【作者】 王宇；

【导师】 尹华；

【作者基本信息】 暨南大学 ， 环境科学， 2013， 硕士

【摘要】 考察了十溴联苯醚（BDE-209）在沉积物-水体系中的微生物降解和沉积物吸附，主要内容有：环境因素的改变和添加重金属Cd、Pb对沉积物吸附BDE-209的影响；短短芽孢杆菌（Brevibacillus brevis）对水体系中BDE-209的降解效果；重金属Cd、Pb对沉积物-水体系中BDE-209的微生物降解和沉积物吸附的影响及其机理。沉积物对BDE-209的吸附动力学和热力学研究表明，沉积物吸附BDE-209经历了2个比较快速的阶段，吸附平衡时间为24h。当BDE-209在2^-10mg L^-1浓度范围内时，沉积物对BDE-209的吸附等温线能较好地符合Freundlich模型。改变水体系中的pH对BDE-209的吸附影响不显著；随着沉积物浓度的增加，沉积物对BDE-209的吸附量也相应增加，但并非简单的等比增加关系。当表面活性剂浓度为20mg L^-1时，离子型表面活性剂SDBS、CTAB能促进沉积物对BDE-209的吸附，非离子型表面活性剂Tween80、TX^-100抑制其吸附。平衡吸附量由小到大依次为：Q_e(TX^-100)＜Q_e（Tween80）＜Q_e（无）＜Q_e（CTAB）＜Q_e（SDBS）。当Cd、Pb在1-6mg L^-1浓度范围内时， Cd、Pb均会抑制BDE-209在沉积物上的吸附。当BDE-209浓度为2mg L^-1时，抑制作用不明显；当BDE-209浓度大于等于4mg L^-1时，抑制作用变得十分显著。B. brevis降解水体系中的BDE-209能较好地符合一级动力学反应方程。当BDE-209浓度为2mg L^-1时，B. brevis在24h内对水体系中BDE-209的降解效率达到21.4%，7d的降解率为44.8%。当BDE-209浓度为2、4、6mg L^-1时，B. brevis对沉积物-水体系中BDE-209的降解率分别为30.5%、38.4%、25.7%。BDE-209浓度为2mg L^-1时B. brevis对去除铁锰氧化物和有机质组分后的沉积物-水体系BDE-209的降解率为45.7%。Cd、Pb均对B. brevis降解水体系中BDE-209有抑制作用，且随着重金属浓度增大，抑制作用增强。当Cd、Pb浓度为1mg L^-1时，B. brevis对沉积物-水体系中BDE-209的降解率均高于不添加重金属；但当Cd、Pb浓度大于2mg L^-1时，降解效率会大幅下降。当Cd、Pb浓度为6mg L^-1时，4d后B. brevis对BDE-209的降解率趋近于零。更多还原

【Abstract】 BDE-209degradation by microbial and adsorption on sediment were studied.The main works included the effects of BDE-209adsorption on sediment by changingenvironmental factors and adding heavy metals Cd, Pb; degradation of BDE-209byBrevibacillus brevis in water system; researching the effects and the mechanisms ofBDE-209degradation by microbial and adsorption by sediment in sediment-watersystem through addition of heavy metals cadmium, lead. The results were as follows.The adsorption kinetic and isotherm of BDE-209on sediment indicated thatthere were two relatively fast stages of BDE-209adsorption on sediments, and theadsorption equilibrium time was about24h. When BDE-209concentration rangedfrom2to10mg L^-1, its adsorption on the sediment fit well with the Langmuir model.In addition, changing pH in water exhibited little effect on adsorption of BDE-209onsediment. With the increase of sediment concentration, sediment adsorption amount ofBDE-209also increased, but not simple geometric increase.Addition of surfactants had significant influence on the saturated adsorptionamount of BDE-209on sediments. At the concentration of20mg L^-1, ionicsurfactants SDBS, CTAB promoted BDE-209adsorption on sediment, whilenon-ionic surfactants Tween80, TX^-100restrained it. The equilibrium adsorptionamount （Q_e） of BDE-209exhibited the following sequence: Q_e(TX^-100)＜Q_e（Tween80）＜Q_e（No）＜Q_e（CTAB）＜Q_e（SDBS）. When heavy metals concentrationranged from1to6mg L^-1, the mount of BDE-209on sediment would be inhibited.When the concentration of BDE-209was2mg L^-1, the inhibition was unconspicuous;while it became significant when the concentration of BDE-209was equal or greaterthan4mg L^-1.Degradation of BDE-209by B. brevis in water system fit well with the first orderkinetics reaction equation. When the BDE-209concentration was2mg L^-1, B. brevisdegradation efficiency of BDE-209in water system reached21.4%within24h,7days of the degradation rate was44.8%. When the concentration of BDE-209was2,4, 6mg L^-1, degradation rate of BDE-209in sediment-water system reached30.5%,38.4%,25.7%respectively. When the BDE-209concentration was2mg L^-1,degradation rate of BDE-209in sediment-water system reached45.7%afterremoving of iron and manganese oxides and organic matter from sediment.Heavy metals Cd and Pb showed inhibitory effect in B. brevis degradation ofBDE-209in water system, and with the heavy metal concentration increases, theinhibition enhanced. When the concentration of heavy metal Cd, Pb was1mg L^-1, thedegradation rate of BDE-209were higher than without heavy metal in sediment-water system. While the degradation rate will fall obviously if the concentration ofheavy metal Cd, Pb greater than2mg L^-1. When the concentration of heavy metal Cd,Pb was1mg L^-1, B. brevis degradation rate of BDE-209close to zero after4days.更多还原