Solvent degradation during coal liquefaction in a flowing-solvent reactor

We have previously observed that primary coal extracts recovered from the flowing solvent reactor appeared to be of large molecular mass. Short residence times in the reaction zone following the solubilisation of the extracts tended to limit their thermal degradation. This observation offered the vista of detailed characterisation and analysis of most (∼80-90%) of the coal mass in solution-and in a state relatively free of thermal degradation. Point of Ayr coal was extracted with tetralin and with non-donor solvents, quinoline and NMP at 350 and 450 °C. Structural evaluations have been carried out using size exclusion chromatography, UV-fluorescence spectrometry, GC-MS and probe-MS. Little coal derived material could be found in the pentane-soluble part of the reaction mixture; solvent dimers and trimers were prominent and coal-derived components, such as alkanes, were only minor components. In attempting to characterise the main, pentane-insoluble fraction of the coal extract, the level of interference from solvent-derived material emerged as the decisive parameter for the success or failure of the general method. However, the predominantly pentane-insoluble coal extracts from each solvent were contaminated by solvent polymerisation products. For all three solvents, the level of contamination of extracts with solvent derived material tended to interfere with the detailed characterisation/analysis of material extracted from the coal.     

Photocatalysis of V-bearing rutile on degradation of halohydrocarbons

Natural rutile TiO₂ shows photocatalysis on degrading trichloroethylene and tetrachloroethylene. In natural rutile, V, Fe, Cu, etc. substitute for Ti, resulting in lattice distortions and defects. We found that rutile, after heating, quenching and electron irradiation, changes its surface characteristics and photoactivity. The quenched rutile has the highest concentrations of adsorbed water and V on its surface, resulting in high photoactivity. For example, quenching at 1273 and 1373 K significantly improved photoactivity of rutile. The heated rutile also increased the concentration of adsorption water on the surface, e.g., rutile heated to 1273 K improved degradation rate of halohydrocarbons. On the contrary, electron irradiation decreased the concentration of adsorbed water on the rutile’s surface, which results in lower degradation rate for trichloroethylene. Therefore, heating and quenching over 1237 K improve the photocatalytic efficiency of the natural V-bearing rutile on degrading halohydrocarbons. The XRD spectra of the rutile samples showed that heating, quenching and electron irradiation did not result in formation of new phases or phase transitions.     

桩西联采油废水氧化塘去除COD的数学模型

基于动力学和水力停留时间分布研究结果，研究了带纵向扩散的推流式反应池模型(模型Ⅰ)和完全混合式反应池串连模型(模型Ⅱ)对桩西联合站采油废水氧化塘的适用性。给出了两种数学模型中包含的各参数的数值或表达式，其中包括：扩散准数Pe=0．780，COD降解速率常数K(28．8℃)=0．07175h^-1，K值温度系数θ=1．054，COD生化降解率27%，平均水力停留时间tM=75h。2001年7月进行16次测试，得到氧化塘平均出口COD值(CODe)=127．6mg／L(平均水温TM=35．8℃，平均进口COD值169．4mg/L)，按模型Ⅰ计算,CODe=126．2mg／L，相对偏差为-1．10％，按模型Ⅱ计算，CODe=126．5mg／L，相对偏差为-0．860％。用模型Ⅰ和Ⅱ计算的2000年12月到2001年8月9个月的月平均CODe值(月平均水温TM在10．9～36．0℃)，与平均实测值的相对偏差范围分别为-4.50％～ 4.52％和-4.42％～ 4．18％，相对偏差平均值分别为 0．453％和 0．581％。这两个数学模型均可用于废水氧化塘的处理结果预测和设计。表2参4。     

Isolation of a yeast,Trichosporon cutaneum,able to use low molecular weight phenolic compounds: application to olive mill waste water treatment

This study deals with the degradation of phenolic compounds in olive oil mill waste; a highly polluting material in olive oil‐producing countries because of its abundance and the toxicity of its phenolic compound content. This investigation confirms the ability of an isolated yeast, identified as Trichosporon cutaneum, to degrade phenolic compounds extracted from olive mill waste water (OMW). The yeast was adapted to the OMW by an enrichment culture. The results of this biotransformation were a decrease in the phenolic content and hence a reduction in the phytotoxic effects of the effluent after the yeast treatment. The kinetic growth of the isolated yeast on phenol over a range of concentrations (0.3–3.0 g dm^?3) was studied. The ability of the strain to assimilate simple monomeric phenols and alkyl phenols, at a concentration of 1 g dm^?3, in a synthetic liquid medium used as the sole carbon source was investigated in a batch culture. The aromatic ring cleavage pathway occurred in the yeast through catechol oxidation. Using various concentrations of ethyl acetate extract from OMW as the sole carbon source, the yeast exhibited growth on the substrate up to 7 g dm^?3 equivalent of phenols. A significant reduction of COD after the treatment of the OMW extract by the yeast isolate was noticed. The removal of phenol and COD exceeded 80% of the original loading after 8 days of treatment, for extracts containing initial COD in the range 19 to 72 g dm^?3. Copyright © 2004 Society of Chemical Industry     

Ozonation of unstretched natural rubber film from Hevea brasiliensis studied by ozone consumption and 13C NMR

Unstretched films of natural rubber (NR) from Hevea brasiliensis were exposed to ozone flow of 15 ml min^?1 from 4 to 300 min. The efficiency of reaction was determined by ozone consumption of NR films. Plots of reacted ozone mass versus film thickness show that the ozone penetration and the ozone reaction progressed into deeper layers (170 µm) than described in the literature (～0.5 µm). The previous proposed model based on viscometry measurements was corroborated by ozone consumption results. The effect of thickness on the O₃/NR stoichiometric ratio indicated that the diffusion process that controls the ozonation in unstretched film does not consist of the boundary progression behind which all reactive sites have been saturated. Ozonation in unstretched rubber film, while being less efficient than ozonolysis in solution, does have a reaction efficiency of the same order of magnitude. NMR spectroscopy was used to characterise the products formed by ozonation. Copyright © 2004 Society of Chemical Industry     

Potential protein degradation balance and total metabolizable protein supply to dairy cows from heat‐treated faba beans

The effects of pressure toasting (100, 118 and 136 °C for 3, 7, 15 and 30 min) on potential protein nutritional value of faba beans were evaluated with the NRC 2001 dairy model, by determining undegraded (RUP) and degraded rumen protein (RDP), undegraded (RUST) and degraded rumen starch (RDST), truly absorbed undegraded protein (ARUP), microbial protein (MCP_RDP) synthesized in the rumen from rumen‐available protein, truly absorbed rumen synthesized microbial protein (AMCP), truly absorbed rumen endogenous protein (AECP), total metabolizable protein (MP) in the small intestine, and the protein degradation balance (PDB). The treatments increased RUP, RUST, ARUP and MP (p < 0.001), and decreased RDP, RDST, MCP_RDP and PDB (p < 0.001), the effects increasing with increasing temperature and time. The treatments increased (p < 0.001) ARUP without affecting AECP and AMCP, so that the net absorbable total MP in the small intestine was increased. The PDB was reduced (p < 0.001) but never became negative. These results indicated that potential microbial protein synthesis would not be impaired due to sufficient nitrogen in the rumen, but the high positive PDB values with most treatments, except 136 °C for 15 min (PDB 2.0 g kg^?1 DM) indicated that there were large potential losses of nitrogen in the rumen, particularly for the control with a value of 88.9 g kg^?1 dry matter. It is concluded that predicted potential protein degradation balance and total metabolizable protein supply from faba beans were improved by the treatments. Copyright © 2005 Society of Chemical Industry     

土壤中吸附性溶质运移对流-弥散模型的准解析解及其数值模拟

给出了稳定流条件下，同时考虑随深度变化的一阶降解和随深度变化的线性平衡吸附时，一维溶质运移的对流-弥散方程。在初始浓度为零，半无限一维空间内定通量边界条件下，推导出了溶质相对浓度的准解析表达式。用特征有限元法建立了相应的数值模型，从数值解和准解析解的计算数据可以看出：数值计算所产生的误差很小，能满足实际工作对计算精度的要求。     

新型二氧化铅电极降解苯胺废水的动力学研究

以自制的一种新型二氧化铅电极为阳极,多孔石墨为阴极,在不同的温度条件下为苯胺废水进行电催化降解。研究表明,苯胺废水的降解过程符合准一级反应动力学过程,其相关系数在0.99以上,电催化降解苯胺的活化能约为10.62kJ·mol-1,远低于一般化学反应的活化能力60～250kJ·mol-1,表明电催化过程降解高浓度有机废水具有很大的潜力。     

二氧化碳降解塑料产业前景广阔

阐述了国内外二氧化碳降解塑料的研发生产现状,分析了它的市场前景,并提出了建议.     

Irradiation Effects on Free Radical Scavenging and Antioxidant Activity of Phytic Acid

ABSTRACT: Free radical scavenging and antioxidant activities of irradiated phytic acid at various concentrations were studied. Phytic acid sodium salt dissolved in deionized distilled water was irradiated at 0, 5, 10, 15, and 20 kGy. The degradation of phytic acid by irradiation was observed, and it was found that the concentrations had an effect on the degree of degradation. Stable 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability of phytic acid was significantly increased by irradiation ( P < 0.05) and was positively correlated with irradiation dose ( P < 0.01). Antioxidant activity of phytic acid in lipid model systems was slightly increased by irradiation; however, at higher concentrations, the activity was reduced or was the same compared with nonirradiated phytic acid.