炎性因子在大气细颗粒物(PM2.5)心血管毒性中的作用

PM2.5染毒心血管内皮细胞24h后,提取内皮细胞中的mRNA,通过逆转录多聚酶链式反应(RT-PCR)技术及电泳的方法,确定PM2.5染毒前后心血管内皮细胞中IL-4、嗜酸性粒细胞活化趋化因子(extaxin)相对含量的变化.结果表明,随着大气PM2.5染毒浓度的增加,0.05,0.20mg/mL染毒组心血管内皮细胞中IL-4和extaxin mRNA表达产物的相对含量显著增高,说明IL-4、extaxin等I型变态反应相关炎性因子在PM2.5的心血管毒性中可能起一定作用.     

纳米TiO2光催化降解对甲基苯磺酸的研究

采用TiO2/UV光催化降解法处理对甲基苯磺酸的水溶液,探讨了二氧化钛的投加量、溶液的初始浓度、溶液的pH、紫外光照射时间和强度、常见无机离子等因素对对甲基苯磺酸的降解效率的影响.结果表明,在浓度为0.030 g·L-1对甲基苯磺酸溶液中,光催化剂TiO2最佳投加量为0.10 g·L-1,控制空气分压为5.2kPa,紫外光照射2h,溶液为中性时,对甲基苯磺酸废水降解率达到67.4%.二氧化钛的用量、溶液的pH是影响纳米TiO2光催化降解对甲基苯磺酸的主要因素.在此基础上还考察了无机阳离子和无机阴离子对反应的影响,并取得了满意的效果.     

Photochemical behaviour of the systemic fungicide carboxin

Irradiation of carboxin (1) with a 500 W UV lamp (filter Pyrex) in CH3CN leads to the products 3, 5-8, 12-14 depending upon the reaction conditions. All photo-products were isolated and characterized. Photooxidation occurred even if unsensitized, while photoalteration was very slow in the absence of oxygen. The main oxygenated-products 3 and 13 were also recovered under biomimetic conditions by exposure of an aqueous solution of 1 to sunlight.     

Bioassay zur Bestimmung von TCDD-Toxizit?ts?quivalenten (TEQ) von Umweltproben und Reststoffen

Zusammenfassung  Polychlorierte aromatische Kohlenwasserstoffe (PHAK), z.B. 2,3,7,8-Tetrachlordibenzo-p-dioxin (TCDD), weisen eine Vielzahl von toxischen Wirkungen und biologischen Effekten auf. Die Substanzklasse der PHAK besitzt die Eigenschaft der Bindung an ein cytosolisches Rezeptor-Protein, gefolgt von der Synthese bestimmter Genprodukte, u.a. von Cytochrom P450 1A1 (CYP 1A1). In dieser Arbeit wird ein Bioassay beschrieben, der erlaubt, die Induktion von CYP 1A1 als Summenparameter für die biologische Wirksamkeit der kritischen, halogenierten Verbindungen in komplexen Umweltmatrizes zu bestimmen. Zur Abtrennung von Substanzen aus den Extrakten von Umweltproben (z. B. Naturstoffe und polyzyklische aromatische Kohlenwasserstoffe), die den Bioassay st?ren k?nnen, wurde ein Ein-S?ulen-Clean-up entwickelt. Die biologisch ermittelten TEQ-Werte stimmen gut mit den Resultaten der chemischen Analytik überein. Der Bioassay in Kombination mit dem Clean-up bietet eine zeitsparende und kostengünstige M?glichkeit zur Untersuchung von Umweltproben.      

以改进的化学沉淀法处理硫酸铵废水

针对MAP化学沉淀法处理氨氮废水中存在的问题。如处理成本高、处理后的废水中磷浓度高，对化学沉淀法进行了改进研究，考察Mg^2＋以外的二价金属离子（Ni^2＋，Mn^2＋，Zn^2＋，Cu^2＋，Fe^2＋）在磷酸根作用下对氨氮的去除效果。针对废水中磷浓度高的问题，进行了MAP沉淀法的条件优化实验。结果表明。通过体系pH值和沉淀剂投加比例的合理控制，可以使在高浓度氨氮废水在出水氨氮浓度达标的同时，实现废水中的氮磷浓度同时控制；针对NaOH作pH调节剂成本过高，而以Ca（OH）2作pH调节剂时，钙离子严重影响MAP沉淀效果。对硫酸铵废水体系提出了CaSO4沉淀——MAP沉淀新工艺。结果表明，这一改进完全可以消除钙离子的影响。实现以石灰取代传统的NaOH调节剂。     

土壤改良剂对油菜富集238U、226 Ra及232 Th的影响

通过网室盆栽试验,研究了施加磷矿粉(PR)、羟基磷矿粉(HA)、豆渣(SM)、骨碳(BC)及硫酸亚铁等土壤改良剂对油菜(Brassica oleracea L.)自铀矿区污染农田土壤吸收铀(238U)、镭(226Ra)及钍(232Th)的影响.结果表明,不同处理下油菜茎叶对238U、226Ra及232Th的富集系数分别在3.6×10-3～6.2×10-3、6.2×10-3～10.0×10-3及0.9×10-4～2.0×10-4之间.上述不同改良剂处理均能在一定程度上降低植物对238U、226Ra及232Th的吸收,以SM、HA处理效果较显著,其中SM处理下238U、226Ra及232Th的富集系数分别比对照降低42.9%、39%和71%.SM及HA对降低铀矿区污染土壤中植物对上述核素的吸收和富集具有潜在的应用价值.     

Photochemical degradation and mineralization of 4-chlorophenol

INTENTION, GOAL, SCOPE, BACKGROUND: Since the intermediate products of some compounds can be more toxic and/or refractory than the original compund itself, the development of innovative oxidation technologies which are capable of transforming such compounds into harmless end products, is gaining more importance every day. Advanced oxidation processes are one of these technologies. However, it is necessary to optimize the reaction conditions for these technologies in order to be cost-effective. OBJECTIVE: The main objectives of this study were to see if complete mineralization of 4-chlorophenol with AOPs was possible using low pressure mercury vapour lamps, to make a comparison of different AOPs, to observe the effect of the existence of other ions on degradation efficiency and to optimize reaction conditions. METHODS: In this study, photochemical advanced oxidation processes (AOPs) utilizing the combinations of UV, UV/H2O2 and UV/H2O2/Fe2+ (photo-Fenton process) were investigated in labscale experiments for the degradation and mineralization of 4-chlorophenol. Evaluations were based on the reduction of 4-chlorophenol and total organic carbon. The major parameters investigated were the initial 4-chlorophenol concentration, pH, hydrogen peroxide and iron doses and the effect of the presence of radical scavengers. RESULTS AND DISCUSSION: It was observed that the 4-chlorophenol degradation efficiency decreased with increasing concentration and was independent of the initial solution pH in the UV process. 4-chlorophenol oxidation efficiency for an initial concentration of 100 mgl(-1) was around 89% after 300 min of irradiation in the UV process and no mineralization was achieved. The efficiency increased to > 99% with the UV/H2O2 process in 60 min of irradiation, although mineralization efficiency was still around 75% after 300 min of reaction time. Although the H2O2/4-CP molar ratio was kept constant, increasing initial 4-chlorophenol concentration decreased the treatment efficiency. It was observed that basic pHs were favourable in the UV/H2O2 process. The results showed that the photo-Fenton process was the most effective treatment process under acidic conditions. Complete disappearance of 100 mgl(-1) of 4-chlorophenol was achieved in 2.5 min and almost complete mineralization (96%) was also possible after only 45 min of irradiation. The efficiency was negatively affected from H2O2 in the UV/H2O2 process and Fe2+ in the photo-Fenton process over a certain concentration. The highest negative effect was observed with solutions containing PO4 triple ions. Required reaction times for complete disappearance of 100 mgl(-1) 4-chlorophenol increased from 2.5 min for an ion-free solution to 30 min for solutions containing 100 mgl(-1) PO4 triple ion and from 45 min to more than 240 min for complete mineralization. The photodegradation of 4-chlorophenol was found to follow the first-order law. CONCLUSION: The results of this study showed that UV irradiation alone can degrade 4-CP, although at very slow rates, but cannot mineralize the compound. The addition of hydrogen peroxide to the system, the so-called UV/H2O2 process, significantly enhances the 4-CP degradation rate, but still requires relatively long reaction periods for complete mineralization. The photo-Fenton process, the combination of homogeneous systems of UV/H2O2/Fe2+ compounds, produces the highest photochemical elimination rate of 4-CP and complete mineralization is possible to achieve in quite shorter reaction periods when compared with the UV/H2O2 process. RECOMMENDATIONS AND OUTLOOK: It is more cost effective to use these processes for only purposes such as toxicity reduction, enhancement of biodegradability, decolorization and micropollutant removal. However the most important point is the optimization of the reaction conditions for the process of concern. In such a case, AOPs can be used in combination with a biological treatment systems as a pre- or post treatment unit providing the cheapest treatment option. The AOP applied, for instance, can be used for toxicity reduction and the biological unit for chemical oxygen demand (COD) removal.     

Acute toxicity of cadmium to fish Labeo rohita and copepod Diaptomus forbesi pre-exposed to CaO and KMnO4

96-h LC₅₀ values of cadmium (Cd) to fish Labeo rohita and the copepod Diaptomus forbesi, determined by static bioassays, were, respectively, 89.5 and 10.2 mg/l. LC₅₀ values increased significantly when fish pre-exposed to 100–350 mg/l CaO or 0.5–1.5 mg/l KMnO₄ for 4 d and the copepod to 20–70 mg/l CaO or 0.25–1.0 mg/l KMnO₄ for same period. The LC₅₀ values also increased when the pre-exposure period of CaO was increased to 12 d at concentration 100 mg/l for fish and 20 mg/l for copepod. All fish died when pre-exposed to 1.5 mg/l KMnO₄ for 8 d. But LC₅₀ values of Cd to copepod increased when pre-exposure period of 0.5 mg/l KMnO₄ was increased from 4 to 8 d.     

竹炭对2,4-二氯苯酚的吸附特性及影响因素研究

研究了水溶液中竹炭对 2 ,4-二氯苯酚的吸附特性及其影响因素。结果表明 ,竹炭对 2 ,4-二氯苯酚具有较强的吸附性能 ,吸附效果与竹炭粒径、用量、污染物浓度以及吸附平衡时间和平衡方式有关。     

富氧条件下不同泄爆面积对CH4燃烧诱导快速相变的影响

为了研究富氧条件下不同泄爆面积对CH4燃烧诱导快速相变的影响,基于自主设计搭建的CH4燃烧诱导快速相变试验台,通过改变富氧系数和泄爆面积对CH4燃烧的压力振荡特性进行研究,分析了不同富氧系数E(0.21,0.3,0.4,0.6)及泄爆面积比(0,0.25,0.5,0.75,1)下CH4燃烧的压力峰值、到达压力峰值的时间及特征时间等参数的变化趋势。结果表明,随富氧系数增大,爆炸压力峰值逐渐增大。富氧系数E=0.21时,压力峰值低于相应的绝热压力,无压力振荡;当E=0.3时,压力峰值低于相应的绝热压力且伴随压力振荡。当E为0.4、0.6时,压力峰值高于相应绝热压力且伴随压力振荡;在泄爆条件下,随富氧系数增加,到达压力峰值的时间逐渐减小。通过分析不锈钢管道中的燃烧诱导快速相变现象,发现泄爆可以有效降低爆炸压力峰值,且随泄爆面积比增大,到达压力峰值的时间提前。