interaction with arsenic (purple).

María Monserrat Enriquez González, PhD student working on this topic.

María Monserrat Enriquez González, PhD student working on this topic.

Science and Poverty

A few days ago it was announced that almost 50% of the population in Mexico lives in conditions of poverty. This means that 53.3 million people do not have access to at least one of the following: a proper house, health system, food, water or education. The numbers are frightening and put my life and work into perspective. Under these circumstances, it is justifiable that the society question the money spent on science and technology. First hand I have seen the reluctance of an older generation to engage with society. We need to do more not only to answer the needs of the people but also we need to show them why what we do is important. Publishing in peer-reviewed journals and graduating students is not enough.

At this moment we are preparing an outreach project focused on rural and poor communities. I hope we can have the people and funding to carry it out. I am confident that this initiative will flourish one way or another.

Additionally, starting this September we will embark on a new area of research (at least for me): water treatment. In collaboration with Dr. Joaquin Barroso (Centro Conjunto de Investigación en Química Sustentable) we will look at nano-arquitecture to improve the efficiency and selectivity of carbon-based materials (graphene, calixarenes and pyrolytic carbon) in the elimination of arsenic in water, a serious problem in most of the north of Mexico.

With 50% of the population living in poverty the problems are for sure huge, but I guess we need to take action if we want to be part of the solution.

If you are interested, we have a webpage in facebook where we post science related news (in spanish):