Small but mighty – using nanomaterials to provide communities with clean drinking water

Tiny technology with life-changing potential for communities. Nanotechnology researcher, Anita Etale, Global Climate Change Institute at the University of the Witwatersrand, Johannesburg, is a FLAIR (Future Leaders – African Independent Research) funded recipient. She used her FLAIR funding to research the use of nanomaterials to produce clean water from the contaminated supply produced from mine draining. Here’s her research journey from material investigation to community engagement.

FLAIR is implemented through the AESA Platform. AESA (The Alliance for Accelerating Excellence in Science in Africa) is a funding, agenda-setting, programme management initiative of  the African Academy of Sciences (AAS) in partnership with the African Union Development Agency (AUDA-NEPAD) and with the support of Wellcome, Bill and Melinda Gates Foundation and the United Kingdom Department for International Development (DFID).

Mining and water contamination  

I am trained as an environmental scientist with undergraduate training in Chemistry and Biochemistry. My research focuses on the use of nanomaterials for water treatment. Nanomaterials are simply materials with a dimension in the nanometer scale. As such, they are too small to be seen with the naked eye, but possess valuable qualities not seen in larger materials, and this is what I try to exploit in my research. For example, nanomaterials have a larger surface area per size of material. This means that for adsorption of contaminants, smaller quantities are needed.

I live in Johannesburg whose legacy of mining now includes acid mine drainage and the contamination of ground and surface water. Several techniques exist for treating mine-drainage contaminated water, but I wanted to investigate the application of nanomaterials and the benefits this approach would have for treatment, particularly at the small scale.

Pursuing research through the FLAIR program

As in many large cities the world over, a good number of low-income residents in Johannesburg do not have access to clean drinking water sometimes because their dwellings are set up in areas that are not served by municipal services. In many cases, people will use whatever water sources are close to them for the various domestic purposes, including drinking. However, in locations such as Johannesburg, where water sources are contaminated with a host of elements, including mercury and uranium, this poses a health risk to these already vulnerable populations.

I have been fortunate to secure a considerable amount of funding to pursue this line of research, even as an early career researcher. Establishing an independent line of research is key for academic progress. This is why the FLAIR program of the Royal Society, and the Volkswagen Foundation postdoctoral fellowship have been crucial to me. They have helped me to establish an independent research track and acquire research equipment that is sometimes prohibitively expensive, enabling me to make considerable progress early in my career.

Access to clean water

My research is currently investigating the possibility of applying graphene oxide in the treatment of mine drainage. In the beginning, we found that the low pH of this water (typically around 2.7) presented challenges for the use of this material, most importantly, a low capacity to remove impurities. Recently, we have discovered that addition of other reactive groups, e.g. phosphates to the surface of graphene oxide, allows for higher removal capacities of specific ions at the low pH levels of mine drainage.

Nanomaterials for sustainability

Nanomaterials have been known to be superior adsorbents for water treatment. However, as demonstrated by the example above, this efficiency was not always replicated in mine drainage conditions. My research therefore tries to find ways by which nanomaterials can be effective under these unusual conditions.

We are in the process of creating a membrane incorporating these nanomaterials, that we can then employ in portable water treatment devices.

Access to clean water is particularly important for health outcomes and poverty reduction. When people lack access to clean water, their health is impaired and their ability to earn a living and improve their current and future living conditions is diminished. The findings of our work contribute to the development of materials that can be used for small-scale water treatment, as a first step to increasing access to clean water and sustainable livelihoods.

Alongside our research, we conducted interviews and surveys with potential users of nanomaterial-containing water treatment devices, to determine what their perceptions of this approach to water treatment is and whether our proposed solution would be acceptable.

Not surprisingly, we found that the target population has little knowledge of the subject. So, we saw the need for community engagement on the subject, working with the community to improve their knowledge about nanotechnology and its applications, even beyond water treatment. We were also able to correct several misunderstandings regarding water treatment processes and the appropriate methods for removing contaminants.

Making an impact

This study has wide-reaching impacts for Africa on various fronts. Firstly, exposure to mining contaminated water is widespread on the continent, including east and west Africa, where artisanal mining contaminates water consumed by large rural and semi-urban populations with such heavy metals as mercury and lead, with serious health implications. Our work provides a means for such populations to have access to clean potable water, avoid adverse health outcomes and begin to escape poverty through the use of their limited income for other beneficial uses.

Thanks to the FLAIR programme, we’ve managed to train students; extend the knowledge of nanotechnology to lay populations; and have established national and international networks to further improve this research. For instance, I have just been awarded a collaboration grant by the Royal Society to fund work with Prof Steve Eichhorn of Bristol University, a globally renowned scientist in the field of cellulose materials.