Quick determination of malodor-causing fatty acids in manure by capillary electrophoresis

The analysis of odor components in livestock waste has been extensively studied. Past research has identified volatile fatty acids, especially from C3 to C6, as indicators of malodor. Originally, the odorous components were analyzed by gas chromatography after a tedious absorption and troublesome extraction procedure or by a subjectively olfactory system or sense of smell. Thus, there is a need for the development of highly specific, quantitative analytical methods. In this research, a comprehensive liquid manure analysis approach-capillary electrophoresis (CE) with a systematic optimization procedure-was adopted to measure the concentration of propanoic acid (C2H5COOH, C3), butyric acid (C3H7COOH, C4), valeric acid (C4H9COOH, C5) and caproic acid (C5H11COOH, C6) in swine manure. Liquid samples after filtration were injected into CE directly. The following condition is finally proposed: fused-silica capillary, effective length 40 cm, 50 microm I.D.; buffer, 20 mM Tris and 10 mM p-anisate, pH 8.0; voltage 30 kV; temperature 25 degrees C. The results showed that CE provided a quantitative analysis of volatile fatty acids in liquid manure at the ppm level with minimum sample needed (nanoliter). Moreover, the use of CE is a timesaving technique; one measurement for the separation of those VFAs could be completed within 10 min.     

Properties of pyrolytic chars and activated carbons derived from pilot-scale pyrolysis of used tires

Used tires were pyrolyzed in a pilot-scale quasi-inert rotary kiln. Influences of variables, such as time, temperature, and agent flow, on the activation of obtained char were subsequently investigated in a laboratory-scale fixed bed. Mesoporous pores are found to be dominant in the pore structures of raw char. Brunauer-Emmett-Teller (BET) surfaces of activated chars increased linearly with carbon burnoff. The carbon burnoff of tire char achieved by carbon dioxide (CO2) under otherwise identical conditions was on average 75% of that achieved by steam, but their BET surfaces are almost the same. The proper activation greatly improved the aqueous adsorption of raw char, especially for small molecular adsorbates, for example, phenol from 6 to 51 mg/g. With increasing burnoff, phenol adsorption exhibited a first-stage linear increase followed by a rapid drop after 30% burnoff. Similarly, iodine adsorption first increased linearly, but it held as the burnoff exceeded 40%, which implied that the reduction of iodine adsorption due to decreasing micropores was partially made up by increasing mesopores. Both raw chars and activated chars showed appreciable adsorption capacity of methylene-blue comparable with that of commercial carbons. Thus, tire-derived activated carbons can be used as an excellent mesoporous adsorbent for larger molecular species.     

改性甘蔗渣对Cu^2＋和Zn^2＋的吸附机理

研究了均苯四甲酸二酐（PMDA）和乙二胺四乙酸二酐（EDTAD）改性甘蔗渣对重金属离子Cu^2＋和Zn^2＋的吸附性能,包括吸附动力学和吸附等温线。结果表明,改性后的甘蔗渣对重金属离子Cu^2＋和Zn^2＋的吸附容量有显著提高,对Cu^2＋和Zn^2＋吸附等温线均符合Langmuir方程,吸附为单分子层吸附。根据Langmuir方程,PMDA和EDTAD改性甘蔗渣对Cu^2＋的吸附量分别为60．21和33．45mg／g,对Zn^2＋的吸附量分别是70．53和36．53mg／g。两种改性甘蔗渣对两种金属离子的吸附在30min内均可完成,用准二级吸附动力学方程模拟动力学过程得到较好的线性相关性。以EDTA溶液为洗脱剂对吸附Cu^2＋和Zn^2＋的改性甘蔗渣进行洗脱再生,再生的吸附剂可反复使用。     

可张孔曝气器曝气能耗试验研究

通过试验研究,总结出可张孔曝气阻力损失的影响因素,以优化产品的结构设计参数,降低产品在工程应用中的能耗,获取更好的经济效益。     

可张孔曝气器曝气能耗试验研究

通过试验研究，总结出可张孔曝气阻力损失的影响因素，以优化产品的结构设计参数，降低产品在工程应用中的能耗，获取更好的经济效益。     

城市天然气管道风险特征与肯特法的改进

根据城市高压天然气管道特点,将适合于城市天然气管道风险分析的肯特评分法加以改进,包括调整评分项目和事故因素权重,使其成为适于城市天然气管道的风险分析法。将改进后的肯特评分法应用于常州21km高压天然气管道的风险评价,得出8个相对高风险管段,其分析结果可作为安全管理人员合理分配维护资源的理论依据。工程应用实例证明:改进后的肯特法具有较强的可行性,是城市高压天然气管道风险评估的有效工具。     

Application of Tradable Emission Permits in Europe

Abstract

The purpose of this study is merely to review the current situation in the designing and implementation of the emission trading programs in Europe. Historical data show that although there is a series of shortcomings in their current functioning, employing such instruments for GHG reduction policy making is strongly expected to be efficient and effective. The European Union Emission Trading Scheme (EU ETS), Clean Development Mechanism (CDM) and Joint Implementation (JI) are just a few examples of the ambitious EU initiative that heavily relies on such instruments. We dwell on their operations and achievements by far and all the content in this article is expected to convince the Chinese government and regional public authorities to take positive actions and attitudes in promoting these instruments.     

淀山湖浮游植物叶绿素a粒径组成及其与水质因子相关性

于2005年6月至2006年5月对淀山湖小型（20～200 μm）、微型（2～20 μm）和微微型（<2 μm）浮游植物叶绿素a和水质因子进行逐月调查研究。结果表明：小型和微型浮游植物是淀山湖水体年均叶绿素a的主要贡献者,二者贡献率之和为7479%。淀山湖叶绿素a粒径组成百分比的季节变动与水体浮游植物群落结构季节演替密切相关：小型浮游植物叶绿素a浓度所占百分比春季最高,而微型、微微型的则分别在秋、冬季最高。相关性分析显示,小型、微型浮游植物叶绿素a浓度百分比与NH3 N含量分别呈显著正、负相关,微微型浮游植物叶绿素a百分比与BOD5呈极显著负相关。对应滤食性鱼类等水生动物的食性粒级,探讨了运用非经典生物操纵技术防治淀山湖富营养化的可行性。〖     

公众太湖蓝藻水华生态风险感知特征研究——以无锡市区为例

蓝藻水华暴发已成为全球性生态环境问题。太湖作为流域重要的水源地,2007年蓝藻水华事件的暴发引起公众的高度关注。运用问卷调查法,研究无锡市区489名公众的太湖蓝藻水华生态风险感知特征及其主要影响因素。研究结果表明：蓝藻水华生态风险被公众知觉为总体风险是陌生和完全可控的;蓝藻水华暴发原因是陌生和不可控的,这是引起公众风险意识的主要因素。影响公众蓝藻水华生态风险感知水平的主要因素有媒体、信息和个体因素。报纸广播电视是主要的媒体因素。信息因素有灾害信息、灾害治理信息、政府防范措施信息。灾害治理信息的影响作用最大,其次是灾害信息和政府防范措施信息。不同性别、年龄段、教育程度、收入水平及职业的人群,对不同类别的风险信息关注程度不同,影响到个体风险偏好的不同。研究结果有助于决策者更全面地理解蓝藻水华风险的本质,开展风险沟通,针对不同特征的人群选择有效的风险管理方案。〖     

Pollution levels and characteristics of phthalate esters in indoor air of offices

The pollution status and characteristics of PAEs (phthalate esters) were investigated in indoor air of offices, and PAEs of both gas-phase and particulate-phase were detected in all the samples. The concentration (sum of the gas phase and the particulate phase) was 4748.24 ng/m³, ranging between 3070.09 and 6700.14 ng/m³. Diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate were the most abundant compounds, together accounting for 70% of the Σ6PAEs. Dividing the particulate-phase PAEs into four size ranges (<2.5, 2.5-5, 5-10, >10 μm), the result indicated that PAEs in PM_2.5 were the most abundant, with the proportion of 72.64%. In addition, the PAE concentration in PM_2.5 correlated significantly with the total particulate-phase PAEs (R² = 0.85). Thus, the amount of PAEs in PM_2.5 can be estimated from the total amount of particulate-phase PAEs using this proportion. In a comparison between the offices and a newly decorated study room, it was found that pollution characteristics were similar between these two places. Thus, it is implied that the PAE concentration decreased by 50% 2 yr after decorating.