从废水中回收沼气能及氢能与电能

厌氧发酵制沼气、厌氧发酵制氢和微生物燃料电池技术是利用微生物在废水处理的同时回收能源的三种主要方式。文章结合相关研究现状,介绍了这三种技术的基本原理及其在废水处理领域的发展状况和展望,并对三种生物能源进行了比较。     

Quantum dots enhance Cu2+-induced hepatic L02 cells toxicity

As a new class of xenogenous nanoparticle,quantum dots (QDs) possess the potential to co-exist with Cu2+ in human liver.The combined toxicity is thus concerned.Considering QDs and Cu2+ are known ROS (reactive oxygen species) inducer,we investigated the combined oxidative stress and corresponding protective strategy using human hepatic L02 cells.The results demonstrated that the presence of a small amount of MPA-CdTe QDs (2 μg/mL) in a Cu2+ solution (2.5-20 μg/mL) resulted in a higher toxicity with up to 8-fold cell viability decrease,which was accompanied by cell morphology changes.The combined toxicity was then confirmed as ROS associated oxidative stress with up to 300% and 35% increase of the intracellular ROS level and glutathione S-transferase (GST) activity,respectively.N-acetylcysteine (NAC) can also provide almost complete protection against the induced toxicity.Therefore,the ROS associated oxidant injury might be responsible for the QDs-Cu2+/Cu2+ induced toxicity and could be balanced through cytoprotective antioxidant enzyme GST.     

饮用水消毒中一氯胺的衰减动力学研究

对饮用水消毒过程中一氯胺的衰减过程,采用二级反应速率模型对其衰减规律进行了非线性拟合;分别考察了pH值、温度、碳酸盐、溴离子、碘离子和天然有机物(NOM)浓度等水质参数变化对一氯胺衰减速率的影响.结果表明,pH值是影响一氯胺衰减速率的重要因素,pH<7.0时尤为明显;温度和碳酸盐对一氯胺的衰减速率均有明显影响;在pH=6.60时,随着溴离子浓度的增加一氯胺的衰减加快;在pH>7.60,0.1 mg/L的溴离子浓度对一氯胺的衰减影响不明显,碘离子对一氯胺的衰减影响较相同反应条件下溴离子的影响明显.此外,一氯胺衰减动力学模拟结果表明,采用二级动力学反应模型可以较好地拟合在卤素离子(Br-I、-)共存条件下的一氯胺衰减规律,对在沿海地区饮用水消毒工艺中不同条件下氯胺消毒剂浓度预测可以提供一定的理论和技术支持.     

生物阴极型微生物燃料电池同步降解偶氮染料与产电性能研究

构建了生物阴极型微生物燃料电池(BCMFC),研究了以葡萄糖-偶氮染料(活性艳红X-3B)为共基质条件下,BCMFC产电性能及偶氮染料的降解特性.结果表明,电能的产生源于BCMFC对葡萄糖的降解,共代谢下活性艳红X-3B的(ABRX3B)的生物降解是主要的脱色机理.当葡萄糖初始浓度为500mg·L-1(以COD计),ABRX3B浓度低于300 mg·L-1时,功率密度维持50.7 mW·m-2,最终脱色率在94.4%以上,而ABRX3B浓度的进一步提高对BCMFC产电会产生抑制作用.阳极液的COD去除率和UV-Vis光谱表明,ABRX3B的降解过程中,有中间产物的积累.共基质条件下,BCMFC可成功实现同步电能输出和高效脱色.     

Dynamic contact angle effects on gas-liquid behaviors in the cathode of proton exchange membrane fuel cell with stirred tank reactor design

Liquid water management is still a critical issue in the improvement of proton exchange membrane fuel cell (PEMFC) performance. In this work, for the first time, the liquid water behavior and transport inside the cathode of a PEMFC with a stirred tank reactor (STR) design, rather than the conventional PEMFC flow channel design, are numerically studied. The dynamic contact angle (DCA) is applied to multiple wall boundaries in the numerical model through a user-defined-function (UDF) code, i.e., STR-DCA model. Another numerical model with the static contact angle (SCA) and same operating conditions, i.e., STR-SCA model, is also developed for comparison. The volume of fluid (VOF) method is employed in the simulation to track the gas-liquid interface. The results show that the liquid water distribution and transport are significantly different between these two models, indicating the remarkable effects of DCA on the simulation results. It is also verified the capability of STR-PEMFC to reduce the liquid water flooding, showing the potential of this channel-less type fuel cell in the further development.     

陶瓷材料放射性衰变时间及最佳平衡周期研究

简述了有关放射性样品衰变平衡及平衡时间的基本理论,运用碘化钠γ谱仪对衰变时间介于0～27 d区间内的三组陶瓷样品进行放射性比活度测定,采取t检验法分析了同一样品在0d～7d、7d～12d、15 d、21 d等不同衰变时间条件下,放射性核素226Ra、232Th、40K比活度测试结果之间的差异程度,通过实验验证陶瓷样品衰变时间对其放射性测定结果准确性的影响.研究表明,当每组检测结果数据的显著性差异水平为5％,若兼顾科学性和经济性,则陶瓷样品的最佳放射性衰变时间应为至少21 d.     

In vitro evaluation of inorganic and methyl mercury mediated cytotoxic effect on neural cells derived from different animal species

To extend the current understanding of the mercury-mediated cytotoxic effect,five neural cell lines established from different animal species were comparatively analyzed using three different endpoint bioassays:thiazolyl blue tetrazolium bromide,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay(MTT),neutral red uptake assay(NRU),and Coomassie blue assay(CB).Following a 24-hr exposure to selected concentrations of mercury chloride(HgCl_2) and methylmercury(Ⅱ) chloride(MeHgCl),the cytotoxic effect on test cells was characterized by comparing their 50%inhibition concentration(IC_(50)) values.Experimental results indicated that both these forms of mercury were toxic to all the neural cells,but at very different degrees.The IC_(50)values of MeHgCl among these cell lines ranged from 1.15±0.22 to 10.31 ± 0.70 μmol/L while the IC_(50) values for HgCl_2 were much higher,ranging from 6.44 ± 0.36 to 160.97±19.63 μmol/L,indicating the more toxic nature of MeHgCl.The IC_(50) ratio between HgCl_2and MeHgCl ranged from 1.75 to 96.0,which confirms that organic mercury is much more toxic to these neural cells than inorganic mercury.Among these cell lines,HGST-BR and TriG44 derived from marine sea turtles showed a significantly high tolerance to HgCl_2 as compared to the three mammalian neural cells.Among these neural cells,SK-N-SH represented the most sensitive cells to both chemical forms of mercury.     

1株草除灵高效降解菌的分离鉴定与降解特性研究

从农药厂废水处理池的活性污泥中分离得到1株能以草除灵为唯一碳源生长的菌株.经生理生化鉴定和16S rRNA基因序列同源性分析,将此菌株初步鉴定为Methyloversatilis sp.,命名为MBLHC-2.对菌株MBLHC-2的生长特性研究表明,液体培养时,菌株呈絮状生长;在30℃、pH 8.0的R2A培养基中生长...     

农药污染对蚯蚓的群落结构与超微结构影响的研究

报道了农药污染对蚯蚓的群落结构与超微结构影响的研究,结果表明：随着农药污染程度增加,蚯蚓的种类和数量则减少。超微结构在扫描电镜下可观察到重污染区壮伟环毛蚓（Pheretimarobusta）胃粘膜出现溃疡灶,并产生穿孔现象;在中污染区只有微绒毛萎缩病变;在重污染区发现肠粘膜上的纤毛发生紊乱及萎缩,纤毛顶端膨大呈球形。对精子观察可见在中污染区就出现了畸形精子。在透射电镜下观察可见重污染区壮伟环毛蚓胃肠道粘膜上皮细胞中的粗面内质网（RER）出现扩张,高尔基复合体也产生扩张状,线粒体发生肿胀,线粒体嵴消失呈空泡状。另可见细胞核膜间隙扩张、断裂,核染色质边集或减少,胞质呈大片空白。蚯蚓以上病变指标均能很灵敏反映土壤农药污染程度。     

模拟酸雨对葡萄叶片和花粉的影响

以巨峰葡萄为试材,研究了模拟酸雨对叶片和花粉的影响,结果表明：（１） 经ｐＨ２ ．５ 和ｐＨ２ ．０ 的酸雨处理后叶片在短期内均出现不同程度的可见性受害伤斑,叶绿素含量和净光合速率下降．（２） 酸雨使叶片ＳＯＤ活性及不饱和脂肪酸指数（ＩＵＦＡ）下降,膜脂过氧化产物ＭＤＡ 含量及细胞膜透性显著增加,并且这些指标的变化与酸雨ｐＨ值有显著的相关性．（３）叶片对酸雨处理引起的生理伤害有一定的自我修复功能．（４） 酸雨对叶片的生长和花粉发芽有明显的抑制作用