食品企业周边空气中异味挥发性有机物测定方法比较

以1个典型食品生产企业(酱菜厂)周边的异味挥发性有机物监测为例,介绍了罐采样-GC/MS、便携式GC/MS、SPME-GC/MS以及SPME-异味分析系统等4种监测方法的实际应用,从定性、定量监测结果等方面,比较了4种监测方法的特点。罐采样-GC/MS、便携式GC-MS 2种方法适用于定性、定量检测,在有标准样品的前提下,定量结果总体可比;SPME-GC/MS以及SPME-异味分析系统2种方法更适用于定性检测。     

回灌型准好氧填埋场脱氮特性及加速稳定化研究

采用2个模拟填埋生物反应器,1号柱渗滤液简单回灌,2号柱为渗滤液回灌准好氧联合运行方式,研究了渗滤液回灌准好氧生物反应器填埋场的脱氮特性及加速垃圾稳定化特性.研究结果表明:渗滤液回灌准好氧填埋场具有很强的脱氮能力,2号柱由厌氧运行方式改为准好氧条件下,渗滤液中的氨氮和凯式氮浓度分别由最大值的3 198 mg/L和3 345 mg/L降低到第160 d的73 mg/L和81 mg/L,去除率分别为97.7%和97.6%,pH快速升高到8.0左右,COD浓度快速降低.渗滤液中溶解性有机物(DOM)分级结果表明,2号柱HA和FA含量的增加明显快于1号柱.2号柱DOM的三维荧光光谱特性发生了较大变化,荧光基团从60 d结构简单的类蛋白物质转变为95 d结构复杂的类胡敏酸和富里酸物质,而l号柱渗滤液DOM荧光基团一直是结构简单的类蛋白物质.结果表明回灌准好氧生物反应器填埋场的稳定化速度远快于简单回灌的生物反应器填埋场.     

城镇化发展与城镇生态环境建设研究

当前城镇化发展与城镇生态环境建设应该有机结合起来,走新型城镇化发展道路,结合绿色发展理念,将绿色、低碳、集约和智能贯彻到其中,从而更好推进城镇化发展。本文对此进行了深入探究,旨在促进城镇经济和社会更好发展。     

Neglected skin-associated microbial communities: a unique immune defense strategy of Bufo raddei under environmental heavy metal pollution

Environmental Science and Pollution Research - Amphibians defend against pathogens using skin microbial communities, in addition to innate and adaptive immunity. Despite skin microbial communities...     

Application of surface molecular imprinting adsorbent in expanded bed for the adsorption of Ni(2+) and adsorption model

A new surface molecular imprinting adsorbent (SMIA) was used in an expanded bed. The expansion ratio and adsorption performance were studied at different volumetric rates, inlet concentrations, and pH values. A model based on the Adams-Bohart adsorption model of breakthrough curves was established. The predicted curves had good agreement with the experimental curves. The breakthrough time (T(1/2)) decreased with increasing inlet concentration when the outlet concentration was half the initial concentration (C/C(0)=0.5). The inlet concentration had little effect on the adsorption rate constant (k(1)) value when the initial concentration (C(0)) was above 150 mg/L. However, T(1/2) values increased with increasing initial pH of the inlet solution, and the k(1) value decreased due to the competition between H(+) and Ni(2+).     

Emerging Governance Approaches for Tourism in the Protected Areas of China

This paper examines the recent evolution in the governance of protected area tourism in China. China now sees cooperation in the form of public-private partnerships occurring between authorized private tourism enterprises in various organizational forms and the public managers from specific portfolio departments of governments at different levels. Three types of governance models are visible: the Leasing Model, the Non-listed Share-holding Model, and the Public-listed Share-holding Model. Theories of corporate governance were applied to these models to analyze the internal and external mechanisms of supervision and incentives for both the government agencies and the authorized tourism enterprises for nature-based tourism operations. The Principal-Agent problem and the supervision mechanism are the focus of the analysis. The emerging governance approaches for tourism in protected areas of China are all theoretically viable, as explained by the theory of property rights and corporate governance, and practically viable as elaborated in the cases of the three types of governance models summarized in this paper.     

VASC-SCL工艺在焦炉煤气脱硫中的应用

介绍了真空碳酸钠-克劳斯工艺在焦化厂焦炉煤气脱硫及硫回收中的应用,主要介绍了工艺流程、主要设备和监测结果,并对此工艺进行了简要评价。     

Establishing eutrophication assessment standards for four lake regions, China

The trophic status assessment of lakes in different lake regions may provide important and fundamental information for lake trophic state classification and eutrophication control. In this study, a region-specific lake eutrophication assessment standard was established through a frequency distribution method based on chlorophyll-a concentration. The assessment standards under the oligotrophic state for lakes in the Eastern plain, Yungui Plateau, Northeast Plain and Mountain Mongolia-Xinjiang regions are total phosphorus of 0.068, 0.005, 0.011, 0.005 mg/L; total nitrogen of 1.00, 0.16, 0.37, 0.60 mg/L; Secchi depth of 0.60, 8.00, 1.55, 3.00 m; and CODMn of 2.24, 1.00, 5.1 l, 4.00 mg/L, respectively. Moreover, a region-specific comprehensive trophic level index was developed to provide an understandable assessment method for the public. The results indicated that the frequency distribution analysis based on chlorophyll-a combined with trophic level index provided a useful metric for the assessment of the lake trophic status. In addition, the difference of eutrophication assessment standards in different lake regions was analyzed, which suggested that the sensitivities of algae to nutrients and the assessment standard of trophic status possessed significant regional differences for the four lake ecoregions. Lake eutrophication assessment standards would contribute to maximizing the effectiveness of future management strategies, to control and minimize lake eutrophication problems.     

Characterization of extracellular polymeric substance (EPS) fractions produced by Microcystis aeruginosa under the stress of linoleic acid sustained-release microspheres

Environmental Science and Pollution Research - This paper focuses on the characterization of extracellular polymeric substances (EPS), which are composed of soluble EPS (SL-EPS), loosely bound EPS...