Effect Of Fertilizers On The Remediation Of Combined Contamination Of Heavy Metals And Deca-brominated Diphenyl Ether In Soils

Electronic waste has become a new environmental problem, which is increasingly focused with the worldwide attention. This thesis taking the heavy metals Zn,Pb,Cd and deca-brominated diphenyl ether (BDE-209) as the research object, which is aim to explore the efficiency and mechanism of chemical fertilizers for sedum alfredii hance on the repairing of combined pollution. Meanwhile, some fertilizers are found for improving the combined pollution of Zn,Pb,Cd and BDE-209, which are effectively repairing the combined pollution. The main results are as following:(1) The growth of sedum alfredii hance with different chemical fertilizers are obvious in composite polluted soils. The plants can strongly growed under most of the chemical fertilizers, which are not produced obvious adverse effects.(2) The available contents of heavy metals in soils are increasingly, and the repairing effect of sedum alfredii hance on the heavy metals in combined pollution is preferably. Under different chemical fertilizers, the absorption and collection for sedum alfredii hance of Zn,Pb,Cd were 13814-20534 mg/kg dry matter,122.4-235.8 mg/kg dry matter,1258.9-2439.1 mg/kg dry matter, respectively. The same heavy metals can be absorbed remarkably with different chemical fertilizers, and different heavy metals can be absorbed effectively with the same fertilizers. According to the statistical calculation, the absorption of heavy metals in sedum alfredii hance are increased with the available contents of heavy metals in soils.(3) The contents of BDE-209 are reduced effectively under different chemical fertilizers in soils, and the accumulation of BDE-209 are small in sedum alfredii hance, (NH4)2SO4, NH4HCO3, KH2PO4, Calcium superphosphate and K2SO4 can effectively enhance the absorption of sedum alfredii hance on BDE-209. Compared with the contents of soils and sedum alfredii hance, the reduction of BDE-209 in soil is mainly due to the fertilizers which enhance the microbial degradation of BDE-209, insteading of absorption by plants.(4) The absorption coefficient of Zn,Pb,Cd and BDE-209 are during the 13.81-20.53, 0.122-0.228,28.17-48.78,0.287-0.477 in sedum alfredii hance. Compared with different chemical fertilizers, NH4HCO3, Ca(H2PO4)2 and K2SO4 are the best dealings, but the mechanisms of remediation is still needed further study.