Biodegradation of High Molecular Weight Polycyclic Aromatic Hydrocarbons Mixture by a Newly Isolated Fusarium sp. and Co-Metabolic Degradation with Starch

One native fungal strain, designated ZH-H2, was isolated from an agricultural soil contaminated by HMW-PAHs in a typical coal mining area of Hebei, China. The filamentous fungus was identified as a Fusarium sp. ZH-H2 was able to survive not only in the presence of the individual HMW-PAHs of Chry, BaA, B(K)F, BaP, DB(a,h)A, InP, InP and B(g,h,i)p but in the presence of a mixture of the above seven HMW-PAHs with a total concentration of up to 10 mg L^?1. Biodegradation experiments demonstrated that Fusarium sp. (ZH-H2) was able to degrade the aforementioned individual HMW-PAHs, with a degradation percentage of 77%, 85%, 91%, 42%, 56%, 42% and 38%, respectively, and degrade the aforementioned seven PAHs mixture with a degradation percentage of 48%. The effect of starch addition on the biodegradation efficiency of the PAH mixture was also investigated. The results showed a significant improvement in the degradation extent of the PAH mixture with the increase of starch concentration. The greatest degradation rate (DR; 89%) in 7 d was obtained when starch was added at 1.0 g L^?1, about 2-fold than was achieved without starch. This study implicates that Fusarium sp. (ZH-H2), a potential biodegrader, is suitable for practical field application in effective bioremediation of soils that have been simultaneously contaminated by several HMW-PAHs for a long time.     

Sorption of binary mixtures of toluene + lower aliphatic alcohols C1 – C6 in low‐density polyethylene

Sorption gravimetric and volumetric techniques performed at 25°C and at atmospheric pressure were employed to study the preferential and total sorptions from binary liquid mixtures of toluene + lower aliphatic alcohols (C₁ – C₆) in a high‐pressure low‐density polyethylene membrane and the volume of the swollen membrane. Toluene was preferentially sorbed in all six systems. The total sorbed amount increased from pure alcohol to pure toluene. The experimental volume of the swollen membrane was compared with that calculated under the assumption that interactions between the polymer and liquid mixture were negligible. The composition of the binary liquid mixture sorbed in the polymer as a function of the composition of the bulk solution surrounding the membrane is presented. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

VOCs污染场地地下水监测式自然衰减法可行性评估程序研究

挥发性有机污染物（VOCs）是我国污染场地地下水中高频检出的污染物,在地下水中多以非水相液体（NAPL）形式存在,成为持久的污染源,具有较高的环境和健康风险.监测式自然衰减法修复技术（MNA）可以单独使用,也可以和其他修复技术联合使用,具有费用较低、不会造成其他负面影响等优势,作为地下水污染修复的一种可选方法已得到普遍认可,执行监测式自然衰减法前必须进行自然衰减可行性评估,实施监测式自然衰减法修复技术,具有良好的发展前景.概述了目前国内外主要的地下水中VOCs自然衰减修复技术的研究进展.地下水中VOCs自然衰减可行性评估程序研究的开展,可以为我国制定利用MNA技术修复污染场地章程和规章以及保障地下水安全提供可靠的科学依据.     

MEASUREMENT OF CONCENTRATIONS OF POLYCYCLIC AROMATIC HYDROCARBONS AND DIOXIN COMPOUNDS IN CANINE LUNGS

Polycyclic aromatic hydrocarbons (PAHs) and dioxin compounds remaining in canine lungs were measured with an alkaline decomposition method employing KOH/ethanol. PAHs extracted from the lungs of 31 dogs were between 0.07 and 0.47 ng/wet-g (mean: 0.19 ng/wet-g) for BaA; 0.03 and 0.16 ng/wet-g (mean: 0.08 ng/wet-g) for BkF; 0.05 and 0.29 ng/wet-g (mean: 0.13 ng/wet-g) for BaP; and 0.05 and 0.35 ng/wet-g (mean: 0.17 ng/wet-g) for BghiP. Dioxin concentrations were between 0.047 and 0.870 pg-TEQ/wet-g (mean: 0.179 pg-TEQ/wet-g). There were big differences between the PAH concentrations and dioxin concentrations in the canine lungs. Strong relationships were observed between individual PAHs (r = 0.73–0.95). In this study, we detected PAHs and dioxins in all samples, confirming that canine lungs were contaminated by those pollutants.     

PAH in airborne particulate matter.: Carcinogenic character of PM10 samples and assessment of the energy generation impact

One of the main anthropogenic sources producing Polycyclic Aromatic Hydrocarbons (PAH) is related to combustion processes especially transport, power generation processes and other industrial activities. Therefore, the main cities constitute one of the main pollution sources for population. Due to the carcinogenic character of some of these pollutants, Directive 2004/107/EC established a target value of 1.0 ng/m³ with regard to Benzo(a)pyrene (BaP) for the total content in the particulate matter fraction averaged over a calendar year. Nevertheless, the consideration of only BaP can underestimate the carcinogenic character of the particulate matter.In this work, the carcinogenic character of the airborne PM10 of Zaragoza was studied during 2003-2004 by determining the concentration of BaP equivalents (BaP-eq), using toxic equivalent factors provided by Larsen and Larsen. Diagnostic ratios were used to discern regarding the main pollution sources in Zaragoza city in which the prevailing emission sources were related to diesel emissions and combustion sources. As PAH can travel long distances around the world, the impact of local pollution sources and long-range atmospheric transport on those samples exceeding 1.0 ng/m³ of BaP-eq that imply higher risk for human health were assessed by considering BaA/Chry and BaP/BeP ratios and by studying the origin of the air masses with the backward air trajectories according to the HYSPLIT model. Those samples were mainly produced during cold season. The local pollution sources were the dominant sources although one episode of long-range transport from European countries could be observed.     

EFFECTS OF FLOW RATE AND TEMPERATURE ON THE DISSOLUTION OF POLYCYCLIC AROMATIC HYDROCARBONS TRANSFERRING FROM A NONAQUEOUS PHASE LIQUID TO NONIONIC SURFACTANT SOLUTIONS

The effects of flow rate and temperature on the dissolution of two polycyclic aromatic hydrocarbon (PAH) compounds, naphthalene and phenanthrene, transferring from a synthesized nonaqueous phase liquid (NAPL) comprised of hexadecane and the 2 PAHs into different nonionic surfactant solutions were investigated using a reactor with a spinning cell. The variation of the flow rate was possible by changing the angular velocity of the spinning cell. The flow rate generally increased the values of the mass transfer coefficients and the rates of mass transferred for both aromatics in the absence and presence of a surfactant in the aqueous phase. In comparison to the pure aqueous solution the results suggest that the addition of a surfactant at all doses investigated enhanced the rates of mass transfer for both PAHs. As the temperature increased the rates of mass transfer for both PAHs in the solutions of surfactants increased. The increase in the temperature has a much greater effect on the rates of mass transfer for both PAHs in solutions of the surfactant Triton X-100 than in Brij 35. In solutions of the surfactant Triton X-100 a decrease in the mass transfer coefficient for both PAHs with surfactant concentration was observed for the temperatures investigated.     

Airborne Polycyclic Aromatic Hydrocarbons (PAH) in Bangkok Urban Air: Part II. Level and Distribution

The gas-particle partitioning and particle size distributions of airborne PAH in Bangkok urban air were investigated using an 8 stage size fractionating cascade impactor (Andersen “low volume” sampler) and a downstream XAD-2 adsorbent tube for sample collection. Nine PAH classified as carcinogenic and co-carcinogenic compounds-Pyrene (PYR), Benz(a)Anthracene (BaA), Benzo(e)Pyrene (BeP), Dibenz(a,c)Anthracene (DBacA), Benzo(k)Fluoranthene (BkF), Benzo(a)Pyrene (BaP), Dibenz(a,h)Anthracene (DBahA), Benzo(ghi)Perylene (BghiP) and Trimethylcholanthrene (3MC) - were quantified. The lower molecular weight (MW) PAH such as PYR, BeP and BaA were present mainly in the gaseous phase (80%, 40% and 24%, respectively) while higher MW compounds were present almost totally in the particulate fraction. The results show that 30%–60% of each PAH by mass were found on particles smaller than 0.43 μm and more than 70% on particles with diameter less than 2.1 μm. In addition, the relationship between the particle/gas partition coefficient (K _p ) and the sub-cooled liquid vapor pressure (p°_L) was also determined to describe the gas-particle partitioning of those PAH compounds in a tropical atmosphere.     

Evaluation of polyaromatic hydrocarbon removal from aqueous solutions using activated carbon and hyper‐crosslinked polymer (Macronet MN200)

BACKGROUND: Sorption of polycyclic aromatic hydrocarbons (PAHs) on activated carbon and the Macronet polymeric sorbent MN200 was investigated to determine the effectiveness of each sorbent for removal of pollutants from aqueous solution and their possible use as sorbent materials for groundwater. Experiments were carried out to determine the loading capacities of a family of PAHs (acenaphthene, anthracene, fluoranthene, fluorene, naphthalene and pyrene). RESULTS: Activated carbon was the more effective sorbent, with maximum loadings of PAHs between 90 and 230 g kg^?1, while MN200 resin showed values of 25–160 g kg^?1. Loading isotherms based on the Langmuir, Freundlich and Redlich–Peterson models were determined. The hydrophobic character of the pollutants appeared as an important parameter related to the sorption process. Equilibrium and kinetic parameters were used to determine the retardation factors for each PAH. CONCLUSION: The calculated values for the simulation of barrier thickness using both sorbents, taking into account EU requirements for PAHs in groundwater effluent, were perfectly reasonable as a first estimate. The better kinetic properties of MN200 are evident in lower hydraulic residence times and consequently in a lower barrier thickness. Copyright © 2008 Society of Chemical Industry     

饱和区中非水相有机物溶解的实验研究

地下环境中非水相有机污染物通常会成为地下水污染的持久性污染源,因而更好地了解非水相污染物溶解的过程对于地下水污染和治理会有很大的帮助。采用实验室二维砂箱模拟饱和区地下水流动条件下,非水相甲基叔丁基醚溶解过程,主要考察非水相液体初始饱和度、分布区域大小和地下水流速对于溶解过程的影响。实验结果表明,非水相溶解过程初期水相中质量浓度很高,接近于溶解度,之后逐渐降低进入拖尾期;非水相初始饱和度越高流出质量浓度出现最高点的时间越晚,完全溶解所需时间越长;地下水流速提高会使平衡溶解期变短,而且会减少完全溶解所需的时间;非水相液体源范围越大,出口峰值质量浓度越高,但是峰值出现时间越晚。     

Stability and extraction study of phenolic wastewater treatment by supported liquid membrane using tributyl phosphate and sesame oil as liquid membrane

Phenols pose a risk to the environment and to human health. Phenol and its derivatives are toxic pollutants, frequently found in surface and tap waters, and in aqueous effluents from various manufacturing processes. In this paper, an experimental study regarding transport of phenol through a supported liquid membrane (SLM) using tributyl phosphate (TBP) and sesame oil as liquid membrane (LM) was performed. Factors affecting permeation of phenol such as initial phenol concentration, carrier concentration, feed phase pH and stripping phase concentration were analyzed using Taguchi method. Optimal experimental condition of phenol transport was obtained using analysis of variance (ANOVA) after 7 h extraction (feed concentration: 200 mg/L; carrier concentration (%TBP): 40%; feed pH: 2; strip phase concentration: 1.1 M). Mass transfer coefficient for this system was evaluated, and compared with similar works, and it was shown that it has the highest mass transfer rate. In addition to transport study, stability of the membrane was investigated by examination of stripping phase concentration, carrier concentration and salt concentration effects.     

地下水修复中纳米零价铁材料制备及应用综述

纳米零价铁（nZVI）具有较强的还原和吸附能力,能有效去除多种类型的污染物质,在地下水环境修复领域一直备受关注。但由于其易团聚和易钝化等缺陷,在实际应用过程中还存在着许多问题。本文综述了nZVI的常用制备方法,并对nZVI的常用改性方法进行归纳,分析各种改性方法起到的具体作用,指出改性过后的复合材料依然存在着的问题。在此基础上,阐述了改性nZVI在去除地下水中有机污染物和无机污染物的应用进展,总结了改性nZVI材料在去除过程中起到的具体作用和反应机制,并进一步归纳现阶段nZVI在地下水修复中的传输手段。根据已有研究成果,指出应改进现有制备方法实现nZVI的量产,在考虑nZVI生物毒性和材料再回收的前提下,合理使用多种改性方式实现nZVI的材料制备,选择符合污染场地实际情况的传输手段,从而提高nZVI在地下水污染修复中的使用寿命和对目标污染物的处理效果。     

生物通风过程中的甲苯运移及生物降解

Bioventing is conducted on one-dimensional soil columns.A numerical model is developed for simulating the mass exchange,advective and dispersive transport and biodegradation of toluene.The model parameters are estimated independently through laboratory batch experiments,or from literature.Simulations are found to provide reasonable agreement with experimental data.Experimental results show that toluene removal due to biodegradation is more important at the later stage.The total cleanup time when NAPL(non-aqueous phase liquid)phase exists was twice more than that without NAPL.Sensitivity analysis of parameters suggests that model predictions are mainly dependent on mass transfer coefficient and microbial parameters,such as the half-saturation coefficient and maximum specific substrate utilization rate.     

LEAVES OF NERIUM OLEANDER L. AS BIOACCUMULATORS OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH) IN THE AIR OF PALERMO (ITALY): EXTRACTION AND GC-MS ANALYSIS,DISTRIBUTION AND SOURCES

Polycyclic Aromatic Hydrocarbons (PAH) were determined in the leaves of Nerium oleander L. an evergreen plant that occurs widely in both urban and rural areas, to monitor the degree of pollution in the urban area of Palermo (Italy) compared to remote areas. Twenty sites (urban roadside, urban, urban park, suburban and rural) in and around Palermo city were investigated.

The purpose of this research was to investigate concentration levels and distribution patterns and relate them to possible sources. Analysis of 19 PAH was performed by gas chromatography/mass spectrometry (GCMS) using selected ion monitoring (SIM). The total amount of PAH ranged from 10 to 166 μg/Kg d.w.

Each source gives rise to a characteristic PAH pattern, and it is therefore possible to get access to the processes that generate the compounds. To this aim, the recommended as priority pollutants by the Environmental Protection Agency (EPA), perylene and three additional alkylated compounds were analyzed.

Positive correlations were found between total PAH content of the leaves with CO, benzene and particulate levels measured in air of Palermo.     

SOLID-LIQUID MASS TRANSFER AND WETTING FACTORS IN TRICKLE BED REACTORS: EFFECT OF THE TYPE OF SOLID PHASE AND THE PRESENCE OF CHEMICAL REACTION

The solid-liquid wetting factor, f, for solid dissolution in a liquid with and without chemical reaction was experimentally determined in a fixed bed three-phase reactor with downward concurrent gas and liquid flows (Trickle Bed Reactor). The method employed consisted of comparing the volumetric solid-liquid mass transfer coefficient obtained when two phases (liquid and gas) circulated through the bed, with those coefficients obtained at liquid full bed conditions, maintaining the intrinsic liquid velocity constant. The chemical system selected was benzoic acid and acetylsalicylic acid as solid phases, water and sodium hydroxide in aqueous solution, and atmospheric air. Experiments were carried out in which the flow of both phases was modified, obtaining a direct dependency of f with the flow and holdup of liquid. The gas flow effect over f was not important in the flow regime studied, defined as the low interaction regime. Furthermore, the wetting factor is not affected by the nature of the solute and by the presence of a chemical reaction.     

SORPTION PROPERTIES OF SYNTHETIC FERRIERITE

Limiting sorption volumes of the hydrogen form of a synthetic ferrierite sample were determined for sorbates--water, methanol, propane, hexane, and o-, m-, p-xylenes--at 298 K and at a relative pressure of P/P o = 0.5 using a gravimetric sorption apparatus. Methanol, which has a kinetic diameter significantly smaller than the pore dimensions, was sorbed relatively rapidly and by the greatest amount. The sorption rates of other sorbates were very slow and for some it took several days for equilibrium to be established. The results indicated that, although their kinetic diameters are similar, the adsorption behavior of propane and hexane are quite different. Hexane is able to fill only ten-membered ring channels whereas propane is able to fill both ten- and eight-membered ring channels, at least partially. The inability of the hexane molecules to be sorbed into eight-membered ring channels is attributed to chain length effect. Xylene isomers are sorbed by the H-ferrierite but to smaller extents, consistent with the significantly larger kinetic diameters of these molecules compared to the reported pore dimensions of ferrierite. Among the xylene isomers, p-xylene, with the smallest kinetic diameter of three isomers, is sorbed to a greater extent than either o-xylene or m-xylene.     

WHERE ARE THE LIMITS OF THE GAS-PHASE FLUORESCENCE ON THE POLYCYCLIC AROMATIC COMPOUND ANALYSIS?

The aim of this work has been centered on the development of a detection system which could be useful to determine polycyclic aromatic hydrocarbon (PAH) emissions in power generation processes where PAHs are released to the atmosphere in the gas phase. In this way, a suitable sensor based on gas phase fluorescence spectroscopy was designed to facilitate the PAH analysis, avoiding previous steps necessary to determine liquid samples such as extraction, concentration, and cleaning. This gas cell was applied for two experimental installations at laboratory scale. One of them was used to determine adsorption capacities and breakthrough curves of PAH binary mixtures and the other installation allowed the separation of PAH mixtures by using, previous to the gas phase fluorescence spectroscopy, a packed column.     

DISTRIBUTION OF PRIORITY POLYCYCLIC AROMATIC HYDROCARBONS IN THE SEDIMENT OF LAKE BALATON,HUNGARY

The determination of 13 PAH pollutants was carried out on sediment samples collected at 27 sites at the Lake Balaton, Hungary. The aim was to investigate the distribution patterns of PAHs and the correlation of source-sink relationship. Sediment samples were collected from the upper 10 cm and from 20 to 70 cm depth. The dry mass ratio of the fine grain-size fraction (<0.063 mm) and the coarse sand sediments (0.063–500 mm) were analyzed. Principal component analysis (PCA) was performed on the PAH compositional data for 110 samples to estimate the distribution of PAHs in different compartments. The average concentration of PAHs was found as 132 μg/kg dry weight (11–1734 μg/kg) for all sites and depth. Considering the harbors, at some sites, 930–950 μg/kg of total PAHs were obtained. The ratio of phenantrene/anthracene (PHE/AN) and fluoranthene/pyrene (FA/PY) indicated that most of the samples showed pyrogenic origin. It can be established that the upper 10 cm of the sediment is significantly more polluted than the deeper layers. The interim sediment quality guideline (ISQG) values and the probable effect level (PEL) were used to compare our findings with other data. No concentrations of PAHs were found higher than either ISQG and PEL values of samples collected inside of the lake, so the sediment has not been associated with adverse biological effects. However, the maximum concentrations of 7 out of 9 PAH compounds found in samples of harbors were higher than ISOG values but lower than PELs. Analysis of the harbor sediments revealed an elevated amount of contamination probably derived from the fuel of ships.     

EFFECTS OF GLASS MICROFILLERS ON THE WATER-TRANSPORT BEHAVIOR OF POLYURETHANE COMPOSITES

Glass microspheres with unique composition and diameter, and modified by different surface treatments, were blended with polyurethane (PU) in various proportions to improve the liquid transport properties of the PU composites. Transport properties such as diffusion, permeability, and sorption coefficient were measured on various filler-filled PU composites at three different temperatures. These temperature-dependent parameters were used to provide a quantitative way to examine the effects of filler loading and the surface properties on the improvement of the water transport properties of PU composites. Results show that due to trapping at interfacial boundaries between filler and polymer, a high water affinity and large space for water activity is expected inside all the filler-filled composites. As a result, lower water diffusion (or high water resistivity) was found among all the filler-filled composites compared to that of filler-free composites. Besides, the more filler present in the composite, the longer the paths of the water molecules within the composites as the water penetration proceeds. Thus, lower diffusion coefficient values were observed for composites with large amounts of filler addition.     

UiO-66复合材料用于典型有机污染物吸附和光催化氧化的研究进展

UiO-66系列金属有机骨架（MOFs）材料因具有较高的比表面积、丰富的孔结构、优异的结构稳定性和类半导体特性而广泛应用于污染物的吸附和催化领域。文中指出：液相有机污染物主要通过物理吸附、静电、氢键、π-π相互作用被UiO-66基材料吸附去除,同时由于电性等性质差异,UiO-66基材料可从性质差异显著的多种有机污染物中选择性吸附污染物,而气相有机污染物主要通过氢键或UiO-66基材料孔道被吸附去除,同时环境中的水汽对污染物的吸附去除具有显著影响;针对光催化,由于载流子的快速复合,纯UiO-66基材料具有较低的光催化活性,通过与半导体材料复合可显著提高材料载流子分离速率,同时活性位点高度均匀分散在UiO-66基材料表面,利于光的激发及污染物与活性位点的充分接触,进而显著提高材料的光催化活性。与此同时,本文也提出了UiO-66基材料在有机污染物吸附和去除中的不足之处。最后展望了UiO-66基材料的发展前景。     

FACTORS THAT INFLUENCE THE COALESCENCE OF BUBBLES IN OILS THAT CONTAIN SILICONE ANTIFOAMANTS

This paper deals with several factors that contribute to the dual nature of silicone antifoamants. For example, soluble silicones can concentrate at the air/oil interface to stabilize bubbles, while dispersed drops of silicone can accelerate the coalescence process by rapidly spreading at the gas/liquid interface of a bubble causing film thinning by surface transport. In this paper, experiments are described that show that the apparently low solubility of silicone in different oils is actually a slow rate of dissolution that depends on the viscosity of the oil and the concentration of dispersed drops. Furthermore, it is shown that there is a critical size for the coalescence of air bubbles in different oils and with different amounts of silicone. Insight into the mechanisms of the critical bubble size and the reason why significantly faster coalescence occurs at a lower concentration of silicone can be explained in terms of higher interfacial mobility (as determined by bubble rise velocities).