| With the rapid development of industry,the problem of heavy metal pollution has become more and more serious,and it threatens the survival and health of human beings.Therefore,the repair of heavy metals in soil is very important at this stage.Chelating agents are widespread uses in the stabilization/solidification of heavy metals for its convenience.Water-soluble Thiourea-Formaldehyde?WTF?resin is a novel water soluble chelating agent which can transform heavy metals from active fraction to stable fraction.According to the previous study,expanded application concentration of Cd and Cu and the effect on soil health were studied.According to the toxicity leaching procedure experiment,the results show the stability rates of WTF resin for different concentrations of Cd and Cu are all above 80%.Especially,the stabilization rates of Cd and Cu can reach to 90.47%and 99.85%respectively at 30 and 2000 ppm respectively after remediation of WTF resin.The stabilization rate of heavy metals after the remediation of Na2S is at 75-80%,which is lower than the stabilization rate of WTF resin.Therefore,WTF resin can stabilize heavy metals in different concentrations,and has better stabilization effect than Na2S.In the experiments on the effects of enzyme activity and soil nutrient content,WTF resin has remediation effect on sucrase and ALP activity,which indicates that it has repairing effect on soil enzymes after passivating heavy metals.What's more,WTF resin may occupy the urease active site that decomposing urea and cause inhibition effect on urease activity,which can be a kind of urease inhibitor.However,Na2S has inhibition effect on the three enzymes.In the meanwhile,WTF resin can increase the content of WOC and AP and decrease the content of ammonium nitrogen,which indicated that WTF resin is innocent and beneficial to the soil health.As a result,WTF resin is a suitable material for Stabilization/Solidification of heavy metal contaminated soil. |
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