Research On Remediation Effect Of Different Stabilization And Solidification Materials To Heavy Metal Contaminated Soil Of Tongling

(1)Heavy metal pollution in soil has been frequent in recent decades,which has caused huge impact on human health,especially the tailing bank formed by mineral exploitation,serious to the surrounding environment.In this paper,the heavy metal poll ution in the soil surrounding the 3 large tailings banks in Tongling is investigated,and the comprehensive pollution index is used to evaluate the heavy metal pollution.The results showed that all the pH values of the cultivated soil around the tailings reservoir were all neutral,and the arable land around the poplar tailings pond was heavily polluted by As,mild Cd pollution,and the arable land around the tailings of the B and C valley were all affected by a slight As pollution.The comprehensive index of the comprehensive pollution index showed that the soil comprehensive index of the cultivated land surrounding the A tailing pond was 4.58,which belonged to serious poll ution.The comprehensive pollution index of the cultivated land around the Tailings Bank of the B and C valley was less than 2,which belonged to the mild pollution.The heavy metal correlation analysis showed that Cu and Cr were significantly negatively correlated with Zn and Mn,and Cd was positively correlated with Pb,As,Zn and Mn,and Pb was positively correlated with As and Cr.Off.The analysis of all kinds of metals by cluster analysis shows that when the clustering distance is 5,the metals are divided into 4 categories:(1)Cu(2)Cr(3)As and Hg(4)Pb,Zn,Cd,Mn;(2)The effect of stabilization and solidification heavy metal contaminated soil is remarkable,but various materials have different effects,each has its own advantages and disadvantages.In order to explore the restoration effect of single or compound treat ment of different stabilization and solidification materials,this study selected lime,magnesium phosphate,bamboo charcoal,straw and chicken manure,and carried out exper iments in the field location plot.The results showed that the pH value of lime treated soil rose most quickly and increased by 1.64 compared with the control.The effective concentration of heavy metals in lime soil was the lowest,and the concentration of effective As,Cu,Cd and Pb in soil decreased by 64.56%,59.98%,61.29% and 40.43% respectively.(3)In order to study the repair effect of different stabilization and solidification materials with fertilizer application and the distribution of heavy metals in Rape after trea tment,lime?calcium superphosphate?activated carbon?silicon fertilizer? chicken man ure and cake fertilizer were used in the experiment.The results showed that the effective concentration of Cu,As,Pb and Cd in the soil treated with lime + superphosphate + cake fertilizer were the lowest.Lower than the control was 45.08%,58.71%,48.09% and 56.4% respectively.The accumulation of heavy metals in rape showed that Cu and Cd accumulated more in the stem of rapeseed.As and Pb accumulated more in the rape roots.The Cu concentration of lime + calcium superphosphate + Cake Fertilizer in rape seeds was the lowest,and 66.56% decreased compared with the control,and the Cd concentration in grain was thicker than the control.The treatment of lime+ silicon fertilizer and cake fertilizer was the lowest,and 90% decreased compared with the control.The Pb concentration of lime + calcium superphosphate + chicken m anure in grain was lowest,and 91.6 was decreased compared with the control.The content of As in each grain was lower than that of the control.The control of the national food safety standard found that the concentration of Pb in the grain of control was beyond the standard,and the heavy metals in other grains were not exceeding the standard.(4)The effect of stabilization and solidification treatment on the weed community diversity in the field was studied by the sample method.The results showed that the weed dominance was higher in each treatment.The diversity index showed that the diversity of the weed community was not affected by the treatment of lime + superphos phate + chicken manure,and there was no effect on the weed community diversity in the field.Significant differences.The similarity index of community similarity showed that the similarity between the treatments and the control weeds was not high,which was less than 0.4,and the composition of the weeds treated with lime + silicon fertilizer and cake fertilizer was the most similar to that of the control.(5)In order to preliminarily screen weeds with high accumulation of heavy metals,21 common weeds near the tailing pond were collected.The concentration of heavy me tals in the body were measured,and the enrichment and translocation coefficients were calculated.The results showed that Geranium wilfordii Maxim.might be a Cu high accumulation plant.Rumex patientia Linn.,Crassulaceae J.St.-Hil.,Avena fatua L.and Youngia Japonica may be Cd high accumulating plants.