Nanotechnology: The Breakthrough in Water and Wastewater Treatment

Nanotechnology is the engineering and application of atoms, molecules, and particles whose sizes are on the nanometer scale (1 100 nm). Studies have shown that nanoparticles (NPs), most especially the nano metal oxides have improved and/or unusual physico-chemical properties when compared with the corresponding bulk materials. Thus, these unique properties make NPs very useful in medicine, electronics, biomaterials, energy production, water and wastewater treatment, etc. Different methods such as the gas phase synthesis (gas condensation processing, chemical vapour condensation, microwave plasma processing, and combustion flame synthesis), ball milling, co-precipitation, sol gel, micro emulsion, and surfactant have been widely reported over the years for the production of NPs. There are conventional technologies which are affordable and can be produced locally for effective removal of contaminants from water and wastewater. However, there are several challenges with regards to the cost and the removal efficiency of certain pollutants, most especially, the persistent organic pollutants and endocrine disruptors by these conventional technologies. Environmental nanotechnology vis. nanotechnology and/or nanotechnology combined with conventional technologies are able to treat organic and inorganic contaminants to acceptable levels. There is currently intense scientific interest in nanotechnology for water and wastewater treatment; nevertheless, there are concerns about the toxicity and environmental impact of NPs.