环境内分泌干扰物前处理方法研究新进展

环境内分泌干扰物因其能够紊乱生物体正常内分泌功能而引起人们的广泛关注,然而内分泌干扰物在水环境中浓度极低,水体中复杂机质的干扰较大,在分析监测前一般要经过样品前处理过程,以起到富集痕量组分、消除基体干扰、提高方法灵敏度的作用。针对不同环境样品中内分泌干扰物的前处理方法不同,分别介绍了液体、固体或类固体环境样品的前处理技术,提出了各前处理方法的优缺点,总结并展望了环境内分泌干扰物样品前处理方法的发展方向。     

Adsorption of isoxaflutole degradates to aluminum and iron hydrous oxides

Isoxaflutole is a preemergence herbicide that has been marketed as a substitute for atrazine. It is rapidly transformed to a more stable and soluble diketonitrile degradate (DKN) after field application and can further degrade to a benzoic acid degradate (BA) within soil. However, no previous research has been conducted to investigate DKN and BA sorption to metal oxide minerals. The primary objective of this research was to elucidate the interactions of DKN and BA with synthetic hydrous aluminum and iron oxides (HAO and HFO, respectively) to understand how variably charged minerals may influence adsorption of these compounds in soil. The herbicide degradates did adsorb to HAO and HFO, and the data were well described by the Freundlich model (R2 > 0.91), with Nvalues ranging from 0.89 to 1.2. Adsorption isotherms and Kd values demonstrate that BA is adsorbed to HFO to a greater extent than other degradate-mineral combinations that were studied. The degree of hysteresis between adsorption/desorption isotherms was characterized as slight (hysteresis index values < 1.7), suggesting weak DKN and BA retention to HFO and HAO oxide surfaces. Degradate adsorption was observed to greatly diminish as suspension pH increased. Attenuated total reflectance-Fourier transform infrared spectra show no evidence that DKN or BA adsorb to mineral surfaces as inner-sphere complexes under hydrated conditions. Instead DKN and BA adsorb to positively charged metal oxide surfaces as outer-sphere or diffuse ion swarm complexes via electrostatic attraction. This research indicates that metal oxides may serve as important retardants for DKN and BA migration through acidic soils enriched with aluminum and iron oxides.     

低压天然气回收再利用与节能环保

凝析油气藏在开采后期,由于地层压力自然递减加快,开采难度加大,而后期的工业及民用天然气需求量不断增加,导致凝析气藏产气量逐年缩减与天然用量逐步增多的矛盾日益明显。为缓解这一矛盾,考虑将不能输送的放空低压气进行技术增压,达到输送压力后,进入输送管道,从而增加天然气输送量,减少天然气放空对环境的污染。     

甘蔗蔗糖磷酸合成酶SPSⅡ cDNA片段克隆与表达分析

蔗糖磷酸合成酶(Sucrose phosphate synthase,SPS)是蔗糖合成途径的关键限速酶,在蔗糖积累和碳分配中具有重要作用.在茎组织中SPSⅡ表达量占SPS转录总量的40%,表明SPSⅡ cDNA的克隆与表达对蔗茎中蔗糖的积累有着重要的影响.通过RT-PCR技术克隆分离SPSⅡ基因cDNA片段.序列分析表明该cDNA片段包含1个3 183 bp的开放读码框,可编码1 060个氨基酸.GenBank登录号为EU269038.通过实时荧光定量PCR检测SPSⅡ基因在甘蔗糖分积累的不同时期、不同组织部位的相对表达量.结果表明,在糖分积累初期蔗茎中的SPSⅡ相对表达量最大,在糖分积累中期蔗叶中的SPSⅡ相对表达量达到最高峰;同组织部位中,糖分积累初期SPSⅡ相对表达量高于糖分积累中期、后期.图6参11     

The function of constructed wetland in reducing the risk of heavy metals on human health

Irrigation with polluted water from the upper Yellow River (YR) channel of Northwest China has resulted in agricultural soil being contaminated by heavy metals (HMs). This causes major concerns due to the potential health risk to the residents in this area. The present study aims to assess the efficiency of constructed wetland (CW) in reducing the heavy metal contamination in irrigation water and food crops, thus in reduction of potential health risk to the residents. The associated risk was assessed using hazard quotient (HQ) and hazard index (HI). The results showed a potential health risk to inhabitants via consumption of wheat grain irrigated with untreated water from YR. However CW could greatly reduce the human health risk of HMs contamination to local residents through significantly decreasing the concentrations of HMs in wheat grain. In theory, the reduction rate of this risk reached 35.19% for different exposure populations. Therefore, CW can be used as a system to pre-treat irrigation water and protect the residents from the potential HMs toxicity.     

NO2对二甲苯光氧化生成SOA及其吸光度影响

NO₂是大气中常见污染气体,影响大气二次有机气溶胶（Secondary organic aerosol,SOA）的形成.运用实验室烟雾箱模拟二甲苯大气光氧化反应过程,研究NO₂对二甲苯SOA生成量、光学特性和化学组成的影响.结果显示,NO₂促进二甲苯SOA的形成,NO₂浓度从0增长到900×10^-9,二甲苯SOA的质量浓度增长2倍左右,并且邻二甲苯SOA质量浓度大于对二甲苯SOA.这是因为邻位取代基相比于对位取代基更倾向于形成醛,有利于聚合反应形成低聚物,促进SOA形成.此外,NO₂浓度增加显著提高所生成SOA的单位质量吸光度（Mass absorption coefficients,MAC）,这是由于前体物邻二甲苯和对二甲苯化学结构不同,邻二甲苯所生成的含氮有机物具有更强吸光性,从而导致邻二甲苯SOA的MAC_{λ=365 nm}大于对二甲苯SOA的MAC_{λ=365 nm}.在线气溶胶质谱仪分析结果进一步显示：二者光化...     

超临界水氧化法处理固体废物的研究进展

超临界水氧化法作为一种新兴的高级氧化技术具有广阔的应用前景,该方法在处理固体废物方面具有独特的优势。介绍了超临界水的特性和超临界水氧化法的反应机理及超临界水氧化法在固体废物处理方面的应用现状,提出了该方法要达到工业化应用亟待解决的理论和实际问题,对超临界水氧化法的发展方向进行了展望。     

利用多模式集合和多元线性回归改进北京PM_(10)预报

本研究将多模式集合预报和多元线性回归集成方法结合起来减小空气质量预报的不确定性.首先评估了北京空气质量多模式集合预报系统中3个模式成员(NAQPMS、CAMx、CMAQ)对北京地区PM10日均浓度的预报性能,在此基础上引入多元线性回归将历史观测信息纳入进来对3个模式预报结果进行集成,并将集成预报结果与3个模式算术平均的预报结果进行比较.结果发现:1不同模式的预报结果差异较大,并没有一个模式的预报技巧完全优于其它两个模式,其中CMAQ对北京PM10变化趋势的预报优于其它两个模式,NAQPMS预报的均方根误差整体低于其他两个模式.2多模式预报结果的算术平均在趋势预报和偏差两项指标上都低于部分单模式预报,并不能有效改进PM10预报;基于分站点的模式和观测数据构建的多元线性回归集成预报模型能显著提高PM10预报的准确率,选定合适的训练天数(36 d)后,28个站点PM10日均值预报的均方根误差相对单模式预报或集合平均预报下降32%~43%,预报偏差大幅减小至5.8μg·m-3,总体预报技巧显著优于单模式和多模式算术平均的预报结果,并且采用线性回归集成方法大幅提高了对污染过程的预报能力.     

武进港流域地表水中新污染物的高通量筛查与源解析

新污染物长期存在于水环境中,其对生态、人类健康存在的潜在危害和风险是不可忽视,而研究其在地表水中的分布特征及其来源可对新污染物的源头治理与管控提供帮助.武进港是太湖西北部的主要入湖河流之一,为了解武进港流域新污染物的分布,采用液相色谱-高分辨率质谱仪（LC-HRMS）对19处地表水样（包括主河道12个水样、支流7个水样）和污水处理厂出水水样中的新污染物进行高通量筛查.共识别出294种新污染物,其中药物类和农药类新污染物占比较大,分别为35.4%和32.3%.主成分分析表明,污水处理厂出水受新污染物污染的情况与地表水具有显著差异,同时19个地表水点位中,新污染物的分布在武进港流域存在南北地区差异.通过Mann-Whitney U检验,并绘制火山图,北部筛选出70种特征新污染物,其中药物类新污染物占比最大,为48.6%,包括咖啡因、金刚烷胺、缬沙坦等.南部筛选出17种特征新污染物,农药类占比最大,为52.9%,包括2-甲基-4-氯苯氧乙酸（MCPA）、灭草松等.相关性分析结果显示,农药类特征新污染物与农田占比呈正相关.     

全球气候变化的成因探析

探析了引起全球气候变化的温室气体效应、太阳变化、火山喷发、对流层气溶胶等外部强迫效应，以及导致大气和海洋间能量再分配的埃尔尼诺事件等所引起的气候变化。进一步讨论了气候系统内部的、涉及地球生物学和化学的几种气候反馈机制。