Adsorption Behavior Of Pb(â…¡) Ion On Macroporous Styrene Chelating Resin And Its Application

In this study,the related fundamental issues of treating the lead from K.D double salt primary explosive wastewater,using the ion exchange resin technique were carried out to provide theoretics direction for further application.In this paper,the D418 resin was selected a suitable adsorptive material based on study of ion exchange capacities,adsorptive ratio.In the static adsorption experiment,the results indicated that the equilibrium time was about 10 h;high temperature was good for the adsorption.The best pH was about 4.Na⁺ in the wastewater was a competitive,leading to a negative effect on the adsorption.Effects of the temperature and flow rate on the dynamic adsorption had been examined. The results of column dynamic adsorption show'ed that lower flow rate and higher temperature were beneficial for the adsorption,and the suitable conditions were as follows: the flow rate 6 BV/h,the temperature 328 K.The desorption experiments showed that lower flow rate,lower temprature were good for the desorption.The suitable conditions for the desorption were the consumption 5 BV strippant(3%HNO₃),the flow rate 3 BV/h and the temprature 293 K.Effects of the flow rate and the initial lead concentration on the adsorption breakthrough curve had also been investigated.The results showed that with increasing the flow rate and initial concentration,the breakthrough point reached ahead,and the efficiency of the resin function groups and the adsortption efficiency of Pb decreased.The behavior of the resin adsorption and exchange process was studied.Langmuir isotherm was more suitable for simulating the adsorption between the isotherm models of Langmuir and Freundlich.The thermodynamic study of the adsorption process showed that the Pb adsorption-ion exchange process is spontaneous,endothermal,and the entropy is positive. The results showed the kinetics of ion exchanging was controlled by liquid film diffusion.The fourier transform infrared(FTIR)spectroscopy on blank and lead-loaded resins demonstrated that two kinds of atoms,namely nitrogen atom on group -NH- and oxygen atom on group≡P＝O,combined with Pb²⁺by coordination bond,and ion exchange occurred between Pb2 and H⁺ that P-OH group ionized.