Hexabromocyclododecane Distribution And Microbial Degradation Research In The Typical Marine Environment

Hexabromocyclododecane (HBCDs) is one kind of pollution with persistence, bioaccumulation and amplification, long distance mobility and high toxicity.and widely used as one of the bromine flame retardants. In 1998 the first time to detected the HBCDs in the fish and sediment. Then people graduly detected HBCDs in various environmental media.The Research on HBCDs relatively late in China, ocean as one of the most important sink of the HBCD. Nowadays, people pay more and more attention to the HBCDs pollution, in the environment. And as the serious petroleum hydrocarbon pollution and industrial pollution in the nearshore of the nothern yellow sea, it has become the hot topic in this area. the research of the HBCDs are still in the initiatory period, So far the research on the HBCDs for the marine environment in the nearshore of the nothern yellow sea is still very limited.This paper we used the HPLC/MS/MS analysis of HBCDs content in water, sediment and biological samples to study the topicl area of the nearshore in the northern Yellow Sea, and we also analyzes the bioaccumulation of HBCDs in this area. Based on the state of HBCDs pollution in the northern Yellow Sea shore. Marine is considered to be the important sink of the HBCDs. We also use the microbial in marine sediments to degradate the HBCDs, and the biodegradation of HBCDs has also been analysed. We screened 5 strains of HBCDs-degrading bacteria from the sediment, To study their degradation effects to HBCDs, The main results were as follows.The results showed that concentrations of HBCDs in water is 0.1～2.2 ng·L-1, average content of HBCDs in water is 0.6 ng·L-1, content of HBCDs in the sediment is 0.6～24.8 ng·g-1, average content of HBCDs in sediment is 6.4 ng·g-1.Concentrations of HBCDs in organism is 0.9～67.1 ng·g-1, y-HBCD is the main isomer of three kinds of medium in northern Yellow Sea coastal. It indicate that HBCDs main source is the industrial HBCDs. The bioaccumulation factor show that HBCDs bioaccumulation in organisms are relatively high and there are potential environmental risks in the northern Yellow Sea.Microorganism aerobic degradation of the HBCDs results show that the biodegradation rate of HBCDs is 38 to 61 days. The HBCDs have degradated 72% in the 120 days.The spectural of HBCDs show that the content of HBCDs in the microbial and have new peak, but the specific things in the degradation are still need further study.。In addition, we enrich and separate 5 strains from the sediment as the HBCDs to be the sole carbon source and energy source, they named CTF711-A、 CTF711-C、 CTF711-D、 CTF711-E、 CTF711-X1 respectively. Through the morphology observation, physiological and biochemical test and 16S rDNA sequence analysis, the 5 strains are pseudomonas sp., Rhodococcus ruber, acinetobacter baumannii, Microbacterium paraoxydans and halomonas venusta respectively. We also compare the degradation rate of the 5 strains and mixed strains, the results show that the mixed have the highest degradation rate indicate the mixed strains are beter for the degradation of HBCDs.