强化土著微生物处理硝基苯和苯胺污染地下水

以硝基苯、苯胺为主要污染物的污染地下水为研究对象,加入激活剂(乳糖、Na2HPO4、乳糖+Na2HPO4、乙醇、牛肉膏、蛋白胨)激活土著微生物,并考察其对土著微生物生长及硝基苯、苯胺降解效果的影响。加入激活剂3d后测各个水样的脱氢酶活性,对培养9d后的水样进行气相色谱/质谱(GC/MS)分析。结果表明,加入乳糖的水样中,其微生物相对增长率达157.2%,硝基苯、苯胺的相对去除率分别为14.90%和0.79%;加入Na2HPO4和乙醇的水样中,其微生物增长和硝基苯、苯胺降解情况均没有明显变化;加入乳糖+Na2HPO4的水样中,微生物相对增长率达180.3%,硝基苯、苯胺的相对去除率分别为24.20%和1.21%;加入牛肉膏的水样中,微生物的相对增长率为830.7%,硝基苯、苯胺的相对去除率分别为99.99%和99.67%;加入蛋白胨的水样中,其微生物相对增长率为686.0%,硝基苯、苯胺的相对去除率分别为99.33%和58.94%。GC/MS分析结果表明,加入激活剂后对氯苯胺、1-甲基-4-硝基苯等其他有机物的降解率均有提高。由此可见,通过激活土著微生物修复有机物污染地下水是可行的。     

辉县市城区环境空气质量现状及污染防治对策

对辉县市城区2006—2011年间环境空气质量监测数据进行了评价，并对城区污染物浓度时空变化进行了分析。结果表明，辉县市城区大气污染主要表现为可吸入颗粒物污染严重，主要是能源结构不合理、锅炉废气污染严重、城区道路保洁方式落后等原因造成的，由此提出了合理规划城市布局、减少结构性污染等对策。     

Photodegradation of quinestrol in waters and the transformation products by UV irradiation

Quinestrol is synthetic estrogen used in contraceptive and hormone replacement therapy and occasionally for treating breast cancer and prostate cancer. It can make its way into the environment through sewage discharge and waste disposal produced by human excretions. In this study, the photodegradation kinetics of quinestrol in various conditions was investigated by UV and solar irradiation. The affecting factors were studied including concentration of hydrogen peroxide, different water types, and the initial concentrations of quinestrol. Concurrently, the transformation products and presumed pathways of quinestrol in distilled water by UV irradiation were identified and proposed. The results showed that the degradation of quinestrol in both irradiation conditions followed the pseudo-first-order kinetics. More rapid degradation was observed by UV irradiation (k = 0.018 min⁻¹) than solar irradiation (k = 0.004 h⁻¹), and the photodegradation rate of quinestrol depended on the concentration of hydrogen peroxide, the initial concentration of quinestrol and water types. The transformation products of quinestrol in distilled water were identified by gas chromatography/mass spectrometry. When exposed to UV irradiation, quinestrol in aqueous solution was rapidly degraded, giving at least ten photodegradation products. The chemical structures of ten degradation products were identified on the basis of mass spectrum interpretation and literature data.     

输美轮胎特保案对中国贸易的影响及对策

分析了2009年9月26日美国对中国轮胎进口实施的特别保护措施,运用国际贸易和国际经济学的相关理论,对美国轮胎特保法案进行了剖析。在目前中美轮胎贸易情况下,从宏观和微观的角度探讨了轮胎贸易顺差形成的原因,以及长期和短期内对中国经济的影响,并对中国轮胎出口贸易提出了几点政策建议。     

海上平台采油工艺设计浅析

文章通过实例,简要阐述了滩海、浅海、深海三种开发模式的特点、主要工艺及其适用性。指出各自存在的问题,并提出相应的建议,为海上勘探开发提供借鉴。     

Chronic toxicity of copper on embryo development in Chinese toad, Bufo gargarizans

This study examined the effects of copper exposure on embryonic development of Chinese toad, Bufo gargarizans. Firstly, the LC₅₀ values from 24 to 96 h of exposure were 3.61 × 10⁻⁶ M, by means of a 4 d toxicity test with B. gargarizans embryos. Secondly, Chinese toad embryos were exposed to 10⁻⁹-10⁻⁶ M copper from mid gastrula stage to operculum completion stage. Measurements included mortality, tadpole weight, tadpole total length, growth retardation, duration of different embryo stages and malformation. Embryonic survival was not affected by copper. Relative to control tadpoles, significantly decreased weight and total length were found at 10^-9-10^-6 M reduced percentage of the embryos in right operculum stage after 10 d exposure to copper and reduced percentage of embryos in operculum completion stage after 12 d exposure to copper were also observed. Moreover, the duration of embryonic development increased at neural, circulation and operculum development stage in copper-treated groups. For the scanning microscope and histological observation, the abnormalities were malformation of wavy dorsal fin, flexural tail, curvature body axis, yolk sac oedema and reduced pigmentation in the yolk sac. Histopathological changes in olfactory, retinal epithelium and skin were also observed. DNA strand breaks exposed to the copper were analyzed by DNA ladder. In conclusion, copper induced toxic effects on B. gargarizans embryos. The present study indicated chronic toxicity tests may provide more accurate way in formulating the “safe levels” of heavy metals to amphibian.     

Quantifying interactions between propranolol and dissolved organic matter (DOM) from different sources using fluorescence spectroscopy

Beta blockers are widely used pharmaceuticals that have been detected in the environment. Interactions between beta blockers and dissolved organic matter (DOM) may mutually alter their environmental behaviors. To assess this potential, propranolol (PRO) was used as a model beta blocker to quantify the complexation with DOM from different sources using the fluorescence quenching titration method. The sources of studied DOM samples were identified by excitation–emission matrix spectroscopy (EEMs) combined with fluorescence regional integration analysis. The results show that PRO intrinsic fluorescence was statically quenched by DOM addition. The resulting binding constants (log K _oc) ranged from 3.90 to 5.20, with the surface-water-filtered DOM samples claiming the lower log K _oc and HA having the highest log K _oc. Log K _oc is negatively correlated with the fluorescence index, biological index, and the percent fluorescence response (P _i,n) of protein-like region (P _I,n) and the P _i,n of microbial byproduct-like region (P _II,n) of DOM EEMs, while it is correlated positively with humification index and the P _i,n of UVC humic-like region (P _III,n). These results indicate that DOM samples from allochthonous materials rich in aromatic and humic-like components would strongly bind PRO in aquatic systems, and autochthonous DOM containing high protein-like components would bind PRO more weakly.     

个体防护装备在应急救援处置中的作用

个体防护装备是保护人体不受外来有害因素伤害,保证人体安全与健康的重要装备.在工农业生产中,各国政府针对生产过程中可能出现的各种危害采取一系列工程技术措施保护劳动者的安全与健康,个体防护装备作为保护劳动者安全与健康的重要手段或最后一道防线,要求生产经营单位必须为劳动者配备.     

降低企业库存风险问题研究

大多数企业都面临着库存风险问题 ,库存过多 ,造成积压 ,不仅占用大量资金和场地 ,加重企业的利息负担 ,而且长期存放会使物品陈旧过时 ,失去原有的价值和使用价值。如何降低库存风险 ,使库存经常处于合理水平 ,是每个企业都十分关心的问题。笔者分析了库存管理中存在的问题 ,提出需求预测和安全库存的确定 ,是降低库存风险的两个重要前提 ,同时讨论了安全库存的计算方法 ,以及降低库存风险的主要措施     

Comparison of different liquid anaerobic digestion effluents as inocula and nitrogen sources for solid-state batch anaerobic digestion of corn stover

Effluents from three liquid anaerobic digesters, fed with municipal sewage sludge, food waste, or dairy waste, were evaluated as inocula and nitrogen sources for solid-state batch anaerobic digestion of corn stover in mesophilic reactors. Three feedstock-to-effluent (F/E) ratios (i.e., 2, 4, and 6) were tested for each effluent. At an F/E ratio of 2, the reactor inoculated by dairy waste effluent achieved the highest methane yield of 238.5 L/kgVS_feed, while at an F/E ratio of 4, the reactor inoculated by food waste effluent achieved the highest methane yield of 199.6 L/kgVS_feed. The microbial population and chemical composition of the three effluents were substantially different. Food waste effluent had the largest population of acetoclastic methanogens, while dairy waste effluent had the largest populations of cellulolytic and xylanolytic bacteria. Dairy waste also had the highest C/N ratio of 8.5 and the highest alkalinity of 19.3 g CaCO₃/kg. The performance of solid-state batch anaerobic digestion reactors was closely related to the microbial status in the liquid anaerobic digestion effluents.