Reduction of ochratoxin A during the fermentation of Italian red wine Moscato

The interaction between ochratoxin A (OTA) and 16 yeast strains of Saccharomyces cerevisiae during alcoholic fermentation of the Italian wine Moscato was studied. Levels of OTA in the fermentation liquid, on the cell walls and on the internal part of the cells were determined using a high-performance liquid chromatography (HPLC) system with a fluorescence detector. Results showed that yeast cells adsorbed the mycotoxin on the external and internal part of the cells and also that OTA presence did not affect the alcoholic fermentation in any tested yeast. All the yeasts analyzed in this study showed a significant reduction in the OTA content during the fermentation process.     

Dibenzothiophene removal from model fuel using an acid treated activated carbon

Sulfur containing compounds are one of the most concerning pollutants in fossil fuels. The increasing rate of fuel consumption around the globe reveals the necessity of further purification of the fuels. In this study, application of adsorption process in removing dibenzothiophene from a model fuel is investigated. A granular activated carbon is treated with aqueous solution of nitric acid and implemented as the sorbent. Treatment of the activated carbon with nitric acid resulted in increasing the adsorption capacity of the activated carbon. Freundlich and TÓth isotherms are capable of sufficiently describing the equilibrium data. Investigation of the kinetics of the process is carried out using the homogeneous surface diffusion model. Internal and external mass transfer coefficients are 9.3917 × 10^-6?m²/min and 1.4153 × 10^-2?m/min for the virgin activated carbon (VAC) and 4.8738 × 10^-6?m²/min and 5.2529 × 10^-2?m/min for acid treated activated carbon (AAC), respectively.     

活性炭去除油田废水CODCr的研究

采用吸附法,于室温下用活性炭脱除油田废水中的CODCr。结果表明,在吸附时间为30 min,废水pH值为5.9,活性炭用量为2 g的条件下,CODCr去除率大于50%。活性炭对CODCr的吸附过程为Freundlich等温吸附。     

EAC-2型、EAC-3型活性炭精脱硫剂的研制

研究了ＥＡＣ－２型、ＥＡＣ－３型活性炭精脱硫剂的主要性能与特点。结果表明，与Ｔ１０１相比，ＥＡＣ－２、ＥＡＣ－３的工作硫容、脱硫精度和强度均有了大幅度的提高。     

成型活性炭胶粘剂的选择与开发

采用胶粘剂将活性炭粉粘接成型的方法有着很多其它成型方法所无法比拟的优点。目前用于成型活性炭的胶粘剂主要可以分为有机胶粘剂和无机胶粘剂两种。采用以下方案制备两种不同的胶粘剂作为粉末活性炭成型的胶粘剂：（1）甲醛交联后的腐殖酸钠;（2）乳化沥青,腐殖酸钠中固含量19．7％,100mL腐殖酸钠甲醛（O．01m01／L）用量0．4mL,交联时间90min,交联温度95℃。乳化沥青中阴离子添加剂约为0.5％,助剂约为0．2％,NaOH约为2．5％,乳化剂温度在70℃左右,煤沥青温度在120℃左右,制备出浓度为50％～60％的阴离子乳化沥青。采用不同浓度新型胶黏剂制成活性炭,通过实验结果的对比,发现碘吸附值、强度等指标均符合要求,可以实际应用到工业生产中。     

改性煤基活性炭在高氟水处理中的应用研究

采用改性煤基活性炭处理高氟水,实验结果表明改性的煤基活性炭吸附反应速度快,最佳的pH为5-8,而且对氟离子具有较好的离子选择性能。     

ELISA and HPLC analysis of ochratoxin A in red wines of Croatia

Ochratoxin A (OTA) contaminates wine all round the world, and its consumption may significantly increase human exposure to this toxin. In this study, enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC) for OTA analysis were tested on must and wine samples collected in Croatia. The results of ELISA and HPLC analysis of OTA in naturally contaminated red wines correlated well (r = 0.821), and the correlation was better at higher OTA concentrations. In contrast to HPLC, ELISA could not detect very low OTA concentrations. OTA concentrations in must (range 19–50 ng/l) were higher than in the wines (range 0–21 ng/l). No must samples showed the presence of Aspergillus carbonarius, which is a common OTA-producing mould affecting grapes.     

MDEA及其复合胺溶液对CO_2吸收与解吸研究进展

随着环境压力的与日俱增,二氧化碳气体的捕集与回收技术已成为全球关注的焦点。甲基二乙醇胺(MDEA)及其复合胺溶液是目前工业上应用较为广泛的脱碳剂。本文阐述了MDEA及其复合胺溶液的二氧化碳吸收与解吸性能的研究进展,并且总结了其工业脱碳技术的发展;重点强调其解吸性能对脱碳剂选择的重要性,提出了在研究高效脱碳剂的过程中需要从吸收机理、溶解度、吸收负荷、解吸速率、解吸操作条件、能耗等方面综合考虑,为其工业脱碳技术的应用提供依据。     

活性炭吸附法脱除VOCs的研究进展

吸附法是控制挥发性有机物(VOCs)对环境造成污染的有效手段。综述了活性炭吸附法在控制VOCs污染方面的研究进展,特别是活性炭的表面改性技术及改性活性炭在治理VOCs方面的研究成果。     

一种乳液型清防蜡剂的研制及现场应用试验

针对新安边区块油井原油性质、蜡质特点及油井结蜡规律,研制开发出一种乳液型清防蜡药剂,该药剂的溶蜡率为0.025 g/min、防蜡率为38.53%,且稳定性良好。对新安边4口高含蜡油井的现场应用结果表明,该清防蜡剂可使抽油井平均清蜡周期从1.57月/次延长到5.2月/次,单井清蜡次数平均减少5.3次/年,应用效果显著。     

The fate of ochratoxin A during the Pekmez production from mouldy grapes

The grape juices produced from mouldy grapes that are contaminated naturally with OA between 2.1 and 9.8 μg/l were used in pekmez production. In the processing steps of pekmez, changes in OA amount were examined. The amounts of OA in pekmez samples were found to be 5–6 times higher than OA amount of grape juice.

The dry matter (%), total sugar (%) and pH values were 18.93, 17.82 and 3.36 at the beginning of the experiment while they were 71.42, 67.35 and 3.91 at the end of the experiment, respectively.     

Determination,content analysis and removal efficiency of fining agents on ochratoxin A in Chinese wines

A simple and convenient HPLC-FD detection method for ochratoxin A (OTA) with a high detection limit and a short run time has been developed. OTA has been found in most samples of Chinese market wine, including domestic and imported wines, but the content was not very high. Only a few wines showed an OTA content that exceeded the EC and OIV limits, indicating that most Chinese market wines were safe. The OTA intake for Chinese from wine was 0.017 ng/kg (bw) per day, which was lower than the SCF and JECFA limits and also lower than in many other countries. This was mainly due to the low per capita wine consumption in China, but it is still necessary for the Chinese government and wine makers to monitor OTA levels in wine and to establish relevant regulations. An egg white treatment (0.20 mg/mL, 48 h) was the best removal method for OTA.     

The application of D-optimal design for modelling the red wine ageing process

The aim of this study was to investigate effects of grape seed content in pomace and ageing time on phenolic compounds and colour of red wine using a statistical experimental design. In accordance with the results, it was planned to evaluate a potential use of obtained model for determination of wine shelf life, in terms of its chromatic characteristics. Response surface methodology was used and experiments were carried out according to the two-factor D-optimal design with cubic model. According to the design, wines were obtained from pomace supplemented with 30–120 g/L of seeds and left for ageing from 3 to 48 months. Parameters (responses) monitored in this study were: total phenols content, total anthocyanins content, flavan-3-ols content, colour intensity and hue. Modified third order polynomial equations, which represent fitted models for investigated responses, are shown as adequate (R² > 0.90 and P < 0.001). The validation of models obtained showed good agreement between modelled and independent experimental results. This study has shown that addition of supplementary quantities of grape seeds in pomace led to stabilization of red wine colour during longer storage periods. Despite a sharp fall of anthocyanins content during first year (decrease even by 80%), colour intensity of red wines did not suffer greater changes (decrease by 10%) and it was still acceptable after four years of storage. The use of obtained models for determination of wine's shelf life, as well as, the necessity of further examination, is shown.     

Study of Saccharomyces cerevisiae W13 as a functional starter for the removal of ochratoxin A

In this paper, a wild strain of Saccharomyces cerevisiae (W13) was studied for its OTA-removal ability, growth pattern and alcoholic fermentation profile at two different temperatures (25 and 30 °C) and two different sugar levels (200 and 250 g l⁻¹), with or without supplementation of medium with diammonium phosphate (DAP). A commercial strain (Lallemand EC1118) and a collection isolate (DBVPG 6500) of S. cerevisiae were also studied. All the strains were able to conclude fermentation, with S. cerevisiae W13 producing higher ethanol and glycerol contents; moreover, the wild strain was able to remove OTA (reduction of 6–57.21%), with the highest removing effect observed at 30 °C with 250 g l⁻¹ sugar and after 3 days.In addition, S. cerevisiae W13 was studied for its technological and qualitative traits, as it showed a high tolerance to single and combined stress conditions, β-d-glucosidase, pectolytic and xylanase activities, a low level of hydrogen sulphide production, a low-to-medium parietal interaction with phenolic compounds and no biogenic amines formation.The findings of this work have an applicative value for the potentiality of using S. cerevisiae W13 as functional starter for the production of wines with improved qualitative and food safety characteristics.     

甲烷吸附量与活性炭孔隙结构关系的研究

以太西无烟煤为原料,制取不同活化程度的活性炭。利用甲烷吸附量、比表面积、孔径分布对其吸附性能及孔隙结构进行表征。研究发现,制备的活性炭拥有发达的微孔结构,线性拟合表明0.60nm~1.15nm范围内的微孔结构为甲烷吸附有效区间,大于此范围的孔结构在甲烷吸附过程中起通道作用。     

固废基活性炭制备及其甲苯吸附机制研究

采用固废资源废弃活性炭为炭源前驱体,加入碱性助剂,经炭活化制备了再生活性炭（RAC, regeneration activatied carbon）样品,并进一步通过高铁酸钾改性处理,最终制备得到高性能VOCs吸附炭。同时通过SEM、RAMAN、FT-IR、XPS、动/静态吸附等表征设备,对改性前后的样品进行系统研究。研究结果表明,经过强氧化剂高铁酸钾改性后的RAC比表面积和孔体积提升了1.4倍,缺陷程度增强,表面含氧官能团含量显著增加。其中高铁酸钾改性24h后的样品对甲苯动态吸附性能最好（375.5mg/g）,相比于原始样品RAC动态吸附量（192.8mg/g）增加了一倍;静态吸附测试结果发现RAC-6%K2FeO4+H2SO4-24h最大静态吸附量为796mg/g,表明高铁酸钾改性处理,能够显著增加RAC的VOCs吸附性能。此外,通过连续吸-脱附循环实验测试发现,第五次再生后的样品RAC-6%K2FeO4+H2SO4-24h仍然保持91%的吸附性能,具有良好的循环稳定性,对于工业VOCs废气的高效净化具有重要应用价值。     

Heterogeneity in genetic and phenotypic characteristics of Saccharomyces cerevisiae strains isolated from red and white wine fermentations

The genetic and phenotypic variability of 27 Saccharomyces cerevisiae isolates from naturally fermented Greek wines was studied. RAPD-PCR allowed species identification of the isolates, while mtDNA restriction analysis enabled a considerably high discrimination at strain level. Moreover results on hydrolase profiles obtained by the API-ZYM system and some technological characteristics of the test strains, suggested a high heterogeneity and allowed the selection of strains with interesting vinification properties.     

Kinetics of carbon dioxide removal from water in flat membrane contactor

The problem of regeneration of a carbon dioxide physical absorbent in gas-liquid membrane contactor has been addressed using water as the absorbent. An analytical solution for the mass transfer equation has been obtained with taking into account not only axial, but also radial diffusion of the solute in the liquid flow and thereby significantly extending the area of applicability of the solution. The kinetics of carbon dioxide desorption from aqueous solutions has been described for the membrane contactor based on asymmetric gas separation membrane made of polyvinyltrimethylsilane (PVTMS). It has been shown that the model agrees well with experimental data for different pressures of water saturation with carbon dioxide and desorption temperatures.     

甲烷在活性炭上的吸附平衡及充气试验

为探索缓解家庭用ANG储罐在使用过程中受热效应影响的热管理措施,在温度区间263.15K～313.15K、压力范围0MPa～8MPa,测试了甲烷在比表面积为2074m2.g-1的SAC-02椰壳活性炭上的吸附平衡数据,并由Toth方程确定了相应的绝对吸附等温线。其次,在室温、3.5MPa、5L.min-1～25L.min-1的甲烷流率下,对装填有390g活性炭、中心区域布置U型换热管的储罐进行充气试验。结果表明,Toth方程在试验范围内的预测相对误差小于3.25%;储罐吸附床压力的上升速率是影响实际充气流率、吸附床温度变化和充气总量的关键因素;在试验范围内,U型管内循环30℃的冷却水可降低吸附床的平均温度和最大温升约3.6℃和7.3℃,但仅能提高约6.5%的总充气量。Toth方程可用于分析甲烷在活性炭上的吸附平衡,延长储罐吸附床压力上升至充气压力的时间可改善ANG储罐的充气性能。