Emerging contaminants: Evaluation of degradable chelators towards enhancing cadmium phytoextraction efficiency of bioenergy crop grown on polluted soil  

作　　者：Segun O.Oladele Blessing B.Oladele Rasheedat Ajala Bukola F.Dada 

机构地区：[1]Department of Agronomy,Faculty of Agriculture,Adekunle Ajasin University Akungba Akoko,Nigeria [2]Department of Physics,Radiation and Environmental Health Unit,Federal University of Technology Akure,Nigeria [3]Department of Crop Soil and Pest Management,Federal University of Technology Akure,Nigeria

出　　处：《Emerging Contaminants》2021年第1期139-148,共10页新兴污染物（英文）

摘　　要：Exogenous application of chelators towards enhancing heavy metals extraction efficiency of bioenergy crop has received considerable attention in recent time.However,little is known about optimal application rate,comparative evaluation of degradable versus non-degradable chelators and their impact on cadmium(Cd)speciation and uptake,physiological and biochemical activity of sweet sorghum grown under Cd stress.Four chelators namely,Nitrilotriacetic acid(NTA),tetrasodium N,N-diacetate(TDA),Ethylenediamine tetraacetic acid(EDTA),iminodisuccinic acid(IDA)and control(CK)were applied and compared at rates of 2,5,and 10 mmol kg^(-1) towards augmenting phytoextraction efficiency of sweet sorghum for Cd remediation in a screen house study.Results showed that sweet sorghum augmented with TDA significantly(P<0.05)increased biomass,enhanced Cd uptake and accumulation when compared to EDTA at application rate of 2-5 mmol kg1.TDA influenced Cd speciation via increasing acid-soluble,reducible,oxidizable,and residual fractions of Cd,thus increasing Cd bioavailability.NTA and TDA increased proline concentrations,antioxidant enzymes and net photosynthetic activity rate(Pn)comparably to EDTA in sweet sorghum,thus enhancing stress tolerance and stabilizing photosynthetic activities.Overall,exogenous application of degradable TDA at 2-5 mmol kg^(-1) could be recommended as replacement for non-degradable EDTA in a chelate assisted approach towards augmenting bioenergy crop for phytoremediation of Cd polluted soil.

关 键 词：PHYTOEXTRACTION Antioxidant enzymes Photosynthetic rate Stress tolerance Cadmium speciation 

分 类 号：X53[环境科学与工程—环境工程]