自愿减排项目碳泄漏：内涵、类别及应对

自愿减排项目是碳排放交易市场抵消机制的运行载体,灵活的自愿减排抵消机制是碳排放交易市场的补充,对应对全球气候变化问题具有重要意义。碳泄漏,作为严重影响抵消项目减排效率的热点问题值得关注。目前,中国已形成较大规模的自愿减排市场,截至2018年底,国家发展改革委共签发了约7200万tCO_2当量减排量,我国在建立健全自愿减排抵消市场机制的过程中,需要把握项目碳泄漏的负外部性这一实质,厘清其运行机理并积极应对。本文旨在系统阐述该问题,并为进一步实现抵消项目减排潜力提供思路和方向:从自愿减排项目碳泄漏的内涵与定义出发,首先对项目碳泄漏的分类进行梳理,并依据产生途径的不同重点分析了活动转移排放、生命周期、市场路径、生态以及技术泄漏的作用机制、影响因素及其相应的研究方法;其次从具体项目应用、系统项目应用和宏观应用三个层面讨论了应对自愿减排项目碳泄漏问题的管理对策;最后结合我国自愿减排抵消市场的实际情况,建议未来抵消项目碳泄漏的应对和管理应在分门别类对其概念进行精准定义的基础上将解决措施的成本效益考虑在内,此外,在评估泄漏量时需要同时测算不同类型的碳泄漏,探究其协同效应以免高估其泄漏程度。     

辉县市城区环境空气质量现状及污染防治对策

对辉县市城区2006—2011年间环境空气质量监测数据进行了评价,并对城区污染物浓度时空变化进行了分析。结果表明,辉县市城区大气污染主要表现为可吸入颗粒物污染严重,主要是能源结构不合理、锅炉废气污染严重、城区道路保洁方式落后等原因造成的,由此提出了合理规划城市布局、减少结构性污染等对策。     

A process integration approach to industrial water conservation: a case study for a Chinese steel plant

A systematic approach to optimizing water network has traditionally been utilized to exam and plan water conservation in industrial processes. In the present case study, water-pinch technology was used to analyze and optimize the water network of a steel plant near China's Zhangjiakou city. A system design was developed and a limiting constraint (Cl(-) concentration) was identified based on investigations of water quality then the minimum freshwater and wastewater targets were determined without considering water losses. The analysis was then extended by calculating the additional input of freshwater required to balance the actual water losses. A nearest-neighbor algorithm (NNA) was used to distribute the freshwater and recycled water among each of the plant's operations. The results showed that with some reconstruction of the water network, the flow rates of freshwater and wastewater could be decreased by 57.5% and 81.9%, respectively.     

Estimation and characterization of PCDD/Fs and dioxin-like PCBs from Chinese iron foundries

The iron foundry industry is considered to be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study investigated the emission factors and total emission amounts of PCDD/Fs and dioxin-like polychlorinated biphenyls (DL-PCBs) from iron foundries in China. The concentrations and the World Health Organization toxicity equivalents (WHO-TEQs) are presented and the congener profiles are discussed in this paper.In the present work, 26 fly ash samples were collected and tested to quantify the PCDD/Fs and DL-PCBs generated by 14 plants of different scales, and five stack gas samples were collected from two (named as EFG and LFG) of those plants. The emission levels of PCDD/Fs and DL-PCBs indicated that hot-air cupolas had lower emissions than cold-air cupolas. When iron ore lump and sinter were used as raw material, the emission factors were about 250 ng TEQ t⁻¹ of product. However, if the raw material was scrap, the emission factors varied owing to the different contents of organic materials in the raw materials. It was found that the mean WHO-TEQ values of PCDD/Fs and DL-PCBs were 144 and 34.2 pg Nm⁻³ in stack gas and 20.0 and 1.58 pg g⁻¹ in fly ash. In multiple tests, it was estimated that the mean emission factors of PCDD/Fs and DL-PCBs were 365 and 10.9 ng WHO-TEQ t⁻¹ released to residue and 2719 and 555 ng TEQ t⁻¹ released to air. The total emission amounts of PCDD/Fs and DL-PCBs from Chinese iron foundries with cupola furnaces released to residue and air were 16.8 and 146 g WHO-TEQ in 2008, respectively.     

亚硝态氮胁迫下菲律宾蛤仔实时定量P CR内参基因的筛选

为了更好地从基因角度研究亚硝态氮对贝类的生态毒性,需要筛选一个合适的内参基因作为参考,对其毒性相关基因进行定量表达分析。本研究以菲律宾蛤仔(Ruditapes philippinarum)作为研究对象,以亚硝态氮胁迫的鳃组织cDNA作为模板,利用geNorm软件和NormFinder软件对6个候选内参基因进行表达稳定性分析,并对2个结果做了综合赋权分析。结果显示,geNorm分析的基因表达稳定性结果为ActinCyPAEF1αUbi18STubu,NormFinder软件分析的结果为ActinUbiCyPAEF1α18STubu,最后经加权赋值法综合分析获得6个候选基因的表达稳定性为ActinCyPAUbiEF1α18STubu,即Actin为表达最稳定的基因。因此,Actin可以作为衡量亚硝态氮胁迫后菲律宾蛤仔鳃组织中基因表达的内参基因。     

Effects of organic acids on Cd adsorption and desorption by two anthropic soils

The objective of this experiment was to study the effects of malic, tartaric, oxalic, and citric acid on the adsorption and desorption characteristics of Cd by two typical anthropic soils (lou soil and irrigation-silted soil) in North-west China. Cadmium adsorption and desorption were studied under a range of temperatures (25°C, 30°C, 35°C, 40°C), organic acid concentrations (0.5–5.0 mmol·L^-1), and pH values (2–8). The results showed that the Cd adsorption capacity of the lou soil was significantly greater than that of the irrigation-silted soil. Generally, Cd adsorption increased as the temperature increased. In the presence of NaNO₃, the adsorption of Cd was endothermic with ΔH values of 31.365 kJ·mol^-1 for lou soil and 28.278?kJ·mol^-1 for irrigation-silted soil. The endothermic reaction indicated that H bonds were the main driving force for Cd adsorption in both soils. However, different concentrations of organic acids showed various influences on the two soils. In the presence of citric acid, chemical adsorption and van der Waals interactions were the main driving forces for Cd adsorption rather than H bonds. Although the types of organic acids and soil properties were different, the effects of the organic acids on the adsorption and desorption of Cd were similar in the two soils. The adsorption percentage of Cd generally decreased as organic acid concentrations increased. In contrast, the adsorption percentage increased as the pH of the initial solution increased. The exception was that adsorption percentage of Cd increased slightly as oxalic acid concentrations increased. In contrast, the desorption percentage of Cd increased with increasing concentrations of organic acids but decreased as the initial solution pH increased.     

食品烹调处理过程中砷的浓度、形态和生物可给性研究进展

食品作为人体砷暴露的主要途径,其砷的含量和形态备受关注。由于食品原料通常要经过烹饪加工后才会被人食用,因此,食品的烹调处理过程及方式对砷的形态及生物有效性的影响在砷的健康风险评价研究中,需要作为重要因素进行研究。通过综述不同食品烹调处理前后砷浓度、形态和生物可给性变化的相关研究,分析了砷变化的特征,探讨了相关机理,并得出如下结论:烹调处理能使食品中砷的浓度发生升高或降低;高温烹调能使食品中砷形态发生变化,目前研究结果确定的变化主要是砷甜菜碱的分解,烹调中食品砷形态变化的机理尚不明确。不同烹调方式下,食品中砷的生物可给性差异较大,砷的形态变化可能是其生物可给性差异的主要原因。烹调特别是高温烹调下食品砷浓度升高及形态变化导致的健康风险值得进一步关注。     

表观遗传学机制与空气污染的健康效应

空气污染是一个全球性的问题,并且具有深远的环境影响。暴露于空气污染会对人体健康产生许多不同的影响,理解空气污染的健康效应又是一个复杂命题,既要考虑不同类型的污染物同时也要考虑相关疾病的复杂性。然而越来越多的研究表明,表观遗传学在空气污染相关疾病的发生、发展中发挥着重要的作用。空气污染物可引起DNA甲基化、组蛋白修饰和miRNA表达等表观遗传学改变,这种改变往往发生在疾病产生的早期,因此相关研究不仅可以了解疾病的发病机制,而且还为疾病早期诊断和预防筛选可能的标志物。本文综述了表观遗传学的几种修饰方式和空气污染物造成不良健康损伤机制的一些研究进展。     

应用概率物种敏感度分布法研究太湖重金属水生生物水质基准

目前广泛使用的水质基准推导方法—物种敏感度分布法存在曲线拟合模型不确定、曲线拟合效果不佳、种内差异欠考虑、基准值不准确等诸多问题,概率物种敏感度分布法可有效解决上述问题。应用概率物种敏感度分布法构建了太湖水体中5种重金属Ag、Pb、Cd、Hg和Zn的概率物种敏感度分布曲线,在此基础上得到了保护水生生物的急性水质基准分别为1.079μg·L~(-1)、637.973μg·L~(-1)、19.465μg·L~(-1)、8.729μg·L~(-1)和105.506μg·L~(-1),慢性水质基准分别为0.108μg·L~(-1)、63.797μg·L~(-1)、1.947μg·L~(-1)、2.340μg·L~(-1)和52.753μg·L~(-1);不同类群间生物对重金属的敏感度存在差异,不同重金属对同一类群生物的毒性也存在差异;通过与国内外已有的重金属水质基准值比较,发现水质基准具有明显的区域性,目前基于国外水质基准或我国整体水域特点来制定的太湖水质标准,往往造成对太湖水生生物欠保护或过保护的状况。     

超高压工程电缆绝缘油对海洋生物的生态毒性效应

随着超高压联网工程建设项目不断增多,取得巨大经济效益的同时,其电缆安全性日益受到关注。采用标准实验方法,研究电缆绝缘油对8种占据不同生态位的海洋生物(费氏弧菌(Vibrio fischeri)、牟氏角毛藻(Chaetoceros mueleri)、卤虫(Artemia sp.)、蒙古裸腹溞(Moina mongolica)、凡纳滨对虾(Litopenaeus vannamei)、裸项栉鰕虎鱼(Ctenogobius gymnauchen)、双齿围沙蚕(Perinereis aibuhitensis)、菲律宾蛤仔(Ruditapes philippinarum))的急性毒性,同时进行了电缆绝缘油对裸项栉鰕虎鱼14 d延长毒性实验和电缆绝缘油对蒙古裸腹溞的慢性毒性。结果表明,电缆绝缘油在50%饱和溶解浓度下未对费氏弧菌产生明显的发光抑制作用;对牟氏角毛藻、凡纳滨对虾、裸项栉鰕虎鱼、双齿围沙蚕和菲律宾蛤仔等5种生物未表现出急性毒性影响,其LC50均大于饱和浓度;对卤虫的96 h-LC50为17.07%,LOEC为12.5%,NOEC为6.25%;对蒙古裸腹溞96 h-LC50为29.75%,LOEC为25.0%,NOEC为12.5%;电缆绝缘油对卤虫和蒙古裸腹溞有剧毒。对裸项栉鰕虎鱼成鱼14 d延长毒性LC50大于500 000 mg·L~(-1);对蒙古裸腹溞母溞存活数的NOEC为625μg·L~(-1),LOEC为1 250μg·L~(-1);对母溞存活期的NOEC为312μg·L~(-1),LOEC为625μg·L~(-1);对产胎数的NOEC为625μg·L~(-1),LOEC为1 250μg·L~(-1);对产幼溞数的NOEC为625μg·L~(-1),LOEC为1 250μg·L~(-1)。