溴阻燃剂对肝细胞的毒性

为评价四溴联苯醚(2,2,4,4-tetrabromodipheny lether,PBDE-47)、五溴联苯醚(2,2',4,4',5-pentabromodiphenylether,PBDE-99)、九溴联苯醚(polybrominated dipheny lethers206,PBDE-206)、六溴环十二烷(hexabromocyclododecane,HBCD)、四溴双酚A(tetrabromobisphenol A,TBBPA)对人肝细胞(LO2)的体外细胞毒性。将5种溴阻燃剂与人肝细胞LO2共同培养,采用四甲基偶氮噻唑蓝比色法(MTT法)检测5种溴阻燃剂对LO2细胞的相对增殖率,并按照GB/T16886.5-2003/ISO10993-5:1999标准评价5种溴阻燃剂对LO2的细胞毒性。体外实验表明,5种溴阻燃剂对LO2细胞均具有抑制作用,其中PBDE-47、PBDE-99和HBCD呈现剂量依赖关系。     

Preparation of nZVI embedded modified mesoporous carbon for catalytic persulfate to degradation of reactive black 5

• The MCNZVI is prepared as an interesting material for PS activation. • Graphitized carbon shells facilitate electron transfer from Fe⁰. • The MCNZVI exhibits excellent performance to degrade RB5 by ¹O₂. • The MCNZVI has high stability and reusability in the oxidation system. High-efficiency and cost-effective catalysts with available strategies for persulfate (PS) activation are critical for the complete mineralization of organic contaminants in the environmental remediation and protection fields. A nanoscale zero-valent iron-embedded modified mesoporous carbon (MCNZVI) with a core-shell structure is synthesized using the hydrothermal synthesis method and high-temperature pyrolysis. The results showed that nZVI could be impregnated within mesoporous carbon frameworks with a comparatively high graphitization degree, rich nitrogen doping content, and a large surface area and pore volume. This material was used as a persulfate activator for the oxidation removal of Reactive Black 5 (RB5). The effects of the material dosage, PS concentration, pH, and some inorganic anions (i.e., Cl⁻, SO₄²⁻) on RB5 degradation were then investigated. The highest degradation efficiency (97.3%) of RB5 was achieved via PS (20 mmol/L) activation by the MCNZVI (0.5 g/L). The pseudo-first-order kinetics (k = 2.11 × 10⁻² min⁻¹) in the MCNZVI/PS (0.5 g/L, 20 mmol/L) was greater than 100 times than that in the MCNZVI and PS. The reactive oxygen species (ROS), including ¹O₂, SO₄^·−, HO^·, and ·O₂⁻, were generated by PS activation with the MCNZVI. Singlet oxygen was demonstrated to be the primary ROS responsible for the RB5 degradation. The MCNZVI could be reused and regenerated for recycling. This work provides new insights into PS activation to remove organic contamination.     

稠油乳化段废水厌氧处理过程中COD与BOD5的协同变化及可生化性研究

稠油乳化段废水中的主要污染物为有机聚合物和石油类污染物，BOD5／COD值极低，可生化性差，通过厌氧处理可使污染物发生水解反应，BOD5／COD值由0．08升为0．15（288h)，与其它难降解有机废水的厌处理结果不同，在BOD5增加的同时，COD亦大幅度增加，而在全部厌氧反应过程中，TOC一直呈下降趋势，表明水样中的污染物在生物作用下不断得到消减；在COD达到最高时，石油类污染物中胶质的浓度大幅度降低，烷烃的浓度升高，说明以胶质为代表的大分子污染物因子解反应，由K2Cr2O7不能氧化状态变为可氧化状态，导致COD测量值显著升高。     

红球菌J-5菌株降解聚乙烯醇的研究

从土壤样品中分离到一株能以聚乙烯醇(PVA)为唯一碳源、能源生长的纯菌株,经生理生化鉴定和16S rRNA基因序列分析,该菌株属于红球菌属(Rhodococcus sp.),对该菌株降解PVA的特性进行了研究.结果表明,该菌株降解PVA的适宜条件为10000mg/L PVA,25℃,摇床培养;此外,添加0.1%的酵母膏可以明显促进PVA的降解.在该条件下通气培养7d,可以降解58%的PVA,通过红外光谱分析PVA的代谢产物,说明PVA降解的中间产物带有羰基.