I want to conduct research on waste water treatment by using Nano technology, therefore I want to Know more about nano technology and its application for waste water treatment especially for the removal of heavy metals.
Read fare number of recent articles. You can use google scholar, web of science or any other site you are familiar with. Any research starts with good literature survey.
If you want to fresh start the nanotechnology application in water treatment, please read the recent review papers. There are plenty of review papers. You can look into the minute details such as chemistry, materials, reactors design, etc. in the literature cited in.
I support what Raj Kamal Singh said. I could say graphene nanomaterials would be a good alternative for the applications in wastewater and water treatment area. If you are interested, you can also check this arcticle showing an example of how these nanomaterials can be applied to remove color from water:
Article Systematic study of graphene oxide production using factoria...
Generally the wastewater to be treated must be described in detail: e.g. pollutants present and their concentration, pH, suspended solids present, inorganic salts content etc.etc. Also the treatment goal must be clearly specified. If you know these input and output data, you can decide what should be the treatment technology, does not matter if nano or other.
If you are a beginner then prepare an activated carbon and then put them into ball milling apparatus. Do an optimisation study. Some days you might get a nano particle. You can analyse them with the help of Particle size analyser and Surface Area Analyser.
In order to proceed further first you must list down your objective,aim and expected outcomes.Then only you can judge and understand the actual needs for your project.