八角金盘水浸提液和GLDA强化马缨丹修复镉污染土壤的效果研究

Effect of Water Extract of Fatsia japonica Combined with GLDA on Phytoextraction of Cd Contaminated Soil by Lantana camara L.

【目的】探明八角金盘水浸提液(FJ)和谷氨酸N,N-二乙酸四钠(GLDA)复合活化剂强化马缨丹修复镉污染土壤的效果及机理。【方法】采用盆栽试验,研究FJ和GLDA对马缨丹生物量、镉富集特征及根际土壤镉有效性的影响。【结果】GLDA对马缨丹生长无影响,FJ和FJ+GLDA均能促进马缨丹地上部的生长,其地上部干重较CK分别增加了29.26%和19.47%。马缨丹根和茎中的镉含量受FJ的影响较小,而经GLDA和FJ+GLDA处理后分别提高了52.39%、60.66%和34.95%、40.36%。3种活化剂均显著增加了马缨丹地上部的镉富集量,分别较CK增加了53.11%、53.53%和88.79%,其中FJ+GLDA处理的效果最好。土壤DOC含量在3种活化剂处理下均显著提高,分别为CK的1.22、1.34和1.28倍。同时,3种活化剂促进了土壤中可还原态和可氧化态镉向酸提取态镉的转化以及有效态镉含量的增加,其中有效态镉在FJ+GLDA处理下增加了24.26%,优于其他处理。【结论】利用复合活化剂强化马缨丹修复镉污染土壤是可行的。复合活化剂促进了马缨丹的生长,并通过提高土壤DOC含量,增强了土壤镉的有效性,从而促进了马缨丹对镉的吸收和富集,显著提高了马缨丹修复镉污染土壤的效率。

【:Objective】The current study is conducted to explore the effect and mechanism of Lantana ca⁃mara L.in remediation of cadmium(Cd)contaminated soil enhanced by the composite activator of Fatsia japonica water extract(FJ)and L-glutamic acid N,N-diacetic acid(GLDA).【Method】Pot experiments were conducted to study the effects of FJ and GLDA on the biomass,Cd accumulation characteristics of L.camara,and Cd availability in rhizosphere soil.【Result】GLDA had no effect on the growth of L.camara,while FJ and FJ+GLDA could promote the shoot growth of L.camara,and the shoot dry weight increased by 29.26%and 19.47%compared with control.The Cd concentration in the roots and stems of L.camara was less affected by FJ,but increased by 52.39%,60.66%,and 34.95%,40.36%,respectively,after applied with GLDA and FJ+GLDA.The three activators significantly increased the Cd accumulation in the shoot of L.camara,which were 53.11%,53.53%and 88.79%higher than control,respectively,and FJ+GLDA treatment had the best effect.The soil DOC content was significantly increased under the three activator treatments,which were 1.22,1.34 and 1.28 times of control,respectively.At the same time,the three activators promoted the conversion of reducible and oxidized Cd to acid-extracted Cd and increased the content of DTPA-Cd in soil.The DTPA-Cd increased by 24.26%under FJ+GLDA treatment,which was superior to other treatments.【Conclusion】It is feasible to use compound activators to strengthen the effect of L.camara on phytoextraction of Cd contaminated soil.The compound activator promoted the growth of L.camara,and enhanced the availability Cd in soil by increasing the content of soil DOC,thus it promoted the absorption and accumulation of Cd by L.camara,and significantly improved the efficiency of L.camara in phytoextraction Cd contaminated soil.