Applications of nanotechnology in water and wastewater treatment: A review

Water pollution due to heavy metals, organic and inorganic matters and biological organisms is a matter of serious concern all around the globe. Thus, providing clean and safe drinking water at a reasonable cost has become a challenge nowadays. Therefore the importance of technological advancement to facilitate integrated water management cannot be overruled. Due to this, emergence of nanotechnology has delivered pioneering solution to problems in the field of medicine, engineering, physics, chemistry, etc. Nanotechnology is basically the world of science employing nanoparticle for various engineering applications including environmental remediation. Among the nano-based techniques, use of nanoadsorbents, nanomembranes, and nano-photocatalysts has been quite promising in water and wastewater treatment, at both small and commercial scale. Nanoparticles have a higher aspect ratio, larger pore-volume, electrostatics, a higher specific surface area which is quite useful in processes like sorption, catalysis, censoring in the field of water treatment having higher efficiency, flexibility, being multifunctional and affordability. Considering these aspects, nanotechnology has proved to be an innovative, eco-friendly and an advanced treatment technique. The main limitation in applying nanotechnology is that uptil now most of the researches are confined to laboratory or pilot scale only. In this review, we have discussed in brief about a few recently used nanomaterials that are presently employed in treating water, with a focus on nano-based adsorbents and filtration membranes.