脉冲电晕放电治理有机废气的研究--放电反应器结构

对脉冲电晕法治理甲苯有机废气进行了实验,考察了放电反应器结构及参数对其性能的影响.结果表明,对线-筒式反应器,当直径较小时,去除率较高,但易发生火花放电,实验条件下直径20mm的反应器效果较好.若采用陶瓷管反应器,其效果较金属管明显提高,脉冲峰值电压Vp为42kV时,可使甲苯的去除率由40%提高到61%左右.对线-板式反应器,放电间隙越大,甲苯的去除率越低,使用陶瓷板反应器可使甲苯去除率明显提高.     

脉冲电晕放电治疗有机废气的研究—放电反应器结构

对脉冲电晕法治理甲苯有机废气进行了实验，考察了放电反应器结构及参数对其性能的影响。结果表明，对线－筒式反应器，当直径较小时，去除率较高，但易发生火花放电，实验条件下直径２０ｍｍ的反应器效果较好。若采用陶瓷管反应器，其效果较金属管明显提高，脉冲峰值电压Ｖｐ为４２ｋＶ时，可使甲苯的去除率由４０％提高到６１％左右。对线－板式反应器，放电间隙越大，甲苯的去除率越低，使用陶瓷板反应器可使甲苯去除率明显提高，     

Synthesis, characterization and experimental investigation of Cu-BTC as CO2 adsorbent from flue gas

Porous Cu-BTC material was synthesized by the solvothermal method. Powder X-ray diffraction (PXRD) was used to test the phase purity of the synthesized material and investigate its structural stability under the influence of flue gas components. The thermal stability of the material was determined through thermal gravimetric (TG) analysis. Scanning electron microscopy (SEM) was employed to study the microstructure of the material. Cu-BTC was demonstrated not only to have high CO₂ adsorption capacity but also good selectivity of CO₂ over N₂ by means of packed bed tests. The adsorption capacity of Cu-BTC for CO₂ was about 69 mL/g at 22°C. The influence of the main flue gas components on the CO₂ capacity of the material were discussed as well.     

Chemical characteristics of fine particulate matter emitted from commercial cooking

The chemical characteristics of fine particulate matter (PM_2.5) emitted from commercial cooking were explored in this study. Three typical commercial restaurants in Shanghai, i.e., a Shanghai-style one (SHS), a Sichuan-style one (SCS) and an Italian-style one (ITS), were selected to conduct PM_2.5 sampling. Particulate organic matter (POM) was found to be the predominant contributor to cooking-related PM_2.5 mass in all the tested restaurants, with a proportion of 69.1% to 77.1%. Specifically, 80 trace organic compounds were identified and quantified by gas chromatography/mass spectrometry (GC/MS), which accounted for 3.8%–6.5% of the total PM_2.5 mass. Among the quantified organic compounds, unsaturated fatty acids had the highest concentration, followed by saturated fatty acids. Comparatively, the impacts of other kinds of organic compounds were much smaller. Oleic acid was the most abundant single species in both SCS and ITS. However, in the case of SHS, linoleic acid was the richest one. ITS produced a much larger mass fraction of most organic species in POM than the two Chinese cooking styles except for monosaccharide anhydrides and sterols. The results of this study could be utilized to explore the contribution of cooking emissions to PM_2.5 pollution and to develop the emission inventory of PM_2.5 from cooking, which could then help the policymakers design efficient treatment measures and control strategies on cooking emissions in the future.     

过渡金属元素掺杂改性SCR对零价汞的催化氧化性能

为提高商用SCR催化剂对Hg0(零价汞)的催化氧化活性,研究了过渡金属对其进行掺杂改性的方法,并利用固定床反应平台考察了不同试验条件下改性催化剂对Hg0的氧化效率. 结果表明:Y、Zn、Ni和Zr等过渡金属的掺杂可明显抑制SCR催化剂的催化活性,而Fe、Cu掺杂改性SCR催化剂对Hg0的催化氧化性能有显著提升. 在反应温度为350 ℃、空速比为370 000 h-1、φ(HCl)为1×10-5的条件下,Fe、Cu掺杂改性的SCR催化剂对Hg0的氧化效率均能达到90%以上,并且Fe掺杂改性后的SCR催化剂的脱硝性能也未受到明显影响. 借助XRD和XPS等表征手段,对反应前后Fe掺杂改性SCR催化剂进行了研究,表明Fe改性SCR催化剂遵循Mars-Maessen和Langmuir-Hinshelwood机制,可明显提高对Hg0的催化氧化效率,因此,应用前景较好.      

湿法脱硫浆液中石膏与汞的结合特性模拟研究

燃煤烟气湿法脱硫石膏中汞的大量富集限制了其应用范围且容易产生汞的二次逃逸问题.因此,本文对脱硫浆液中的汞在固相石膏的迁移转化规律进行了模拟研究,考察了不同操作条件和离子浓度的影响,探求汞进入石膏的量和形态的变化趋势.同时考察了温度、p H、石膏老化时间和结晶方式等对汞与石膏结合特性的影响,并对机理进行了探讨.结果表明,当液相汞浓度从0.16 mg·L-1增加到2.67 mg·L-1时,进入石膏的汞含量相应从0.38 mg·kg-1增加到4.17 mg·kg-1,但其占液相总汞的比例却呈先下降后不变的趋势.当石膏浆液浓度从1%增加到20%时,由液相进入石膏中的汞比例不断上升,但石膏汞含量却不断下降.基于实验结果推测汞与石膏结合的两种方式:石膏的内部包裹作用和石膏的表面吸附作用.另外,酸根离子浓度会改变浆液中游离汞的含量,从而影响石膏中汞的富集量:Cl-和NO-3对汞进入石膏有抑制作用,而SO2-4的存在会起到促进作用;铁、铝阳离子的存在会促进汞进入石膏,钙、镁阳离子对汞的富集基本无影响.     

玻璃减薄蚀刻液中氟硅酸的选择性脱除方法

光电玻璃减薄蚀刻液中氟硅酸(H2SiF6)的累积,是导致蚀刻液无法连续使用而转化为废液的主要原因。尝试对蚀刻废液中氟硅酸进行选择性脱除工艺,探索刻蚀液循环利用的有效处理方法。鉴于氟硅酸的碱金属盐具有溶解度较低的特点,研究考察了利用钠盐或钾盐为沉淀剂,将废液中的H2SiF6以氟硅酸盐的形式沉淀去除,为实现蚀刻液的循环利用提供可能。结果表明,KCl相比NaCl对H2SiF6处理效果更好,但生成的K2SiF6的结晶颗粒过细,难以自然沉降,过滤效果较差;而Na2SiF6结晶沉降特性较好,且使用NaCl为沉淀剂具有价廉易得等特点,可作为氟硅酸的理想沉淀剂。H2SiF6去除率与碱金属盐H2SiF6摩尔计量比正相关,当摩尔计量比NaCl/H2SiF6=2,H2SiF6含量10%的模拟废液,其H2SiF6去除率可达到90%以上。     

零价汞在MnOx/α-Al2O3-氯气体系中的催化氧化

为强化烟气中零价汞向二价汞的转化,利用模拟含汞烟气研究了以MnOx/α-Al2O3作为催化剂、利用氯气作为氧化剂催化氧化零价汞的方法.着重考察了氯气浓度、温度、空速和SO2对催化氧化零价汞性能的影响,并与HCl作为氧化剂的结果进行了对比.同时,对催化剂进行表征,探讨了催化剂表面吸附态汞的形态.研究结果表明,Cl2较HCl更易活化且活性温度区间更广,在100～300℃范围内,Cl2体积分数为2.0×10-6时的催化氧化效率即可达80%以上;在1.6×104-6.4×104 h-1空速范围内,零价汞氧化率保持在90%以上.空速继续提高到1.92×105h-1时,零价汞氧化率呈现线性下降趋势;烟气中的SO2与Cl2:反应会消耗Cl2,Cl2体积分数低时对催化氧化反应抑制作用显著,但Cl2体积分数增至5.0×10-6时对催化氧化反应的抑制效果较弱,仅为10%左右.     

Enhanced simultaneous absorption of NOx and SO2 in oxidation-reduction-absorption process with a compounded system based on Na2SO3

Oxidation of sulfite and competitive absorption existed in Na₂SO₃ solution for simultaneous removal of NO_x and SO₂, inhibited the long-term high-efficiency when used for practical applications. A matching strategy was developed to solve these problems. Antioxidants combination was used to retard the oxidation of antioxidant and enhance inhibition of S（IV）(tetravalent sulfur) oxidation. Hydroquinone（HQ） and sodium thiosulfate（ST） showed a positive syner...