长江三角洲地区城市污泥中苯并[a]芘和菲的初步研究

To evaluate the contaminated conditions of benzo[a]pyrene (B[a]P) and phenanthrene (PA) in sludge and to ascertain whether B[a]P limit for land application of sludge exists, the contents of B[a]P and PA in 46 sludge samples from 15 cities in the Yangtze River Delta area of China were determined using high performance liquid chromatography (HPLC) coupled with a fluorescence detector after ultrasonic extraction and silica gel cleanup. B[a]P contents ranged from non-detectable to 1.693 mg kg^-1 dry weight (DW), averaged 0.402 mg kg^-1 DW, and were < 1.0 mg kg^-1 DW in most of the sludge samples. PA was found in all the sludge samples analyzed; its contents ranged between 0.028 and 1.355 mg kg^-1 DW, with an average value of 0.298 mg kg^-1 DW. Most of the sludge samples contained < 0.5 mg kg^-1 DW PA. All 46 municipal sludge samples analyzed in this study showed B[a]P contents < 3.0 mg kg^-1 DW, which is the limit value for sludge applied to agricultural lands in China. The contents and distributions of B[a]P and PA in municipal sludge were related to sludge types, sources and treatment technologies, along with the physical and chemical properties of these pollutants.     

噬氨副球菌HPD-2对苯并[a]芘的降解特性及代谢途径初探

通过溶液培养的方法初步探讨了噬氨副球菌HPD-2对苯并[a]芘(B[a]P)的降解特性及代谢途径。结果表明,噬氨副球菌HPD-2对B[a]P的降解率随其初始浓度的增大而逐渐减小。当HPD-2在B[a]P初始浓度分别为5.0、50.0mg/L的培养液中生长5天后,B[a]P的降解率分别为66.1%和31%。经衍生化后GC-MS鉴定结果发现,8-羧酸-7-羟基芘和双羟基菲为噬氨副球菌HPD-2降解B[a]P的两种主要代谢中间产物。     

Liquid chromatographic determination of benzo[a]pyrene in total particulate matter of cigarette smoke

The benzo[a]pyrene (BaP) delivery of reference and commercially available tobacco cigarettes, as well as reference and placebo marijuana cigarettes, is determined using a sequential liquid chromatographic/liquid chromatographic procedure. The total particulate matter of sample cigarette smoke is collected using a Cambridge filter pad, which is ultrasonically extracted with acetone. The resulting extract is filtered, then fractionated using semipreparative-scale normal phase liquid chromatography (LC). Quantitative determination is achieved using analytical-scale reverse phase LC equipped with a fluorescence detector. The method is precise (+/- 10-15% relative standard deviation) and yields 85% or better BaP recovery at the ng/cig. level. A single pad may be analyzed in 8 person-hours, while a more typical lot of 12 pads (6 pads each for 2 cigarette brands) may be analyzed in 10 person-days.     

Features of accumulation,migration, and transformation of benzo[a]pyrene in soil-plant system in a model condition of soil contamination

Journal of Soils and Sediments - The investigation of accumulation, migration, and transformation features of benzo[a]pyrene (BaP) in a soil-plant system by using new ecologically friendly...     

氧化节杆菌生物降解苯并芘

A pot experiment was conducted with multi-metal (Pb, Cd, Cu, and Zn) contaminated acidic soil to investigate changes in available metal burden resulting from the application of industrial wastes (fly ash and steel slag). The efficiency of amendments-induced metal stabilization was evaluated by diffusive gradients in thin films (DGT), sequential extraction, and plant uptake. The stability of remediation was assessed by an acidification test and by chemical equilibrium modeling. Addition of fly ash (20 g kg-1 ) and steel slag (3 g kg-1 ) resulted in similar increase in soil pH. Both amendments significantly decreased the concentrations of metals measured with DGT (C DGT) and the metal uptake by Oryza sativa L. Significant correlations were found between C DGT and the concentration of a combination of metal fractions (exchangeable, bound to carbonates, and bound to Fe/Mn oxides), unraveling the labile species that participate in the flux of metal resupply. The capability of metal resupply, as reflected by the R (ratio of C DGT to pore water metal concentration) values, significantly decreased in the amended soils. The C DGT correlated well with the plant uptake, suggesting that DGT is a good indicator for bioavailability. Acidification raised the extractable metal concentration in amended soil but the concentration did not return to the pre-amendment level. Equilibrium modeling indicated that the soil amendments induced the precipitation of several Fe, Al and Ca minerals, which may play a positive role in metal stabilization. Chemical stabilization with alkaline amendments could be an effective and stable soil remediation strategy for attenuating metal bioavailability and reducing plant metal uptake.     

Development of biomarkers inAporrectodea caliginosa andLumbricus rubellus for detecting exposure to benzo[a]pyrene

Objectives and Methods. The sensitivity of two biomarkers, the neutral red retention assay (NRRA) and cytochrome P450 were evaluated in the earthwormAporrectodea caliginosa for their potential to detect exposure to benzo[a]pyrene (BaP). Cytochrome P450 was also evaluated in the earthwormLumbricus rubellus, and measured using the substrate ethoxycoumarin. Optimal assay conditions (pH, and temperature) were determined, followed by exposure of earthworms to 20 mg/kg BaP (a typical concentration at contaminated sites in New Zealand). Ethoxycoumarin-O-dealkylase (ECOD) activity was measured after 7, 14, and 21 days exposure. The NRRA was evaluated in earthworms exposed to 0.2, 20, and 100 mg BaP/kg, and biomarker responses were compared with effects on body weight. Results and Discussion Benzo[a]pyrene failed to induce ECOD activity in either earthworm species, and therefore it is not useful as a biomarker of BaP exposure and was not evaluated further. In all cases, the NRRA was significantly affected in the absence of any effects on earthworm body weight, indicating that this assay can detect exposure to BaP at a range of concentrations comparable to those found at contaminated sites. The NRRA should be linked to reproductive endpoints, then it can be used as an early warning indicator of adverse effects. Establishing biomarker stability under environmental conditions is an important step in biomarker development. Therefore, the effects of soil type (sandy soil, silt loam, and a clay soil), moisture content (15–30%), and temperature (5–20°) on the NRRA were determined. In all cases, there was no effect on the NRRA, indicating that this assay is very stable under varying environmental conditions. Conclusion and Outlook In conclusion, cytochrome P450 activity does not appear to be a useful indicator of PAH exposure in eitherA. caliginosa or L.rubellus, and due to the inherently low activity, it is not suitable as a routine biomarker for detecting environmental contamination by these compounds. In contrast, the NRRA in the earthworm A.caliginosa is a promising indicator of PAH exposure at the concentrations likely to be found in contaminated sites in New Zealand, and therefore has potential for evaluating these contaminated sites. If the NRRA can be linked to ecologically important life-cycle endpoints, such as reproduction, then it could be used as an early warning indicator of adverse effects at contaminated sites, i.e., by measuring biomarker responses in earthworms from a ‘contaminated area’ and comparing these with earthworms from a matched control area.     

New alternative method of benzo[a]pyrene extractionfrom soils and its approbation in soil under technogenic pressure

Purpose

The optimization of benzo[a]pyrene extraction conditions by subcritical water extraction method from soils is the purpose of the research. The optimal conditions for benzo[a]pyrene recovery are 30-min extraction by water in a special steel cartridge at 250 °C and 100 atm.

Materials and methods

Studies were conducted on the soils of monitoring plots subjected to Novocherkassk Power Station emissions. Monitoring plots were established at different distances from the Novocherkassk Power Station (NPS; 1.0–20.0 km).

Results and discussion

It was shown that the use of water in subcritical state as a solvent for benzo[a]pyrene extraction from soil allows to avoid large volumes of organic solvents and to decrease the time of sample preparation. It is shown that the maximum benzo[a]pyrene maintenance was observed in soils of the monitoring plots located most close (to 5 km) to a pollution source in the area of the prevailing direction of a wind rose. Dynamics of pollutant accumulation in soils depend on number of Novocherkassk state district power station emissions.

Conclusions

The method of benzo[a]pyrene subcritical water extraction from soil was developed and approbated during long-term monitoring researches of technogenic polluted territories. The optimum conditions for benzo[a]pyrene extraction from soil have been determined: the soil is treating by subcritical water at 250 °C and 100 atm of pressure for 30 min. Trends in the accumulation of benzo[a]pyrene in soil zones of the thermal power plant influence have been researched over a 5-year period of monitoring observations by subcritical water extraction method. Benzo[a]pyrene accumulation in soils depends on the technogenic emissions to the atmosphere from Novocherkassk power station and on the soil physical and chemical properties.

     

Influence of mixtures of acenaphthylene and benzo[a]anthracene on their degradation by Pleurotus ostreatus in sandy soil

Purpose

Polycyclic aromatic hydrocarbons (PAHs) are a class of organic compounds commonly found as soil contaminants. Fungal degradation is considered as an environmentally friendly and cost-effective approach to remove PAHs from soil. Acenaphthylene (Ace) and Benzo[a]anthracene (BaA) are two PAHs that can coexist in soils; however, the influence of the presence of each other on their biodegradation has not been studied. The biodegradation of Ace and BaA, alone and in mixtures, by the white rot fungus Pleurotus ostreatus was studied in a sandy soil.

Materials and methods

Experimental microcosms containing soil spiked with different concentrations of Ace and BaA were inoculated with P. ostreatus. Initial (t ₀) and final (after 15 days of incubation) soil concentrations of Ace and BaA were determined after extraction of the PAHs.

Results and discussion

P. ostreatus was able to degrade 57.7% of the Ace in soil spiked at 30 mg kg^?1 dry soil and 65.8% of Ace in soil spiked at 60 mg kg^?1 dry soil. The degradation efficiency of BaA by P. ostreatus was 86.7 and 77.4% in soil spiked with Ace at 30 and 60 mg kg^?1 dry soil, respectively. After 15 days of incubation, there were no significant differences in Ace concentration between soil spiked with Ace and soil spiked with Ace + BaA, irrespective of the initial soil concentration of both PAHs. There were also no differences in BaA concentration between soil spiked with BaA and soil spiked with BaA + Ace.

Conclusions

The results indicate that the fungal degradation of Ace and BaA was not influenced by the presence of each other’s PAH in sandy soil. Bioremediation of soils contaminated with Ace and BaA using P. ostreatus is a promising approach to eliminate these PAHs from the environment.     

High-pressure liquid chromatography of benzo(a) pyrene and benzo (ghi) perylene in oil-contaminated shellfish.

A high-pressure liquid chromatographic procedure is described for the determination of benzo(a) pyrene and benzo(ghi) perylene. These polynuclear aromatics are extracted with acetonitrile and partitioned into petroleum ether, the petroleum ether is removed, and the residue is saponified. The compounds are purified and isolated by passing the residue through a silica gel column and a high-pressure liquid chromatographic column, and detected by their ultraviolet absorption. Recoveries of standards through the procedure averaged 104%.     

Influence of kaolinite and montmorillonite on benzo[a]pyrene biodegradation by Paracoccus aminovorans HPD-2 and the underlying interface interaction mechanisms

Clay minerals play an important role in biogeochemical cycling.Here,kaolinite and montmorillonite,the two most abundant and widespread clay minerals with typical layered structures,were selected to investigate and compare their effects on the biodegradation of benzo[a]pyrene(BaP)by Paracoccus aminovorans HPD-2 and to investigate the underlying interface mechanisms.Overall,the BaP degradation efficiency was significantly higher 7 d after montmorillonite addition,reaching 68.9%(P<0.05),when compared with that of the control without addition of clay minerals(CK,61.4%);however,the addition of kaolinite significantly reduced the BaP degradation efficiency to 45.8%.This suggests that kaolinite inhibits BaP degradation by inhibiting the growth of strain HPD-2,or its strong hydrophobicity and readily agglomerates in the degradation system,resulting in a decrease in the bio-accessibility of BaP to strain HPD-2.Montmorillonite may buffer some unfavorable factors,and cells may be fixed on the surface of montmorillonite colloidal particles across energy barriers.Furthermore,the adsorption of BaP on montmorillonite may be weakened after swelling,reducing the effect on the bio-accessibility of BaP,thus promoting the biodegradation of BaP by strain HPD-2.The experimental results indicate that differential bacterial growth,BaP bio-accessibility,interface interaction,and the buffering effect may explain the differential effects of the different minerals on polycyclic aromatic hydrocarbon biodegradation.These observations improve our understanding of the mechanisms by which clay minerals,organic pollutants,and degrading bacteria interact during the biodegradation process and provide a theoretical basis for increasing the biodegradation of soil pollutants by native microorganisms under field conditions.     

Influences of kaolinite and montmorillonite on benzo[a]pyrene biodegradation by Paracoccus aminovorans HPD-2 and the underlying interface interaction mechanisms

Clay minerals play an important role in biogeochemical cycling. Here, kaolinite and montmorillonite, the two most abundant and widespread clay minerals with typical layered structures, were selected to investigate and compare their effects on the biodegradation of benzo[a]pyrene (BaP) by Paracoccus aminovorans HPD-2 and to investigate the underlying interface mechanisms. Overall, the BaP degradation efficiency was significantly higher 7 d after montmorillonite addition, reaching 68.9% (P < 0.05), when compared with that of the control without addition of clay minerals (CK, 61.4%); however, the addition of kaolinite significantly reduced the BaP degradation efficiency to 45.8%. This suggests that kaolinite inhibits BaP degradation by inhibiting the growth of strain HPD-2, or its strong hydrophobicity and readily agglomerates in the degradation system, resulting in a decrease in the bio-accessibility of BaP to strain HPD-2. Montmorillonite may buffer some unfavorable factors, and cells may be fixed on the surface of montmorillonite colloidal particles across energy barriers. Furthermore, the adsorption of BaP on montmorillonite may be weakened after swelling, reducing the effect on the bio-accessibility of BaP, thus promoting the biodegradation of BaP by strain HPD-2. The experimental results indicate that differential bacterial growth, BaP bio-accessibility, interface interaction, and the buffering effect may explain the differential effects of the different minerals on polycyclic aromatic hydrocarbon biodegradation. These observations improve our understanding of the mechanisms by which clay minerals, organic pollutants, and degrading bacteria interact during the biodegradation process and provide a theoretical basis for increasing the biodegradation of soil pollutants by native microorganisms under field conditions.     

Addition of porphyrins to cigarette filters to reduce the levels of benzo[a]pyrene (B[a]P) and tobacco-specific N-nitrosamines (TSNAs) in mainstream cigarette smoke

Tobacco-specific N-nitrosamines (TSNAs) and benzo[a]pyrene (B[a]P) in mainstream cigarette smoke (MSS) cause smoking-related diseases and environmental pollution. Porphyrins were added to cigarette filters to reduce B[a]P (porphyrins A-E) and TSNAs (porphyrin F) in MSS. The porphyrin-B[a]P and porphyrin F-TSNAs (N'-nitrosoanabasine (NAB), N'-nitrosoanatabine (NAT), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and N-nitrosonornicotine (NNN)) interactions were investigated by fluorescence quenching and UV-visible spectroscopy. The correlation coefficients were 0.987-0.997 (B[a]P) and 0.994-0.999 (TSNAs), and the binding constants were (1.67-5.02) × 10(5) (B[a]P) and 3.42 × 10(3)-1.40 × 10(4) (TSNAs). Up to 36.72% of B[a]P and 46.67% of the TSNAs were eliminated from MSS, with greater reductions when more porphyrin was included in the filter. With the same mass of porphyrin in the filter, the reduction trend for B[a]P by porphyrins A-E was A > B > C > D > E. The reduction trend for TSNAs by porphyrin F was NNN > NAB > NNK > NAT. The porphyrin mode of action is possibly through strong π-π interactions.     

Levels of benzo[a]pyrene (BaP) in "mozzarella di bufala campana" cheese smoked according to different procedures

The content of benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon, was determined by HPLC-FL in "mozzarella di bufala campana" cheese, a stretched cooked cheese, either experimentally smoked according to traditional procedures, using straw, cardboard, and wood shavings or aromatized with smoke flavoring. The BaP residues, researched also in cheese samples sold at retail, were detected in the rind, in the core, and in the slice (outer and inner parts). In the cheeses experimentally smoked with straw and cardboard the BaP levels, ranging from 0.38 to 2.12 microg kg(-1) and from 0.46 to 2.40 microg kg(-1), respectively, were statistically higher than those of the cheeses smoked with wood shavings and aromatized with liquid smoke (from 0.19 to 0.80 microg kg(-1) and from 0.18 to 0.50 microg kg(-1), respectively). However the cheeses treated with liquid smoke flavor showed a BaP content exceeding the level allowed by the European Union. In the samples sold at retail, smoked with straw, values were lower than those obtained from samples smoked experimentally with the same combustible. This is probably due to different smoking technologies among the several provinces of the Protected Designation of Origin (PDO) area. PDO is a term used to characterize foodstuffs produced and prepared in a given geographical region by the means of a recognized process. A standardization of the traditional smoking procedures and an improvement of liquid smoke purification treatments are recommended for mozzarella cheese.     

Enhanced degradation of pyrene and phenanthrene in sediments through synergistic interactions between microbial fuel cells and submerged macrophyte Vallisneria spiralis

Journal of Soils and Sediments - Submerged macrophyte Vallisneria spiralis and sediment microbial fuel cell (SMFC) systems are cost-effective methods for the remediation of polycyclic aromatic...     

Selective enrichment of a pyrene degrader population and enhanced pyrene degradation in Bermuda grass rhizosphere

Rhizosphere soil has a more diverse and active microbial community compared to nonvegetated soil. Consequently, the rhizosphere pyrene degrader population (PDP) and pyrene degradation may be enhanced compared to nonvegetated bulk soil (NVB). The objectives of this growth chamber study were to compare (1) Bermuda grass (Cynodon dactylon cv. Guymon) growth in pyrene-contaminated and noncontaminated soils and (2) pyrene degradation and PDP among NVB, Bermuda grass bulk (BB), and Bermuda grass rhizosphere soil (BR). Soils were amended with pyrene at 0 and 500 mg kg^–1, seeded with Bermuda grass, and thinned to two plants per pot 14 days after planting (DAP). Pyrene degradation was evaluated over 63 days. The PDP was enumerated via a most probable number (MPN) procedure at 63 DAP. Bermuda grass root growth was more sensitive to pyrene contamination than shoot growth. Pyrene degradation followed first-order kinetics. Pyrene degradation was significantly greater in BR compared to BB and NVB with rate constants of 0.082, 0.050, and 0.052 day^–1, respectively. The PDPs were 8.01, 7.30, and 6.83 log₁₀ MPN g^–1 dry soil for BR, BB, and NVB, respectively. The largest PDP was in soil with the most rapid pyrene degradation. These results indicate that Bermuda grass can grow in pyrene-contaminated soil and enhance pyrene degradation through a rhizosphere effect.     

Algal degradation of a known endocrine disrupting insecticide, alpha-endosulfan, and its metabolite, endosulfan sulfate, in liquid medium and soil

The role of algae in the persistence, transformation, and bioremediation of two endocrine disrupting chemicals, alpha-endosulfan (a cyclodiene insecticide) and its oxidation product endosulfan sulfate, in soil (incubated under light or in darkness) and a liquid medium was examined. Incubation of soil under light dramatically decreased the persistence of alpha-endosulfan and enhanced its transformation to endosulfan sulfate, over that of dark-incubated soil samples, under both nonflooded and flooded conditions. This enhanced degradation of soil-applied alpha-endosulfan was associated with profuse growth of indigenous phototrophic organisms such as algae in soil incubated under light. Inoculation of soil with green algae, Chlorococcum sp. or Scenedesmus sp., further enhanced the degradation of alpha-endosulfan. The role of algae in alpha-endosulfan degradation was convincingly demonstrated when these algae degraded alpha-endosulfan to endosulfan sulfate, the major metabolite, and endosulfan ether, a minor metabolite, in a defined liquid medium. When a high density of the algal inoculum was used, both metabolites appeared to undergo further degradation as evident from their accumulation only in small amounts and the appearance of an endosulfan-derived aldehyde. Interestingly, beta-endosulfan was detected during degradation of alpha-endosulfan by high density algal cultures. These algae were also capable of degrading endosulfan sulfate but to a lesser extent than alpha-endosulfan. Evidence suggested that both alpha-endosulfan and endosulfan sulfate were immediately sorbed by the algae from the medium, which then effected their degradation. Biosorption, coupled with their biotransformation ability, especially at a high inoculum density, makes algae effective candidates for remediation of alpha-endosulfan-polluted environments.     

Using composted wheat residue as a growth medium in culture of tomato

A greenhouse experiment was carried out to investigate the effects of different growing media on some properties of tomato (Lycopersicom esculentum L. cv. Falcato). Four growing media including wheat residue, composted wheat residue, coco peat + perlite, and coco peat + soil were applied in pot experiment with completely randomized design with three replications. The results showed that fruit yield, chlorophyll, and vitamin C contents of tomatoes grown in the composted wheat residue and coco peat + perlite treatments were significantly greater than the other growth media. Fresh weight of root and inflorescence were higher in the tomatoes cultivated in the composted wheat residue pots than the other media. Higher internode length and nutrient concentrations in leaf and fruit at the coco peat + perlite treatment were obtained as compared to the other growth media treatments. According to the results, it can be concluded that the coco peat + perlite can be substituted for by composted wheat residue for the cultivation of tomato.     

生物表面活性剂及Tween-80在一株菲降解菌降解过程中的作用研究

Numerous studies have been devoted to the physical-chemical weathering processes leading to the creation of unique soil formations having their own history that induce soil-biotic diversity. However, the extent to which unique geomorphic formations influence soil biotic seasonal variation is not clear. Our aim was to define seasonal variations of soil biota in soils of different-aged terraces of the Makhtesh Ramon anticline erosional cirque in southern Israel. The strong effect of Makhtesh Ramon (Ramon Crater) erosional fluvial terrace age initiated by climatic changes during the Late Pleistocene–Early Holocene period on seasonal variations in both soil properties and the abundance and composition of soil biota were demonstrated. However, age dependence was not constant and values for observed soil properties and microbial activity were negligible between younger and older terraces for certain seasons, while free-living nematodes along with bacteria-feeding group were strongly dependent on the geomorphic features of the ages throughout the study period.     

土壤pH、水分及温度对长期污染土壤中苯并[a]芘动态变化的影响初探

以受多环芳烃长期污染农田土壤中苯并[a]芘(B[a]P)为研究对象,采用室内模拟试验研究了pH、水分和温度对土壤中B[a]P的动态变化的影响。结果表明,供试污染土壤中B[a]P能被土著微生物快速去除,其消减过程受到pH、水分和温度的影响。初始pH为4.6、5.9和7.3的泥浆中B[a]P在7天内的去除率分别为43.8%、37.8%和14.0%。在土壤水分为22%、43%、65%和87%田间持水量,温度为28℃条件下培养80天后土壤中B[a]P的去除率分别为42.5%、96.6%、96.3%和34.3%。在土壤pH为4.5,土壤水分为60%±5%田间持水量,温度为25℃和40℃条件下土壤中B[a]P的半衰期分别为33天和16天。可见,pH、水分和温度等环境条件对土壤中B[a]P的消减过程具有明显的影响,可通过人为调控强化B[a]P污染土壤的生物修复。