BPAC-UF对二级出水中抗生素抗性基因的去除及膜污染缓解机制

采用生物粉末活性炭(BPAC)-超滤(UF)组合工艺去除控制二级出水中抗生素抗性基因(ARGs),并对ARGs的去除和BPAC缓解膜污染机制进行了探讨。结果表明：与直接超滤工艺相比,组合工艺对水中四环素类抗性基因(tetA、tetW)、磺胺类抗性基因(sul Ⅰ、sul Ⅱ)以及溶解性有机碳(DOC)的去除效果均有较大的改善,这主要是由于BPAC对ARGs的吸附降解作用所致;水中16S rDNA、int Ⅰ 1和DOC含量与不同种类ARGs浓度具有显著相关性,强化上述指标的去除可有效促进ARGs的削减;在BPAC投加量较低时,组合工艺的膜比通量较直接UF有所提高,膜污染状况明显改善;直接UF时,膜污染状况与滤饼层过滤模型的拟合度最好,而组合工艺的膜污染状况与标准膜孔堵塞模型和滤饼层过滤模型拟合度均较好。BPAC-UF组合工艺是一种较好的去除ARGs的工艺。     

Validation of temporal and spatial consistency of facility- and speed-specific vehicle-specific power distributions for emission estimation: A case study in Beijing,China

Vehicle-specific power (VSP) has been found to be highly correlated with vehicle emissions. It is used in many studies on emission modeling such as the MOVES (Motor Vehicle Emissions Simulator) model. The existing studies develop specific VSP distributions (or OpMode distribution in MOVES) for different road types and various average speeds to represent the vehicle operating modes on road. However, it is still not clear if the facility- and speed-specific VSP distributions are consistent temporally and spatially. For instance, is it necessary to update periodically the database of the VSP distributions in the emission model? Are the VSP distributions developed in the city central business district (CBD) area applicable to its suburb area? In this context, this study examined the temporal and spatial consistency of the facility- and speed-specific VSP distributions in Beijing. The VSP distributions in different years and in different areas are developed, based on real-world vehicle activity data. The root mean square error (RMSE) is employed to quantify the difference between the VSP distributions. The maximum differences of the VSP distributions between different years and between different areas are approximately 20% of that between different road types. The analysis of the carbon dioxide (CO₂) emission factor indicates that the temporal and spatial differences of the VSP distributions have no significant impact on vehicle emission estimation, with relative error of less than 3%.

Implications: The temporal and spatial differences have no significant impact on the development of the facility- and speed-specific VSP distributions for the vehicle emission estimation. The database of the specific VSP distributions in the VSP-based emission models can maintain in terms of time. Thus, it is unnecessary to update the database regularly, and it is reliable to use the history vehicle activity data to forecast the emissions in the future. In one city, the areas with less data can still develop accurate VSP distributions based on better data from other areas.     

锆负载型树脂用于含氟废水深度处理的研究

本文研制了一种以火力发电厂废树脂为载体的锆负载型氟离子吸附剂 ,并在评价了该树脂对氟离子的吸附性能之后探讨了该树脂用于火力发电厂含氟废水深度处理的可能性。研究结果表明 ,锆的最佳负载的最佳浓度为0 .5mol/L ,该负载树脂的最佳吸附pH为 3.0— 4 .0 ,用填充柱进行的动态实验结果表明 ,pH =3时的吸附容量显著高于 pH=4时的值。利用该树脂对火力发电厂模拟含氟废水进行了双柱串联吸附工艺处理 ,当柱流量为 35mL/min(SV10 )、第二柱穿透时 ,第一柱的吸附容量为 10 2 2 8mg/L湿树脂 ;用 0 .1mol/L的NaOH溶液进行再生 ,柱流量选择为 35mL/min(SV10 )时 ,脱附率在 95 %以上。     

可用于去除高盐废水中有机污染物的混凝-Fenton氧化联合工艺

以某环氧树脂生产厂产生的高盐有机废水为对象,对比研究了Fenton、Fenton-混凝、混凝-Fenton等工艺去除废水中有机污染物的效能。考察了Fenton反应中Fe2+、H2O2投加比、初始pH、反应时间以及混凝反应中混凝剂种类、投加量等参数对处理效果的影响。结果表明：Fenton工艺的最佳条件为亚铁和过氧化氢投加比1：20,投加量分别为25 mmol·L-1和500 mmol·L-1,初始pH 3,反应时间120 min,TOC去除率为62.50%;混凝工艺选择FeSO4混凝剂,投加量为300 mg·L-1,TOC去除率为23.78%;废水经过Fenton-无混凝剂混凝、Fenton-混凝剂混凝、混凝-一级Fenton氧化和混凝-二级Fenton氧化工艺处理,TOC去除率分别为68.32%、71.51%、80.69%和89.27%。     

Fe0-C微电解去除地下水中2,4-DNT的影响因素

采用批实验研究初始pH值、溶解氧（DO）和地下水中常见的阴、阳离子等因素对Fe0-C微电解对地下水中2,4-二硝基甲苯（2,4-DNT）去除率的影响,并分析Fe0-C降解2,4-DNT的产物。结果表明,在pH=7,DO=0.23 mg·L-1的条件下,Fe0-C去除溶液中2,4-DNT有明显的效果,反应200 min时,去除率达到83.09%,比Fe0和C的去除率提高了74.56%和9.89%;酸性条件下有利于2,4-DNT去除,初始pH=5的条件下,溶液中2,4-DNT的去除率为82%,而初始pH=10时,2,4-DNT的去除率分别为64%;反应体系中含有较高浓度的溶解氧有利于2,4-DNT的去除,在DO=9.26 mg·L-1条件下,2,4-DNT的去除率比 DO=0.23 mg·L-1时提高了9.5%;地下水中一定浓度的阴（Cl-、SO2-4）、阳离子（Ca2+、Mg2+、Na+、K+）可以提高2,4-DNT的去除率,提高率小于10%。反应过程中2,4-DNT降解的产物包括2-氨基-4-硝基甲苯（2A4 NT）、4-氨基-2-硝基甲苯（4A2 NT）和2,4-二氨基甲苯（2,4-DAT）。     

Quantitative structure-activity relationships for the inhibition toxicity to root elongation of Cucumis sativus of selected phenols and interspecies correlation with Tetrahymena pyriformis

The comparative toxicities of selected phenols to higher plants Cucumis sativus were measured and the negative logarithm molar concentration of the root elongation median inhibition (IRC50) were derived. Quantitative structure-activity relationships (QSARs) were developed to explore the toxicity influencing factors and for predictive purpose. The toxicity data, fell into two classes: polar narcosis and bio-reactive. For polar narcotic phenols, a highly significant two-parameter QSAR based on 1-octanol/water partition coefficient (logKow) and energy of the lowest unoccupied orbital (E(lumo)) was derived (IRC50 = 0.77 log Kow - 0.39E(lumo) + 2.36 n = 22 r2 = 0.89). The five bio-reactive chemicals proved to show elevated toxicity due to their typical substructure involved diverse reactive mechanisms. In an effort to model all chemicals, a robust multiple-variable QSAR combining logKow, E(lumo) and Qmax, the most negative net atomic charge, was developed (IRC50 = 0.65 logKow - 0.72E(lumo) + 0.23Qmax + 2.81 n = 27 r2 = 0.94), indicating that hydrophobicity, electrophilicity and hydrogen bond interaction contribute mainly to the phytotoxicity. The toxicological data was compared with Tetrahymena pyriformis 2-d population growth inhibition toxicity (IGC50) and excellent interspecies correlations were observed both for the polar narcotics and for five reactive chemicals (for polar narcotics: IRC50 = 0.95IGC50 + 1.07 n = 16 r2 = 0.89; for bio-reactive chemicals: IRC50 = 0.98IGC50 + 2.19 n = 5 r2 = 0.97; and for all: IRC50 = 0.93IGC50 + 1.63 n = 21 r2 = 0.87). This suggested that T pyriformis toxicity could serve as a surrogate of C. sativus toxicity for phenols and interspecies correlation also could be established for reactive chemicals.     

Impairments of cadmium on vitellogenin accumulation in the hepatopancreas of freshwater crab <Emphasis Type="Italic">Sinopotamon henanense</Emphasis>

During ovary maturation of crabs, vitellogenin (Vg), a precursor molecule of vitellin (Vn) needed for embryogenesis, can be produced in large quantities in the hepatopancreas and then transported to the ovary by the hemolymph. In the present study, effects of Cd on Vg accumulation in the hepatopancreas and Vg transportation of the freshwater crab Sinopotamon henanense were investigated. We also studied the impacts of Cd on the mRNA expression of genes involved in energy metabolism, protein metabolism, and metallothionein (MT) and glutathione (GSH) synthesis. After Cd treatment, the Vg concentration and the Vg mRNA expression in the hepatopancreas were downregulated. Pearson’s correlation coefficient showed that the Vg level in the hepatopancreas correlated positively with those of the ovary and hemolymph (correlation coefficients 0.844 and 0.749, respectively), suggesting that the Vg transport from the hepatopancreas to the ovary can be impaired by Cd. The levels of carbohydrate and protein in the hepatopancreas of Cd-exposed crabs were decreased, and an inhibited protein metabolism was also observed. Energy production related isocitrate dehydrogenase and cytochrome C oxidase mRNA expressions, and MT and GSH synthesis increased after 10 days of Cd treatment and decreased after 20 days. Cd also caused a time-dependent upregulation of malondialdehyde. Our findings showed that Cd decreased Vg accumulation in the hepatopancreas due to partially excessive energy consumption and an activated defense system in the hepatopancreas, suggesting a possible regulatory mechanism in S. henanense which is the competitive advantage of energy reserves in metabolic Cd stress responses over the high-energy flux during vitellogenesis to ensure a continuous supply of metabolic energy. Moreover, the damage of Vg accumulation in the hepatopancreas caused by Cd could lead to an insufficient accumulation of Vn in the ovary and cause a retardation of oocyte development.     

催化湿式氧化法处理糖蜜酒精废液的研究

以非贵金属Cu、Fe、Mn和Ce为主要活性成分和TiO2、-γA l2O3为载体,制备了10种用于催化湿式氧化法处理糖蜜酒精废液的催化剂。考察了载体、焙烧温度、成分配比对催化剂催化活性与稳定性的影响,研究了氧气分压、催化剂投加量、反应温度和反应时间对催化湿式氧化过程的影响规律。结果表明:(1)Fe-Mn/-γA l2O3(3∶1∶1)催化剂是催化湿式氧化法处理糖蜜酒精废液的可选催化剂;(2)适宜的氧气供应量为理论需氧量的3.4~4.6倍,催化剂的投加量以10 g/L为佳;在300℃下反应30 m in或在280℃下反应60 m in,处理水可达到污水综合排放标准GB9878-1996的三级标准。     

次氯酸钠处理终冷水中氰化物硫化物的研究

以次氯酸钠为氧化剂,用正交实验研究了次氯酸钠处理终冷水中氰化物和硫化物,得出正交实验中各因素的主次关系及对除氰除硫的影响。研究结果表明,反应体系的pH是影响脱氰脱硫的重要因素。在最佳处理条件,即pH为10．0,反应温度为25℃,投氯量系数为1．4,反应时间为45min．能使氰化物的质量浓度降至0．267mg／L,脱氰率高达99．8％,硫化物的质量浓度降到0．387mg／L,脱硫率达92．0％,达到≤0．5mg／L的国家排放标准。文章还对工业化提出了一些设想。     

Biohydrogen production through fermentation using liquid swine manure as substrate

In this paper, continuous production of hydrogen through fermentation with liquid swine manure as substrate was researched using a semi-continuously fed fermenter (8 L in total volume and 4 L in working volume). The pH and temperature for the fermenter were controlled at 5.3 +/- 0.1 and 35 +/- 1 degrees C, respectively, throughout the experiment. Three hydraulic retention times (16, 20, and 24 h) were investigated for their impact on the efficiency and performance of the fermenter in terms of hydrogen yields. The results indicate that hydraulic retention time (HRT) has a strong influence on the fermenter performance. An increasing HRT would increase the variation in hydrogen concentration in the offgas. To produce hydrogen with a fairly consistent concentration, the HRT of the fermenter should not exceed 16 h, which, however, did not appear to be short enough to control methanogenesis because the offgas still contained about 5% methane. When methane content in the offgas exceeded 2%, an inverse linear relationship between hydrogen and methane was observed with a correlation coefficient of 0.9699. To increase hydrogen content in the offgas, methane production has to be limited to below 2%. Also, keeping oxygen content in the fermenter below 1.5% would increase the hydrogen concentration to over 15%. The product to substrate ratio was found to be around 50% for the fermenter system studied, evidenced by the observation that for every 6 liters of manure fermented, 3 liters of pure hydrogen were produced, which was significant and encouraging.