AGC公司100DID对羰基硫的分析应用

对于羰基硫的分析,使用AGC公司100DID色谱仪来分析COS中H_2、O_2/Ar、N_2、CH_4、CO、CO_2等杂质。     

舰船大空间舱室水幕防火分隔的数值模拟

建立了舰船大空间舱室模型,设置了6种工况,对不同喷头间距和喷头排数下的水幕的防火分隔效果进行了数值模拟,得到了舱室内温度、遮光率、O_2浓度、CO_2浓度及CO浓度。结果表明水幕能够有效阻止火灾蔓延,降温控温,延缓烟气蔓延和O_2的消耗,减少CO_2、CO等气体浓度,随着水幕喷头间距的减小和喷头排数的增多,这些效果会更加明显,但到了一定程度增加作用会变得很小,因此喷头间距和排数等参数存在一个合适的范围,进行水幕系统设计时需综合考虑和具体对待。     

脱除CO2的膜吸收过程研究

研究了用中空纤维膜组件脱除CO2的吸收过程,制备了一系列不同装填率的中空纤维膜组件．用这些膜组件进行实验,以不同浓度的单乙醇胺（MEA）溶液为吸收剂,研究了气液两相的流量和浓度、组件的装填率、吸收剂的循环使用等因素对CO2膜吸收过程的影响．实验结果表明：气、液相流量的增大和液相MEA浓度的增加都可使CO2的传质通量增大;气相CO2浓度的增加会使总传质系数减小;在组件进口气液流量和浓度相同的条件下,组件装填率（0．5％～21％）的变大有利于CO2的脱除;随着吸收液循环次数的增加,CO2的传质通量和其脱除率都会降低．     

复合盐类侵蚀对硅酸盐水泥固化氯离子影响研究

研究了硫酸盐、碳酸盐和硝酸盐与氯盐复合侵蚀下硅酸盐水泥固化氯离子性能,采用水溶法测定了水泥净浆中自由氯离子含量并计算得出其氯离子固化率,对试样进行了XRD物相分析以及其水溶液的pH值测定。结果表明,水泥浆体的氯离子固化率随水化龄期的增长而增加;随氯离子浓度增大,水泥浆体中F盐的生成量增加,其氯离子固化率先增大后减小。随硫酸盐和碳酸盐浓度增大,水泥浆体的氯离子固化率均降低,硫酸盐的降低程度稍微比碳酸盐大。硫酸盐和碳酸盐通过结合AFm分别生成钙矾石(3CaO·Al_2O_3·3CaSO_4·31H_2O)和单碳硫铝酸钙(3CaO·Al_2O_3·CaCO_3·12H_2O)提高了水泥浆体的pH值,减少了F盐的生成量。硝酸盐对水泥浆体的氯离子固化率和F盐的生成没有影响。     

防护工程非火源房间火灾烟气特性研究

为讨论防护工程火灾时非火源房间内烟气特性,根据相似原理搭建了模型与实体比例为1:4的单室-走廊-单室模型实验台,进行了2个工况的模型实验,对比研究分析了烟气扩散室内和门口走廊中烟气温度、CO浓度、CO_2浓度及O_2浓度等烟气特性。结果表明,火灾发展阶段,扩散室内的烟气温度比门外走廊处低,烟气中CO、CO_2和O_2对人体的危害性比走廊处小,烟气温度和浓度变化滞后于走廊;火灾充分发展阶段烟气扩散室中烟气温度和浓度与走廊中几乎相同。火灾时,远火源端单室中烟气危害更大。     

不同氧组分气调对黄冠梨品质及酶活性的影响

目的研究不同气调处理对黄冠梨贮藏品质和相关酶活性的影响,以筛选出较优的气调贮藏条件。方法研究以黄冠梨为实验材料,在温度为(0±1)℃、相对湿度为90%～95%条件下,采用3种不同的O_2组分气调处理(O_2(1%～2%)+CO_2(1%～2%),O_2(3%～4%)+CO_2(1%～2%),O_2(5%～6%)+CO_2(1%～2%)),观察梨果品质和酶活性的变化情况。结果与对照组相比,3种不同O_2和CO_2组合的气调贮藏均降低了黄冠梨的褐变率、呼吸强度和乙烯释放量,保持了较高的好果率和果皮色泽,抑制了果实的软化和果心PPO酶活性的下降,保持了较高的CAT酶活性,从而抑制了梨果褐变。尤其处理组2(O_2(3%～4%)+CO_2(1%～2%))的效果最为显著。结论气调贮藏保持了黄冠梨较高的贮藏品质,抑制了果实褐变,处理组2(O_2(3%～4%)+CO_2(1%～2%))是黄冠梨的最优气调组合。     

固体超强酸与蒙脱土改性聚磷酸铵协同阻燃环氧树脂

将固体超强酸(SO_4~(2-)-M_XO_Y)与蒙脱土改性聚磷酸铵(AM)进行复配,协同阻燃环氧树脂(EP)。通过热重分析(TGA)、极限氧指数(LOI)和锥形量热(CCT)研究3种SO_4~(2-)-M_XO_Y(SO_4~(2-)-Fe_2O_3,SO_4~(2-)-ZrO_2和SO_4~(2-)-TiO_2)对EP热性能和阻燃性能的影响。结果表明,与EP/AM相比,加入固体超强酸后,样品的初始分解温度、最大失重率温度和燃烧热释放降低;LOI值和TG残碳率升高。说明SO_4~(2-)-M_XO_Y加强了AM作为膨胀阻燃剂酸源的催化能力,促进EP/AM的分解、脱水和成炭,SO_4~(2-)-M_XO_Y与AM之间存在阻燃协同作用。其中EP/AM/(SO_4~(2-)-TiO_2)的残炭量(26.22%)最高,LOI值(28.4%)最大,热释放速率峰值(PHRR)、总热释放量(THR)、CO产率和CO_2产率也最低,而且其防火性能指数比EP/AM提高了56%,火灾蔓延指数降低了44%,且扫描电镜表明EP/AM/(SO_4~(2-)-TiO_2)的残炭结构也更连续和致密,有效地阻止了气体交换和热量传递。     

某特种车辆海上闭舱行驶时舱室内有害气体的测试分析

目的通过对某特种车辆三次海上闭舱2 h行驶时舱室内无机类有害气体(CO、CO_2、NO_2、NH_3、H_2S、SO_2)的测试,结果与国军标对比分析,判断其是否能够满足国军标的限值要求,并探讨对有害气体测试结果影响因素。方法某特种车辆2 h海上闭舱作业过程中,运用有害气体连续自动测试记录仪分别对舱室内三个位置的有害气体进行测试分析,按照GJB5834-2006规定的有害气体限值的计算方法计算其MAC(最高容许浓度)、TWA(时间加权平均容许浓度)以及STEL(短时间接触容许浓度),并进行对比分析。结果在对特种车辆的三次测试结果中,驾驶员位的CO、CO_2、NO_2、SO_2与载员舱左前位的CO、CO_2、NO_2、SO_2以及载员舱右后位的CO、CO_2、NO_2出现了不符合标准限值的要求。结论通过与GJB5834-2006规定的有害气体限值对比,本次所测结果中部分有害气体浓度不符合标准限值的要求。特种车辆海上闭舱行驶时舱室内有害气体测试结果的影响因素主要有发动机尾气的渗漏、行驶速度、以及闭舱时间。     

火源位置对防护工程火灾烟气扩散影响研究

为讨论火源位置对防护工程火灾时走廊内烟气扩散的影响,根据相似原理搭建了模型与实体比例为1:4的单室-走廊模型实验台,进行了2个工况的模型实验,分析了走廊内烟气温度分布,研究了火灾分别位于走廊和单室时走廊内烟气温度、CO浓度、CO_2浓度及O_2浓度等烟气特性。结果表明,火源位于走廊时,走廊内烟气最高温度、平均温度及烟气温度变化速率均大于火源位于单室时,火源位于走廊时走廊内CO浓度、CO_2浓度及O_2浓度与火源位于单室相比对人员也更不利,应避免在工程的走廊内放置易燃、可燃物品,尤其是高热值物品。     

程序升温热脱附法表征SmMnO_3及SmFeO_3的表面

本文用程序升温热脱附谱(TDS)及程序升温表面反应谱(TPRS),研究了SmMnO_3及SmFeO_3表面上CO与O_2的吸附与反应。实验表明,在SmMnO_3表面上,室温时就存在能与CO反应生成CO_2的氧物种,而对SmFeO_3来说,在温度为620K以前检测不到能与CO反应生化CO_2的氧物种。当CO与O_2先后吸附于SmMnO_3及SmFeO_3表面,则它们的TPRS都出现CO_2,但两者仍有区别。对SmMnO_2在室温以上的TPRS谱都有两个CO_2脱附峰,而对SmFeO_3则只有在较高温度吸附时才出现CO_2的第二个峰,且第二个峰的峰高在333K与451K间有一个极大值,表明在SmFeO_3上O_2在第二吸附中心的吸附是一个活化吸附过程。     

Reaction characteristics of Ca(OH)2, HCl and SO2 at low temperature in a spray dryer integrated with a fabric filter

The objective of this research was to evaluate the reaction characteristics of CaOH2, HCl and SO2 in the flue gas emitted by a laboratory incinerator. The amount of sulfur retained in the residues (including the spray dryer ash and baghouse ash) was also evaluated in this study. The experimental parameters included HCl concentration (500-2000 ppm), SO2 concentration (500-2000 ppm), relative humidity (40-80% RH), and the addition of CaCl2 (30 wt.%).The results indicated that an HCl concentration of 500-2000 ppm did not affect HCl removal efficiency in the spray dryer at 150 degrees C and 45+/-5% RH. On the other hand, increase in SO2 concentration from 500 to 2000 ppm enhanced SO2 removal at 150 degrees C and 75+/-5% RH. Moreover, increase in removal efficiency of SO2 was more obvious when the relative humidity was greater than 80%. When the flue gas contained both HCl and SO2 simultaneously, the removal efficiency of SO2 could increase from 56.7 to 90.33% at HCl concentration of 236 ppm. However, when the concentration of HCl exceeded 535 ppm, the removal efficiency of SO2 decreased with increasing concentration of HCl. The removal efficiency of SO2 could be increase to 97.7% with the addition of CaCl2.     

Biological pre-treatment of wastewater containing sulfate using anaerobic immobilized cells

Biological reduction of sulfate to sulfide using sulfate reducing bacteria (SRB) was investigated. A respirometer was used to study the sulfide toxicity in the systems fed glucose, the results showed that sulfide would start to inhibit methanogens when the dissolved sulfide and total sulfide concentrations were 276.4 and 304.6 mg/L, respectively. When chemostats were used to study the Monod kinetic coefficients, Y, kd, Ks, and k were 0.36 mg VSS (volatile suspended solids) using SRB/mg SO4-S, 0.05/day, 147.30 mg SO4-S/L, and 6.50 mg SO4-S/mg VSS using SRB-d, respectively. Using pure cultural techniques, SRB were found to be 29.45% of the VSS in the chemostats. Sulfate removal using an upflow anaerobic filter packed with immobilized cells was also investigated. Under sulfate loading rates of 0.2 and 0.4 g SO4-S/L day, and a hydraulic retention time (HRT) of 2 days, a sulfate removal efficiency greater than 93% could be achieved. When the filter was operated under COD (chemical oxygen demand)/S from 10/1 to 5/1 and HRTs of 2, 1 and 0.5 days, sulfate removal efficiency was between 98.1 and 70.9%. It is believed that protection by the immobilized cell structure caused the microbial cells in the filter to tolerate higher dissolved sulfide (447.8 mg/L) and total sulfide (940.3 mg/L) levels, allowing a much higher biomass concentration (13.2-13.5 g VSS/L) to be reached.     

热处理活性半焦的表面性质和SO2脱除活性

前驱体和表面改性过程都影响着活性半焦脱除SO2的活性.在氮气中、800℃下对原料半焦进行热处理,并在固定床反应器上测试了其脱除SO2的活性.利用酸碱滴定、工业分析和元素分析、X-射线光电子能谱(XPS)、傅立叶转换红外光谱(FTIR)等表征原料半焦和活性半焦表面化学性质.结果表明:石墨碳是原料半焦和活性半焦样品表面的主要碳功能团.表面C=O基团(酮、内酯、羰和醌类中)和吡咯-N分别是原料半焦表面的氧、氮功能团.热处理导致半焦表面含氧基团分解、表面含氧和含氮基团分布改变、表面C=O基团(酮、内酯、羰和醌类中)明显下降;而化学吸附氧和水增加,吡咯-N变成类吡啶结构.醚类和π - π* 离域基团的增加提高了活性半焦表面的碱性.热处理提高了活性半焦脱除SO2的活性.影响SO2脱除活性的表面基团可能是具有碱性性质的醚类、π - π* 离域及含氮基团.     

Simultaneous removal of SO2 and NO by wet scrubbing using aqueous chlorine dioxide solution

The present study attempts to generate chlorine dioxide (ClO(2)) gas continuously by chlorate-chloride process and to utilize it further to clean up SO(2) and NO(x) gases simultaneously from the flue gas in the lab-scale bubbling reactor. Experiments were carried out to examine the effect of various operating parameters like input SO(2) concentration, input NO concentration, pH of the reaction medium, and ClO(2) feeding rate on the SO(2) and NO(x) removal efficiencies at 45 degrees C. Complete oxidation of NO into NO(2) occurred on passing sufficient ClO(2) gas into the scrubbing solution. SO(2) removal efficiency of about 100% and NO(x) removal efficiency of 66-72% were achieved under optimized conditions. NO(x) removal efficiency decreased slightly with increasing pH and NO concentration. Input SO(2) concentration had marginal catalytic effect on NO(2) absorption. No improvement in the NO(x) removal efficiency was observed on passing excess of chlorine dioxide in the scrubbing solution.     

Adsorption of dimethyl sulfide from aqueous solution by a cost-effective bamboo charcoal

The adsorption of dimethyl sulfide from an aqueous solution by a cost-effective bamboo charcoal from Dendrocalamus was studied in comparison with other carbon adsorbents. The bamboo charcoal exhibited superior adsorption on dimethyl sulfide compared with powdered activated carbons at different adsorbent dosages. The adsorption characteristics of dimethyl sulfide onto bamboo charcoal were investigated under varying experimental conditions such as particle size, contact time, initial concentration and adsorbent dosage. The dimethyl sulfide removal was enhanced from 31 to 63% as the particle size was decreased from 24-40 to >300 mesh for the bamboo charcoal. The removal efficiency increased with increasing the adsorbent dosage from 0.5 to 10mg, and reached 70% removal efficiency at 10mg adsorbed. The adsorption capacity (μg/g) increased with increasing concentration of dimethyl sulfide while the removal efficiency decreased. The adsorption process conforms well to a pseudo-second-order kinetics model. The adsorption of dimethyl sulfide is more appropriately described by the Freundlich isotherm (R(2), 0.9926) than by the Langmuir isotherm (R(2), 0.8685). Bamboo charcoal was characterized by various analytical methods to understand the adsorption mechanism. Bamboo charcoal is abundant in acidic and alcohol functional groups normally not observed in PAC. A distinct difference is that the superior mineral composition of Fe (0.4 wt%) and Mn (0.6 wt%) was detected in bamboo charcoal-elements not found in PAC. Acidic functional group and specific adsorption sites would be responsible for the strong adsorption of dimethyl sulfide onto bamboo charcoal of Dendrocalamus origin.     

The photocatalytic degradation of trichloroethane by chemical vapor deposition method prepared titanium dioxide catalyst

The purpose of the investigation was to study the photocatalytic reaction of trichloroethane using a TiO(2) catalyst deposited in an annular reactor by the chemical vapor deposition (CVD) method. The experimental results indicated the highest decomposition rate of the trichloroethane was 2.71 micro mol/(sm(2)) and the conversion ratio reached a maximum of 99.9%. When the humidity was below 154 micro M, the reaction rate slightly increased with increasing humidity. However, the reaction rate decreased as the humidity increased >154 micro M. Oxygen played a role as an electron acceptor in the reaction, and reduced the recombination of the photogenerated electron-hole pairs. Therefore, the reaction rate rose as the oxygen concentration increased. Nevertheless, after the oxygen concentration reached 12%, the reaction rate reached it maximum and was constant in spite of increasing oxygen concentration. As the initial reactant concentration increased, the reaction rate increased, but the conversion ratio dropped. An increase of light intensity resulted in an increase in the number of photons and thus increased the reaction rate. Accordingly the decomposition of trichloroethane could be fitted by the semi-empirical bimolecular Langmuir-Hinshelwood model. Moreover, the reaction rate was proportional to the 0.48-order of the light intensity.     

Simultaneous control of acid gases and PAHs using a spray dryer combined with a fabric filter using different additives

The purpose of this research was to simultaneously evaluate the removal efficiency of acid gases and PAHs from the flue gas emitted by a laboratory incinerator. This flue gas contained dust, acid gases, organics and heavy metals. A spray dryer combined with a fabric filter was used as the air pollution control device (APCD) in this study. The operating conditions investigated included different feedstock additives (polyvinyl chloride (PVC) and NaCl) and spray dryer additives (SiO2, CaCl2 and NaHCO3).The removal efficiency for SO2 could be enhanced by adding inorganic additives, such as SiO2, CaCl2 and NaHCO3. The presence of PVC in the incinerator feedstock also increased the removal efficiency of SO2in the spray dryer. The improved removal of PAHs could be attributed to the addition of feedstock additives (PVC and NaCl) and spray dryer additives (SiO2, CaCl2 and NaHCO3).     

Evaluation of feed COD/sulfate ratio as a control criterion for the biological hydrogen sulfide production and lead precipitation

The ability of sulfate-reducing bacteria to produce hydrogen sulfide and the high affinity of sulfide to react with divalent metallic cations represent an excellent option to remove heavy metals from wastewater. Different parameters have been proposed to control the hydrogen sulfide production by anaerobic bacteria, such as the organic and sulfate loading rates and the feed COD/SO4(2-) ratio. This work relates the feed COD/SO4(2-) ratio with the hydrogen sulfide production and dissolved lead precipitation, using ethanol as carbon and energy source in an up-flow anaerobic sludge blanket reactor. A maximum dissolved sulfide concentration of 470+/-7 mg S/L was obtained at a feed COD/SO4(2-) ratio of 2.5, with sulfate and ethanol conversions of approximately 94 and 87%, respectively. The lowest dissolved sulfide concentration (145+/-10 mg S/L) was observed with a feed COD/SO4(2-) ratio of 0.67. Substantial amounts of acetate (510-1730 mg/L) were produced and accumulated in the bioreactor from ethanol oxidation. Although only incomplete oxidation of ethanol to acetate was observed, the consortium was able to remove 99% of the dissolved lead (200 mg/L) with a feed COD/SO4(2-) ratio of 1.5. It was found that the feed COD/SO4(2-) ratio could be an adequate parameter to control the hydrogen sulfide production and the consequent precipitation of dissolved lead.     

Removal of carbonyl sulfide from a liquid hydrocarbon with activated alumina

The removal of carbonyl sulfide from hydrocarbons to vanishing levels is an industrially important problem. Activated alumina of a special grade was used to successfully remove dissolved carbonyl sulfide by chemisorption from n-heptane as a model substance. The rate of removal was found to be controlled by surface reaction.