Study On Biochemical Parameters Of2,2’,4,4’-tetrabrominateddiphenyl Ether-contaminated Soil, Sediment And Degradation

Polybrominated diphenyl ethers (PBDEs), being extensively used as brominatedflame retardant (BFRs), have now become a novel class of organic pollutants. Theconcerns about PBDEs will continue due to their possible adverse effects on wildlifeand human beings, persistence in the environment and potentiality forbioaccumulation.2,2’,4,4’-tetrabrominated diphenyl ether (BDE-47) as one of PBDEshas been detected in soil and sediment in many places of China.This study aimed at the changes of biochemical parameters and microbialdegradation of BDE-47-contaminated soil and sediment. Soil and sediment samplescollected from Yuelu Moutain and Xiangjiang River were prepared by adding BDE-47to2ug/g at8℃and30℃. Urease activities, soil respiration, the number of bacteriaand fungi colonies and seed germination were detected. Meanwhile, soil and sedimentsamples with the initial concentration of BDE-471ug/g and10ug/g were alsoprepared to assess the changes of urease activity, soil respiration, t he number ofbacteria and fungi colonies and seed germination as well as the degradation ofBDE-47. Furthermore, another soil and sediment samples by adding commercialhumic and nutrient solution were prepared to conduct the changes of biochemicalparameters and microbial degradation of BDE-47since BDE-47was hydrophobic.It was shown by the results that biochemical parameters characterized by ureaseactivity, soil respiration, the number of bacteria and fungi colonies, seed germinationwere significantly affected by BDE-47exposure. The differentiation of thetemperature was not obvious to biochemical parameters. However, with the increaseof BDE-47initial concentration, the biochemical parameters had a decreasing trend. Itis very necessary to focus on the10ug/g sediment sample which had a positive effecton urease activity. The result indicated that microorganisms have adapted to theenvironment in60days and can use BDE-47as a carbon source. Additionally thebiochemical parameters of soil and sediment samples were enhanced by addingcommercial humic and nutrient solution.The degradations of BDE-47were compared by a method which had beendeveloped for the determination of BDE-47by gas chromatography/massspectrometry (GC/MS). The results showed that BDE-47removol rate was notsignificant on the whole samples. The best highest BDE-47removal rate of10%occurred in the soil sample by adding commercial humic and nutrient solution. TheBDE-47removal in the sediment samples were not found in our investigation.