| With the continuous acceleration of the urban process,the pollution of urban river water is becoming more and more serious.Therefore,in this paper sponge iron and ceramic mixed filler were used to purify and treat a river in lintong district of xi 'an city,and the treatment effect of different mixed fillers was investigated,also the packing itself and the microorganism of the packing surface after the system were stable was studied deeply.In this paper,SEM characterization,EDS spectroscopy analysis and XRD characterization of fresh sponge iron and ceramsite were studied,and the SEM characterization after the packing;the organics and nitrogen phosphorus removal of effect test were carried out by using the BAF reactor for the pure sponge iron fillers,pure ceramic fillers,sponge iron and ceramic particles with different mass ratio and blank control group,the water inflow concentration and removal rate of different pollutants were fitted linearly by means of statistical method;the high-variable region sequencing of the microorganism 16S rDNA gene was carried out,and the relations of microorganism species and microorganism structure of the door to the genus levels of each reactor as well as richness and diversity were obtained.The main conclusions of the paper are:(1)SEM characterization,EDS spectroscopy analysis and XRD characterization indicate that the surface of fresh sponge iron filler is rough and porous,having a spongy three-dimensional surface structure.The composition elements are mainly Fe,C and O,and the content is 58.79%,21.85%and 19.36%respectively,the compounds are composed of Fe3O4,Fe2O3,Fe3C and Fe2CO3.The surface of the fresh ceramic packing is distributed by the raised rough surface of different shapes and sizes within the range of 0-8,the elements consist of O,C,Si,Al,Ca,K,S,Mg,Fe,Na and Cl elements,with the content of 51.35%,21.04%,10.45%,7.55%,6.83%,0.67%0.65%0,57%0.54%0.27%and 0.1%the compounds are composed of LiGaSi2O6,NaAlSi3O8,Cu(HSeO3)2,LiNbMoO6,SC(N2H3)2,Na4H4,SH6N4S and so on.sponge iron and ceramic packing are ideal biological fillers.(2)Through the electron micrograph,the surface of each packing material was covered by various microorganism,The surface becomes rougher and has more pores.(3)The removal efficiency of stuffing mix to TN was improved,and the effect of different mixing ratio on removal rate was not significant.The pure sponge iron filler has the phenomenon of the plate knot,the mixing with other fillers can prevent it,but the removal effect of pure sponge iron on COD,TP,NH3-N and TN is ideal.(4)NH3-N removal efficiency is the best in the pure ceramsite reactor with the best growth potential.When the temperature is below 10 ?,even choosing relatively hardy plants waterweed,also because of various reasons such as cold,the plants died off.Therefore,mainly through the biofilm in the wetland method should be used to reduce pollutants in the cold northwestern region in winter.(5)It was found that there was a significant positive correlation of 0.01 level between in the reactor of 3:1 of the mass ratio of sponge iron ceramic particles water inlet COD and the corresponding removal rate(the concentration of COD is between 100 and 500mg/L)with between control group water intake TP and removal rate(the concentration of TP is between 8 and 32mg/L).There is a significant positive correlation of 0.01 between the pure sponge iron reactor water inlet COD and the removal rate.between in the reactor of 1:1 of the mass ratio of sponge iron ceramics water inlet COD and the removal rate and between the pure ceramsite reactor TP water inlet and the removal rate.(6)By sequencing the microorganism of 16S rDNA gene on the surface of the filler,the microorganism door on the surface of biological packing was obtained.For example,the dominant population of the dominant species in the control group,such as horizontal all reactors were mainly proteobacteria(35.74%59.79%53.02%51.14%83.20%and 69.33%respectively),In the reactor of control group,pure ceramic granule and 3:1 and 1:3 of mass ratio of sponge iron ceramic granule bacteroides second(36.02%,22.15%,7.64%and 20.50%respectively),In the reactor of the pure sponge iron and the 1:1 of mass ratio of sponge iron ceramic particle firmicutes second(14.91%and 45.46%respectively),The bacteria gate and actinomycetes were increased,and the bacilli door and other fungi were all decreased compared with raw water by cultivated.The observed_species index and Shannon index showed that the diversity and richness of species in the spongy iron reactor were highest,next is the blank group,the quality ratio of sponge iron and ceramsite of 1:3 in reactor was the highest.However,the uniform degree of the species composition is quite similar.The dominant bacteria group in samples The reactor of 1:1 and 3:1 of the mass ratio of sponge iron to ceramsite has a high proportion and low diversity,and the species diversity of control group and pure ceramic particle reactor samples is relatively high. |
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