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91.
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为了解渭河流域西安段地表水中邻苯二甲酸二丁酯(DBP)的污染状况,采用高效液相色谱法(HPLC),于2018年1、5和8月检测分析了渭河流域西安段地表水中DBP的含量和污染分布特征,并采用物种敏感分布曲线法(SSD)对水体中的DBP进行生态风险评价。结果表明:2018年1、5和8月流域水体中DBP浓度分别为nd~58.28("nd"表示未检出)、2.78~42.61和1.45~39.34μg/L,平均浓度分别为15.60、12.87和12.71μg/L。受点源污染和地表径流带来的污染物影响,泾河水体中DBP含量最高。生态风险评价结果表明,渭河干流及4条支流全年水体中DBP存在的风险大小为泾河﹥皂河﹥渭河干流﹥灞河﹥沣河。与国内外其他流域水体中DBP含量比较,渭河流域西安段地表水体中DBP含量处于较高水平,污水厂废水排放、工业污染和地表径流带来的污染物是流域水环境中DBP的主要来源。 相似文献
93.
研究区域ρ(PM2.5)的时空分布特征和污染天气类型的关系是开展大气污染防治和空气质量预报预警的关键支撑技术之一.基于2015—2016年广西14个城市环境空气质量日监测数据和相关气象资料,分析了2015—2016年广西空气质量概况和污染的基本特征,采用EOF(经验正交函数)分析和后向轨迹聚类分析方法表征了广西ρ(PM2.5)时空分布模态,统计了广西两年间24次区域范围(3个及以上连片城市)大气轻度及以上污染过程,分析了不同污染过程的天气类型和空气质量变化特点.结果表明:PM2.5是广西大气污染首要污染物,ρ(PM2.5)年均值呈北高南低的区域特征,月际变化基本呈正V字型分布;EOF分析和后向轨迹聚类分析显示,广西ρ(PM2.5)的时空结构主要有3种模态,其方差贡献率分别为78.9%、5.7%和3.7%,基本反映了广西ρ(PM2.5)变化的时空模态的主要特征,桂林和玉林两年间的后向轨迹聚类很好地解释了第二和第三模态的南北浓度和东西浓度异常反相位分布特征;广西14个城市两年间PM2.5区域性污染天气类型主要有10种,其中污染天气类型中占比较大的是弱冷高压脊型(24.4%)、均压场型(20.2%)、高压后部型(16.1%)和高压后部配合西南暖低压型(8.5%),是引发广西大范围大气污染的典型天气类型.研究显示,广西大气污染具有地域性、季节性和南北输送特征,污染过程的天气形势变化具有一定规律性. 相似文献
94.
Sorption of tylosin and sulfamethazine on solid humic acid 总被引:3,自引:0,他引:3
Tylosin(TYL) and sulfamethazine(SMT) are ionizable and polar antimicrobial compounds,which have seeped into the environment in substantial amounts via fertilizing land with manure or sewage. Sorption of TYL and SMT onto humic acid(HA) may affect their environmental fate. In this study, the sorption of TYL and SMT on HA at different conditions(pH, ionic strength) was investigated. All sorption isotherms fitted well to the Henry and Freundlich models and they were highly nonlinear with values of n between 0.5 and 0.8, which suggested that the HA had high heterogeneity. The sorption of TYL and SMT on HA decreased with increasing p H(2.0–7.5), implying that the primary sorption mechanism could be due to cation exchange interactions between TYL~+/SMT~+ species and the functional groups of HA.Increasing ionic strength resulted in a considerable reduction in the K_d values of TYL and SMT,hinting that interactions between H bonds and π–π EDA might be an important factor in the sorption of TYL and SMT on HA. Results of Fourier transform infrared(FT-IR) and ~13C-nuclear magnetic resonance(NMR) analysis further demonstrated that carboxyl groups and O-alkyl structures in the HA could interact with TYL and SMT via ionic interactions and H bonds,respectively. Overall, this work gives new insights into the mechanisms of sorption of TYL and SMT on HA and hence aids us in assessing the environmental risk of TYL and SMT under diverse conditions. 相似文献
95.
工业腐殖酸提纯前后对泰乐菌素的吸附特性 总被引:1,自引:0,他引:1
本文采用稀碱法对购买的工业腐殖酸进行了提纯,研究了腐殖酸提纯前后对泰乐菌素的吸附特性,并对其吸附机制进行了初步的探讨.研究结果表明:在对腐殖酸提纯之后,其C、H、O、N、S的含量明显增加,灰分含量显著减小.腐殖酸经提纯后对泰乐菌素的吸附明显增强,在24h可以完全达到吸附平衡,其吸附动力学曲线可以用拉格朗日二级动力学方程和颗粒扩散模型较好的拟合;吸附等温线可以用线性吸附模型和Freundlich吸附模型较好的拟合;且提纯后的腐殖酸对泰乐菌素的吸附随着溶液的p H值和离子强度增加而逐渐减小.综上,推测腐殖酸对泰乐菌素的吸附机制可能以疏水性分配、氢键作用和离子交换作用为主. 相似文献
96.
In the present study, a separation/preconcentration procedure for determination of aluminum in water samples has been developed by using a new atomic absorption spectrometer concept with a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator, and a charge-coupled device array detector. Sample solution pH, sample volume, flow rate of sample solution, volume, and concentration of eluent for solid-phase extraction of Al chelates with 4-[(dicyanomethyl)diazenyl] benzoic acid on polymeric resin (Duolite XAD-761) have been investigated. The adsorbed aluminum on resin was eluted with 5 mL of 2 mol L-1 HNO3 and its concentration was determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Under the optimal conditions, limit of detection obtained with HR-CS FAAS and Line Source FAAS (LS-FAAS) were 0.49 μg L?1 and 3.91 μg L?1, respectively. The accuracy of the procedure was confirmed by analyzing certified materials (NIST SRM 1643e, Trace elements in water) and spiked real samples. The developed procedure was successfully applied to water samples. 相似文献
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98.
Kristina Douglass Jonathan Walz Eréndira Quintana Morales Richard Marcus Garth Myers Jacques Pollini 《Conservation biology》2019,33(2):260-274
The human communities and ecosystems of island and coastal southeast Africa face significant and linked ecological threats. Socioecological conditions of concern to communities, governments, nongovernmental organizations, and researchers include declining agricultural productivity, deforestation, introductions of non-native flora and fauna, coastal erosion and sedimentation, damage to marine environments, illegal fishing, overfishing, waste pollution, salinization of freshwater supplies, and rising energy demands, among others. Human–environment challenges are connected to longer, often ignored, histories of social and ecological dynamics in the region. We argue that these challenges are more effectively understood and addressed within a longer-term historical ecology framework. We reviewed cases from Madagascar, coastal Kenya, and the Zanzibar Archipelago of fisheries, deforestation, and management of human waste to encourage increased engagement among historical ecologists, conservation scientists, and policy makers. These case studies demonstrate that by widening the types and time depths of data sets we used to investigate and address current socioecological challenges, our interpretations of their causes and strategies for their mitigation varied significantly. 相似文献
99.
Huang Xianfeng Wang Xiran Guan Dong-Xing Zhou Huabin Bei Ke Zheng Xiangyong Jin Zhan Zhang Yejian Wang Qi Zhao Min 《Environmental science and pollution research international》2019,26(9):8516-8524
Environmental Science and Pollution Research - Most prevailing processes are incapable of removing Cr(III)-organic complexes efficiently and facing the problem of in-process formation of highly... 相似文献
100.