Towards the Nano-future to Deal with Metal and Metalloid Contamination

The widespread occurrence of metal and metalloid in water resources and crop plants beyond the maximum permissible limits is a concerning issue for environmental and human health. There is a need to develop efficient, low-cost methods for the clean-up of water to ensure a safe drinking water supply. Further, the methods should be robust enough to clean up contaminated groundwater resources and prevent continuing metal(loid) build-up in soil. In addition, the existing metal(loid) contamination of soil also needs remediation through suitable technologies to avoid metal(loid) accumulation in crop plants. There has been a plethora of research on metal(loid) remediation, and a number of physical, chemical, and biological methods have been developed. The world today, however, is focused on and is marching rapidly towards the methods based on nanoparticles (NPs). This is because NPs are extremely effective in the remediation process, can be used easily in various forms and proportions, and have low-cost considering their lifetime and multiple cycle use. Nanoparticles can adsorb metal(loids) in soil and reduce their bioavailable levels to the crop plants. Further, the application of NPs in fields has been found to positively stimulate plants' growth and augment tolerance of plants to a variety of stresses. Further, NPS-based clean-up methods, columns and filters have been developed for contaminated water. Therefore, the nanoremediation of metal(loids) holds promise and this review article discusses the pros and cons of this.