Effects of EDDS on Growth, Heavy Metals Accumulation of Miscanthus sacchaiflorus and Its Remediation Capability to Contaminated Soils under Cd, Pb Pollution

ZHENG Liming; ZHANG Jie; YANG Hongfei; YUAN Jing

doi:10.15933/j.cnki.1004-3268.2017.08.011

Abstract：The effects of different EDDS concentrations [0 (control),1,3,5 mmol/kg] on growth,heavy metals accumulation of Miscanthus sacchariflorus and its remediation capability to contaminated soils were studied under slight Cd,Pb contamination,so as to ascertain the potential of EDDS for the phytoremediation of heavy metals contaminated soils combined with Miscanthus sacchariflorus.The results indicated that on the whole,there were no significant differences between the control and EDDS treatments in photosynthetic pigments contents,plant heights and dry biomasses under Cd,Pb stress;photosynthetic pigments contents of 5 mmol/kg EDDS treatment was relatively higher,plant heights and dry biomasses of 3 mmol/kg EDDS treatment were relatively higher.Under Cd stress,with the increase of EDDS concentrations,Cd concentration and bioconcentration factor of aboveground,underground parts increased at first and then decreased,reached the maximum values at 1 mmol/kg EDDS,which were 72.8％,15.4％ and 73.6％,15.4％ higher than the control,respectively,3 mmol/kg EDDS was the second;Cd translocation factors increased all the time,all EDDS treatments were significantly higher than the control;total Cd accumulation increased at first and then decreased,the maximum appeared at 3 mmol/kg EDDS,which was 44.2％ higher than the control;translocation amount factors of different EDDS treatments were significantly higher than the control,and the maximum appeared at 5 mmol/kg EDDS;remediation efficiency of Cd contaminated soils met the maximum at 3 mmol/kg EDDS,which was 44.2％ higher than the control.Under Pb stress,the Pb concentrations and bioconcentration factors of aboveground part met the relatively higher value at 5 mmol/kg,but there was no significant difference compared with control;Pb concentrations and bioconcentration factors of underground part reached the peak value at 5 mmol/kg,which were 37.5％ and 35.3％ higher than the control;aboveground,underground and total Pb accumulation decreased at first and then increased with the increase of EDDS concentrations,the maximums appeared at 5 mmol/kg EDDS,which were 9.4％,56.7％ and 46.6％ higher than the control,but there were no significant difference;remediation efficiency of Pb contaminated soils decreased at first and then increased with the increase of EDDS concentrations,the maximum appeared at 5 mmol/kg EDDS,which was 45.2％ higher than the control,but there was no significant difference.In conclusion,under Cd stress,3 mmol/kg EDDS improved the Cd concentration,accumulation and remediation efficiency of contaminated soil;under Pb stress,5 mmol/kg EDDS enhanced the Pb accumulation and remediation efficiency,but the promotion were insignificant.As a result,there was a great potential to remediate the Cd contaminated soils by the combination of EDDS and Miscanthus sacchariflorus.