Nanomaterials-enabled Technologies for Clean Water and their Sustainability Aspects

Materials are used for sustenance of life and for improving living standards, thus becoming indispensable for human life. They are used across industries and all sectors of the economy. The 21st century saw the rise of several advanced materials that are highly functional and are therefore implemented in areas such as energy, environment, healthcare, construction and many more. Rapid advances in science and technology involving polymers and ceramics in the 20th century were made in the field of structural material science. The path was paved by rigorous research in thermochemistry in the 17th and 18th centuries and in electrochemistry in the 18th and 19th centuries, leading to the entire periodic table being accessed for engineering purposes by the mid-20th century. Subsequently, inventions on materials with greater functionalities such as semiconducting, magnetic, optoelectronic, piezoelectric and thermoelectric materials followed later in the 20th century. Many such products may demand heavy utilization of metals from restricted geographical and industrial sources like highly localized ores or by-product extracts, making their supply limited, costly and non-eco-friendly (Koltun 2010). In addition, governments may categorize such materials as “critical” due to economic, political or environmental reasons. Reckless production of materials without considering their long-term environmental, economic and societal impacts would lead to undesired consequences such as degradation of air, water and land, loss of biodiversity, resource depletion and increasing disparity (Qu et al. 2013). Due to growing concerns of the magnitude of the impact on the planet by global population, there is an emergence of the concept of sustainable development, if that ideates “development that meets the needs of the present without compromising the ability of future generations to meet their own needs”, according to the Brundtland Report (1987) (Mensah 2019). Since then, a wide range of interpretations of the concept can be seen. Under the umbrella of the United Nations (UN), key agencies like ECOSOC (Economic and Social Council) have prioritized their work towards sustainable development encompassing all its three pillars, namely environmental, economic and social sustainability. Sustainable Development Goals (SDGs) containing 17 action plans were adopted by the UN as “a universal call to action to end poverty, protect the planet and improve the lives and prospects of everyone, everywhere” as a part of the 2030 Agenda for Sustainable Development. Environmental sustainability emerged to be most important when it was realized that the earth has limited natural resources like water, land, etc., and there exist boundaries within which equilibrium between natural capital for economic input and treating it as a sink for waste has to be maintained. It is about conserving the quality of the natural environment and climate, and its ability to support healthy generations. Clean water forms the basis of SDG 6, which promises to ‘ensure availability and sustainable management of water and sanitation for all’ (‘GOAL 6: Clean water and sanitation | UNEP - UN Environment Programme’). Under this goal, there are clean water-related targets like (a) access to safe and affordable drinking water for all; (b) improvement in water quality by decrease in pollution, eliminating or minimizing release of untreated hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally; (c) amplify international cooperation and capacity building for developing countries in water and sanitation activities and programs, including water reclamation, desalination, water efficiency, wastewater treatment, recycling and reuse technologies, etc. Materials Science is central to achieving the aforementioned targets under SDG6 (Green et al. 2012).