The team of Thalappil Pradeep – Indian Institute of Technology, Madras
Dr. Pradeep and his team have developed advanced and affordable nanomaterials to bring down the concentration of arsenate and arsenite ions in water to well below minimum drinking-water limits. Core to this development is the creation of functional “water positive” nanoscale materials, prepared in water with soluble ingredients, making insoluble sand-like particles without the use of power, in a green process akin to biology.
The team provides a cellulose-based adsorbent with improved uptake capacity along with better mass-based sustainability and due consideration of socio-economic parameters. The have demonstrated that cellulose microstructures are more efficient than corresponding nanostructures for the purpose of arsenic remediation. They have also performed an evaluation of several sustainability metrics to understand the “greenness” of the composite and its manufacturing process.
Their nanomaterials exhibit the highest possible uptake of arsenic in field conditions and the kinetics of the uptake have been shown to be high. Importantly, these materials do not impact the environment even after their useful life, and the arsenic removed by the filters gets released only slowly at concentrations below the background concentration, and it goes back to the field where it came from. There is no need to take the arsenic laden waste to processing plants outside the villages.
With such benefits, gravity-fed water purification solutions are now possible with the adsorbents replaced only once in two years. With a simple backwash, these units work reliably for years in arsenic and iron affected communities.
Team members include Avula Anil Kumar, Chennu Sudhakar, Sritama Mukherjee, Anshup, and Mohan Udhaya Sankar.
Dr. Thalappil Pradeep
Dr Pradeep is Institute Professor, Deepak Parekh Institute Chair Professor and Professor of Chemistry in the Department of Chemistry at the Indian Institute of Technology Madras (IIT Madras) in Chennai, India.
• 1993 – Post-doctoral research; Purdue University, Indiana
• 1992 – Post-doctoral research; Lawrence Berkeley Laboratory, University of California, Berkeley
• 1991 – PhD; Indian Institute of Science, Bangalore
• 1985 – MSc; BSc; Calicut University
2021 – Vishwakarma Medal of the Indian National Science Academy
2021 – IISc Distinguished Alumnus Award
2020 – National Water Award
2020 – Silver medal of the Chemical Research Society of India
2020 – Nikkei Asia Prize
2020 – Padma Shri (the fourth highest civilian award in India)
2012 – India Nanotech Innovation Award
2011 – Professor S. S. Deshpande National Award
2010 – Kerala Sahitya Academy Award for Knowledge Literature
2008 – Shanti Swaroop Bhatnagar Prize in Chemical Sciences
2008 – National Research Award in Nano Science and Technology by the Department of Science and Technology, Government of India
2007 – Swadeshi Sastra Puraskaram, Swadeshi Science Movement of Kerala, part of Vignana Bharati
2004 – Chemical Research Society of India Medal
2003 – B.M. Birla Science Prize of 2000
2003 – Young Scientist Award, Chemical Research Society of India
2002 – Materials Research Society of India Medal
2000 – Tamilnadu Scientist Award
Ladies and Gentlemen,
I am honored to receive this recognition which is counted amongst the highest recognitions in water-related innovation. Let me thank the Prize Council, the Jury and the award secretariat for recognising our work.
My work has been on developing affordable clean water solutions for the poor, especially in regions affected by water contamination.
I, along with several of my students and associates, some of whom have been named by the award, developed environmentally friendly water positive nanoscale materials for affordable, sustainable and rapid removal of arsenic from drinking water.
There are now over ~1700 community installations across the country using such materials, serving 1.3 million people with arsenic and iron-free water every day.
Key to the development of such solutions is a range of materials, one example is shown here. This is a biopolymer reinforced nanostructure, which is water positive. These materials, prepared in water at room temperature, produce sand-like composites at room temperature which are stable in water, in a process similar to the making of sea-shells, and they remove contaminants and cause disinfection of water.
Another such material removes all the forms of arsenic in drinking water down to undetectable levels. About 20 grams of materials are enough to deliver over 1000 litres of clean water, just by gravity filtration. The materials after their useful life do not cause contamination of the soil and the spent media are safe for disposal.
Today, such a technology called, AMRIT, meaning Elixir is implemented as an attachment to hand pumps, or as community filtration units or as treatment plants in villages.
These products are available at 25 kilolitres per day up to one million litres per day. As such solutions are implemented across the country in diverse water quality affected regions, we know that they can be implemented anywhere in the world.
By expanding these solutions to every part of the country, we believe that arsenic in drinking water will no more be a threat to people.
In the course of this work, we have also encountered other contaminants such as manganese, chromium, uranium, fluoride, etc., and all can be treated similarly. The cost of providing clean water is less than $0.36 per 1000 litres, including all costs – capital, consumables and maintenance - put together. These units are now monitored through the Internet.
Such an effort has been possible only with the tremendous support of all my group members, present and past, especially my AMRIT team who are now owners of a company.
Over the years, over 250 student - PhD, postdocs and masters -have worked with me, many have contributed to clean water, time is not enough to mention all of them.
However, let me thank especially, Avula Anil Kumar, Chennu Sudhakar, Sritama Mukherjee, Anshup, and Mohan Udhaya Sankar, whose work helped me win this award.
Such an effort is impossible without the support of various organisations, governments and start-ups.
I thank my great institution, Indian Institute of Technology Madras, under the leadership of Professors Bhaskar Ramamuthi and V. Kamakoti, for giving me everything that is needed to pursue my passion. I am sure that this recognition will make many others to take up most down to earth problems of life and solve them through materials.
I cannot thank adequately my wife and family for the sacrifices they have made to reach this far.
Let me thank my country which has made me stand up.
 A. A. Kumar, A. Som, P. Longo, C. Sudhakar, R. G. Bhuin, S. Sen Gupta, Anshup, M. U. Sankar, A. Chaudhary, R. Kumar, and T. Pradeep, Adv. Mater. 2017, 29, 1604260 (1-7). DOI: 10.1002/adma.201604260
 C. Sudhakar, A. A. Kumar, R. G. Bhuin, S. Sen Gupta, G. Natarajan, and T. Pradeep, ACS Sustainable Chem. Eng. 2018, 6, 9990−10000. DOI: 10.1021/acssuschemeng.8b01217
 S. Mukherjee, A. A. Kumar, C. Sudhakar, R. Kumar, T. Ahuja, B. Mondal, P. Srikrishnarka, L. Philip, and T. Pradeep, ACS Sustainable Chem. Eng. 2019, 7, 3222−3233. DOI: 10.1021/acssuschemeng.8b05157
 C. Sudhakar, S. Mukherjee, A. A. Kumar, G. Paramasivam, P. K. Meena, Nonappa, and T. Pradeep, J. Phys. Chem. C. 2021, 125, 22502−22512. DOI: 10.1021/acs.jpcc.1c04317
 A. Nagar and T. Pradeep, ACS Nano 2020, 14, 6420−6435. DOI: 10.1021/acsnano.9b01730