Removal Of Antimony By P.aeruginosa PA-1 And Its Biological Manganese Oxides

In this paper,Pseudomonas aeruginosa strain PA-1 with manganese oxidation activity was screened,which could remove Mn（Ⅱ）from the solution and form biological manganese oxide,and was identified by 16S r DNA sequencing.The adsorption and oxidation of Sb（Ⅲ）and Sb（V）by biological manganese oxides and chemical manganese oxides produced by the strain were studied by adsorption（oxidation）kinetics and adsorption isotherm experiments.The adsorption and removal effects of two manganese oxides on Sb（Ⅲ）and Sb（V）were studied The morphology and structural changes of oxygen were characterized and analyzed in order to have a deeper understanding of the adsorption characteristics of biological manganese oxides.Finally,the removal effect of Mn（Ⅱ）and Sb（Ⅲ）in biological manganese sand filter was studied by inoculating manganese oxidizing bacteria into the manganese sand filter.The conclusions are as follows:（1）The strain can remove Mn（Ⅱ）in the solution and form black biological manganese oxide.Meanwhile,the strain can convert Sb（Ⅲ）in the solution to Sb（V）and adsorb Sb（V）during the process of manganese oxide generation.Under oligotrophic conditions,the removal efficiency of Mn（Ⅱ）and Sb（Ⅲ）can be improved and prolonged by inoculating Mn oxidizing bacteria into the manganese sand filter.（2）Biological/chemical manganese oxides all exhibit weak crystallinity and have a crystal phase structure similar to that ofδ-Mn O₂.Biological manganese oxides mainly contain Mn,O,C,N elements.Chemical manganese oxides mainly contain Mn,O,C elements.The surface Mn valence of the biological Mn oxides is dominated by Mn（Ⅳ）,while the chemical Mn oxides are dominated by Mn（Ⅱ）.（3）The adsorption of Sb（Ⅲ）by the biological manganese oxides was more in line with the Freundlich adsorption isotherm model,with a maximum adsorption capacity of 143.15 mg/g;the adsorption of Sb（Ⅲ）by the chemical manganese oxides was more in line with the Langmuir adsorption isotherm model,with a maximum adsorption capacity of 106.35 mg/g;the adsorption process of Sb（V）by the two manganese oxides was controlled by the chemical The adsorption of Sb（V）by the two manganese oxides was controlled by the chemical adsorption mechanism;the adsorption of Sb（V）by the two manganese oxides was more consistent with the Freundlich adsorption isotherm model;the adsorption of Sb（V）by the biological manganese oxides was better than that by the chemical manganese oxides at different temperatures.（4）The differences in the oxidation rate of Sb（Ⅲ）and the adsorption of Sb（V）between the biological manganese oxides and the chemical manganese oxides were explained by:the Mn valence state on the surface of the biological manganese oxides was dominated by Mn（IV）;the bacterial secretions on the surface of the biological manganese oxides were involved in the adsorption process;the hydroxyl groups on the surface of the biological manganese oxides were more likely to complex with Sb（Ⅲ）or Sb（V）.