Remediation Of Drilling Mud Contaminated Soil By Adding Straw And Planting Alfalfa

With the rapid development of petroleum and natural gas mining industry,the production of drilling mud has also increased year by year.The waste drilling mud produced each year not only occupies valuable land resources,but also brings a series of ecological pollution problems to be solved.China is a big grain country,the yield of crop straw is very high.Rational utilization of resources can improve the comprehensive utilization of straw and make it waste into treasure.In this paper,the abandoned drilling mud(N)contaminated soil as the research object,adding different proportions of corn stalks(J),to study the effect of adding straw on soil physical and chemical properties,enzyme activity and heavy metal content in soil after one year of cultivating in rot.Planting alfalfa on drilling mud contaminated soil after rot,study on the remediation effects of Alfalfa on heavy metals in drilling mud contaminated soil,the following conclusions are drawn:(1)The addition of straw is beneficial to the reduction of pH and total salt in soil contaminated by drilling mud,it shows that the addition of straw can adjust its salinity and alkalinity to a certain extent,the results showed that the addition of straw could regulate the salinity and alkalinity to a certain extent,and reduce the degree of salinization of soil contaminated by mud.The higher the amount of straw added,the more significant the regulation of pH and total salt of soil was.(2)Increasing the amount of straw added to make the content of organic carbon?total N?P?K and available N?P?K are obviously improved in contaminated soil,improve the physical and chemical properties of soil contaminated by mud.The content of available phosphorus in contaminated soil is up to the most,the J5N0 treatment increased 48.02% over the J0N0 treatment.(3)After adding straw,urease activity,invertase activity and catalase activity in mud contaminated soil have been promoted in different degrees,increasing the activity of the three enzymes and improving the soil quality.(4)pH,total salt content and total and available N,P and K were negatively correlated,the correlation between total and available N,P and K showed significant positive correlation;Three kinds of enzyme activity and total and available N,P,K showed a significant positive correlation,there is a significant negative correlation with pH and total salt;there was a very significant positive correlation between the activity of the three enzymes.(5)(1)Adding straw decomposition had no significant effect on the total amount of Zn and Cr in the soil contaminated by mud.(2)The addition of stalks reduced the available Zn and Cr contents of the soil in the two stages before and after the decomposition,and the effective content of Zn and Cr in the year of straw decomposition compared with non-decomposition was significantly reduced,and the range of decline was 9.60% to 17.18% and 16.20% to 24.80%,the effect of straw decomposition on effective Cr is even more pronounced.(3)Planting alfalfa can significantly reduce soil Zn and Cr content,and J5N50 treatment had the best removal effect,which was reduced by 12.90% and 13.12%.(4)The combined repair method of adding straw and planting alfalfa has a certain repairing effect on drilling mud contaminated soil,and has a better repairing effect on Cr.