Adsorption Performance Of Manganese Onto Citric Acid-treated Yeast Biosorbent

In this study,four different kinds of adsorbent, 732 ion exchange resin, D113 ion exchange resin, actived zeolites and yeast had been tested for their adsorption toward Mn(II). For carboxy group on the D113 ion exchange showed strong affinity towards Mn(II), yeast is cheap,widely available and show no side effect; A new adsorbent(CA-Y) synthesized by coating carboxy group onto the surface of yeast using Citric acid treatment was investigated on its adsorption towards Mn(II). Batch experiments and column study had been conducted to study the mechanism of Mn(II) adsorption onto Yeast and CA-Y together with characterization by XRD, XPS, FTIR.The static adsorption experiments indicated that Mn(II) adsorption onto Yeast and CA-Y were significantly affected by pH, and maximum adsorption was achieved at pH= 6. The thermodynamic study showed that the adsorption process was spontaneous, endothermic, randomness. The kinetic study showed that the adsorption process was mainly controlled by surface reaction and fitted better with pseudo first-order model. The desorption study showed that Mn(II) sorbed CA-Y could be regenerated well by sulfuric acid solution(H2SO4), and after 5 cycles of adsorption and desorption the adsorption capacity could reach 91.4mg/g;while H2SO4 showed negligible effect on desorption and regeneration of Yeast.In addition, column adsorption study was also conducted on the Mn(II) removal of real leachate containing Mn(II). The results showed that Mn(II) could be removed by both of CA-Y and Yeast achieved with adsorption capacity of 6.91mg/g, 3.99mg/g respectively. While the co-existing cations showed adverse effect on Mn(II) removal. And Mn(II) could be desorbed quickly from Yeast and CA-Y after adsorption by eluting using H2SO4 with concentrations of 0.75 times and 2 times as the initial concentration of Mn(II).Yeast and CA-Y were characterized by SEM, FTIR, XPS before and after adsorption, the results showed that hydroxyl group, Carbonyl group, nitrogen functional groups were involved with interactions between Mn(II) and Yeast; while hydroxyl group and Carbonyl group were involved in the reaction between Mn(II) and CA-Y.