Factors affecting the direct mineralization of CO2 with olivine

Olivine, one of the most abundant minerals existing in nature, is explored as a CO2 carbonation agent for direct carbonation of CO2 in flue gas. Olivine based CO2 capture is thermodynamically favorable and can form a stable carbonate for long-term storage. Experimental results have shown that water vapor plays an important role in improving CO2 carbonation rate and capacities. Other operation conditions including reaction temperature, initial CO2 concentration, residence time corresponding to the flow rate of CO2 gas stream, and water vapor concentration also considerably affect the performance of the technology.     

Silver impregnated carbon for adsorption and desorption of elemental mercury vapors

The Hg0 vapor adsorption experimental results on a novel sorbent obtained by impregnating a commercially available activated carbon (Darco G60 from BDH) with silver nitrate were reported. The study was performed by using a fundamental approach, in an apparatus at laboratory scale in which a synthetic flue gas, formed by Hg0 vapors in a nitrogen gas stream, at a given temperature and mercury concentration, was flowed through a fixed bed of adsorbent material. Breakthrough curves and adsorption isotherms were obtained for bed temperatures of 90, 120 and 150°C and for Hg0 concentrations in the gas varying in the range of 0.8–5.0 mg/m3. The experimental gas-solid equilibrium data were used to evaluate the Langmuir parameters and the heat of adsorption. The experimental results showed that silver impregnated carbon was very effective to capture elemental mercury and the amount of mercury adsorbed by the carbon decreased as the bed temperature increased. In addition, to evaluate the possibility of adsorbent recovery, desorption was also studied. Desorption runs showed that both the adsorbing material and the mercury could be easily recovered, since at the end of desorption the residue on solid was almost negligible. The material balance on mercury and the constitutive equations of the adsorption phenomenon were integrated, leading to the evaluation of only one kinetic parameter which fits well both the experimentally determined breakthrough and desorption curves.     

有机质对土壤气相抽提去除四氯化碳效率的影响

某重要岩溶地下水源地因附近农药厂排放含四氯化碳污水而受到严重污染,实验采用土柱通风试验模拟土壤气相抽提(SVE),研究环境温度为20℃,通风速率为40mL/min,土壤含水率10%,而土壤有机质含量分别为3.02%和0.13%条件下的两种供试土壤中四氯化碳污染物的去除过程.结果表明,土柱通风能有效去除土壤中的四氯化碳污...     

车辆非尾气管颗粒物排放特征研究

车辆尾气排放控制技术和排放标准在近年来得到了快速发展,但非尾气管(non-exhaust)排放却很少涉及.非尾气管排放主要包括车辆制动磨损、轮胎磨损、路面磨损和车辆扬尘,本研究调查了北京典型道路车流量和车辆运行速度等参数,应用欧盟非尾气管排放因子分析车辆制动磨损、轮胎磨损和路面磨损PM10排放.结果显示:不同类型道路的...     

电厂二氧化碳捕捉技术对比研究

由于全球温室效应的不断加剧,发展二氧化碳捕捉技术变得十分必要.通过分析燃烧前捕捉、燃烧后捕捉和富氧燃烧捕捉三种二氧化碳捕捉方式流程及其特点,指出三种不同的二氧化碳捕捉技术的发展现状以及应用途径.通过具体对比现有二氧化碳捕捉技术的工作原理以及优缺点,针对现有的几种具体的二氧化碳捕捉技术进行详细的分析,积极应用各种物理、化...     

福建省能源消费碳排放和低碳能源发展研究

能源消费导致的碳排放对全球气候变化带来严峻挑战.区域经济迅速发展,不但对区域能源安全提出挑战,也对碳减排提出新的课题.文章总结了改革开放以来福建省能源消费的特点和趋势,计算由能源消费引起的碳排放量.研究表明,虽然碳强度有显著下降,但是碳排放总量增长比较明显,特别是从2000年开始,增长幅度加大.利用Kaya恒等式对碳排...     

淀山湖沉积物碳-氮垂直分布特征

近年来,经过一系列污染治理措施,淀山湖的营养水平持续下降,但每年仍有不同程度的蓝藻水华暴发,严重影响其作为水源地的安全性。为了进一步探讨淀山湖水质改善策略,本研究对淀山湖沉积物营养状况进行了调查研究,分析了淀山湖沉积物碳、氮分布特征及垂直变化规律,并用沉积物肥力评价了淀山湖沉积物营养程度。结果表明,淀山湖沉积物营养盐存在明显的富集作用,二十多年来沉积物碳、氮含量大幅上升,表层沉积物均属于重污染状态。空间分布上,沉积物营养盐北部高,南部低,北部样点大部分属于重污染状态,南部样点基本属于中污染状态。垂直分布上,受航道回淤与北部围网养殖影响,部分样点营养盐垂直分布规律不显著,其他样点均表现出随深度增加营养盐显著降低的趋势。除出水口D1样点外,淀山湖有机质与TN表现出显著的同源相关性,表明有机质是淀山湖内源负荷的主要来源。     

美国氮氧化物排放交易经验及启示

综述了美国氮氧化物排放交易项目的演进过程,总结其实践经验,并探讨美国经验对中国氮氧化物排放控制的借鉴意义。     

县级城市人居环境主客观指标体系与评价模型对比研究

本文对人居环境相关研究进行了阐述,并就城市人居环境指标体系与评价模型进行了分析研究。提出了人居环境质量主客观评价结合模型,其中指标体系包括四个一级指标和18个单项指标,并依据我国黄河三角洲高效经济区内14个县级城市2007年的调查统计资料,对人居环境客观建设水平和居民满意度进行了对比评价。运用因子分析法处理指标数据,问卷调查的方法进行满意度评价。评价结果科学可行,并揭示出影响县级城市人居环境的根本因素。     

Inhibitory effects of nisin-coated multi-walled carbon nanotube sheet on biofilm formation from Bacillus anthracis spores

Multi-walled carbon nanotube（MWCNT） sheet was fabricated from a drawable MWCNT forest and then deposited on poly（methyl methacrylate） film. The film was further coated with a natural antimicrobial peptide nisin. We studied the effects of nisin coating on the attachment of Bacillus anthracis spores, the germination of attached spores, and the subsequent biofilm formation from attached spores. It was found that the strong adsorptivity and the super hydrophobicity of MWCNTs provided an ideal platform for nisin coating. Nisin coating on MWCNT sheets decreased surface hydrophobicity, reduced spore attachment, and reduced the germination of attached spores by 3.5 fold, and further inhibited the subsequent biofilm formation by 94.6% compared to that on uncoated MWCNT sheet. Nisin also changed the morphology of vegetative cells in the formed biofilm.The results of this study demonstrated that the anti-adhesion and antimicrobial effect of nisin in combination with the physical properties of carbon nanotubes had the potential in producing effective anti-biofilm formation surfaces.