Estrogenic effects of phenolic compounds on glucose-6-phosphate dehydrogenase in MCF-7 cells and uterine glutathione peroxidase in rats

In this study, we tested phenolic compounds such as bisphenol A (BPA), 4-nonylphenol (NP), 4-octylphenol (OP) and 4-propylphenol (PP) by using glucose-6-phosphate dehydrogenase (G6PD) in estrogen sensitive human breast cancer cells (MCF-7 cells) and glutathione peroxidase (GPx) in female immature Sprague-Dawley (SD) rats. This study was designed to investigate whether phenolic compounds have estrogenic effects in these useful screening methods for endocrine disruptors. We chose 6 h as the incubation period for the G6PD assay through a preliminary experiment using 17beta-estradiol (E2). Above the concentration of 1 x 10(-8) M, BPA significantly increased the G6PD activity in a concentration-dependent manner, relative to the control. NP (over the concentration of 1 x 10(-9) M) also enhanced the G6PD activity by about 1.8 times that of the control. OP produced weaker effects on G6PD than NP, and showed a tendency to increase the G6PD activity. PP did not affect the G6PD activity. These results show that BPA and NP have the effect of enhancing G6PD activities in MCF-7 cells. In the in vivo GPx assay, both BPA and E2 significantly increased the uterus wet weights and dramatically enhanced uterine GPx activities in immature female rats in a dose-dependent manner. Treatment with NP (500 mg/kg/day) increased significantly both the uterine GPx activity and the uterus wet weights in immature female rats. OP (500 mg/kg/day) also caused a significant increase in uterine GPx activity, but had no effect on the uterus wet weights. This finding indicates that the change in uterine GPx activities could be a more sensitive parameter than that of uterus wet weights in immature rats. This study implies that phenolic compounds have a weak estrogenic effects.     

The influence of air–fuel ratio on engine performance and pollutant emission of an SI engine using ethanol–gasoline-blended fuels

Ethanol–gasoline-blended fuel was tested in a conventional engine under various air–fuel equivalence ratios (λ) for its performance and emissions. The amount of fuel injection was adjusted manually by an open-loop control system using a CONSULT controller. It was found that without changing throttle opening and injection strategy, λ could be extended to a leaner condition as ethanol content increased. The results of engine performance tests showed that torque output would increase slightly at small throttle valve opening when ethanol–gasoline-blended fuel was used. It was also shown that CO and HC emissions were reduced with the increase of ethanol content in the blended fuel, which resulted from oxygen enrichment. At an air–fuel equivalence ratio slightly larger than one, the smallest amounts of CO and HC and the largest amounts of CO₂ resulted. It was noted that under the lean combustion condition, CO₂ emission was controlled by air–fuel equivalence ratio; while under the rich combustion condition, CO₂ emission is offset by CO emission. It was also found that CO₂ emission per unit horse power output for blended fuel was similar or less than that for gasoline fuel. From the experimental data, the optimal ethanol content in the gasoline and air–fuel equivalence ratio in terms of engine performance and air pollution was found.     

工业烟气净化系统的风量平衡调节及数值模拟应用研究

为了对某钢铁集团烧结机尾气净化系统的风量平衡进行调节,提出了利用Fluent仿真软件对通风管道内部流场进行数值模拟,在主管和部分支管上设置节流管、调节管径的改进措施。风量模拟结果表明,通风管道的原风量存在严重的不平衡性,吸尘点的风量不平衡率高达75.0%,在部分管道增加节流管可以有效调整管道的风量不平衡性,调整后吸尘点风量的不平衡率为18.8%;对于压力损失较大、风量偏小的管道,可通过管径调节使其风量基本达到设计要求;Fluent仿真软件的风量模拟值与现场实测值有较高的吻合性,数值模拟方法可以为工业烟气净化系统的改造提供参考依据。不仅能够为前期工程设计提供帮助,大大节省工程调试费用,缩短工期,并有助于风量不平衡管道的调节和改造。     

Altitude dependence of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in surface soil from Tibetan Plateau, China

Remote mountain areas besides high latitude regions are beginning to receive increased attention in studying the transport and behavior of persistent organic pollutants (POPs). In the present work, surface soil samples were collected from the Tibetan Plateau, the highest plateau in the world which includes the northern slope of Mt. Qomolangma, to investigate the levels and trends of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) along the altitudinal gradient. The average PCB and PBDE concentrations were 185.6 ng kg⁻¹ dry weight (dw) (range 47.1–422.6 ng kg⁻¹ dw) and 11.1 ng kg⁻¹ dw (range 4.3–34.9 ng kg⁻¹ dw), respectively. Regression analysis between the log-transformed TOC-normalized concentrations and the altitudes of the sampling sites showed two opposite trends with regard to altitude dependence: negative relationship with altitude below about 4500 m followed by a positive altitude dependence above this point. Considering minimum anthropogenic activities and very sparse precipitation in the north of Himalayas, the trends above 4500 m imply that the significant altitude dependence of these two groups of POPs were irrespective of pollution sources, but could be predicted by the global distillation effect involving cold condensation in high altitude mountain areas. Increasing levels of heavier congeners were found in higher altitude sites, although the lighter congeners were the main contributors to the total amount, suggesting that less volatile congeners seem to become enriched easier than those more volatile at higher altitudes in this region.     

Evaluation of atmospheric sources of PCDD/Fs, PCBs and PBDEs around a steel industrial complex in northeast China using passive air samplers

The concern about emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) from steel industrial parks has increased in the past decades. In this study, polyurethane foam (PUF)-disk based passive air samples were collected in and around a big steel industrial park of Anshan, Northeast China from June 2008 to March 2009. The levels, seasonal variations and potential sources of PCDD/Fs, PCBs and PBDEs in the atmosphere around the steel industrial complex were investigated, and potential contribution of these three groups of persistent organic pollutants (POPs) from iron and steel production was also assessed. The air concentrations of ∑₁₇PCDD/Fs (summer: 0.02-2.77 pg m⁻³; winter: 0.20-9.79 pg m⁻³), ∑₁₉PCBs (summer: 23.5-155.8 pg m⁻³; winter: 14.6-81.3 pg m⁻³) and ∑₁₃PBDEs (summer: 2.91-10.7 pg m⁻³; winter: 1.10-3.89 pg m⁻³) in this targeted industrial park were relatively low in comparison to other studies, which implied that the industrial activities of iron and steel had not resulted in serious contamination to the ambient air in this area. On the whole, the air concentrations of PCDD/Fs in winter were higher than those of summer, whereas the concentrations of PCBs and PBDEs showed opposite trends. The result from principal component analysis indicated that coal combustion might be the main contributor of PCDD/F sources in this area.     

Temporal trends (2005-2009) of PCDD/Fs, PCBs, PBDEs in rice hulls from an e-waste dismantling area after stricter environmental regulations

Primitive e-waste dismantling activities have been of increasing concern due to serious environmental and human health problems, and therefore authorities in China have strengthened the regulations on illegal e-waste recycling activities. In this work, we used rice hull as a passive sampler and investigated temporal trends of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) in areas near e-waste recycling sites after the stricter regulations. Furthermore, the distribution patterns and composition profiles of these contaminants were also discussed. The average concentrations of the three groups of persistent organic pollutants (POPs) in rice hulls have markedly decreased during the period of 2005-2009. Specifically, from 12.9 (average value in 2005) to 0.37 pg WHO-TEQ/g (dry weight, dw) (in 2009) for PCDD/Fs, 47.6 (2005) to 7.10 ng g⁻¹ dw (2009) for PCBs, and 2.51 (2005) to 0.89 ng g⁻¹, dw (2009) for PBDEs. The significant decrease of combustion markers 2,3,4,7,8-PeCDF, 1,2,3,6,7,8HxCDF and PCB126, and the PCDD/PCDF ratio from 1:9 (2005) to 7:3 (2009) is likely a result of stricter regulations on open combustion activities. This study suggests that stricter control measures, strengthened laws and regulations and more environmental friendly techniques could be effective measures in reducing the release and formation of related POPs in typical e-waste dismantling sites, and these measures could further improve the quality of the environment and health of the local inhabitants.     

泥磷液相催化氧化氮氧化物

采用磷化工行业的固体废物泥磷液相催化氧化氮氧化物。实验结果表明,该方法是可行且有效的。随着温度的升高,泥磷吸收液的脱硝效率提高,当温度达到泥磷熔点时脱硝效率最佳。泥磷吸收液的脱硝效率随固液比的增大而有所下降,而随着NO体积分数和气体流量的增大,泥磷吸收液的脱硝效率呈先升后降的趋势。各因素对脱硝率的影响大小顺序为：气体流量>反应温度>固液比>NO体积分数。在反应温度60 ℃、固液比1∶4、NO体积分数0.03%、气体流量0.3 L/min的最佳工艺条件下,反应160 min的平均脱硝率可达97.38%。     

炼油污水深度处理回用的中试

采用两级曝气生物滤池和多介质滤池相串联的中试装置,连续处理某炼油厂污水车间二浮出水,主要考察了中试装置对污水中主要污染物的去除效果和规律,并确定了适宜的气水比。试验结果表明:采用该工艺时,除石油类外,其它各项指标都达到《循环冷却水用再生水水质标准》(HG/T3923-2007)要求的水质指标;两级曝气生物滤池的气水比分别选用5.6∶1和5∶1为宜;验证了BAF是通过生物氧化和过滤两种作用来去除COD,第一段BAF以去除污水中碳化有机物为主,第二段BAF主要以去除污水中的NH4+-N为主。