| Wth the development of the national economy,the improvement of people’s living standard,the number of city sewage treatment plant will increase,which leads to city sludge yield year after year.City sludge only waste treatment pressure increase,resource utilization of city sludge has become a problem that can not be ignored.In heavy polluted and nutrient poor in tailings,apply environmental toxicity weak city sludge,and plant characteristics of pollutants strong tolerance reclamation plant,Amorpha fruticosa,in order to achieve the purpose of improving soil.Lead-Zinc Tailing soil has poor soil and water conservation ability and poor nutrition.Compared with city sludge,lead-zinc tailings have environment strong toxicity.City sludge rich in nutrients such as nitrogen and phosphorus,organic matter content as high as 30%or more,can provide nutrients for the reclamation plant;adhesion of sludge is better,which can improve the soil physical properties.Contains a lot of lead zinc cadmium and cyanide,flotation reagent and other harmful components of lead-zinc tailings,the reclaimed land not used for farming;lead-zinc tailings belong to the general industrial solid waste,its location away from the environmental sensitive targets,and the design of anti flood control facilities.City sewage sludge application on the tailings,will not cause the secondary contaminated soil and water.Amorpha fruticosa belongs to Amorpha,legume,and it is fast growth,relatively easy to survive.Amorpha fruticosa have leaves dense,fibrous roots flourishing and root verrucous,which are plants of soil and water conservation.Amorpha fruticosa good at lead and zinc metal tolerance,able to adapt to the growth environment of lead-zinc tailings,is an important plant for ecological restoration in tailings of lead and zinc.This research used lead-zinc tailing and city sludge in different proportions(volume fraction of 10%,20%,30%,40%,50%,60%,70%,80%and 100%respectively)pot experiment to analyse the difference of different city sludge dose applied to the characteristics of Amorpha fruticosa seedlings growth and uptake of heavy metal.This paper can provide reference for field planting experiment,theory and fact custom for city sludge modified contaminated tailings standards.The main conclusions of this paper are as follows:1.In the tailings powder application of city sludge can significantly improve the Amorpha fruticosa seedlings dry weight,plant height,basal diameter;and with the increase of volume ratio of sludge application,Amorpha fruticosa seedlings dry weight,plant height,ground diameter growth index has maintained a rising trend.Application of city sludge can effectively solve nutrient soil problems of the tailings,which promotes Amorpha fruticosa seedlings growth in tailings reclamation.In addition,in high concentration sludge application rate,increase the application ratio of sludge to promote the role of Amorpha fruticosa mainly in:the dry weight of leaf,stem thickening and root growth,at the same time,height growth is not significant.2.Results show that applying sludge in tailings can improve the content of each part of nitrogen phosphorus and potassium of Amorpha fruticosa seedlings,and increased with the application rate of sludge,the organ of Amorpha fruticosa seedlings N,P,K content kept increasing trend.Amorpha fruticosa seedlings of nitrogen,phosphorus,the potassium content in general is:when the sludge content low,the gains are not large;when high,nitrogen phosphorus potassium concentration between adjacent processing grows larger,with significant differences.3.In the lead-zinc tailings nutrient poor environment,keeping the moisture adequate,city sludge can be effectively applied to improve Amorpha fruticosa seedlings photosynthesis,and promote the growth of seedlings;and with the application of sewage sludge ratio increased the photosynthetic indexes keep rising trend.The stomatal conductance and transpiration rate with strong correlation,when the proportion of sludge changes,each shows linear characteristics,which are similar:the proportion of sewage sludge can improve greatly increased stomatal Amorpha fruticosa leaf conductance and transpiration rate.The net photosynthetic rate,when sludge mixing ratio is high,such as between H,I,J increase slowly.4.Different kinds of heavy metal,in Amorpha fruticosa,distribution of various.In Amorpha fruticosa planted in lead-zinc tailings,mixed with different proportion of applying sludge,heavy metal copper,lead,zinc,cadmium and other different parts in the enrichment.Research shows that,the main absorption site lead and copper is the roots of Amorpha fruticosa seedlings,while the main absorption site for zinc,cadmium is leaf Along with the increase of sludge application rate,4 kinds of heavy metals in the content of each part of Amorpha fruticosa seedlings always exhibited a decreasing trend.When high concentration sludge applied the proportion of heavy metal content changed less,when low concentration of heavy metal sludge ratio decreased significantly in vivo concentration of Amorpha fruticosa.5.It preliminary judge that the best volume ratio of city sludge application was 70%;Amorpha fruticosa seedlings growth at which time is good,with adequate nutrition and photosynthesis in good condition.When ludge is relatively lower,Amorpha fruticosa seedlings are inhibited by the growth of harmfial substances and nutritional deficiencies of tailings powder,when ludge is relatively higher,it will lead to mild Excessive fertilizer,which shows that new leaf color is too deep and the old leaves appearyellow phenomenon. |
