成都市推进水环境综合治理的实践与思考

介绍成都市多年来开展水环境治理的具体实践,分析成都市开展水环境综合治理的主要特点和存在的主要问题,提出深入开展水环境综合治理的对策及建议。     

Monitoring gas- and particulate-phase short-chain polychlorinated paraffins in the urban air of Dalian by a self-developed passive sampler

The concentration of short-chain polychlorinated paraffins(SCCPs) in the urban air of Dalian,China was monitored from September 2016 to August 2017 with a self-developed passive sampler(PAS1) and an active high-volume sampler, simultaneously. PAS1 successfully collected the entire target SCCPs in the ambient air. Air SCCPs sampled by PAS1 were found be in the linear uptake stage during 181 days of sampling. Passive and active samples showed comparable congener profiles, and the dominant contributors of SCCPs in the two kinds of samples were similar. A significant linear correlation was observed between the total concentration of SCCPs sampled by PAS1 and active sampler in the four seasons. The passive sampling rates of the PAS1 for the gas and particulate phases of SCCPs were measured. The quantitative structure–property relationship of the sampling rate of PAS1(Rair) for gas-phase SCCPs was studied. From the molecular point of view, Rairwas mainly affected by the molecular weight and sub-cooled liquid vapor pressure of SCCPs. In general, SCCPs in the urban air of Dalian mainly existed in gas phase,lower molecular weight SCCPs primarily occurred in the gas phase, whereas higher molecular weight SCCPs were predominately adsorbed or absorbed on airborne particles. The air concentration of SCCPs in the four seasons were different, the correlation of the concentration of SCCPs in the air with the meteorology parameters was conducted. The exposure risk by intake air SCCPs of the residents around the sampling sites was evaluated according to the European risk assessment standards.     

醇胺类物质促进飞灰中氯代芳烃加氢脱氯的研究

分别以三乙醇胺(TEA)和一乙醇胺(MEA)作为氢源,六氯苯(HCB)作为模型化合物,研究了在密闭体系下飞灰中氯代芳烃的加氢脱氯作用.考察了TEA或MEA添加量、热处理温度和时间对脱氯效率的影响,证实有明显的脱氯反应发生.当MEA或TEA添加量为8%时,经过250℃,2 h热处理,脱氯效率分别可达94.7%和78.6%...     

川渝天然气管网维抢修点布局方法与原则

针对川渝管网分布特点,提出了适于维抢修单点、多点分布的中心、内环最优布局方式,并给出了最优路径算法,这将有效地缩短维抢修响应时间,提高抢修效率.     

韶钢2200 m3高炉优化休复风操作生产实践研究

韶钢2200 m³高炉投产运行近16年,处于炉役后期生产,受操作炉型不规则且炉缸保温性能极大下降等影响,高炉休风检修后,炉况恢复较困难。通过科学调剂精料管理、优化休风料加入方式、上下部操作制度并改进造渣制度和出铁模式等一系列措施,实现了高炉在短时间内快速恢复炉况的目的。     

Driving factors and the implications of work choices of rural laborers in ecologically vulnerable areas in North China

Using rural survey data for the year 2009,we provide evidence of work choices of rural laborers in ecologically vulnerable areas in North China,and model these choices as a function of characteristics of individuals,households,and land endowments.The findings reveal large differences between males and females,and between non-farm employment and part-time farming engagement Land scarcity is still an important driving factor in non-farming participation of rural laborers in the study area;and in the current case of land productivity and the total amount of land,there are still surplus rural labor forces in the study area.Diversification of livelihood reduces the pressure on land,thus facilitating ecosystem conservation.So,the paper concludes with the argument that establishing coordination mechanisms among non-farm employment of rural laborers,agricultural production,and restoration of ecosystems are essential for mitigating the conflicts of ecological security,agricultural production,and rural development in mis area.     

Pollution level and distribution of PCDD/PCDF congeners between vapor phase and particulate phase in winter air of Dalian,China

In December 2009, ambient air was sampled with active high-volume air samplers at two sites: on the roof of the No. l building of Dalian Jiaotong University and on the roof of the building of Dalian Meteorological Observatory. The concentrations and the congeners between vapor phase and particulate phase of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the air were measured. Sample analysis results showed that the concentrations of PCDD/Fs in particulate phase was higher than that in gaseous phase. The ratio of PCDD to PCDF in gaseous phase and particulate phase was lower than 0.4 in all samples. The total I-TEQ value in gaseous phase and particulate phase was 5.5 and 453.8 fg/m³ at Dalian Jiaotong University, 16.6 and 462.1 fg/m³ at Dalian Meteorological Observatory, respectively. The I-TEQ value of Dalian atmosphere was 5.5-462.1 fg/m³ which was lower than international standard, the atmospheric quality in Dalian is better.     

半挥发性有机污染物的气相色谱纯化方法

以六氯苯作为模型化合物,建立了半挥发性有机污染物样品净化的气相色谱方法.采用进样阀切换载气吹扫的进样方式,通过保留间隙柱和溶剂放空装置实现大体积进样,经过气相色谱分离后将分析物所在的半挥发性组分选择性冷凝在收集管中.本方法对模型化合物六氯苯的制备回收率为90%,对半挥发性有机污染物样品净化方法的发展具有重要意义.     

雾霾期北京大气中多环芳烃污染特征及暴露风险评估

雾霾对我国尤其是华北平原地区造成了极大的困扰,其发生常以颗粒物浓度急剧增长为特征,给人群健康带来了极大的风险。为进一步阐释雾霾的形成过程及其健康效应,在冬季雾霾期对北京城区大气颗粒态及气态中18种多环芳烃(PAHs)进行了连续测定,同步监测颗粒物、痕量气体污染物以及气象参数的变化,并对PAHs的浓度、组成、气粒分配等大气行为以及其与气象因素的作用机制进行了探讨。北京城区大气气相和颗粒物相中ΣPAHs浓度分别为585 ng·m~(-3)和705 ng·m~(-3)。雾霾发生时,PM_(2.5)浓度升高了3.6倍,PAHs浓度升高了2.6倍,18种PAHs同系物的浓度均随PM_(2.5)的浓度线性增加,其线性相关性受PAHs来源以及氧化活性的影响;夜间较重质量数的PAHs相对比例增加,主要受日间交通源以及夜间燃烧源贡献强度影响。受颗粒物组成以及湿度的影响,雾霾天气下PAHs颗粒相分配率降低。进一步评估了北京城区人群的PAHs吸入健康效应,冬季雾霾频繁发生下其对人群癌症风险为6.2×10~(-5)。     

短、中、长链氯化石蜡暴露对细胞代谢影响的比较研究

氯化石蜡(chlorinated paraffins, CPs)在中国大量生产和使用,导致其在环境介质中的含量较高。采用拟靶向代谢组学技术,比较研究了短、中和长链氯化石蜡在人体内暴露水平下(100μg·L~(-1))对HepG2细胞代谢的影响。结果表明,短、中和长链氯化石蜡暴露引起了HepG2细胞增殖活力的降低与代谢活动的显著变化。短链氯化石蜡(SCCPs)暴露对细胞代谢的影响强度略高于中链氯化石蜡(MCCPs)和长链氯化石蜡(LCCPs)。3种氯化石蜡均显著扰乱了脂质代谢,且影响程度相近。显著受影响的代谢通路包括:甘油磷脂代谢、亚油酸代谢、α-亚麻酸代谢、花生四烯酸代谢和鞘磷脂代谢。同时,3种氯化石蜡暴露也显著扰乱了甘氨酸、丝氨酸和苏氨酸代谢,缬氨酸、亮氨酸和异亮氨酸生物合成,牛磺酸和亚牛磺酸代谢;此外,LCCPs还扰乱了苯丙氨酸、酪氨酸和色氨酸生物合成通路。相比于SCCPs和MCCPs,LCCPs对氨基酸代谢表现出更强的干扰效应。