Brown Bag Lunch: Water goes nano

Nanotechnology for sustainable water treatment
Joydeep Dutta

If the proliferation of today’s technologies is any indication of the speed and power of changes in economies across the world, in the near future nanomaterials will lead to an even more dramatic paradigm shift. The next few decades will experience this “sunrise technology” as a platform for the convergence of diverse technologies and materials resulting in innovative products and processes for the benefit of mankind. In this talk we will discuss about possible strategies to contribute to efforts to save the planet from further environmental problems using nano-functional materials. Ground water pollution due to industrialization and urbanization solicits new ways of removal of unwanted chemicals, biohazardous microorganisms, solid wastes and dissolved gases to be suitable for drinking. In order to address the future water scarcity a combination of approaches including water conservation, recycling, and treatment of impaired water from non-traditional resources to "create" new water needs to be considered. Some of these areas utilising visible light photocatalysis and electrocatalysis will be discussed. Possibilities of prevention of biofouling utilising visible light photocatalytic coatings will also be presented. We will discuss about one dimensional ZnO nanorods epitaxially grown under various conditions on seeded substrates by a low temperature hydrothermal process and its application in removing harmful chemicals and in the prevention of biofouling. We will also introduce a novel capacitive device for water desalination and treatment during this talk.

When small meets smaller
Sulena Pradhan

As we all know, secured and healthy life under water is one of the 17 goals from the UN sustainable goals that has been planned to be achieved by 2030. This goals includes the conservation of aquatic animals and also providing safe drinking waters as most of the counties still rely on water bodies for drinking. Chemical pollutants emitted from industries into water bodies and their extraction or filtration has been studied since long time. But the new age pollutants are the nanoparticles and nanomaterials. Most of the industries now use nanotechnology and so nanoparticles/nanomaterials directly or indirectly because of their many smart properties. Nano-substances are also emitted from different domestic products such as cosmetics, electronics and transport vehicles such as from tungsten nanoparticles from tyres studs. What happens when they are liberated out in the environment during their life cycle or after their disposal? Where is the end of life for such tiny nanoscale pollutants? Furthermore, it has been found out that nanoparticles/nanomaterials are very chemical active and so they interacts with even smaller molecules called natural organic matter in the environment (Organic molecule formed from the decomposition of plants and animals). The interaction is different in different environmental matrices as the solution chemistry (such as pH, ionic strength and type of natural organic matter) is different in different geographic area. This interaction of small Nano-substances interacting with smaller molecules needs to be studied to assess their potential risk in the environment. Though there are few ongoing studies in this regard but study from the actual industrial waste needs to be studied for their risk assessment and to achieve the goal of safe life under water and Nano free water environment.