Air contains various pollutants like CO, chlorofluorocarbons, volatile organic compounds, hydrocarbons, and nitrogen oxides. Water and soil contaminated with organic and inorganic compounds, t sewage water, industrial effluents, random use of pesticides, fertilizers, and oil spills . Nanomaterials are excellent adsorbents, catalysts and sensors due to their large specific surface areas and high reactivates . Nanoparticles have unique properties such as magnetic, optical, electrical and high structural properties, they have a considerable potential to substitute existing material .
I think this is directly related to the target pollutants and experimental conditions. In general, for finding the optimum parameter for any experiments, we can use design of experiment (DOE) in which all of the effective parameters will be considered.