Effects of thermal desorption on the composition of two coking plant soils: impact on solvent extractable organic compounds and metal bioavailability

To evaluate the efficiency and the influence of thermal desorption on the soil organic compartment, contaminated soils from coking plant sites (NM and H) were compared to their counterparts treated with thermodesorption. The extractable organic matter, and the metal content and distribution with soil compartments were studied.In both thermodesorbed soils, PAH (polycyclic aromatic hydrocarbon) degradation exceeded 90%. However, the thermal desorption led not only to a volatilization of the organic compounds but also to the condensation of extractable organic matter.The treatments only affected the Fe and Zn distribution within the more stable fractions, whereas the organic compound degradation did not affect their mobility and availability.     

Assessment of honey contamination with polycyclic aromatic hydrocarbons

The aim of this study was to assess honey contamination by polycyclic aromatic hydrocarbons. Six species of honey were examined, as well as rape blossom and soil from villages P?czerzyno and Przybys?aw in West Pomerania, Poland. The instrumental analysis was performed using a HP 6890 gas chromatograph coupled to a HP 5973 mass spectrometer with selected ion monitoring (SIM). Quantification was done by gas chromatography-mass spectrometry (GC-MS) using perdeuterated internal standards. Both soil samples showed high levels of all 23 PAHs, whereas honey contained mostly non-carcinogenic PAHs of low molecular weight. The most contaminated honey from P?czerzyno contained 0.24 μg kg-1 benzo[a]pyrene. Moreover, despite low contamination of honey, a positive correlation was found between PAH content in honey, blossom and soil.     

基于统计方法的辽东湾沉积物中多环芳烃来源特征分析

为研究辽东湾表层沉积物中多环芳烃(PAHs)的来源特征,2014年5月采集了20个辽东湾海域表层沉积物样品,并利用气相色谱质谱联用仪对优先控制的16种PAHs进行测定,采用聚类分析、主成分分析-多元线性回归分析、异构体比值3种统计方法对辽东湾表层沉积物中PAHs来源特征进行了研究。结果表明,辽东湾表层沉积物中PAHs含量范围88.5~199.3 ng·g-1,平均值为(126.3±35.3)ng·g-1,其中,萘、菲和荧蒽是PAHs优势组分。通过统计分析结果表明,辽东湾北部表层沉积物中PAHs含量低于西南部,沉积物中PAHs的来源包括石油燃烧来源、煤炭、木材等生物质燃烧来源和石油来源,其中燃烧来源是主要来源,煤炭、木材等生物质燃烧来源占49.9%,石油燃烧来源和石油来源占50.1%。     

典型印染废水处理过程中芳香烃化合物的污染特征及污泥生态风险评价

采用GC-MS测定了典型综合印染废水处理厂废水和污泥中芳香烃化合物的含量.结果表明,原水中苯系物总量为203.96±15.18μg·L-1,其中二甲苯占62.7%,尾水中苯系物总量为0.2±0.029μg·L-1,整个处理工艺对苯系物的去除效率为99%.原水中多环芳烃(PAHs)总浓度达1349.51±35.77 ng·L-1,以3—6环为主,主要富集在颗粒物上.整个工艺对PAHs的去除效率为95%,尾水中PAHs总浓度为65.81±20.99ng·L-1,以2—3环为主.干污泥中PAHs含量高达2996.10±151.0 ng·g-1,污泥吸附为水相中PAHs去除的主要机理之一.印染污泥直接填埋或农用会引起潜在的生态危害.     

太原市污灌区农田土壤中多环芳烃污染特征及生态风险评价

通过对污灌区农田土壤多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)的分布特征、污染程度及来源进行解析,深入了解污水灌溉引发的土壤污染问题,实现污水灌溉农田土壤的污染预警和科学合理利用.在太原污灌农田共采集110个土壤样品,使用气相色谱-质谱仪(Gas Chromatography...     

Characteristics of microorganisms isolated from technogenic soils of the Kama region

Microorganisms capable of degrading monocyclic and polycyclic aromatic hydrocarbons and several chlorinated aromatic compounds were isolated from soils polluted with industrial waste from chemical plants. They were identified as representatives of the genera Pseudomonas, Flavobacterium, Alcaligenes, Rhodococcus, Microbacterium, Cellulomonas, Arthrobacter, and Brevibacterium. Among them, bacteria capable of utilizing xenobiotics in a wide range of ambient temperatures and pH and in the presence of high sodium chloride concentrations were revealed.     

Optimization of the recovery of plastics for recycling by density media separation cyclones

Material recovery processes are presented as the optimum option for recycling plastic wastes as a means of recovering hydrocarbon resources. There exist a large variety of automated material recovery processes for recycling of such wastes but each with significant limitations. Of these, the separation based on differences in densities is advocated as the optimum process either for producing recycled products or preparing wastes for subsequent recovery processing.Density separation processes based on cyclone type density media separation (DMS) is presented as an important, potential method for increasing plastics recycling process capacities. It is demonstrated to have the capacity to separate a significantly larger range of particle sizes than those presently processed industrially. The mathematical relationship for the prediction of quality of typical LARCODEMS type density media separations by particle size and density as expressed by the Ecart Probable is presented.A proposed device configuration is presented for density media separation to optimize the recovery and purity of both density fractions produced. It is also suggested that to be economically viable, a large scale of operation is required for industrial plastics recycling operations recovering and producing a number of different plastics with a purity to be used as a substitute for virgin material.     

Factors influencing on the bioaccessibility of polybrominated diphenyl ethers in size-specific dust from air conditioner filters

Size-specific concentrations and bioaccessibility of polybrominated diphenyl ethers (PBDEs) in dust from air conditioner filters were measured, and the factors influencing the PBDE bioaccessibility were determined. Generally, the PBDE concentrations increased with decreasing dust particle size, and BDE209 (deca-BDE) was generally the predominant congener. The bioaccessibility ranged from 20.3% to 50.8% for tri- to hepta-BDEs, and from 5.1% to 13.9% for BDE209 in dust fractions of varied particle size. The bioaccessibility of most PBDE congeners decreased with increasing dust particle size. The way of being of PBDE (adsorbed to dust surface or incorporated into polymers) in dust significantly influenced the bioaccessibility. There was a significant negative correlation between the tri- to hepta-BDE bioaccessibility and organic matter (OM) contents in dust. Furthermore, tri- to hepta-BDE bioaccessibility increased with increasing polarity of OMs, while with decreasing aromaticity of OMs. The tri- to hepta-BDE bioaccessibility significantly positively correlated with the surface areas and pore volumes of dust. Using multiple linear regression analysis, it was found that the OM contents and pore volumes of dust were the most important factors to influence the tri- to hepta-BDE bioaccessibility and they could be used to estimate the bioaccessibility of tri- to hepta-BDEs according to the following equation: bioaccessibility (%) = 45.05 − 0.49 × OM% + 1.79 × pore volume. However, BDE209 bioaccessibility did not correlate to any of these factors.     

Impact of solids on biphasic biodegradation of phenanthrene in the presence of hydroxypropyl- β -cyclodextrin (HPCD)

The consequence of polycyclic aromatic hydrocarbons (PAHs) in the environment is of great concern. The hydrophobic properties of PAHs significantly impact phase distribution causing limited bioavailability. Enhanced biodegradation has been extensively carried out by surfactants and the redeployment effect was recognized. However, the quantitative relationship concerning the impact of solids was rarely reported. A batch of biphasic tests were carried out by introducing Mycobacterium vanbaalenii PYR-1 and hydroxypropyl-β-cyclodextrin (HPCD) into a mixture of phenanthrene solution and various glass beads (GB37-63, GB105-125, and GB350-500). The comparative results demonstrated that HPCD had little effect on microbial growth and was not degradable by bacterium. A model was proposed to describe the biodegradation process. The regression results indicated that the partition coefficient k_d (1.234, 0.726 and 0.448 L·g⁻¹) and the degradation rate k (0 mmol·L⁻¹: 0.055, 0.094, and 0.112; 20 mmol·L⁻¹: 0.126, 0.141, and 0.156; 40 mmol·L⁻¹: 0.141, 0.156 and 0.184 d⁻¹) were positively and negatively correlated with the calculated total surface area (TSA) of solids, respectively. Degradation enhanced in the presence of HPCD, and the enhancing factor f was calculated (20 mmol·L⁻¹: 15.16, 40.01, and 145.5; 40 mmol·L⁻¹: 13.29, 37.97, and 138.4), indicating that the impact of solids was significant for the enhancement of biodegradation.     

Polycyclic aromatic hydrocarbons in medicinal plants from Syria

The levels of 16 US Environmental Protection Agency polycyclic aromatic hydrocarbons (EPA PAHs) in 10 medicinal plants in different used parts of plant (leaves and flowers) have been determined. The analytical method consists of sample preparation by ultrasonic extraction with dichloromethane followed by silica gel clean-up. Subsequently, the analysis was carried out by reversed-phase high-performance liquid chromatography (HPLC) coupled to both ultraviolet and fluorescence detections in series to insure the detection of all 16 EPA PAHs. It was observed that the sum of the 16 PAHs (ΣPAHs) in the investigated medicinal plants ranged from 47 to 890 μg kg^–1 where the highest ΣPAHs was found in Sage plant sample. Light PAHs were dominants in all studied medicinal plants. The sum of eight genotoxic PAHs (ΣPAH8) have shown a better indicator of the degree of contamination with carcinogenic PAHs compared to benzo[a]pyrene in these products.