Optimization of nitrate removal from aqueous solutions using clinoptilolite /CoFe2O4 by surface response methodology

Document Type : Original Research Paper


1 Biomaterials Dep, University of Toronto

2 Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University,Najafabad, Iran



In this study, Merwinite (MW), has been successfully prepared by a modified
sol-gel method. Optimization in calcination temperature and mechanical milling
resulted in a pure and nano-sized powder which characterized by means of
(XRD), (SEM), (TEM) and (FT–IR). We hypothesized that nano-sized MW would
mimic more efficiently the nanocrystal structure and function of natural bone
apatite, owing to the higher surface area, compared to conventional micronsize
MW. Mechanical grinding in a ceramic ball mill for 6 hours resulted in (MW)
nanoparticles in the range of about 33- 55 nm. Conventional micron-size MW
had been previously investigated by many researchers but it is obviously different
from bone mineral in aspect of mimicking the mineral resorption process. Bone
crystals of natural hydroxyapatite (NHA ) are in nano-size dimensions and possess
very large surface area. In contrast micron-size particles with lower surface area
lack the potency of homogeneous absorption by osteoclasts and miss the unique
advantage of nanotechnology for bioactivity and resorbability. Hence, we used
the unique advantage of nano- biotechnology to improve novel nano merwinite
(NMW) particles as a good candidate for tissue regeneration whether as a peri -
implant filling powder or in combination with other biomaterials as a composite