Transformation Of Arsenic Bymicrobial And Itspurification Mechanisms Effect

Arsenic in water pollution in China is serious,Inner Mongolia,Shanxi and other13 provinces are to varying degrees threatened by arsenic contamination,and arsenic is more dangerous to human as well.How to make efficient removal of arsenic in water,inhibiting water treatment field is a priority.Practical method of removing arsenic in water,such as coagulation,adsorption,removal efficiency under the influence of arsenic speciation for arsenic and arsenic species in water directly or indirectly received about the influence,therefore combining biotechnology with conventional treatment process will help improve the removal of arsenic.This paper based on the static flask experiment,studies the mechanisms of arsenic oxidation and adsorption by the iron-manganese oxides,the increase efficiency of removal of As by As⁵⁺reducing bacteria-carrying graphene oxide-hydrated zirconium oxide,competitive relationship of manganese oxidation bacteria strain and arsenic reduction strain on theoxidation and reduction of arsenic.To explore transformation of arsenic bymicrobial and itspurification mechanisms effect.It has lay a foundation for the development of biological process to removal of arsenic.In this paper,the main research results obtained as follows:（1）X-ray absorption near-edge spectra（XANES）and K-edge extended X-ray absorptionfine structure（EXAFS）analysesthe mechanisms of arsenic oxidation and adsorption by the iron-manganese oxides,its revealed that the BFMO was contained two parts:amorphous BMO and Fe OOH.The BMO part was mainly responsible for As³⁺oxidation,and the Fe OOH part dominated As adsorption.In addition,the BMO could oxidize Fe²⁺to form Fe OOH,which may improve As adsorption,and reduce the concentration of Fe²⁺、Mn²⁺at the same time.（2）The combination of the As⁵⁺-reduction bacteria and GO-Zr O（OH）₂（1:100）was 6 mg·L^-1 higher than GO-Zr O（OH）₂（1:100）alone on Asremoval.The results show thatmicroorganism can promote the As⁵⁺removal efficiency and quantity.The mechanism was further analyzed by FTIR and XPS.The difference of the binding energyindicate that As⁵⁺was truly adsorbed onto the BGZ.（3）Analysethe competitive relationship of manganese oxidation bacteria strain and arsenic reduction strain revealed that,the concentration and valence of Mn and As varied with different reaction time.biological manganese oxides dominated the arsenic redox by oxidizing the As³⁺existing in the existing system or reduced by arsenic reductase into As⁵⁺.PCR and RT-PCR results indicated that the arsenic reductase（ars C）was inhibited by the manganese oxidase（Cum A）.The expression of 16S r RNA in QJX-1 was two orders of magnitude higher than that in LSJ-9,which implied QJX-1was dominant in the bacterial growth.Our study showed that the iron-manganese oxides can removal the arsenic efficiently,and reduce the concentration of Fe²⁺、Mn²⁺at the same time.The microorganism can promote the Asremoval efficiency and quantity.Manganese oxidation bacteria strain was dominant both in the arsenic redoxandbacterial growth.The microorganismcan influence the content and redox of arsenic in waterdirectly or indirectly,explore itspurification mechanisms effect could development of biological process to removal of arsenic.