Effect Of Nano Zero-Valent Iron On The Stabilization Of Arsenic By Biogenic Mn Oxides In Contaminated Soil

In this paper,the effect of nano zero-valent iron on the stabilization of arsenic by biogenic Mn oxides in contaminated soil were studied.The main research contents were as follows: Zeta potential,particle size distribution,SEM-EDS,TEM,FTIR,Raman spectroscopy,XRD analysis of n ZVI to BMO mineral properties and As removal the effect of efficiency;the effects of zero-valent iron addition on the As effect in BMO stabilized soil were studied by using indoor simulated stabilization experiments and pot experiments.The leaching concentration changes of soil before and after stabilization were studied by leaching experiments and morphological analysis experiments.Morphological changes,analysis of crystal composition changes in soil by XRD.In addition,16 S RNA high-throughput sequencing was used to analyze soil microbial structure and biodiversity changes.The main conclusions are:(1)nZVI will combine and adsorb to the BMO surface and form a cluster assembly,which increases the BMO surface,average particle size and surface electronegativity.The results of FTIR and Raman spectroscopy indicate that the presence of hydroxyl groups,Mn-O and iron oxides and iron hydroxides on the surface of the particles before and after As can increase the oxidative adsorption capacity of As.The XRD pattern before and after As removal only monitored the absorption peak of Fe0,and no other high-crystalline new substances were detected.n ZVI can significantly improve the removal effect of BMO on As(III)and the removal efficiency is higher than 99%.(2)The results of stabilization experiments show that n ZVI changes the combined form of soil As and reduces the leaching concentration and soil risk value of soil As;the combination of As forms from water-soluble and exclusive adsorption to amorphous iron-manganese.The type of iron-manganese combined state and residual state transition;high-throughput analysis showed that n ZVI increased the diversity of soil microbial community and changed the microbial community structure.(3)Pot experiments showed that n ZVI reduced plant As enrichment in soil;reduced As leaching concentration and risk value;low n ZVI dosage increased plant height;high-throughput analysis showed n ZVI The diversity of soil microbial community distribution and the abundance of community distribution were reduced,and the microbial community structure was changed.