Fast removal and recovery of amaranth by iron oxide magnetic nanoparticles

Nanotechnology is fast developing in various fields. Compared to the traditional micro-sized magnetic supports used in separation process and nano-sized magnetic carriers possess quite a good performance due to high specific surface area and the absence of internal diffusion resistance. [1] Nanosize magnetic iron oxide particles have been studied extensively due to their wide range of applications in ferrofluids, biological cell labeling and sorting, separation of biochemicals, targeting, and drug delivery,... [2] They meet the above requirements and can be easily recovered or manipulated with an external magnetic field [3]. For many of these applications, surface modification of nanosize magnetic particles is a key challenge. Surface modification of magnetic particles by organic compounds can be achieved via four major method; organic vapor condensation, polymer coating, surfactant adsorption and direct silanation of silane-coupling agents. [2] Effluents from the dye industries are important sources of water pollution, because dyes in wastewater undergo chemical as well as biological changes, consume dissolved oxygen, and destroy aquatic life. Adsorption is a conventional but efficient technique to remove dyes from aqueous solutions.