Role of nanotechnology in water treatment and purification: Potential applications and implications

Nano-materials have gained special attention in water pollution mitigation researches since last decade. Two vital properties make nanoparticles highly lucrative as sorbents. On a mass basis, they have much larger surface areas compared to macro particles. They can also be enhanced with various reactor groups to increase their chemical affinity towards target compounds. Nanofiltration techniques are now widely used to remove cations, natural organic matter, biological contaminants, organic pollutants, nitrates and arsenic from groundwater and surface water. Nano-membranes are used to treat contaminated water by filtration or separation techniques. Nanosorbents are widely used as separation media in water purification to remove inorganic and organic pollutants from contaminated water. During the last decade, titanium dioxide (TiO2) nanoparticles have emerged as promising photocatalysts for water purification. Consequently, different workers had adopted the methods such as chemical precipitation, sol–gel, vapour deposition, solvo thermal, solid state reaction etc. for the synthesis of some nanostructured mixed oxides, which can be effectively used for groundwater treatment. Nanoagglomerates of mixed oxides such as iron–cerium, iron–manganese, iron–zirconium, iron–titanium, iron–chromium, cerium-manganese etc. have been synthesized, thoroughly characterized in sophisticated instruments like SEM, TEM, FTIR, AFM and successfully employed for water treatment. Among the available different technologies, adsorption is one of the best due to its easy handling, low cost and high efficiency. The environmental fate and toxicity of a material are critical issues in materials selection and design for water purification. The success of the techniques in field conditions is a factor of interdisciplinary works, which need successful collaboration of chemistry, material science and geology and biosciences. © 2013 Universal Research Publications. All rights reserved