Study on Polyaspartic Acid(PASP)and 5-Aminovaleric Acid(ALA)to Enhance Extraction of Heavy Metal Cd from Soil by Sedum plumbizincicola
[Objective]To explore the optimal conditions for enhancing the extraction of soil Cd from S.plumbizincicola by synergistic chela-ting agent polyaspartic acid(PASP)with 5-aminopyruvic acid(ALA).[Method]A pot experiment was conducted to plant S.plumbizincicola in Cd contaminated soil(total Cd 0.68 mg/kg).After 45 d of transplanting,PASP was applied in different doses within 45 days:total appli-cation mounts of 3,6 and 12 g/kg(base on a dry soil)were equally divided into 1-3 applications,respectively,and the time intervals of 2-3 applications were 15,30 days.ALA(25 mmol/L)was applied on the third day after each PASP treatment,and treated according to different application times(0,1,2,3).The interval time was the same as that of PASP.The stem length,biomass,Cd content and amount of Cd ex-tracted from aboveground part of S.plumbizincicola were analyzed,in addition to the correlation between the indexes was established,and fitted the prediction model of biomass and Cd extraction amount on PASP application rate and ALA use times.[Result]ALA combined with medium dose(6 g/kg)of PASP for three consecutive times could significantly increase the stem length,aboveground biomass,Cd content and extrac-tion amount of S.plumbizincicola.Linear regression showed that PASP application rate and ALA application times were the key influencing fac-tors of aboveground biomass and Cd extraction amount.The highest value of Cd extracted from aboveground part was 1.09 g/por when applying PASP in 6 mg/kg,which was 2.79 times higher than CK when it was used 3 times in combination with ALA.The aboveground biomass and stem length were significantly positively correlated with the application times of ALA,but negatively correlated with the application amount of PASP.[Conclusion]The results reveal that ALA assisted PASP had important significance in enhancing the extraction of soil cadmium by S.plumbizincicola,and it was necessary to choose the appropriate combination mode.
Heavy metals5-aminol-vulinic acid(ALA)Polyaspartic acid(PASP)Sedum plumbizincicolaCd
万方数据
维普
