十溴联苯醚(BDE209)对蜡状芽胞杆菌吸附/释放金属离子的影响

针对重金属及多溴联苯醚(PBDEs)复合污染问题,以蜡状芽孢杆菌(Bacillus cereus)复合菌为吸附材料,研究了十溴联苯醚(BDE209)对蜡状芽孢杆菌复合菌吸附及释放金属离子的影响.结果表明,蜡状芽孢杆菌复合菌对低浓度的Pb(II)(0.712mg·L-1)、Zn(II)(4.844mg·L-1)具有快速、高效、稳定的吸附能力,最高吸附率分别达到98.31%和97.83%;对低浓度的Cu(II)(1.915mg·L-1)也能起到一定的去除作用,吸附率最高可达59.90%.复合菌吸附重金属离子的同时,释放了其他金属离子:Ca(II)、K(I)、Na(I),且释放总量大于吸附总量.不同浓度的BDE209对复合菌吸附重金属产生不同的影响.1mg·L-1的BDE209基本表现为促进复合菌对重金属的吸附;而10mg·L-1的BDE209在0～4h之间促进复合菌对Pb(II)、Zn(II)的吸附,在反应4h后明显抑制吸附作用,而对Cu(II)则始终表现为促进作用.BDE209对金属离子释放的影响主要体现在反应的初始阶段(0～4h),表现为高浓度的BDE209减缓K(I)、Na(I)的释放.

Effects of Deca-Brominated Diphenyl Ethers (BDE209) on Adsorption and Release of Metal Ions by Bacillus Cereus

In view of joint contamination of heavy metals and polybrominated diphenyl ethers (PBDEs), combined Bacillus cereus was selected as the adsorbent to research on the effects of BDE209 on adsorption and release of metal ions by Bacillus cereus. Combined Bacillus cereus showed prompt, efficient and stable adsorption character for low concentration of Pb(II) (0.712mg·L-1) and Zn(II) (4.844mg·L-1), with highest adsorption rates of 98.31% and 97.83%, respectively. While for Cu(II) (1.915mg·L-1) the highest adsorption rate was 59.90%. Obvious release of other metal ions, such as Ca(II), K(I), and Na(I), was accompanied with biosorption, and total release quantity was found to be more than total quantity of adsorption. As BDE209 is concerned, the influence of its concentration on adsorption rate was observed. Adsorption capacity was stimulated with existence of 1mg·L-1 BDE209. However, biosorption of Pb(II) and Zn(II) started to decrease 4 hours after 10mg·L-1 BDE209 was added into the system while stimulative effects for Cu(II) were observed all the time. And the delay of K(I) and Na(I) release was found in the period of 1h to 4h at high concentration of BDE209.