Effect of copper chloride on the emissions of PCDD/Fs and PAHs from PVC combustion

The influences of temperature, air flow and the amount of copper chloride upon the types and amount of the toxic emissions such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) during combustion of polyvinyl chloride (PVC) were investigated. The mechanism concerning the effect of temperature and copper chloride on the PCDD/Fs and PAHs formation was discussed. The results shown that without copper chloride, trace amounts of PCDD/Fs and large amounts of PAHs were found in the emissions from the pure PVC combustion under various combustion conditions. The addition of copper chloride enhanced PCDD/Fs formation, but it seems that the formation of PAHs decreased with increasing amount of copper chloride, and greater total amount of PAHs were produced at the higher temperature under our experimental conditions.     

Quantification of variability and uncertainty in air pollutant emission inventories: method and case study for utility NOx emissions

The quality of stationary source emission factors is typically described using data quality ratings, which provide no quantification of the precision of the emission factor for an average source, nor of the variability from one source to another within a category. Variability refers to actual differences caused by differences in feedstock composition, design, maintenance, and operation. Uncertainty refers to lack of knowledge regarding the true emissions. A general methodology for the quantification of variability and uncertainty in emission factors, activity factors, and emission inventories (EIs) is described, featuring the use of bootstrap simulation and related techniques. The methodology is demonstrated via a case study for a selected example of NOx emissions from coal-fired power plants. A prototype software tool was developed to implement the methodology. The range of interunit variability in selected activity and emission factors was shown to be as much as a factor of 4, and the range of uncertainty in mean emissions is shown to depend on the interunit variability and sample size. The uncertainty in the total inventory of -16 to +19% was attributed primarily to one technology group, suggesting priorities for collecting data and improving the inventory. The implications for decision-making are discussed.     

改良型AB生化法在味精废水处理中的应用

AB生化法是城市污水和多种工业废水处理最佳的新型实用技术之一。文章以AB生化法和离交废水苛化脱氨制硫酸铵相结合的工艺处理味精废水的工程实例,阐明改良型AB生化法的原理和设计中应注意的问题。     

基于突变级数法的吉林省生态补偿标准核算

为客观准确地确定各类土地的生态补偿标准,结合已有研究成果,采用突变级数法对生态系统的服务功能价值进行分析与评价,在此基础上提出基于突变理论的各类土地生态系统服务功能价值转换因子、均衡因子和生态补偿标准动态核算模型.应用该模型计算吉林省生态补偿标准,得出2012年吉林省耕地、林地、草地、湿地、水域和未利用地的生态补偿标准分别为1.534 9、2.018 5、1.682 1、2.094 9、1.826 8和0.823 6万元·hm-2,该生态补偿标准符合吉林省经济和社会发展的客观实际情况.基于生态系统服务功能理论和突变理论的生态补偿标准动态核算模型便于应用,具有较高可靠性和普遍适用性.     

Ecological properties of soil water and effects on forest vegetation in the Loess Plateau

In the Loess Plateau of China, soil water has three ecological properties: high infiltration capacity, high storage capacity and availability to deep plant roots. Soil desiccation is the most serious problem for forest vegetation in the Loess Plateau. Arid soils are the result of intensified soil desiccation caused by disturbances in plant succession, which constitute the ecological foundation of soil water. The negative effects of the arid soil layer on surface water infiltration for recharging underground water are discussed in terms of ecological hydrology. The arid soil layer disrupts the link between surface water and underground water and prevents vertical precipitation infiltration from supplementing underground water. Forest vegetation has a significant runoff-retaining efficiency that reduces total runoff from forest areas leading to low surface and ground runoff which affect the water cycle on a watershed scale.     

高密度沉淀-活性砂过滤工艺在钢铁工业废水处理中的应用

采用调节池-高密度沉淀池-活性砂滤池-消毒为主要处理工艺,处理钢铁工业废水并回用,介绍该工艺技术特点、主要构筑物的技术参数以及运行效果。工程监测结果表明,该工艺对总硬度、浊度及COD的去除率分别达到60%、85%及62%以上,出水水质各项指标均达到《城市污水再生利用工业用水水质标准》(GB/T19923-2005)要求。处理系统运行稳定,耐冲击能力强。     

Pathways of soil N2O uptake,consumption, and its driving factors: a review

Environmental Science and Pollution Research - Nitrous oxide (N2O) is an important greenhouse gas that plays a significant role in atmospheric photochemical reactions and contributes to...     

Influence of shrub root combinations and spacing on slope stability: study case at the Yongding River flooding regime,Langfang, China

Environmental Science and Pollution Research - Research on the mechanism of plant root–soil consolidation is a current focus in research into the ecological restoration of banks. The...     

Effects of phosphorus-containing material application on soil cadmium bioavailability: a meta-analysis

Environmental Science and Pollution Research - Diverse phosphorus-containing materials (PCMs) were widely applied in remediation of cadmium-contaminated soils, and their effects on the change of...