阳宗海南岸沉积物对藻砷富集的影响

文中介绍砷(As)在沉积物-水-植物体系的迁移、富集规律。在采样分析云南阳宗海南岸表层沉积物、表层及底层水样、植物As含量的基础上,通过室内藻类静置培养试验,研究阳宗海南岸沉积物对藻类砷富集的影响。结果:60 d室内培养后,对照上清液总As浓度为(1.38±0.11)μg/L,藻总As含量为(0.73±0.01)μg/g;加入表层沉积物后上清液总As浓度为(3.78±2.68)μg/L,藻总As含量为(1.48±0.67)μg/g。加入表层沉积物后上清液总As及藻总As含量平均值和标准差均有所升高,经Kolmogorov-Smirnov秩和检验,表层沉积物加入对上清液总As浓度影响不显著,但对藻总As富集影响显著。     

长株潭城市群二噁英污染水平初探

采集长株潭地区土壤/沉积物样品并对样品中二噁英类物质浓度水平和分布形态进行分析研究。结果表明：表层土壤中PCDD/Fs的浓度范围为267～7 509.61 pg/g,均值为2 175.00 pg/g;I-TEQ浓度范围为0.92～10.21 pg/g,均值为4.82 pg/g。PCDD/Fs与我国其他地区相比,处于高浓度水平。表层沉积物PCDD/Fs含量浓度范围为876.17～497 759.30 pg/g,均值为160 765.91pg/g;I-TEQ浓度范围为2.63～1 031.21 pg/g,均值为332.55 pg/g。50%湘江沉积物样品TEQ的浓度大于80 pg/g,说明该地区河流沉积物已经对某些物种构成了威胁。另外分析了土壤/沉积物中PCDD/Fs同类物的分布特征,并分析可能的污染来源。     

脱硅预热器流化床在线清垢方法研究

将无机非金属材质的球形惰性固体颗粒引入铝土矿溶出粗液预热脱硅系统中，研究液固循环流化床在线清垢方法，解决脱硅预热器硅渣结垢严重、清洗费用高、劳动强度大的等问题。结果表明：液固循环流化床能达到在线清除硅渣结垢的结果，并且在线清垢速率随操作流速及固体颗 料用量的增加而增大；当流速为2．0m/s，对于500mL，和700mL，固体颗粒用量的完全除垢时间分别为2h和1h。     

Surfactants in sediment of Itanhaém Estuary,São Paulo,Brazil

This study investigated surfactant levels in the sediment of Itanhaém Estuary through colorimetric methods with methylene blue active substances (MBAS). Samples were collected with a Van Veen bottom sampler at eight sampling points during autumn, winter, and spring of 2015. The results demonstrate growing detergent deposition in the sediment of the estuary. Surfactant concentration was higher (16.18 μg MBAS g⁻¹) around the sewage treatment plant (STP) than in the estuary in autumn, after the vacation/summer season when the population of the city had increased due to tourism. There was a significant (p < 0.05) reduction in detergent concentration (to 14.94 μg MBAS g⁻¹) in winter, after school vacation, while in spring the surfactants concentration for the STP was high only for the sampling points nearer the ocean. Surfactant concentrations differed significantly among sampling points (p < 0.05), with them being higher at those closer to the STP. Enrichment with high loads from anthropogenic sources associated with urbanization and tourism was responsible for the greater surfactant concentrations in areas near the STP. In conclusion, more efficient treatment of domestic effluent of the city of Itanhaém is needed, as is the control of clandestine discharge into the river since the accumulation of detergents in sediment can have harmful effects on aquatic life.     

Contribution of organic and mineral compounds to the formation of solid deposits inside petroleum wells

Deposit samples collected from three Mexican wells, their asphaltene and residue fractions as well as the sediment and asphaltene fractions separated from the corresponding crude oils were characterized. An appreciable amount of minerals such as CaCO₃, BaSO₄, NaCl, quartz and iron compounds were detected in the deposit compositions. Additionally, aromatic factors and structural parameters such as interlayer distance and crystallite diameters were calculated from the (γ) and (002) characteristic bands from the X-ray diffractograms of the deposits, deposit-asphaltene, oil-asphaltenes as well as oil-sediments. FTIR, elemental analysis and thermal techniques were also used to elucidate the sample compositions. The stages of the deposit formation inside petroleum wells include steel surface corrosion products formed in situ by the presence of brine and sulfur bearing compounds and adsorption or chemisorption of organic compounds on the modified tubing steel surface and mineral pores. Moreover, the high amount of vanadium and nickel indicates a time-dependent process of accumulation of some organometallic compounds independent of the oil-asphaltene amount.     

Modification of the adsorption properties of high surface area graphites by oxygen functional groups

The role of the concentration of oxygen functional groups on the surface of commercial high surface area graphite has been studied in this work. For this purpose, two samples of the parent HSAG have been both oxidized with aqueous HNO₃ solution and pyrolysed at 900 °C under an He flow, in order to remove surface oxygen groups. TPD results, in agreement with XPS experiments, reveal the existence of oxygen groups on the surface of the parent HSAG, whose concentration increases substantially after the oxidative treatment, whereas they disappear after the thermal treatment. The adsorption of different alkanes, aromatics and chlorohydrocarbons on the three samples were compared. Adsorption capacities were derived from the adsorption isotherms, whereas thermodynamic properties have been determined from chromatographic retention data. Both the capacity and the strength of adsorption decrease after the oxidative treatment of the graphites. For n-alkanes and cyclic compounds, it was demonstrated that the presence of oxygen surface groups affects their interaction in lower extension. In the adsorption of aromatics and double-bonded compounds, the influence of surface functionalization is more pronounced, since the removal of electrons from the π-electron system of the basal planes, weaken these forces.     

Investigation of Scents on Cheeks and Foreheads of Large Felines in Connection to the Facial Marking Behavior

We investigated head- and cheek-rubbing behavior in four species of large felines, lions (Leo panther), leopards (Panthera pardus), tigers (Panthera tigris), and cougars (Puma concolor), in captivity. Preliminary behavioral observations found that lions and tigers, but not leopards and cougars, showed behavioral responses to cardboard rubbing samples from head and cheek areas from conspecific felines, compared to the blank cardboard controls. In this context, surface samples on the facial areas of each species were collected to analyze volatile organic compounds that could be involved in the facial marking of felines. Previously developed stir bar surface sampling methodology was used. From all cheek and forehead samples, 100 volatile organic compounds were identified or tentatively identified. Among these, 41 have been previously reported to be present in feline urine and marking secretions. Several new compounds were identified on facial surfaces. Some of the compounds showed substantial quantitative differences among the species. One compound, that has not been reported previously in mammals, 3-acetamidofuran, was found in all investigated species. It was synthesized and tested for behavioral responses. No responses were elicited in a preliminary test. Future research will test other potential signaling compounds and their mixtures for ability to elicit behavioral responses.     

Enhancement of boron removal in treatment of spent rinse from a plating operation using RO

Boron removal is a critical issue in the production of drinking water and of ultra-pure water in the electronics industry. Boron rejection in a RO process is typically in the range of 40-60%. The objective of this study was to distinguish the factor contributing to enhanced boron rejection in reclamation of a spent rinse stream from a plating operation. The effects of different known components used in the feed on boron removal were investigated in the laboratory. The results indicated that glycolic acid and antifoulants could not individually enhance boron rejection in a RO process. A high boron rejection of 95% was achieved as the concentration of iron in the feed was 10 times higher than that of boron, which might be due to formation of a complex between iron oxide and boron. The finding was confirmed in a pilot study.     

Antistatic Modification of Lead Styphnate and Lead Azide for Surfactant Applications

Lead styphnate (LS) and lead azide (LA) must be considered vulnerable to accumulation and discharge of static charge under all conditions. To reduce the risk aroused by static initination hazard in the processing and handling of LS and LA, antistatic modifations of LS and LA are necessary. In this paper, four surfactants were applied to improve the antistatic abilities of lead styphnate and lead azide. The results showed that lauryl dimethylamine betaine (BS‐12) is significantly able to reduce the electrostatic accumulation of LS and LA. In addition, possible correlations of electrostatic accumulation with assumption and approximation could be drawn from the surfactant surface concentration. The electrostatic sensitivities, the 5 s delay explosion temperatures, and the thermal decomposition profiles of the compounds were measured. Selected products were additionally investigated by scanning electron microscopy (SEM). For LS the performance of the products with additives was less affected, whereas for LA the sensitivity of the products in the presence of surfactants was distinctly reduced. The surfactants which are preferably compatible with LS and LA do not affect their thermal stability.     

Modulating the hydroxylamine accumulation in the hydrogenation of substituted nitroarenes using vanadium-promoted RNi catalysts

The effect of vanadium promotion of Raney nickel on aryl hydroxylamine accumulation in the catalytic hydrogenation of electron deficient aromatic nitro compounds was investigated. High accumulation of 70–80% was observed with unmodified Raney nickel. Vanadium promoters were able to modulate the accumulation and depending on the modifier used, an increase (up to 86%) or a decrease (down to 11%) was found. Higher rates were obtained in the former (up to a factor 1.3), lower ones in the latter case (down to a factor 0.1) compared to the unmodified system. Supported or unsupported NH₄VO₃ was usually the most efficient modifier for obtaining low accumulation and reasonable rates, but the optimum concentration and modification procedure had to be determined for every substrate separately. In cases of low accumulation, the vanadium promoters worked as disproportionation catalysts. Dehalogenation was not significantly influenced by the presence of promoters: in all cases dehalogenation took only place after both the nitro arene and aryl hydroxylamine compound had been consumed completely. This revised version was published online in June 2006 with corrections to the Cover Date.     

复合改性表面抑制颗粒污垢积聚特性分析

换热设备颗粒污垢一般指悬浮在流体中的固体颗粒在换热面上的积聚。开发了一种Ni-P-TiO₂防垢型复合改性表面,并将之用于板式换热器抑制纳米MgO颗粒污垢在换热表面的积聚。基于搭建的板式换热器颗粒污垢热阻动态监测实验系统,研究了不同冷却水流速(0.1~0.3 m/s)、入口温度(30~40℃)及纳米MgO浓度(100~400 mg/L)对Ni-P-TiO₂复合改性换热表面抑垢特性的影响。结果表明,随着流速的增加,污垢热阻渐近值减小了27.85%~34.41%;随着冷却水入口温度的升高,污垢热阻渐近值减小了25.15%~39.14%;随着MgO颗粒浓度的增加,热阻渐近值减小了26.15%~45.36%。结合Ni-P-TiO₂复合改性表面的表面能分析了其表面的抑垢性能,发现制备的Ni-P-TiO₂复合改性表面的表面能与纳米MgO颗粒污垢层的表面能相接近,符合Zhao提出的“最优表面能”抑垢理论。与常规板式换热器不锈钢表面相比,Ni-P-TiO₂复合改性表面不仅抑制了颗粒污垢的积聚,还降低了颗粒污垢的固着强度,使得积聚其上的颗粒污垢更容易被剥离换热表面,实现了换热表面持久高效抑垢。     

One step gold (bio)functionalisation based on CS2-amine reaction

Dithiocarbamates have been regarded as alternative anchor groups to thiols on gold surfaces, and claimed to be formed in situ through the reaction between secondary amines and carbon disulphide. In this paper, we further exploit this methodology for a convenient one step biomolecule immobilisation onto gold surfaces. First, the reactivity between CS₂ and electroactive compounds containing amines, primary (dopamine), secondary (epinephrine), and an amino acid (tryptophan) has been investigated by electrochemical methods. Cyclic voltammetric characterisation of the modified electrodes confirmed the immobilisation of all the target compounds, allowing the estimation of their surface concentration. The best result was obtained with epinephrine, a secondary amine, for which a typical quasi-reversible behaviour of surface confined electroactive species could be clearly depicted. Electrochemical reductive desorption studies enabled to infer on the extent of the reaction and on the relative stability of the generated monolayers. Bio-functionalisation studies have been accomplished through the reaction of CS₂ with glucose oxidase in aqueous medium, and the catalytic activity of the immobilised enzyme was evaluated towards glucose, by electrochemical methods in the presence of a redox mediator. Scanning tunnelling microscopy (STM) and Atomic force microscopy (AFM) were used respectively, to characterize the gold electrodes and Glucose Oxidase coverage and distribution on the modified surfaces.     

PAH Distributions in Sediments from High Mountain Lakes

Abstract

The PAH distributions in sediment cores from eight remote lakes distributed over Europe have been investigated. All sites show a similar qualitative composition, being dominated by parent compounds from phenanthrene to coronene. Perylene, a diagenetically produced PAH, dominates the mixtures in deep sediment layers. The distribution and ratios of specific compounds indicate that these hydrocarbons are of pyrolitic origin, mainly from coal combustion processes, but contributions from other sources are also present (i.e., retene is probably indicative of wood combustion inputs). The qualitative differences due to inputs, sources or physico-chemical conditions are discussed.     

Potential antifouling compounds with antidiatom adhesion activities from the sponge-associated bacteria,Bacillus pumilus

Marine biofouling is a common worldwide problem. Current toxic antifouling compounds cause serious harm to marine environment and human health. Natural nontoxic antifouling compound development has been the primary way to solve this problem. In an ongoing survey of sponge-associated bacteria to find an antidiatom adhesion property, one strain named UST050418-683 was isolated from 120 strains with the strongest activity inhibiting diatom adhesion and identified as Bacillus pumilus, based on the 16S rDNA sequence. The crude extract from the spent culture medium of this bacterium could inhibit diatom adhesion. The bioassay-guided fractionation was employed to isolate antifouling compounds. The ethyl acetate extract of the fermentation broth was isolated by multiple chromatograph techniques, (e.g. silica gel column chromatograph and reverse-phase decompression column chromatographic). The active fractions were further purified on the high-performance liquid chromatography equipped with a C18 column. The molecular structures were elucidated by the nuclear magnetic resonance spectroscopy and mass spectrometry, as well as gas chromatography analyses. These results indicated that fatty acids with an antidiatom adhesion property were isolated for the first time from a B. pumilus strain. It was suggested that fatty acids and other compounds from sponge-associated bacteria could be used as potential antifoulants.     

粒度级配对制备高浓度水煤浆的影响

选取典型低变质程度神木柠条塔(NTT)煤,进行球磨式连续型粒度级配提高水煤浆浓度(一定量的水煤浆试样在105℃~110℃干燥至恒重,干燥后试样质量占原样质量的百分数)和成浆性的研究。在不同球磨条件下,考察球磨时间、球磨速度对成浆浓度、流变特性和稳定性能的影响规律,研究粒度级配前后浆体表面润湿性、表面电负性、微观形貌的性能变化对NTT煤成浆性的影响,利用分形维数的计算,进一步探究了粒度级配对提高NTT煤制浆浓度的影响机理。结果表明:在级配M煤样(D50=79.02μm)与M₆煤样(D50=8.727μm)的质量比为8∶2时,成浆浓度与未级配煤样相比提高了约4%;不同球磨条件下的煤样按照不同的质量比进行混合制浆时,初始添加细颗粒使浆体表面的润湿性增强,降低了浆体的性能,当粗细颗粒的质量比大于6∶4时,表面润湿性的变化较小;级配样的成浆浓度与Zeta电位的绝对值呈正相关;当级配煤样之间粒径相差逐渐变大,小颗粒填充到大颗粒孔隙中,增加了空间堆积率,提高了制浆浓度,但随着细颗粒的质量分数增大,大颗粒孔隙被撑开,煤粒空间堆积率下降,制浆浓度降低;M煤样与M₆煤样在质量比为8∶2时,相比于其他级配浆体,分形维数达到最大(2.460),成浆浓度达到最高(63.03%)。     

Nucleation of isotactic polypropylene by triphenylamine-based trisamide derivatives and their influence on charge-storage properties

A new class of triphenylamine-based trisamide compounds has been synthesized and their structure systematically varied in order to explore its influence on the nucleation efficiency for, and on the charge-storage properties of isotactic polypropylene (i-PP). The nucleation behavior was investigated by thermal analysis, polarized light microscopy and rheology in the concentration range from 0.01 to 1 wt% of the compounds in i-PP. It was found that the nucleation efficiency decreased at increasing length of the spacer unit as consequence of increased mobility and induced disorder at the surface of the solid additive. Furthermore, we investigated the influence of the presence of nucleating agents on charge-storage properties of the polymer. The measurements were carried out on 50 μm thick i-PP films, which were charged using with a corona setup. It was found that for this type of additives a strong correlation exists between additive concentration, nucleation efficiency and charge-storage properties.     

The influence of some factors on the electrochemical activity of the oxygen cathode activated with iron polyphthalocyanine

The influence on the surface compounds of a basic character; the method of depositing the iron polyphthalocyanine (pPcFe) on a support; the size of support specific surface area and of the distribution of support pores on the electrochemical activity of support-pPcFe system was investigated for oxygen reduction in an acidic medium. It was found that each of the above specified factors affect the electrochemical activity. The higher the concentration of surface compounds, the higher the electrochemical activity. It was observed that the the higher the concentration of surface compounds of basic type the smaller the potential drop, with time. The highest activity was found for pPcFe which was deposited on a support from the sulphuric acid solution or was synthesized directly on a support after heating a vacuum.     

Surface and Self-Aggregation Properties of Bis-Benzimidazolones Derivatives of <Emphasis Type="SmallCaps">d</Emphasis>-Glucose

The surface and self-aggregation properties in water of a new series of amphiphilic homologues, bis-benzimidazolone derivatives of d-glucose, were investigated. Parameters such as the maximal surface excess concentration, minimal area per molecule at the interface, and critical micelle concentration (CMC) were found to be significantly dependent on the hydrophobic alkyl chain length. The synthesized compounds form micelles at remarkably low concentrations, and CMCs derived from surface tension measurements show a minimum as a function of the alkyl chain length; this unusual trend can be attributed to the formation of submicellar aggregates in compounds with long alkyl chains, as evidenced from fluorescence probe spectroscopy data. At high surfactant concentrations, lyotropic liquid crystalline phases with hexagonal structure are formed. Small angle X-ray scattering measurements indicate that the characteristic nanoscopic lengths increase with water swelling and alkyl chain length.     

Challenges for the Development of New Non-Toxic Antifouling Solutions

Marine biofouling is of major economic concern to all marine industries. The shipping trade is particularly alert to the development of new antifouling (AF) strategies, especially green AF paint as international regulations regarding the environmental impact of the compounds actually incorporated into the formulations are becoming more and more strict. It is also recognised that vessels play an extensive role in invasive species propagation as ballast waters transport potentially threatening larvae. It is then crucial to develop new AF solutions combining advances in marine chemistry and topography, in addition to a knowledge of marine biofoulers, with respect to the marine environment. This review presents the recent research progress made in the field of new non-toxic AF solutions (new microtexturing of surfaces, foul-release coatings, and with a special emphasis on marine natural antifoulants) as well as the perspectives for future research directions.