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991.
The effects of bisphenol A (BPA) were examined on sex hormones of F1 generation male rats during weaning period. Female rats were exposed to BPA from day 0 after pregnancy to the weaning period at doses of 50, 100, or 200 mg kg?1. The sex hormone levels of F1 generation male rats were determined. This study shows that F0 generation female rats fed with 200 mg kg?1 BPA had a significantly higher serum prolactin (PRL) levels at the end of weaning. Significantly higher levels of serum estradiol (E2) were also found in female rats fed 100 or 200 mg kg?1 BPA. Serum levels of E2 in F1 male generation rats were higher in treatment groups compared to control groups while serum testosterone (T) levels were lower. Follicle stimulating hormone (FSH) in F1 generation rats fed 200 mg kg?1 was markedly decreased. The relative testicular weights were significantly less in 100 and 200 mg kg?1 BPA groups. BPA was found to alter the sex hormone levels in F1 male rats during weaning period and thus disrupted endocrine functions. 相似文献
992.
Chung-Ming Liu 《Chemistry and Ecology》2013,29(1-2):147-161
Abstract In this paper, three sensitivity studies are designed to analyze the effect of the NMHC (Non-Methane HydroCarbon) composition, the aerosol back-scattering and the high chimney NO x emission to the photochemical prodution of ozone by using a one-dimensional photochemistry-diffusion model under a favourable meteorological condition. Measurements of the NMHC composition in Taipei indicated that the percentage of iso-butene, cis-2-butene, trans-2-butene and benzene in a unit volume was much higher than of those observed in other major cities. the high ratio of benzene was directly linked to its high percentage in gasoline. As to the unusually high amount of iso-butene, cis-2-butene and trans-2-butene, more researches are needed to identify their source. Concerns are raised as to how productive is NMHC composition is to the photochemical production of the surface ozone. A rough estimate shows that the total reactivity of the Taipei NMHC composition is about 1.21 × 10?9 cm3 s?1 which is 1.6 times that of the Los Angeles (LA) NMHC composition, while the simulated noon peak will be different by 28 ppbv, i.e. 18% more than that simulated with a LA composition. Meanwhile, high aerosol loading is a serious problem in Taipei. the attenuation of the UV radiation by aerosols cannot be ignored. A numerical simulation shows that the noon ozone level will decrease from 178 to 141ppbv, i. e. about 21% reduction, with deterioration of the visual range from 85 to 5 km. In the southern Taiwan, industry parks are mixed with the populated Kaohsiung city, hence the large emission of NO x from high chimneys cannot be ignored. in this study, NO x is assumed to be emitted in the layer between 235–460 m high with an emission rate of 0.05 or 0.145 ppbv/sec. the results show that the NO x emitted from the elevated stack lead to a considerable reduction of surface ozone. Such conclusion is obtained due to the fact that a one-dimensional model is used in this paper. Whereas, if a three-dimensional regional model was used, then a higher productivity of ozone downstream would be simulated. 相似文献
993.
John WANG Peng JIN Paul L. BISHOP Fuzhi LI 《Frontiers of Environmental Science & Engineering》2012,6(2):288-293
Lagoon-based municipal wastewater treatment plants (WWTPs) are facing difficulties meeting the needs of rapid population growth as well as the more stringent requirements of discharge permits. Three municipal WWTPs were modified using a high surface area media with upgraded fine-bubble aeration systems. Performance data collected showed very promising results in terms of five-day biochemical oxygen demand (BOD5), ammonia (NH3) and total suspended solids (TSS) removal. Two-year average ammonia effluents were 4.1 mg·L-1 for Columbia WWTP, 4 mg·L-1 for Larchmont WWTP and 2.1 mg·L-1 for Laurelville WWTP, respectively. Two- year average BOD5 effluents were 6.8, 4.9 and 2.7 mg·L-1, and TSS effluents were 15.0, 9.6 and 7.5 mg·L-1. The systems also showed low fecal coliform (FC) levels in their effluents. 相似文献
994.
干扰素生产废水处理试验及生物相分析 总被引:1,自引:0,他引:1
采用水解酸化与生物接触氧化组合工艺对干扰素生产废水进行试验研究,并考察其处理效果,观察生物接触氧化工艺中生物相。结果表明:该组合工艺对出水COD的去除率大于90%,出水COD低于40 mg/L,且运行稳定后生物接触氧化槽中污泥浓度较低。对生物相的显微镜观察可知生物接触氧化槽中生物相种类以藻类为主。 相似文献
995.
高密度沉淀-活性砂过滤工艺在钢铁工业废水处理中的应用 总被引:1,自引:0,他引:1
采用调节池-高密度沉淀池-活性砂滤池-消毒为主要处理工艺,处理钢铁工业废水并回用,介绍该工艺技术特点、主要构筑物的技术参数以及运行效果。工程监测结果表明,该工艺对总硬度、浊度及COD的去除率分别达到60%、85%及62%以上,出水水质各项指标均达到《城市污水再生利用工业用水水质标准》(GB/T19923-2005)要求。处理系统运行稳定,耐冲击能力强。 相似文献
996.
采用在线柱浓缩-超快速液相色谱联用技术测定水体中痕量百草枯和敌草快.水样无需样品前处理,过滤后即可进样.采用固相萃取小柱富集待测物,以色谱梯度泵完成样品的净化后,利用阀切换技术将待测物反冲至分析柱进行分离,以二极管阵列检测器定量.方法在1.0—20.0μg.L-1范围内线性良好,百草枯和敌草快的线性相关系数分别为0.9997和0.9989.百草枯和敌草快的检出限(S/N=3)分别为0.10、0.12μg.L-1,加标回收率在96.0%—98.0%之间.用所建立的方法测定了水中痕量的百草枯与敌草快的含量,结果令人满意. 相似文献
997.
浅谈高悬浮物废水处理研究中存在的不足 总被引:1,自引:0,他引:1
结合现场实践经验,指出了目前处理高悬浮物废水存在的悬浮物浓度与有机药剂用量不成比例等矛盾.通过分析混凝理论的研究历程,总结出高浓度范围下的絮凝作用机理为包裹机理,目前该机理仅处于定性描述阶段,对其进行定量描述具有重要意义;结合动力学发展过程,了解到以悬浮物浓度为研究对象的动力学模型较多,但特别针对高悬浮物范围下的絮凝动力学方程尚无人研究.并针对高悬浮物废水的处理,提出了今后重点研究方向. 相似文献
998.
999.
改性壳聚糖混凝去除太湖藻研究 总被引:1,自引:1,他引:0
对太湖不同区域的水使用改性壳聚糖做混凝除藻实验。对于泵取水,投加量0.7 mg/L时,藻去除率可达89.6%,对于岸边高浓藻水,投加量4 mg/L,0.5 h内藻去除率即可达为85.77%。改性壳聚糖复配黏土可解决岸边高浓藻絮体的上浮问题,黏土投加0.8 g/L絮体可完全下沉,除藻率fe从85.77%提升到94.35%。但复配黏土造成UV254去除率下降。改性壳聚糖复配0.3 g/L PDMDAAC改性粉煤灰投加或复配0.4 g/L改性沸石时,絮体也可完全下沉,除藻率都可提升到98%以上。同时,两种药剂都加强了系统对有机物的去除,UV254去除率从56.94%提升到72%以上。 相似文献
1000.