Dissolved organic matter fractions formed during composting of winery and distillery residues: evaluation of the process by fluorescence excitation-emission matrix

The aim of the present paper is to assess the maturity degree reached by different samples of several mixtures from winery and distillery residues composted using the Rutgers composting system, by means of excitation-emission matrix (EEM) fluorescence spectroscopy. The composts were sampled once a week for about 200d. EEM spectra indicate the presence of different fluorophores. The fluorescence intensities of these peaks show trends related to the maturity of the composting samples selected. The "contour density" of EEM maps is strongly modified through time. We have used the quantitative method of fluorescence regional integration (FRI). The EEMs were delineated into five excitation-emission regions. The degree of compost maturity could be correlated with the percentage of the volumetric integration under the EEM within each region. Further refinement of these techniques should provide a relatively rapid method for assessing the suitability of the compost to soil application.     

区域水环境污染预警系统的建立

深入分析水环境污染预警系统的目的，结构，实现以及各子系统的耦合，提出区域水环境污染预警系统应由区域内多个主要预警中心组成，每个预警中心包括通讯子系统，技术支持子系统，应急风险分析和决策支持子系统等。区域水环境污染预警系统的实现由实时处理和离线处理2个部分组成，前者包括现场流量，蒸发，降雨实时信息的收集，数据的传递和接收，预警模型计算和输出，决策管理，后者包括历史数据和区域特征输入，预警模式选择；参数率定等。目前建立预警系统面临的主要困难在于实时信息的获取和系统不确定性分析方法，相应地，对系统的持续改进也就是要加强信息交流，提高模型的识别能力，扩展系统的评价与决策功能等。     

浅谈清洁生产在山东焦化行业中的应用

阐述了在焦化行业开展清洁生产的必要性,结合焦化企业开展清洁生产的实例,从废物最小化和资源化等方面概述了清洁生产技术在焦化行业中的应用;并以山东焦化企业为例论述如何做好清洁生产工作。     

天津地区鱼塘水、悬浮物、沉积物和鱼体中的DDT

采样测定了天津地区2典型鱼塘鲫鱼、鲢鱼、水、悬浮物、沉积物和鱼塘周边表土中的DDT及其代谢产物含量。结果发现,2鱼塘各主要介质以及鱼体肌肉和器官中都富集了较高浓度的DDT。鲫鱼和鲢鱼肌肉中DDT的含量分别为(66.4±2.7)ng·g-1和(24.3±23.4)ng·g-1。肝胰脏、肠和鱼鳃中DDT含量一般高于肌肉,其中肠的富集量最大,是肌肉的3倍以上。生物富集系数(lgBCF)分别为3.7和3.3。2鱼塘鱼体和各相含量有较大差别,鱼塘介质中悬浮物富集浓度最高。表土污染相对严重地区的鱼塘中各介质和鱼体DDT含量均高于另一污染较轻的鱼塘。污染严重鱼塘的DDE/ΣDDT含量比值也相对较高,反映早期污染残留的重要特征。尽管如此,仍然较高的DDT含量以及悬浮物中很低的DDE/ΣDDT含量比值说明很可能还有污染源存在。     

Biofilm structure and its influence on clogging in drip irrigation emitters distributing reclaimed wastewater

Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter clogging in drip irrigation systems distributing reclaimed wastewater.Little is known about the biofilm structure and its influence on clogging in the drip emitter flow path.This study was first to investigate the microbial characteristics of mature biofilms present in the emitters and the effect of flow path structures on the biofilm microbial communities.The analysis of biofilm matrix structure using a scanning electron microscopy (SEM) revealed that particles in the matrix of the biofilm coupled extracellular polysaccharides (EPS) and formed sediment in the emitter flow path.Analysis of biofilm mass including protein,polysaccharide and phospholipid fatty acids (PLFAs) showed that emitter flow path style influenced biofilm community structure and diversity.The correlations of biofilm biomass and discharge reduction after 360 h irrigation were computed and suggest that PFLAs provide the best correlation coefficient.Comparatively,the emitter with the unsymmetrical dentate structure and shorter flow path (Emitter C) had the best anti-clogging capability.By optimizing the dentate structure,the internal flow pattern within the flow path could be enhanced as an important method to control the biofilm within emitter flow path.This study established electron microscope techniques and biochemical microbial analysis methods that may provide a framework for future emitter biofilm studies.     

Non-destructive quantification of water gradient in sludge composting with Magnetic Resonance Imaging

Sludge from a slaughter-house wastewater plant, and mixtures of bulking agent (crushed wood pallet) and sludge were studied by Nuclear Magnetic Resonance (NMR). The NMR spin–spin relaxation (T₂) and spin–lattice relaxation (T₁) signals for sludge, wet crushed wood pallet and mixtures of sludge and bulking agent were decomposed into three relaxation time components. Each relaxation time component was explained by a non-homogeneous water distribution on a microscopic length scale and by the porosity of the material. For all samples, the T₂ relaxation time value of each component was directly related to the dry matter content. The addition of wet crushed wood to sludge induced a decrease in the relaxation time, explained by water transfer between the sludge and the wood.Magnetic Resonance Imaging (MRI) and respirometric measurements were performed on sludge and wood mixtures. MR images of the mixtures were successfully obtained at different biodegradation states. Based on specific NMR measurements in an identified area located in the MRI cells, the results showed that grey levels of MR images reflected dry matter content. This preliminary study showed that MRI would be a powerful tool to measure water distribution in sludge and bulking agent mixtures and highlights the potential of this technique to increase the understanding of sludge composting.     

Carbon dioxide capture and recovery by means of TSA and/or VSA

Experimental work is performed with a 5A zeolite on a small laboratory column with heating from the wall. Carbon dioxide adsorption occurs at atmospheric pressure and different CO₂ concentrations in nitrogen. Comparisons of different methods of desorption by heating, purge and/or vacuum are studied. Desorption by heating only leads to almost pure CO₂ (around 99% purity) and a recovery nearly linear to the heating temperature, ranging from 45% at 130 °C to 79% at 210 °C. Recovery can be subsequently increased with a nitrogen purge to more than 98% but the recovered carbon dioxide is diluted due to the dispersive character of the desorption wave and the operation time is long. Increasing the flow rate decreases the desorption time but has no effect on the purity because the total purge volume remains about the same. Substitution of the purge step with a vacuum step leads to pure CO₂ and almost total recovery. Desorption under vacuum only without heating leads to pure CO₂ (around 99% purity) but limited recovery (85% in the present work).Desorption under vacuum seems to be more simple for large-scale applications. When using a water liquid ring pump, the temperature of the ring must be kept as low as possible to provide a high operating capacity.     

Risk on the ramble: The international transfer of risk and vulnerability

In this paper the purpose is to discuss a concept of technology that can explain how the transfer of technology implies the risk of new failures, misuse, accidents and unhealthy workplaces. Production technologies are often transformed through a steady stream of incremental changes appropriate to their social context, and the technology will therefore gradually acquire some contextually dependent preconditions for use. These preconditions will most probably be revealed when a technology is transferred from one context to another. Thus, a technology transfer project may trigger a long process of re-innovations just to make the technology fully operational in its new context. In a transfer process, technological risks may arise due to incomplete transfer of mastering capacity; mismatch between transferred technology and the environment; transfer of latent conditions for failure; and the transformation of latent conditions or known risks when the technology is installed in a new environment. Longitudinal data from the Norwegian petroleum industry indicates that the first phases in a transfer process will create high technological risks. It will take many years before the transferred technologies are adapted to the new context and the risk level has been normalised.     

Trends in environmental education for biodiversity conservation in Costa Rica

Costa Rica is internationally recognized for its abundant biodiversity and being a leader in the promotion of education strategies for biodiversity conservation. We interviewed staff from 16 institutions developing key environmental communication, education, and participation projects for biodiversity conservation in the country. Through content analysis, hierarchical cluster analysis and Chi-square tests, we examined the characteristics of the projects carried out by these institutions and developed a typology of four categories derived from six variables: primary audience, content, project purpose, location, scale, and facility. Then, we designed a conceptual model describing the integration of conservation and economic development in the educational projects. We found two key approaches related to this integration: vision of nature protection which aims to inform audiences of ecological concepts and focuses on schoolchildren and vision of sustainability which engages adult audiences and is management-oriented. Education for community-based environmental management may serve as a good example of educational projects which integrate conservation and economic development, implementing a vision of sustainability.