Investigation of volatile methyl siloxanes in biogas and the ambient environment in a landfill

Landfill biogas is a potential alternative for fossil fuel,but the containing impurities,volatile methyl siloxanes(simplified as siloxanes),often cause serious problems in gas turbines when applied to generate electricity.In this research,a collecting and analyzing method based on solvent adsorption and purge and trap-gas chromatography-mass spectrometry was established to determine the siloxanes in biogas from a landfill in Jinan,China,and adjacent ambient samples,such as soil,air,and leachate ...     

The convergence of alternative food networks within “rural development” initiatives: the case of the New Rural Reconstruction Movement in China†

Rural sociologists and geographers have conceptualised different rural development trajectories including “the agri-industrial model”, “the post-productivist model” and “the rural development model”. Alternative food networks (AFNs) are increasingly recognised as a “forerunner” and a critical component of the emerging “rural development model” in the West. Meanwhile, Marsden and Franklin [2013. Replacing neoliberalism: theoretical implications of the rise of local food movements. Local Environment, 18 (5), 636–641] pointed out that there is a “local trap” in the current conceptualisation of AFNs that overemphasises their local embeddedness and heterogeneity. This “local trap” marginalises AFNs and, therefore, hinders their potential for transforming the industrialised conventional food system. The convergence and scaling-up of fragmented AFNs have been recognised as important ways to address this marginalisation issue and thus have attracted considerable attention. However, current studies of the convergence of AFNs focus mainly on the role of food-centred organisations without recognising the role of the emerging “rural development” initiatives in the convergence of AFNs. Based on in-depth interviews with key stakeholders and analysis of secondary data, this paper uses the New Rural Reconstruction Movement (NRRM), an emerging alternative rural development movement in China, as an example to illustrate how the NRRM opens up a novel space for the convergence of AFNs. We argue that the interrelationship between AFNs and rural development is indeed reciprocal. The NRRM, following the “rural development” trajectory, functions as a hub for the convergence and scaling-up of various alternative food initiatives. Strategies for achieving convergence include constructing a “common ground” for these initiatives, establishing national alliances and organisations, sharing knowledge and exchanging personnel among them.     

吹扫捕集-气相色谱／质谱法测定水中25种挥发性有机物研究

建立了吹扫捕集与气相色谱／质谱联用测定水中25种挥发性有机物的分析方法。该方法的加标回收率在90％-119％之间,响应因子（RF）的相对标准偏差均小于20％,检出限在0．04μg／L-0．22μg／L之间。该方法具有简单、快速、准确、灵敏,无其他有机物的污染等优点,适用于地表水、地下水和饮用水中挥发性有机物的测定,结果令人满意。     

水体中痕量氯苯的气相色谱分析方法研究

根据氯苯在水体中溶解度小,易吹脱且热稳定性好的特点,建立了水体中痕量氯苯的分析方法。该法采用简化的吹脱、捕集装置用ＴｅｎａｘＧＣ富集水体中氯苯,热解吸法浓缩进样,大口径毛细管柱分离,ＦＩＤ测定。方法操作简单、快速,测定水体中氯苯最低检出限为０．４μｇ／Ｌ,相对标准偏差小于８．６％。方法适宜于水体中痕量氯苯的测定     

吹气—吸收法测定废水中硫化物

对吹气－吸收法测定废水中硫化物进行了吸收试验，提出了用去离子除氧水配制硫化物标液，可增加其稳定性；用ＩＳＯ硫化物吹脱器取代普通气吸收装置，可提高硫化物回收率。试验结果表明，改进后方法的精密度，准确度及适用怀强垃令人满意。     

《昆明-蒙特利尔全球生物多样性框架》下的生物多样性监测

生物多样性监测是执行和评估《昆明-蒙特利尔全球生物多样性保护框架》（简称《昆-蒙框架》）长期目标和行动指标所需要的关键数据的主要来源。简要介绍了《昆-蒙框架》下的全球生物多样性观测网络（The global biodiversity observation network,GEO BON）概况、中国已有的生物多样性监测/观测网络,构建全球生物多样性观测系统（A global biodiversity observation system,GBiOS）的目的和核心监测指标,分析了生物多样性监测网络建设的一般步骤和GEO BON建议的4种生物多样性监测新方法。提出,地理空间单元与生物类群的全覆盖监测是建设生物多样性监测网络的主要目标,传统监测方法和新监测技术的互补是当前生物多样性监测的重点工作内容。     

吹扫捕集-气相色谱法测定水中四乙基铅

通过探讨影响四乙基铅富集效率的捕集管类型、吹扫温度和吹扫时间等因素,建立了吹扫捕集-气相色谱法测定水质中四乙基铅的分析方法。实验结果表明,使用Tenax捕集管,在吹扫温度为50℃、吹扫15 min的条件下测定水质中的四乙基铅,捕集效率为97.6%~98.2%,在0~100μg/L范围内线性良好,检出限为0.03μg/L,加标回收率为93.2%~100.5%,相对标准偏差为1.6%~3.2%。方法操作简便快捷、准确、实用且绿色环保不消耗有机溶剂,适于水质中四乙基铅的测定。     

ABS树脂装置丁二烯聚合工段废水水质表征

为确定某ABS树脂装置丁二烯聚合工段废水水质,特别是特征有机物种类,采用吹扫捕集、静态顶空、固相萃取、固相微萃取和液液萃取等预处理方法与GC/MS(气相色谱/质谱)联用,定性检测出该工段废水中含有16种挥发、半挥发性有机物,主要包括烯烃、苯系物、有机腈、多环芳烃、醚、醇和胺. 废水ρ(SS)(SS为悬浮物)为540.31 mg/L;SS粒径主要分布在0.10~5.00 μm之间,可吸附水中4.83%~33.21%的对二甲苯、乙苯、苯乙烯和1,5-环辛二烯等有机物. 与生活污水不同,该工段废水三维荧光光谱图的荧光区域集中在λ_Ex/λ_Em(激发波长/发射波长)=205~285 nm/310~360 nm范围内,主要包括λ_Ex/λ_Em为285 nm/350 nm、260 nm/310 nm、225 nm/345 nm、210 nm/315 nm、230 nm/360 nm的5个荧光峰,由甲苯、靛蓝、苯乙烯、脱氢松香酸、芴、菲等苯系物和多环芳烃类有机物引起. 废水在200~250 nm之间有较强紫外吸收峰,主要由1,3-丁二烯、苯甲醛、苯乙酮、4-苯基-1-环己烯等共轭二烯、不饱和醛、酮和苯系物等有机物引起.      

吹扫—捕集／气相色谱法测定水中挥发性有机物

为提高样品分析效率,研究并建立了吹扫-捕集／气相色谱／氢火焰检测器联用同时测定水中1,2-二氯乙烷、苯、甲苯、氯苯、乙苯、对-二甲苯、间-二甲苯、苯乙烯、邻-二甲苯、异丙苯、1,4-二氯苯、1,2-二氯苯、硝基苯、1,3,5-三氯苯、1,2,4-三氯苯、1,2,3-三氯苯、六氯丁二烯17种挥发性有机物的分析方法。结果表明,当进样体积为25．0ml时,最低检出限为0．0034-0．1088μg/L,相对标准偏差为1．8％～6．4％,加标平均回收率为97．6％-105．8％。该方法可快速、简便、准确、高灵敏度的测定水中17种挥发性有机物,并适用于饮用水和地表水中挥发性有机物的测定。     

地面水中痕量挥发性有机污染物的GC／MS法测定

参考美国EPA624方法,采用LSC_3吹捕富集,色谱/质谱/计算机联用技术,以特征离子峰面积内标法,对若干挥发性有机污染物作定量分析研究。在1至50ppb浓度范围内,混合标样中各化合物均获得线性良好的校准工作曲线。相对标准偏差小于12％,平均回收率在94％～105％。最小检测浓度为0.5～1.0ppb。实际测定了地面水样,测得重点控制挥发性有机物12种,浓度为0.5～279ppb。