Removal of radioactive cobalt/zinc and some heavy metals from water using diethylenetriamine/2-pyridinecarboxaldehyde supported on NZVI

In this study an efficient nanomaterial has been developed for the removal of Co(II), Zn(II), Cd(II), Pb(II), Cu(II), Hg(II) ions and radionuclides from water using synthesized nanozerovalent iron (NZVI). To protect NZVI and enhance the adsorption capacity, it was then modified with diethylenetriamine (DETA) followed by functionalization using 2-pyridenecarboxaldehyde (PY). The efficiency of synthesized nanocomposite (NZVI-DETA-PY) for Co(II) was 2600 mu mol g(-1) at pH 6.0, while for Cu(II), Zn(II), Hg(II), Cd(II) and Pb(II) were 4750, 5600, 5200, 4050 and 4950 mu mol g(-1) at pH 7. NZVI-DETA-PY was applied in removal of Co(II), Zn(II), Cd(II), Pb(II), Cu(H), Hg(II) and radionuclides from real water matrix (tap water, sea water wastewater and simulated radioactive wastewater) and the percent removal range 90-100%. The adsorption data were examined by different kinetic and isotherm models to analyze the adsorption mechanisms and it was found that Cd(II) and Pb(H) obeyed the pseudo-first order, Co(II), Cu(II), Hg(II) and Zn(Il) followed thepseudo-second order. It was also found that Co(II), Cu(II), Cd(II) and Hg(II) obeyed the Temkin model, while Zn(II) fitted with the Langmuir and Pb(II) was most suitable by the DR model. The newly investigated NZVI-DETA-PY nanocomposite was successfully regenerated in this study.