Study Of Effect Of Fly Ash From Pangzhuang Mining Area On Wheat Seedling And Its Microenvironment

Fly ash is one of the main pollutants of air pollution in coal mining areas.Fly ash will settle to the soil and crops within the pollution range through dry and wet deposition,which will often have a series of effects on the growth of these soil and crops.However,the existing research on the process and mechanism of this effect is still insufficient.In this paper,through greenhouse simulation experiments,the environmental effects of coal particles with different concentration gradients on seedling wheat(liangxing 99)were explored.The following conclusions are drawn:(1)Fly ash stress significantly inhibited plant height,root length,leaf length and leaf width of wheat seedlings,and significantly inhibited chlorophyll a,b and total chlorophyll of wheat seedlings,compared with the blank group,the inhibition rates of chlorophyll a,b and total chlorophyll in the high concentration group were 17.3%,18.8% and 17.4%,respectively.(2)There was no significant change of SOD and CAT in the protective enzyme of wheat leaves at seedling stage under the stress of coal-source particulate matter,but there was a significant change in POD.With the increase in the concentration of particulate matter,POD increased first and then decreased.The low concentration group,medium concentration group and high concentration group were 1.06,1.05 and 0.91 times of the blank group,respectively.Rubisco and GAPHD in wheat leaves were significantly changed under high concentration of coal-derived particles,which were decreased by 37.1% and 6.6%,respectively,compared with the blank group.(3)The content of Cu,Zn and Pb in the aboveground part of the seedling stage all showed a trend of increasing with the increase of the concentration of coal source particles,while there was no significant change in Cu and Zn in the underground part,and there was no significant change in Pb in the underground part between the test groups,so the change of the concentration of fly ash had no significant influence on Cu,Zn and Pb in the underground part.However,there was no significant influence of fly ash on Cr content in the aboveground part.The content of Cr in the underground part changed significantly in the spray-added fly ash and the blank group,but there was no significant change with the change of particulate matter.(4)Heavy metal Cr,Cu,Zn and Pb in the fountainhead particles are mainly composed of active lower hydrochloric acid extraction condition,a small amount of water soluble state and liposoluble state,and Cr,Zn and Pb in underground part and aboveground part is given priority to with hydrochloric acid extract and debris states,accounts for over 60% of the total,Cu in seedling stage of wheat in the aboveground and underground parts of the main state is extracted by ethanol and deionized water.The evaluation results of heavy metal activity showed that Cr,Zn and Pb had lower activity in the aboveground and underground parts,while Cu had higher activity in the aboveground and underground parts.(5)Under the treatment of coal source particulate matter,the species richness and diversity of interleaved microorganisms in the seedling stage of wheat had obvious changes,compared with the other three groups,the interleaved microorganisms in the medium concentration group had higher richness and diversity.At the level of phyla,Firmicutes,Proteobacteria,Actinobacteria and Bacteroidetes are the main phyla of the four groups,but their relative abundance is different.The microflora of interleaved microorganisms changed obviously with the concentration of coal particles.From the perspective of the subordinate classification level,the dominant bacteria in the four greenhouse groups were all different.Kruskal-wallis rank sum test and LEfSe analysis showed that there were significant differences in bacteria genera in the four groups of greenhouses,and the dominant bacteria genera in the four groups of greenhouses were also different.It could be seen that the particles from coal had a significant impact on the composition of microbial community between the leaves of wheat at seedling stage.(6)According to RDA analysis,under fountainhead particle stress that Chryseobacterium,Pseudomonas,Rhizobium are positively correlated with plant height,leaf length,leaf width and chlorophyll a and chlorophyll b,total chlorophyll and the ethanol extraction state of Zn,while negatively correlated with the extraction state and residue state of hydrochloric acid of Cu,Zn and Pb.Pedobacter,Flavobacterium and Stenotrophomonas are positively correlated with SOD and CAT,the content of heavy metals Cu,Zn and Cr in wheat leaves,as well as the ethanol extraction state of Cu and Cr,and the relative abundance of the above microorganisms in the four groups of greenhouse has changed.The results indicated that the change of microbe was related to the physiological and biochemical indexes and heavy metal content of wheat under the stress of coal source particulate matter.This paper has 21 pictures,18 tables,167 reference articles.