苏南某焦化厂场地土壤和地下水特征污染物分布规律研究

以苏南某焦化厂为研究对象,在对污染区域初步识别的基础上,采集了0～4.5 m深的22个土壤样品和2个地下水样品,利用GC/MS等检测了多环芳烃类、总石油烃、苯系物、重金属,总氰化物、挥发酚、硫化物的含量,并研究了其在不同功能区土壤和地下水中的特征分布。结果表明：（1）该焦化场土壤和地下水受到了不同程度的污染,其中炼焦炉周边、焦油和洗油储罐区、焦油和粗苯加工车间是污染最严重的区域;（2）土壤中主要超标污染物是多环芳烃、总氰化物、总石油烃、单环芳香烃、二苯呋喃、苯胺、硫化物、挥发酚和一些苯酚类化合物;（3）地下水重点污染区域粗苯车间受到总氰化物、苯胺、苯酚类、萘、总石油烃、单环芳香烃的严重污染,污水处理站区域地下水主要污染物包括总氰化物、萘、总石油烃、苯。     

Volatile Organic Compounds in the Ambient Air of Rousse,Bulgaria

Volatile organic compounds in the ambient air were measured at four locations in Rousse, Bulgaria for a one year period. A gas chromatograph/mass spectrometer equipped with a cryogenic concentrator was used to analyse the air samples. Forty one compounds (aromatic hydrocarbons and halogen-derivatives of aliphatic and aromatic hydrocarbons) were analysed by EPA method TO-14. Aromatic hydrocarbons, benzene, toluene, styrene, isomers of xylene and isomers of trimethyl benzene were the most frequently occurring pollutants. Styrene, isomers of xylene and isomers of trimethyl benzene frequently exceeded the concentration limits. Among the halogen derivatives, the concentration of chloroform was always very high. A concept called ‘degree of pollution’ was proposed to clarify the contribution of each pollutant to the total air-pollution. Suggestions were made on the need to introduce an integral tolerance parameter to describe the total impact on air-pollution.     

Immobilization of Mercury Species under the Influence of Typical Organic Compounds in Waste Gases by the Circulating Fluidized Bed

Hearth furnace coke (HOK), a special type of lignite (brown-coal)coke produced in a manufacturing process called `hearth furnace process', and portlandite (Ca(OH)₂) particles were placed ina circulating fluidized bed reactor. Defined model waste gases containing HCl/SO₂/Hg⁰/Hg²⁺ and organic compounds were injected into the reactor to investigate the adsorption of different mercury species. Elemental mercuryreacted immediately with HCl to form HgCl₂, but for Hg²⁺ further investigations had to be made, because todaygas cleaning plants still have problems in observing national limits for the mercury output. The temperature, the mercury content of the gas, and its content of acid compounds as majorinfluences in cleaning exhaust gases were varied without relevantpositive effects on the adsorption rate which decreased from nearly 100% in the first five minutes to unsatisfactory20% some minutes later. The mercury load on the HOK particles onlyshowed a value of 60 μg Hg g^-1 HOK. Then organic compounds (guide pollutants such as 1-chlorobutane, monochlorobenzene, toluene, and naphthalene, which are alwayspresent in incineration plant exhaust gases) were added to thegas stream and the results improved significantly. The mercuryload on the HOK particles varied depending on the chemical nature of the organic compound and amounted to 300 μg Hg g^-1 HOK maximum. The measured values of mercury in the clean gas stream fell below 10 μg m^-3. The characterization of the dynamic behavior of mercury in hot, acid waste gases and the analytical identification of mercurysticking to HOK under the influence of organic compounds leadto new methods for improving the effectiveness and performanceof gas cleaning plants.     

The Effects of Fuel Evaporation and Biomass Burning on Toluene Concentrations in an Urban Area

Using an automated gas chromatography system coupled with an online sampling/thermal desorption module, benzene, toluene, and their alkylated derivatives were measured in Las Vegas, Nevada from 3 July to 28 August 2008. The levels of hydrocarbons were comparable to those typically found in urban environments. Statistically significant (at 95?% level) higher concentrations were measured on mid-week days as compared with those measured during weekends. This was correlated to a local traffic pattern rather than traffic on highways. The concentrations of aromatic hydrocarbons also increased during periods when transport of smoke from wildfires in central and north California was identified by remote sensing but these levels were comparable to other days with volatile organic compounds concentrations. The high toluene/benzene ratios and the estimated photochemical age of air masses implied the contribution of other local sources. Fuel evaporation accounted for the vast majority of toluene enhanced concentrations in early July (as compared with those measured in June) for sites within the urban grid, but very little for sites located outside the urban area.     

The Chemistry of Intercepted Clouds in Northern Arizona during the North American Monsoon Season

Cloudwater samples have been collected for the first time at a high-elevation site in the US interior Southwest. Cloud samples were collected at the summit of Mt. Elden near Flagstaff, Arizona. The samples were analyzed for pH, ionic composition, trace metals, organic carbon content, and volatile organic compounds. All of the samples showed high pH values (5.12–6.66), which appear to be the result of soil/crustal acid-neutralizing components. Ammonium and nitrate were the dominant ionic species. Organic carbon concentrations ranged from 3 to 18 mg/l. Volatile aromatic compounds (toluene, ethylbenzene, and xylenes) were detected, although they did not contribute significantly to the dissolved organic matter (<1% of dissolved organic carbon). Still, their aqueous-phase concentrations were substantially higher than equilibrium partitioning from the gas phase would suggest. Metal concentrations were high when compared to other cloud studies in remote areas. Overall, with the exception of pH, the cloud chemistry showed marked inter-event variability. The source of the variability was investigated using NOAA HYSPLIT dispersion calculations. Like the cloud composition, the air mass back trajectories differed widely from event to event, and consistently, air masses that passed over highly urbanized areas had higher trace metal, organic, and ion concentrations than more pristine air masses.     

A Pilot-Scale Evaluation of Greenroof Runoff Retention, Detention, and Quality

The aggregate potential health impact due to ambient volatile organic compounds on the population living in the area nearby the petrochemical industrial complex in Thailand was evaluated using measured air contaminants concentration. Airborne volatile organic compounds were collected using canisters and were analyzed by gas chromatography/mass spectrophotometer following the US.EPA TO 15 procedure. Composite samples taken over a 24-h period were collected monthly. Concentrations of volatile organic compounds (VOCs) were analyzed for a suite of 24 compounds covering both carcinogenic and non-carcinogenic substances. Results were determined and analyzed in order to evaluate their spatial variability and their potential health risk. Comparison of data from each monitoring site indicated that patterns of VOCs across sites were different from their major species and their concentrations which might be influenced by nearest potential emission sources. Carcinogenic VOCs such as benzene, 1,3butadiene, and 1,2 dichloroethane were found to be higher than their annual national standards. A potential cancer risk map was drawn based on benzene concentration in order to illustrate the zone of impact and the number in the population likely to be exposed. Results indicated that 82% of the total area, and 89.6% of the total population were within the impact area. It was suspected that high concentrations of benzene and 1,3 butadiene might be attributed by both the mobile source and the point source of emissions while 1,2 dichloroethane was suspected to be emitted from factories located upwind from the monitoring sites. Hazard quotients and hazard indexes were applied to determine chronic health effects with non-cancer endpoints. Calculated values of hazard indexes for each of the target organ systems were lower than 1, which indicated that the non-cancer chronic risk due to level of volatile organic compounds in the study area was less.     

Monitoring Methyl Tertiary Butyl Ether (MTBE) and other Organic Micropollutants in Groundwater: Results from the Danish National Monitoring Program

The paper presents results of analyses of 7671 groundwater samples collected from 1115 screens in the period 1993 to 2001 for the Danish National Groundwater Monitoring Program. In Denmark groundwater is widely used for drinking water and the objectives of the monitoring program is to describe the present conditions, the development of, and the impacts on the groundwater. The design of the Danish National Groundwater Monitoring Program is described and data are provided. Data originate from monitoring areas and are supplemented with data from the waterworks' control of nearly 6000 water supply wells. In addition to pesticides there is a series of other organic compounds that must be considered in relation to possible groundwater contamination. Sources of these compounds and their importance in relation to groundwater contamination is discussed on the basis of the monitoring data. The organic micropollutants monitored are grouped according to chemical properties: aromatic hydrocarbons, chlorophenols, detergents, halogenated aliphatic hydrocarbons, ethers (MTBE), phenols, and phthalates. The most frequently found compounds were toluene (18.7% ), phenol (14.6%), xylene (10.9), trichloromethane (9.5%), and benzene (in 8.8% of the screens monitored). The five compounds most frequently found at a concentration above the maximum residue limits (MRL) for drinkingwater were: dibuthylphthalate (28%), phenol (14%), 2,4-dichlorophenol (10%), trichloromethane (10%), pentachlorophenol (7% of findings exceeding the MRL for drinkingwater). Overall, one or several compound was observed at least once in 57.8% of the 1115 screens monitored within the period 1993–2001. On a yearly basis the median finding frequency was 19%.     

Organic compounds in soils and sediments from unlined waste disposal pits for natural gas production and processing

Samples of soil in dry waste pits and of sediment from waste pits currently in-use for natural gas production in the San Juan Basin of northwest New Mexico were collected for characterization of the presence and concentration of organic compounds. Samples were dried at 25 °C and about 50 g were extracted successively in a Soxhlet apparatus using hexane, benzene, and methanol. Extracts were filtered and condensed to 10 mL. Analyses of hexane extracts of samples using high-resolution gas chromatography showed presence of a complex mixture of 40 to 50 organic compounds in dry soil and in sediment from in-use pits. The range of size for compounds was C₁₀ to C₂₅. Although no compounds were detected in GC analyses of subsequent benzene and methanol extracts of the same soil samples, these extracts were highly colored and contained 5 to 10% of total absorptivity at 254 nm. Total extractable residues in the hexane extracts ranged from 49 to 110 mg g^?1 of soil. Polycyclic aromatic hydrocarbons were detected in hexane extracts at concentrations of 270 to 870μg g^?1 of dry sample.     

PAHs and Petroleum Markers in the Atmospheric Environment of Alexandria City,Egypt

To evaluate the chemical fingerprint of hydrocarbons in airborneorganic matter in the arid environment of Alexandria City, Egypt,the compositions of aliphatic and aromatic compounds were determined in suspended particulate material collected from a street undergoing heavy traffic in central Alexandria and in bulkdeposition samples collected from a site representing an area increasingly influenced by human and industrial activities. Qualitative and quantitative characterizations of individual compounds were based on gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) analyses. More than 100 organic compounds are quantified in each sample, including n-alkanes, isoprenoids, polycyclic aromatic hydrocarbons(PAHs), sulfur-bearing heterocyclics, steranes/diasteranes, terpanes and aromatic steroids. The use of hydrocarbon profilesand ratios for identifying sources and processes is discussed.The molecular distribution of alkanes revealed that the mainsource of these compounds is from petroleum contamination withtrace input of vascular plant wax. The PAH profiles, especiallythe relative abundance of alkyl-PAHs and sulfur-containing heterocyclics, showed that PAHs are chiefly derived from trafficsources. The results further indicated that diesel vehicles aremore important PAH sources than gasoline vehicles. In addition,the source fingerprint of fossil fuel biomarkers such as steranes, terpanes and aromatic steroids agreed well with thefingerprint of unburned lubricating oil, which are probably contributed to vehicle exhaust emissions.     

Synthesis, herbicidal activities, and 3D-QSAR of 2-cyanoacrylates containing aromatic methylamine moieties

A series of novel 2-cyanoacrylates containing different aromatic rings were synthesized, and their structures were characterized by (1)H NMR, elemental analysis, and single-crystal X-ray diffraction analysis. Their herbicidal activities against four weeds and inhibition of photosynthetic electron transport against isolated chloroplasts (the Hill reaction) were evaluated. Both in vivo and in vitro data showed that the compounds containing benzene, pyridine, and thiazole moieties gave higher activities than those containing pyrimidine, pyridazine, furan, and tetrahedronfuran moieties. To further explore the comprehensive structure-activity relationship on the basis of in vitro data, comparative molecular field analysis (CoMFA) was performed, and the results showed that a bulky and electronegative group around the para-position of the aromatic rings would have the potential for higher activity, which offered important structural insights into designing highly active compounds prior to the next synthesis.     

Changes in properties of soil-derived dissolved organic matter induced by biodegradation

Properties of dissolved organic matter (DOM) determine its biodegradation. In turn, biodegradation changes the properties of the remaining DOM, which may be decisive for the formation of stable organic carbon in soil. To gain information on both mechanisms and controlling factors of DOM biodegradation and the properties of biodegraded DOM, we investigated changes in the composition of 13 different DOM samples extracted from maize straw, forest floors, peats, and agricultural soils during a 90-day incubation using UV absorbance, fluorescence emission spectroscopy, FTIR-spectroscopy, ¹H-NMR spectroscopy, pyrolysis-field ionization mass spectroscopy (Py-FIMS), and ¹³C natural abundance before and after incubation. Changes in the DOM properties were related to the extent of biodegradation determined by the release of CO₂. Increasing UV absorption and humification indices deduced from fluorescence emission spectra, and increasing portions of aromatic H indicated relative enrichment of aromatic compounds during biodegradation. This enrichment significantly correlated with the amount of DOC mineralized suggesting that aromatic compounds were relatively stable and slowly mineralized. ¹³C depletion during the incubation of highly degradable DOM solutions indicated an enrichment of lignin-derived aromatic compounds. Py-FI mass spectra indicated increasing contents of phenols and lignin monomers at the expense of lignin dimers and alkylaromatics during incubation. This partial degradation of higher-molecular, lignin-derived DOM compounds was accompanied by relative increases in the proportions of lower-molecular degradation products and microbial metabolites. Carbohydrates, especially when abundant at high initial contents, seem to be the preferred substrate for microorganisms. However, four independent methods suggested also some microbial production of carbohydrates and peptides during DOM degradation. After incubation, the composition of highly degradable DOM samples became similar to relatively stable DOM samples with respect to aromaticity, carbohydrate content, and thermal stability. We conclude that DOM biodegradation seems to result in organic matter properties being a precondition for the formation of stable carbon. These structural changes induced by DOM biodegradation should also result in stronger DOM sorption to the soil matrix additionally affecting DOM stabilization.     

Removal of Benzene Using the Characteristics of Block Copolymers for Encapsulation

This study assessed the aqueous benzene removal capacity of a polymeric adsorbent, based on an amphiphilic material, in a batch experiment. Two types of polystyrene-block-poly(N-isopropylacrylamide) have structures containing a hydrophobic core and hydrophilic shell. The encapsulation mechanism of benzene by a polymeric adsorbent was investigated, and found to be attributable to the Van der Waals interactions between the benzene aromatic ring and the hydrophobic core of the adsorbent. The equilibrium data were analyzed using the Langmuir and Freundlich adsorption isotherms, and found to be a good fit to both. The maximum adsorption capacity for benzene by the polymeric adsorbent was found to be 194.53 mg/g. The kinetic data followed a pseudo-first-order kinetic model. Polystyrene-block-poly(N-isopropylacrylamide) showed the potential to be an effective adsorbent for application to wastewater treatment.     

Gaseous and PM10-Bound Pollutants Monitored in Three Sites with Differing Environmental Conditions in the Venice Area (Italy)

Understanding and controlling air pollution in highly populated areas is very important, although interpreting the levels of gaseous pollutants and airborne particulate matter is complicated by dominant natural and anthropogenic emissions, micro-meteorological processes, and chemical reactions which take place directly in the atmosphere. For this reason, it is very difficult to relate the characteristics of air pollution to one or more specific emission sources. The aim of this paper is to detect associations among elements and organic compounds emitted from specific sources by means of chemical analyses, statistical processing of data, seasonal evolution study, and geochemical considerations to trace their origin. A detailed characterization of air quality during the period September 2000–September 2001 was carried out in three locations of the Venice region: A heavy traffic urban site, a public park, and the island centre of the city of Venice. Twenty-eight inorganic elements, four polycyclic aromatic hydrocarbons, CO and benzene were quantified and processed by a statistical procedure based on factor analysis considering variations on a seasonal basis. Results show the presence of associations between elements and compounds with the same behaviour in all sampling points. This indicates that several pollutants originate from a common source, and are then “diluted” throughout the study area, maintaining the imprint of their origin. Pt, polycyclic aromatic hydrocarbons, CO and benzene originating from the exhaust gas of vehicles are all linked in the traffic factor, whereas Cd is associated with Se, having a common source in industrial processes.     

Qualitative investigation on hydrothermal treatment of Hinoki (Chamaecyparis obtusa) bark for production of useful chemicals

Hydrothermal treatment of an outer layer of a bark of Hinoki (Chamaecyparis obtusa) tree was investigated qualitatively for the possibility of utilizing residual forest biomass to produce valuable chemicals. Experiments were carried out in a semibatch reactor apparatus that allows the study of the effect of reaction temperatures in a single run. Gas chromatography-mass spectrometry analyses show the presence of useful chemicals such as furfural, aromatic compounds (1,3-di-tert-butyl benzene and 2,4-di-tert-butyl phenol), and fatty acids (myristic acid, palmitic acid, and stearic acid) in the products.     

Characterization of the key aroma compounds in cooked grey mullet (Mugil cephalus) by application of aroma extract dilution analysis

Aroma and aroma-active compounds of wild grey mullet ( Mugil cephalus ) were analyzed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O). According to sensory analysis, the aromatic extract obtained by simultaneous distillation and extraction (SDE) was representative of grey mullet odor. A total of 50 aroma compounds were identified and quantified in grey mullet. Aldehydes were qualitatively and quantitatively the most dominant volatiles in grey mullet. Aroma extract dilution analysis (AEDA) was used for the determination of aroma-active compounds of fish sample. A total of 29 aroma-active compounds were detected in aromatic extract of grey mullet, of which 24 were identified. On the basis of the flavor dilution (FD) factor, the most powerful aroma active compounds identified in the extract were (Z)-4-heptenal and nonanal, which were described as the strong cooked fish and green-fruity odor, respectively.     

鸡舍排出空气过滤清洗装置设计与试验

为降低鸡舍排风对场区环境和生物安全的影响,规模化鸡场开始普遍采用在鸡舍排风机外侧设置过滤网的方式拦截羽毛和过滤粉尘。羽毛和粉尘在过滤网积聚易导致鸡舍通风效率降低,因此需要定期进行人工清洗,既费工费时又危害清洗人员呼吸道健康。为实现鸡舍排出空气的自动化高效净化,该研究设计了一种由过滤机构、清洗机构、驱动机构和控制机构组成的鸡舍排出空气过滤清洗装置,并进行了试验验证和运行能耗及成本核算。根据鸡舍排风污染物特性和过滤清洗需求,确定了过滤网材质及孔径、冲洗杆喷头选型及布置方式,以及驱动小车电机选型和车轮直径等关键参数,编写了装置运行控制程序。该装置通过自走式小车沿导轨往返运动驱动连接在过滤网内外侧竖直布置的冲洗杆和收集槽同步运动,冲洗杆采用喷水反向冲洗的方式,将过滤网内侧积聚的羽毛和粉尘冲洗至收集槽中,再排放至鸡场废水收集系统,从而实现过滤网的定期自动清洗功能,保证过滤效果的同时减少人力投入。试验验证结果表明,该装置运行可靠、控制简单,能够过滤拦截收集鸡舍排出空气中的羽毛,对鸡舍排出空气中粉尘的去除率可达到55.0%;运行能耗及成本核算结果表明,装置耗水量为2.17 L/(次·m^2<...     

文洛型温室棚顶清洗机的研制与试验

针对国内文洛型温室棚顶清洗机械缺乏,人工清洗费时费力的问题,该研究设计了一种棚顶电动清洗机与配套换行作业平台,以实现对文洛型温室的自动清洗。为保证清洗机四轮行走的一致性,设计一种单电机两级减速同步驱动装置;针对电缆与水管收放过程中易发生堆积的问题,设计均匀卷线装置,对收放线过程进行分析,明确卷线半径与线速度的对应关系,优化卷线控制流程,满足了线缆、水管收放与清洗机往返同步的要求;为保证清洗辊刷对棚顶进行均匀可靠清洗,对刷毛与棚顶的接触过程进行了优化分析。样机性能测试表明,清洗最高行进速度为0.265 m/s,停机余量为28.4 mm;辅助换行平均时间为22.84 s,平台与屋顶对轨平均误差为1.6 mm。以薄膜透光率为指标,对清洗机的清洗效果进行试验,结果表明,在行进速度为0.25 m/s、辊刷转速120 r/min、水泵流量34 L/min的情况下,透光率为68%的薄膜经过清洗可提高到86%,清洗效果明显。该清洗机可以满足文洛型温室棚顶的清洗作业要求,对改善室内温光环境,提高果实产量与品质具有重要意义。     

中试规模猪粪堆肥挥发性有机物排放特征

为监测堆肥过程挥发性有机物(volatile organic compounds,VOCs)排放情况,该文开展了猪粪堆肥现场试验,采用苏玛罐采样,气相色谱-质谱法分析了猪粪好氧堆肥过程中VOCs浓度。结果表明:猪粪好氧堆肥过程中可以检测出的VOCs有81种,包括烷烃类34种,芳香烃类21种,卤烃类19种,胺类1种,含硫化合物3种,氟利昂类3种;其中检出率高且浓度远远超过其嗅阈值的VOCs包括三甲胺、二甲基硫、二甲基二硫和二甲基三硫,VOCs排放主要发生在堆肥的前2周。该研究将为控制猪粪堆肥过程中VOCs气体排放提供科学数据支持。     

Characterization and phenanthrene sorption of tea leaf powders

The sorption of hydrophobic organic compounds by natural organic matter is mainly regulated by its aromatic and aliphatic fractions, but it is not clear which fraction is more dominant. In this study, six types of Chinese tea leaves (three varieties of tender and three corresponding mature leaves) and their respective brewed ones were analyzed by elemental analysis, 13C NMR, and Fourier transform infrared attenuated total reflectance. Their sorption of phenanthrene was examined using a batch equilibration technique. The aromatic carbon content of tea leaves reduced while the aliphatic carbon content increased with increasing maturity and brewing. Sorption isotherms by all of the 12 tea sorbents were practically linear, showing a partition type sorption. The phenanthrene KOC (organic carbon-normalized sorption capacity) of the 12 sorbents ranged from 6960 to 32,900 mL/g, which increased with increasing aliphatic carbons and decreasing aromatic carbons in the tea leaves. The dissolved organic matter was released into solution from the sorbents during the sorption process, which could bind phenanthrene in the solution, and thereafter leading to underestimation of sorption capacity of the sorbents, but this did not change the correlation trends between KOC and functional carbon group content. Aliphatic fractions rather than aromatic moieties regulated the phenanthrene sorption of the tea leaf powders used in this study.