CO2 emissions in calcium carbide industry: An analysis of China's mitigation potential

China's calcium carbide output has dominated the global market for several years, driven by the demand for PVC (polyvinyl chloride), a fundamental polymer material and also the primary downstream product of calcium carbide in China. The fast growth of this energy-intensive industry leads to an inevitable increase in CO₂ emissions. However, there is a large reduction potential with process improvement in this industry which is currently characterized by widespread outdated facilities. In this study, we attempt to assess the reduction potential of CO₂ emissions in China's calcium carbide production, based on the analysis of CO₂ emission patterns and estimation of the emission amount. Three scenarios regarding process improvement are employed to conduct this assessment. The results imply that the cumulative CO₂ abatement in the Current Policy Scenario and in the Strengthened Policy Scenario from 2008 to 2020, compared with the Baseline Scenario, are 89.0 and 107.6 million t, respectively. The specific measures and policy implications to achieve this potential are also discussed in the article.     

不同改良措施对煤矸石污染土壤上大豆生长的影响

采用盆栽试验,通过添加粉煤灰和牛粪对煤矸石污染土壤进行改良,并研究了不同改良措施对大豆生长、光合特性和产量的影响。结果表明,添加粉煤灰0.07 kg.kg-1(T1)、添加牛粪0.07 kg.kg-1(T2)、添加粉煤灰和牛粪各0.07 kg.kg-1(T3)3种土壤改良措施对大豆的株高、叶面积和单株根瘤数均有显著影响,不同生育期株高、叶面积和单株根瘤数均表现为T3>T2>T1>CK。在花期和鼓粒期,3种土壤改良措施下大豆的叶绿素含量和光合速率均显著高于对照,且T3处理显著高于T2和T1。与对照相比,不同土壤改良措施对大豆的单株荚数、百粒重、单株粒重和产量均有显著影响,T3、T2和T1处理的大豆产量较对照分别提高68.47%、40.99%和30.63%。     

如何提高层燃工业锅炉热能利用率

通过对影响锅炉热能利用率的各种因素分析,提出提高锅炉热能利用率的综合改进措施。     

Age and gender differences in conviction and crash occurrence subsequent to being directed to Iowa's driver improvement program

Introduction

This paper investigates potential gender and age differences in conviction and crash occurrence subsequent to being directed to attend Iowa's Driver Improvement Program (DIP).

Methods

Binary logit models were developed to investigate the factors that influence conviction occurrence after DIP by gender and age. Because of the low crash occurrence subsequent to DIP, association rules were applied to investigate the factors that influence crash occurrence subsequent to DIP, in lieu of econometric models.

Results

There were statistical significant differences by driver gender, age, and conviction history in the likelihood of subsequent convictions. However, this paper found no association between DIP outcome, crash history, and crash occurrence.

Impact on industry

Evaluating the differences in conviction and crash occurrence subsequent to DIP between female and male drivers, and among different age groups can lead to improvements of the effectiveness of DIPs and help to identify low-cost intervention measures, customized based on drivers’ gender and age, for improving driving behaviors.     

2018～2020年北京市大气PM2.5污染特征及改善原因

利用2018～2020年北京市33个环境评价站和5个区域评价站的空气质量数据,以及气象数据和北京市城区PM_2.5组分数据,研究了3年间北京PM_2.5的浓度演变、时空变化和重污染发生情况,并对PM_2.5组分和气象条件变化进行比较分析.结果发现,3年间北京市ρ(PM_2.5)分别为51、42和38μg·m^-3,2020年的PM_2.5相比2017年下降30.9%,但仍超过国际标准8.6%;北京市PM_2.5空间分布依旧维持南高北低的特征,但南北差异逐年减小,区域浓度趋于均一化;1～3月PM_2.5浓度相对较高,8～9月PM_2.5浓度相对较低,采暖季各污染物浓度均显著高于非采暖季,NO_x和CO分别偏高58.4%和52.9%,PM_2.5偏高27.5%;采暖季和非采暖季PM_2.5日变化出现反向特征,采暖季夜间PM_2.5明显...     

Analysis of the chosen thermal and flammability parameters of dried sewage dust

The hazardous sludge disposal process in the form of landfills requires the determination inter alia of the flammable and explosion properties of dried sewage sludge dust, which has the ability to ignite and spontaneously combust when stored in silos. At a constant furnace surface temperature, the minimum ignition temperature of the sludge dust layer with a layer thickness of 5 mm is 270 °C, and for a layer thickness of 12.5 mm it is 250 °C. Two selected fire extinguishing powders for Class A, B, C and D fires were used in the study to determine the possibility of reducing the susceptibility of dried wastewater to ignition from heated surface, self-ignition and explosion parameters. The most effective extinguishing powder was ABC Favorit, which increased the value of the minimum ignition temperature of the layer (5 mm thick) to 360 °C and the spontaneous ignition temperature of the sludge with this powder increased by 22 °C at 169.6 cm³ in comparison to the sludge without extinguishing powder, respectively. The lowest self-ignition temperature of 136 °C was recorded for the largest tested volume (169.6 cm³) for dried sewage dust without any fire extinguishing powders. The biggest values of p_max and (dp/dt)_max dried sewage dust were recorded 4.8 bar and 113 bar/s respectively. By analysing the obtained test results, it can be assumed that dried sewage dust is a combustible material with properties similar to biomass.     

南京市江宁区地表水断面生态补偿机制研究

经济的高速发展不只是为社会带来了便利,也无形中增加了水资源消耗的速率与水环境污染的负担。自“十三五”以来,为提高断面水环境质量、提升整体水质环境,各省市相继出台了水环境提升、水污染防治以及生态补偿政策。南京市江宁区顺应中央要求并结合自身特点,积极制定并实施了断面生态补偿工作方案,建立了由考核指标、补偿方式、核算方法、补偿标准组成的成套断面生态补偿考核系统。明确了补偿标准机制、补偿责任分配以及补偿资金使用等关键问题。为推进江宁区断面水质达标工作与水环境提升的总体目标奠定了夯实的基础。     

某型液体发动机高空环境局部失效和改进分析

通过对某型液体发动机高空环境下局部产品失效问题进行分析,得出了产品失效原因和形成过程。按照不同的需求,针对性地提出了改进措施,提高了发动机高空环境下工作的可靠性和环境适应性,通过实际飞行试验予以验证。     

膜法处理垃圾渗滤液新技术实验研究

将改进间歇式活性污泥法与FIL-MAX膜组合处理工艺相结合,应用于沈阳某垃圾场垃圾渗滤液处理工程实例中。通过实验,分析了COD、NH3-N等指标的处理效率以及影响因素,最终得出改进间歇式活性污泥法与FIL-MAX组合工艺处理在一定程度上改善膜污染、膜堵塞等常见问题。     

基于油水分离的餐饮废水破乳化技术研究

餐饮废水中乳化油的分离处理一直是一个技术难题,文章分别采用物理机械方法和物理化学方法对餐饮废水进行了破乳化研究。通过对比试验结果和分析破乳机理,总结出各方法不同的破乳特点。结果表明,温度越高分离效果越好,但在实际应用中,保持在50～60℃即可。低功率的超声波可以促进破乳效果,但超过30W,又会使溶液发生乳化反应。小分子醇类的加量越多,破乳化作用越强;醇类单链越长,分离效果越好。加入无机盐,在一定程度上可以加快破乳化速度,但效果并不明显。