Effect Of ZVI-ATP On The Stabilization Of Heavy Metals In Farmland Soil

The National Soil Pollution Survey Bulletin shows that heavy metals are the key pollutants in the soil,and their remediation has become a national problem that we have to solve urgently.The zero-valent iron was prepared by using X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM)were used to characterize the modified pharmaceuticals.The soils were polluted by the heavy metals contaminated in the suburbs of Changsha,Hunan Province.The graded extraction and TCLP were different.The immobilization mechanism and effect of the compound on the heavy metals in the farmland soil were studied.The pot experiment was conducted to verify the effect of the treatment and the effect on the toxicity of the crops.The main findings are summarized as follows:1、ZVI-ATP were made through the liquid reduction method,and the adsorption effect of ZVI-ATP on three kinds of heavy metals was studied.The results show that most of the zero-valent iron is filamentous and uniformly supported on the earth,with good crystal form and specific surface area of 149.44m2·m-3.ZVI-ATP has a good effect on the removal of chromium,cadmium and lead in the polluted solution,And the adsorption rate of ZVI-ATP to low concentration Cr(50 mg·L-1)was close to 100%.2、The fixation effect of ZVI-ATP and other four kinds of curing agents on the heavy metals in farmland soils was compared with TCLP.The results showed that the acidity of the above-mentioned five kinds of curing agents was weakened,and the forms of lead,chromium and cadmium in the soil showed a tendency to change from unstable to steady state.The exchangeable heavy metals in soil were more TCLP experiment was leached out.The best curing agents for Pb,Cr and Cd were K-P,ZVI-ATP and CSB respectively.The effects of ZVI-ATP>K-P on the remediation effect of compound contaminated soil were as follows:ZVI-ATP>K-P>CSB>ZVI-SM>ATP,the leaching concentration of lead,cadmium and chromium in the samples decreased by 50.53%,47.45%and 68.23%respectively after ZVI-ATP treatment.3、The effects of the three heavy metals on the toxicity of the above five kinds of materials were evaluated by phytotoxicity test.The results showed that the growth status of the plant was improved and the growth of the plant was alleviated by the addition of the curing agent.In the micronucleus experiment,the micronucleus rate of the plant could be reduced by 55.43%Alleviate the toxic effects of heavy metals on the genetic material of broad bean.The results showed that ZVI-ATP>CSB>ATP>K-P>ZVI-SM could be used to evaluate the phytotoxicity of five kinds of curing agents.