Toxic Effects Of Decabromodiphenyl Ether And Tetrabromobisphenol A On Soil Microbe

Nowadays, e-waste recycling sites (EWRSs) have resulted in severe environment pollution. As the main BFRs, decabromodiphenyl ether (BDE209) and tetrabromobisphenol A (TBBPA) had been found together in soil or sediment, while, there has been no report about their joint toxicity. The experiments were carried out to observe the interaction of BDE209and TBBPA on soil culturable microbial population, enzyme activity and bacterial community structure, so as to reveal the ecological toxicology effects of BDE209and TBBPA on soil. The observations and related findings will establish some useful scientific basis for EWRSs soil ecological risk assessment.(1) The toxic of BDE209and TBBPA to soil enzymes was most obvious at the first7day, during the entire experiment, toxic of high doses of chemicals was stronger than that of low or moderate doses. The interaction between BDE209and TBBPA was mainly antagonistic for saccharase and catalase. While, for urease, toxic addition or synergistic role were dominant. BDE209might play a more important role than TBBPA, and urease was more susceptive than the other two enzymes.(2) BDE209and TBBPA could significantly stimulate the growth and reproduction of soil microbial, except for samples exposed to high doses of the two chemicals. The inhibition ratios of microbial populations increased with incubation time and increasing concentrations of BDE209or TBBPA following certain dose-response relationships and time-effect trends, the joint toxicity of both contaminants on soil microbes was mainly antagonistic effects, and bacteria was more susceptive than the other two microbes.(3) Results showed that BDE209and TBBPA could obviously affect soil bacterial community structure. Soil bacterial diversity decreased with the increasing concentration of BDE209and TBBPA, and moderate or high doses of BDE209and TBBPA had inhibition effect on bacterial diversity. Pectobacteriwn, Sinorhizobium, Stenotrophomonas and Staphylococcus genus were the dominant species detected in our research. Pectobacteriwn, Sinorhizobium and Stenotrophomonas were tolerant to the two chemicals.