RESUMO
The process of biosorption and the adsorbing mechanisms of Fe3 O4/Sphaerotilus natans to Cr(VI) were studied. The experiment results showed that pH value was main influencing factors on adsorption to Cr(VI). In the range of pH 2 to 3, the adsorbance of the composite biosorbent to Cr(VI) is 0.0217 mmol/g. The regeneration efficiency is 90% when the composite biosorbent was regenerated by HCl solution. --CONH2-- and --NH-- were principal activated groups of composite biosorbent. Cr(VI) can primarily combine with the surface of Fe3O4/Sphaerotilus natans by electrostatic attraction.
Assuntos
Cromo/metabolismo , Compostos Férricos/química , Sphaerotilus/metabolismo , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Reatores Biológicos , Cromo/química , Cromo/isolamento & purificação , Nanopartículas Metálicas/químicaRESUMO
Composite biosorbent nano Fe3O4/Sphaerotilus natans was prepared when nano Fe3O4 was used as carrier, then the composite biosorbent characterized by infrared instrument and investigated on adsorbing heavy metal ions from wastewater. Infrared spectrum analysis shows that--CONH--and--OH are principal activated groups of composite biosorbent. The experiment of adsorption shows that biomass concentration and flow velocity are main influencing factors. The composite biosorbent has best effect on the adsorption of Cu2+ under the conditions of biomass 1.5 g/L (Sphaerotilus natans/Fe3O4 = 3:2), flow velocity 0.96 L/h and initial concentration of Cu2+ was less than 20 mg/L. Composite biosorbent can be used for more 10 times when biosorbent was regenerated by HCl solution, and HCl solution can be used 3 times repeatedly. The selective sequence was Ph2+ > Cu2+ > Zn2+ > Cd2+.
Assuntos
Metais Pesados/metabolismo , Sphaerotilus/metabolismo , Eliminação de Resíduos Líquidos/métodos , Adsorção , Biodegradação Ambiental , Cobre/química , Compostos Férricos/química , Chumbo/química , Nanopartículas , Zinco/químicaRESUMO
As biosorbent used Sphaerotilus natans, influencing factors on removal of Pb2+ were investigated such as ratio of the biomass and lead, pH, temperature and time of adsorption. The results show that Sphaerotilus natans has good effect on adsorption of Pb2+. The process of adsorption reached equilibrium in 10 minutes. Temperature has no significant effect on the adsorption. Removal of Pb2+ approached to 100% under the condition of pH 5.5, 0.6 g/L and c0 < or =20 mg/L. The maximum adsorption amount was 2.1 mmol/g dry biomass . The adsorption was fitted with Freundlich isotherm adsorption equation under the concentration of Pb2+ 0-60 mg/L. HCI and EDTA can desorb the Pb2+ from the bacteria effectively.
