聚硫氯化铝和硫酸铝混凝剂使用效果的对比性研究

本文对新型净水剂——聚硫氯化铝和传统的硫酸铝混凝剂的净水效果进行对比研究。聚硫氯化铝在冬季低水温,高氨氮的原水情况下,不仅提高了出厂水水质,而且节省制水成本.并且简化了生产工艺的操作控制,值得推广。     

硫自养反硝化中亚硝酸盐积累的研究现状与展望

以硫化物为基质的硫自养反硝化耦合厌氧氨氧化技术不但能除硫,还可以在硫循环的条件下实现高效脱氮.为实现该技术需要将硫自养反硝化过程控制在亚硝化阶段,随后进行以亚硝酸盐为电子受体的厌氧氨氧化反应.其关键在于如何实现亚硝酸盐的积累.文中介绍了硫自养反硝化的反应机理以及如何对影响亚硝酸盐,积累的因素进行精准调控,探讨了厌氧氨氧化-自养反硝化技术的主要途径.     

氧化脱硫醇尾气净化技术的工业应用

青岛石化氧化脱硫醇尾气由直接进硫磺焚烧炉燃烧处理,改造为先采用"柴油低温临界吸收-碱液脱硫"技术处理后再进焚烧炉燃烧。"柴油低温临界吸收-碱液脱硫"技术对尾气中油气的回收率高达98%,对硫化氢和有机硫化物的去除率达99%以上。净化气进一步在焚烧炉中深度净化,排放烟气中烃的排放浓度可小于50 mg/m3。同时,尾气处理工艺经过改造后,硫磺焚烧炉排放烟气中SO2排放量和排放浓度也大大降低,为进一步降低硫磺焚烧炉排放烟气中SO2排放浓度奠定了基础。     

含硫油品储罐自燃灾源温度场的数值模拟

目前在役储罐的温度场难以准确的描述,对安全作业造成隐患。基于国内外储罐自燃机理研究,建立了含自燃灾源的储罐物理模型和数学模型,利用ANSYS有限元平台分析了自燃灾源、保温层厚度、环境温度及空气对流系数对含硫油品储罐温度场的影响.数值模拟结果表明,随着自燃灾源的持续氧化,外壁温度场异常区域逐渐明显;增加保温层厚度,外壁异常区域温差减小的趋势由大变小,当厚度达到30mm时,最大温差降至0.4℃;升高环境温度,外壁异常区域温差均匀降低,当环境温度达到35℃时,外壁温度基本趋于环境温度;增加空气对流系数,外壁异常区域温差快速减小,当空气对流系数达到100W/(m·℃)时,外壁温度接近环境温度,且外壁温差基本趋于一致.     

Demonstration of the environmental and demand-side management benefits of grid-connected photovoltaic power systems

This study investigated the pollutant emission reduction and demand-side management potential of 16 photovoltaic (PV) systems installed across the US during 1993 and 1994. The US Environmental Protection Agency (EPA) and 11 electric power companies sponsored the project. This article presents results of analyses of each PV system's ability to offset power plant emissions of sulfur dioxide (SO₂), nitrogen oxides (NO_x), carbon dioxide (CO₂) and particulates and to provide power during peak demand hours for the individual host buildings and peak load hours for the utility. The analyses indicate a very broad range in the systems' abilities to offset pollutant emissions, due to variation in the solar resource available and the emission rates of the participating utilities' load following generation plants. Each system's ability to reduce building peak demand was dependent on the correlation of that load to the available solar resource. Most systems operated in excess of 50% of their capacity during building peak load hours in the summer months, but well below that level during winter peak hours. Similarly, many systems operated above 50% of their capacity during utility peak load hours in the summer months, but at a very low level during winter peak hours.     

Trace sulfur promoted Fe,N-codoped carbon black as electrocatalyst for oxygen reduction reaction

Doping carbon materials with Fe and N attracts great attention due to its promising application in preparing ORR electrode with high performance and low cost. Previously, Fe, N-codoped catalyst (Fe/N/C) had been synthesized via a simple one-pot method using carbon materials, dopamine and FeCl₃ by our group. However, the unstable activity and low selectivity (electron transfer number of ∼3.5) are key problems that should be solved. Herein, trace sulfur has been introduced into Fe, N-codoped carbon black by using 2-mercaptoethanol as an adhesive sulfur precursor. By the doping of trace S atoms (∼0.25 at%) into Fe, N-codoped carbon frameworks, the ORR performance has been obviously improved simply without any re-treatment process, such as acid-etching or nitrogen supplement. The mechanism of this process has been systematically investigated by changing the amount of initial sulfur precursor. A moderate amount of trace sulfur can effectively enhance the ORR performance of Fe, N-codoped carbon black due to suitable interactions among Fe, N, S and C elements. Both the content and the state of Fe and N species on the surface of carbon black can be changed and controlled by trace sulfur. The as-synthesized 1.0 SFe/N/C catalyst exhibits a good ORR activity (E_1/2 = 0.749 V, J_k = 54.56 mA cm⁻²) and a total 4-electron selectivity. 1.0 SFe/N/C also shows better catalytic stability and methanol tolerance than 20 wt% Pt/C.     

Sulfur capture for fluidized-bed combustion of high-sulfur content lignites

Sulfur release and capture behavior of lignites with highly combustible sulfur-contents were investigated by extending a previously-developed comprehensive model to incorporate sulfur retention. The predictive performance of the model was tested by comparing the model predictions with on-line concentration measurements of O₂, CO₂, CO and SO₂. Favorable comparisons are obtained between the predicted and measured concentrations of gaseous species along the combustor. Results show that freeboard sulfur-capture is enhanced significantly with recycling of elutriated sorbent particles as the sulfur release to the freeboard is significant for fuels rich in combustible sulfur.     

Defect reduction in electrochemically deposited CdS thin films by annealing in 02

Using the electrochemical deposition method, CdS thin films were deposited from acid solutions (pH = 2.5) containing CdS0₄ and Na₂S₂0₃ on indium-oxide coated glass substrates. These films were annealed in N₂, air, or O₂ atmosphere at 200–500°C for 30 min. Photoluminescence spectra were measured at 77 K. For the films annealed in N₂, the band edge emission became weaker and the luminescence due to defects shifted to longer wavelengths as the annealing temperature was raised above 300°C. However, for the films annealed in air or O₂, the band edge emission was observed strongly irrespective of the annealing temperature and the luminescence due to defects was weak. Thus the O₂ annealing is useful for the defects reduction.