大气中甲硫醇等有机硫化物的分析方法研究

以液体甲硫醇合成固体甲硫醇铅,由固体甲硫醇铅酸解释放的甲硫醇配制标准气体。以5％NaOH为吸收液,采用多孔玻板吸收管,冷阱采样。5％OV—101/Chromosorb GHP为固定相,以气相色谱法测定大气中甲硫醇、甲硫醚及二甲二硫醚。其变异系数分别为8.6％,6.4％,5.5％;回收率分别为93.0％,97.7％,107.3％     

高炉煤气洗涤水处理方法的研究

采用无机混凝剂与有机高分子混凝剂配合使用处理煤气洗涤废水的方法 ,对本溪钢铁公司五号高炉煤气洗涤废水进行了分析研究。通过混凝剂筛选实验 ,确定以氯化铝钙和聚丙烯酰胺作为处理药剂 ;同时研究了影响混凝沉降的各种因素并进行了混凝沉降实验。综合考虑处理效果和药剂费用等各方面因素 ,通过正交实验确定了最佳实验条件。经过一个多月的现场运行实践表明 ,处理效果良好。     

Thermal behaviors, combustion mechanisms, evolved gasses, and ash analysis of spent potlining for a hazardous waste management

An unavoidable but reusable waste so as to enhance a more circular waste utilization has been spent potlining (SPL) generated by the aluminum industry. The combustion mechanisms, evolved gasses, and ash properties of SPL were characterized dynamically in response to the elevated temperature and heating rates. Differential scanning calorimetric (DSC) results indicated an exothermic reaction behavior probably able to meet the energy needs of various industrial applications. The reaction mechanisms for the SPL combustion were best described using the 1.5-, 3- and 2.5-order reaction models. Fluoride volatilization rate of the flue gas was estimated at 2.24%. The SPL combustion emitted CO₂, HNCO, NO, and NO₂ but SO_x. The joint optimization of remaining mass, derivative thermogravimetry, and derivative DSC was achieved with the optimal temperature and heating rate combination of 783.5°C, and 5 °C/min, respectively. Interaction between temperature and heating rate exerted the strongest and weakest impact on DSC and remaining mass, respectively. The fluorine mainly as the formation of substantial NaF and CaF₂ in the residual ash. Besides, the composition and effect of environment of residual solid were evaluated. The ash slagging tendency and its mineral deposition mechanisms were elucidated in terms of turning SPL waste into a benign input to a circular waste utilization.     

气相色谱法测定工业废气中二硫化碳

采用活性炭采样管富集工业放心气中二硫化碳，以无水乙醇为解吸溶剂，１，２，３－三（２－氰基乙氧基）丙烷固定液，Ｃｈｒｏｍｏｓｏｒｂ Ｗ－ＨＰ－ＡＷ－ＤＭＣＳ载体，用火焰光度检测器进行色谱测定。进行了采样方法、样品保存、干扰物质及最佳色谱条件等项条件试验。方法的采样效率为９８－１００％；精密度实验的变异系数为２．８－６．６％；平均加标回收率为８８．０－１００．３％；按１Ｌ采样体积计，方法的最低检出浓度     

Aerobic biodegradability of methyldiethanolamine (MDEA) used in natural gas sweetening plants in batch tests and continuous flow experiments

Mixtures of different amines including tertiary amines (methyldiethanolamine, MDEA) are commonly used for the removal of CO₂ from gas mixtures or in gas sweetening processes for the extraction of CO₂ and H₂S. The absorber solutions used can be released into the industrial waste water due to continuous substitution of degraded MDEA, periodically cleaning processes or an accidental spill. In this study, the aerobic biodegradability of MDEA was investigated in a standardised batch test and a continuous flow experiment (40 l/d). The results of the batch test indicated that the MDEA-solution was non-biodegradable during the test period of 28 days, whereas the continuous flow experiments showed biodegradation of more than 96% based on TOC-measurements. This was probably due to the adaptation of the microorganisms to this particular waste water contamination during continuous flow experiment.     

太湖梅粱湾水体中阿特拉津的毛细管气相色谱法测定

固相萃取（SPE）技术结合毛细管气相色谱（GC-μECD），测定了饮用水源地太湖梅粱湾水体中内分泌干扰物阿特拉津的含量，并用GC-MS进一步验证了分析结果。检测下限为10ng／L，方法回收率为75．58％～97．79％，RSD为0．38％～4．50％，在10ng／L-3640μg／L保持线性，其线性相关系数为0．9994。太湖梅梁湾水体中阿特拉津质量浓度在21．3～613．9ng／L，污染来源可能为太湖周围的农作区。     

The origin of the chemical profiles of fungal symbionts and their significance for nestmate recognition in <Emphasis Type="Italic">Acromyrmex</Emphasis> leaf-cutting ants

Cuticular hydrocarbon profiles are essential for nestmate recognition in insect societies, and quantitative variation in these recognition cues is both environmentally and genetically determined. Environmental cues are normally derived from food or nest material, but an exceptional situation may exist in the fungus-growing ants where the symbiotic fungus garden may be an independent source of recognition compounds. To investigate this hypothesis, we quantified the chemical profiles of the fungal symbionts of 18 sympatric colonies of Acromyrmex echinatior and Acromyrmex octospinosus and evaluated the quantitative variation of the 47 compounds in a multivariate analysis. Colony-specific chemical profiles of fungal symbionts were highly distinct and significantly different between the two ant species. We also estimated the relative genetic distances between the fungal symbionts using amplified fragment length polymorphism (AFLP) and correlated these with the overall (Mahalanobis) chemical distances between the colony-specific profiles. Despite the standardized laboratory conditions, the correlations were generally weak, but a statistically significant portion of the total variation in chemical profiles could be explained by genetic differences between the fungal symbionts. However, there was no significant effect of ant species in partial analyses because genetic differences between symbionts tend to coincide with being reared by different ant species. However, compound groups differed significantly with amides, aldehydes, and methyl esters contributing to the correlations, but acetates, alkanes, and formates being unrelated to genetic variation among symbionts. We show experimentally that workers that are previously exposed to and fed with the fungal symbiont of another colony are met with less aggression when they are later introduced into that colony. It appears, therefore, that fungus gardens are an independent and significant source of chemical compounds, potentially contributing a richer and more abundant blend of recognition cues to the colony “gestalt” than the innate chemical profile of the ants alone. Freddie-Jeanne Richard and Michael Poulsen contributed equally to this work.     

Developing a CFD heat transfer model for applying high expansion foam in an LNG spill

Liquefied natural gas (LNG) is widely used to cost-effectively store and transport natural gas. However, a spill of LNG can create a vapor cloud, which can potentially cause fire and explosion. High expansion (HEX) foam is recommended by the NFPA 11 to mitigate the vapor hazard and control LNG pool fire. In this study, the parameters that affect HEX foam performance were examined using lab-scale testing of foam temperature profile and computational fluid dynamics (CFD) modeling of heat transfer in vapor channels. A heat transfer model using ANSYS Fluent® was developed to estimate the minimum HEX foam height that allows the vapors from LNG spillage to disperse rapidly. We also performed a sensitivity analysis on the effect of the vaporization rate, the diameter of the vapor channel, and the heat transfer coefficient on the required minimum height of the HEX foam. It can be observed that at least 1.2 m of HEX foam in height are needed to achieve risk mitigation in a typical situation. The simulation results can be used not only for understanding the heat transfer mechanisms when applying HEX foam but also for suggesting to the LNG facility operator how much HEX foam they need for effective risk mitigation under different conditions.     

污染源以及环境空气中乙酸含量的测定

通过实验建立了测定污染源及环境空气中乙酸的气相色谱分析方法,给出各项指标。实验结果表明该方法分析结果准确、简单实用。并且以PTA装置气体中不同介质组成为例,探讨了含乙酸可燃气含量的测定方法。     

The gas-photocatalytic degradation of trichloroethylene without water

The photocatalytic degradation of gaseous trichloroethylene (TCE) without water has been studied. The degradation products were determined to be CO₂, HCl and Cl₂, and the reaction stoichiometry, was described as

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. The degradation rate was found to be linear with 0.16 power of the illumination intensity. When the TCE concentration was low (10¹⁴ mol L⁻¹ or a little more), its degradation rate model could be considered as first order kinetics. A mechanism of valence band hole oxidation was proposed.