| Compared with the iron-manganese content generated by earth chemistry, iron-manganese oxides generated by microorgonism is not well-crystallized, small particle in size, disorder accumulation along the c axis, more Mn4 + vacancy exiting, negatively charged, and with large specific surface area, so that it had better adsorption and oxidation activity. In recent years, the removel of heavy metal by biological source of manganese oxides has caused a great attention. Groundwater often contains iron, manganese, concomitant of arsenic and antimony simultaneoursly. It is difficult to remove all the metals at the same time by conventional technology, but iron-manganese oxides generated by microorgonism can remove arsenic and antimony at the same time.This paper studies the iron-manganese oxides generated by Pseudomonas sp. QJX-1 bacteria to explore the adsorption and oxidation between iron-manganese manganese oxides and arsenic and antimony,then fix manganese oxide bacteria on filter materials, study its adsorption and oxidation of arsenic and antimony.It has lay a foundation for the development of process which can remove arsenic and antimony in the groundwater at the same time.In this paper,the main research results obtained are as follows:(1)As3+,Sb3+ with the final concentration of 10 μM adsorbed by iron-manganese oxides showed that 0.6 mg·L-1 As3+ was adsorption oxidation to 0.1 mg·L-1, 1.5 mg·L-1 Sb3+ was adsorption oxidation to 0.0 mg·L-1.,after cultivating 48 h. The mechanism analysis showed that Pseudomonas sp. QJX-1 contains Cum A,and the existence of Mn2+ amplified the activity of Cum A gene,the existence of As3+, Sb3+ decrease of the activity of Cum A gene.(2)Building biological filter and bubbled into groundwater containing iron,manganese, arsenic, antimony, monitoring,the results show that the biological filter has good removal efficiency for wastewater containing arsenic, antimony.and there are little difference between the filter material contain Pseudomonas sp. QJX-1 and exclusive Pseudomonas sp. QJX-1 in removing iron and manganese, but found that the filter material contain Pseudomonas sp. QJX-1 have a great better removal efficiency of arsenic, antimony than the one exclusive Pseudomonas sp. QJX-1.In the process of study,it have been proved the addition of manganese oxide bacteria could accelerate the maturity of biological filter, and can enhance the removal efficiency of the biological filter.(3) Umu was used to evaluate the genetic toxicity of inflow and effluent of the filter, the result has shown that the existence of arsenic and antimony increases the genetic toxicity of water compared with the raw water, but the genetic toxicity of effluent which contain Pseudomonas sp. QJX-1 was lower than exclusive Pseudomonas sp. QJX-1,shown that the presence of manganese oxide bacteria can help to reduce the genetic toxicity of water body.(4) Taking some filter materials from the mature of biological filter, found that under natural condition manganese oxide bacteria Pseudomonas sp. QJX-1 still can keep a superiority growth. real time PCR technique was used to study the activity of Cum A in the biological filter,The results show the one with manganese oxide bacteria have a significantly higher activity than the one without bacteria.(5) The FISH(fluorescence in situ hybridization technology) and Nano SIMS(Nano secondary ion mass spectroscopy) have been combined to study the filter biofilm, the results show that this technology can be used to explore the relationship between the distribution of bacteria and their structural function, in pure culture system and the complex environment.And compared with the complex environment system, there are smaller error and more precise in the pure culture system,when use FISH-Nano SIMS. |
PDF Full Text Request