Dear Dharmendra, researchers are using electrical field to remove nanoparticles from the human body. In fact, nanoparticle removal chips has also been developed by Professor Michael Hellers Lab at the UC San Diego, which claim to remove nanoparticles from the blood with ease. But, I think, it is not possible to remove each and every nanoparticles from the body as nanoparticles are generating inside our body during food digestion and other activities every day.

It depends on nanoparticle physical-chemical properties, and on intake routes. Generally they are completely excreted in few days, by hepatic, renal, and intestinal clearance, but a more specific answer would need a more specific question.

Magnetic nanoparticles are delivered to different parts of the body with the help of strong magnets. Therefore, they can be in front of the right place of the body and removed. Another method can consist in various methods of dissolving nanoparticles and removing them by the usual method of working the human body.

It's difficult due to many factors you need to removal it but electro field you can use it

Nanotechnology and nanomaterials are new subjects and I think no rigid study has been done yet on the methods of removing of nanoparticles from the body. Nanoparticles are very broad in types ( in respect of size, magnetic property, zeta surface charge, elemental composition and etc..). Therefore, diverse methods perhaps are required for cleaning them from the body and even from the environment. We have a long way to to reach these goals.