染料中二噁英类化合物的分析方法研究进展

综述了染料中二噁英类化合物的研究进展,指出染料基质复杂,化学结构差异较大,其中二噁英的预处理和检测需根据染料的性质选择最佳的方法;染料中二噁英含量较高,对环境和人体健康影响较大,而原料中的氯醌类物质是其主要污染源。     

Levels and distribution of PCDD/Fs, dl-PCBs, and organochlorine pesticides in sediments from the lower reaches of the Haihe River basin, China

The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and organochlorine pesticides (OCPs) in surface sediments from the lower reaches of the Haihe River basin, northern China, were determined by high-resolution gas chromatograph–high-resolution mass spectrometer. The concentrations of 2,3,7,8-substituted PCDD/Fs, dl-PCBs, and total OCPs [sum of hexachlorobenzene, hexachlorocyclohexanes, and dichlorodiphenyltrichloroethane (DDTs)] in 17 sediment samples were in the ranges of 11.6–1,180,924 pg/g dry weight (dw), 18.7–50,017 pg/g dw, and 1.7–35,280 ng/g dw, respectively. The contamination levels in the samples varied significantly between the different sites. Abnormally high concentrations of PCDD/Fs, dl-PCBs, and some OCPs were found in sediments from the lower reaches of the main channel of the Haihe River and the Dagu Drainage River, which were attributed to the historical production of pentachlorophenol and other pesticides near these locations. High levels of DDTs were detected in the Yongding New River sediment, which were likely to have originated from the discharge of wastewater from a dicofol factory upstream. In samples taken from other sites, the concentrations of these pollutants were at levels comparable to those documented in other areas of China. This preliminary investigation suggests that historical pesticide production in the Haihe River basin has contributed significantly to the contamination of this aquatic ecosystem and that further attention to this issue is warranted.     

湖北臭氧分布特征及其管控措施

采用地面站点观测、卫星观测以及UWCM 0-D箱子模型模拟的方法研究湖北2013—2015年臭氧时空分布特征,并探讨其管控措施。从地面站点观测看出,时间分布上,这3年臭氧年平均浓度经历先下降后上升的过程,总体呈上升趋势,而二氧化氮年平均浓度则呈现持续下降的趋势;空间分布上,湖北各区域臭氧浓度分布不均匀,呈现东高西低的递减分布趋势。从卫星观测数据看出,2015年湖北的臭氧柱浓度高于2013、2014年同期。从空间分布来看,臭氧的柱浓度是从东北到西南、从省外到省内逐渐递减,因此推测,除了本地生成,湖北的臭氧有一部分是来源于省外传输。最大臭氧生成量法显示,烯烃(乙烯和丙烯)对湖北夏天臭氧生成量的贡献远大于其他挥发性有机化合物。箱子模型模拟的结果显示,湖北应该通过控制挥发性有机化合物的排放来降低臭氧生成速率,控制氮氧化物反而使臭氧生成速率提高。     

武汉市降尘污染特征及影响因素

以武汉市2006—2013年降尘数据为例,采用SPSS19.0软件统计分析了中部地区内陆城市的降尘污染特征及其影响因素。结果表明,月均降尘污染呈5月峰、11月谷三次曲线型,季节降尘污染呈春季夏季冬(秋)季,年均降尘量呈显著下降趋势。各功能区降尘量差异显著,从多到少顺序依次为工业区交通稠密区居商工混区清洁区。根据主成分分析结果,对于武汉这类经济发展中的中部内陆城市来说,气象因素是影响降尘的重要外在因素。社会因素是主要内在影响因素,其中经济发展因子的影响高于环境建设因子。     

固相萃取-液质联用分析药物和个人护理品

建立了固相萃取-液质联用分析药物和个人护理品(PPCPs)的方法,采用Oasis HLB固相萃取柱分别在酸性条件下和碱性条件下对PPCPs进行富集提取,该法对于宜兴地区能够检出的30种PPCPs均具有良好的线性,相关系数为0.990~0.999,检出限为1.37~10.12 ng/L。应用该法对宜兴地区地表水中存在的PPCPs进行分析,结果显示30种PPCPs均有不同程度检出,分布最广泛的7种分别为避蚊胺、阿替洛尔、对乙酰氨基酚、普鲁卡因、β-雌二醇、卡马西平和苯佐卡因,阿替洛尔浓度较高,普遍为5~600 ng/L。避蚊胺虽然出现频率最高,但其在各个采样点浓度偏低,普遍为1~50 ng/L。     

Measurement of HONO flux using the aerodynamic gradient method over an agricultural field in the Huaihe River Basin, China

To investigate nitrous acid(HONO) levels and potential HONO sources above crop rotation fields. The HONO fluxes were measured by the aerodynamic gradient(AG) method from 14 December 2019 to 2 January 2020 over an agricultural field in the Huaihe River Basin. The ambient HONO levels were measured at two different heights(0.15 and 1.5 m), showing a typical diurnal cycle with low daytime levels and high nighttime levels. The upward HONO fluxes were mostly observed during the day, whereas deposition...     

太阳活动和ENSO控制南岭东部有效降水变化

在我国东南地区,器测时代之前的气候环境变化是否与ENSO活动有关还未见报道.本文在210Pb定年基础上,重建了南岭东部过去150 a(分辨率1.86 a)的石笋δ18O记录.对比器测指标,发现该石笋δ18O记录与当地有效降水变化密切相关,并以此重建了南岭东部地区过去150 a有效降水变化历史.南岭东部有效降水变化与EN...     

表面活性剂用量对有机膨润土稳定性的影响

为研究有机膨润土的稳定性,通过添加不同用量的表面活性剂(十六烷基三甲基溴化铵)对有机膨润土进行改性处理.将制成的有机膨润土加入清水中,通过不同振荡时间、振荡强度、超声处理时间、温度、pH值及不同浓度盐溶液的处理后,测定离心得到的上清液中总有机碳(TOC)的含量.结果表明,相同处理条件下(超声处理除外),有机膨润土的稳定性均随着改性时表面活性剂用量的增加而逐渐降低.当表面活性剂用量小于或等于膨润土阳离子交换量(CEC)时,制备的有机膨润土比较稳定.振荡时间、振荡强度及反应温度对有机膨润土稳定性的影响不明显;增加超声波处理时间、pH值过高或过低均会降低有机膨润土的稳定性;提高处理溶液中的NaCl、CaCl2浓度.可增加有机膨膨润土尤其是高表面活性剂用量的改性有机膨润土的稳定性.因此,为避免有机膨润土的二次污染,在利用表面活性剂制造有机膨润土时,应根据膨润土的阳离子交换量确定适宜的表面活性剂用量,并使溶液pH值处于中性范围.     

基于BP神经网络的民航机场安全预警研究

在完善、改进已有民航机场安全预警指标体系及其指标值的基础上,突破民航机场传统的危险预警模式,建立基于BP神经网络的民航机场安全预警模型.采用SPSS主成分分析法对模拟数据进行预处理,基于MATLAB软件实现网络模型的训练与检测,从而实现安全预警.研究表明此模型是可行有效的,可为研究机场安全预警问题提供新的思路和方法.     

Assessing soil Cu content and anthropogenic influences using decision tree analysis

Recent enhanced urbanization and industrialization in China have greatly influenced soil Cu content. To better understand the magnitude of Cu contamination in soil, it is essential to understand its spatial distribution and estimate its values at unsampled points. However, Kriging often can not achieve satisfactory estimates when soil Cu data have weak spatial dependence. The proposed classification and regression tree method (CART) simulated Cu content using environmental variables, and it had no special data requirements. The Cu concentration classes estimated by CART had accuracy in attribution to the right classes of 80.5%, this is 29.3% better than ordinary Kriging method. Moreover, CART provides some insight into the sources of current soil Cu contents. In our study, low soil Cu accumulation was driven by terrain characteristic, agriculture land uses, and soil properties; while high Cu concentration resulted from industrial and agricultural land uses.