Evidence of debromination of decabromodiphenyl ether (BDE-209) in biota from a wastewater receiving stream

Decabromodiphenyl ether (BDE-209) is a high production volume flame retardant. To date, regulation and control of its environmental release have been minimal. Once in the environment, BDE-209 may encounter conditions favoring debromination, potentially forming congeners with greater toxicity, bioaccumulation potential, and persistence. However, (photolytic and in vivo) debromination has only been demonstrated under laboratory scenarios. To examine whether debromination was likely in the field, PBDE congener profiles were tracked from a wastewater treatment plant (sludge) to receiving stream sediments and associated aquatic biota. BDE-209 and 23 additional PBDEs were detected. Sludge congener profiles resembled the commercial penta- and deca- formulations, suggesting minimal -209 debromination during wastewater treatment. Similar profiles were observed in surficial sediments at the outfall and downstream. However, sunfish (Lepomis gibbosus), creek chub (Semotilus atromaculatus), and crayfish (Cambarus puncticambarus sp. c) collected near the outfall contained tri- through deca-PBDEs, including congeners not detected in the commercial deca-mixture, sludges or sediments (BDE-179, -184, -188, -201, and -202). A previous in vivo laboratory study identified these as -209 debromination products. This supports the hypothesis that metabolic debromination of -209 does occur in the aquatic environment under realistic conditions. Hence assessments that assume no BDE-209 debromination may underestimate associated bioaccumulation and toxicity attributable to the less brominated congeners produced.     

In situ removal of 2-chlorophenol from unsaturated soils by ozonation

A mathematical model considering mass transfer process at the gas-liquid interface in soil ozonation was developed and validated with laboratory column experiments. Experimental data, specifically, concentration profiles of the organic contaminant and the ozone breakthrough curves, were obtained. In this model, the mass flux of ozone transferred from the gas phase into the liquid phase was described by the two-film theory incorporated with an enhancement factor approach as to account for chemical reactions. With the enhancement factor, the ozone gas transport in the experimental column can be described by an advection-dispersion-reaction equation with pseudo-second-order kinetics in the liquid film. This greatly simplifies the governing equations of the system. Results show that parameters such as degradation yield factor, diffusion coefficients, thickness of liquid film, ozone gas concentration, and gas-liquid interfacial area play an important role on the soil ozonation process. Using the scaled model, important universal dimensionless variables were obtained. The Stanton number (St) is the most important parameter in controlling the performance of system. When St approaches zero, the process is reaction-controlled. Conversely, when St is large, it is convection-controlled. Only when the system is convection-controlled (i.e., large St values) can an increase of ozone flow rate enhance the removal of soil contaminants such as 2-chlorophenol.     

Discharge of three benzotriazole corrosion inhibitors with municipal wastewater and improvements by membrane bioreactor treatment and ozonation

A set of three benzotriazole corrosion inhibitors was analyzed by liquid chromatography-mass spectrometry in wastewaters and in a partially closed water cycle in the Berlin region. Benzotriazole (BTri) and two isomers of tolyltriazole (TTri) were determined in untreated municipal wastewater with mean dissolved concentrations of 12 microg/L (BTri), 2.1 microg/L (4-TTri), and 1.3 microg/L (5-TTri). Removal in conventional activated sludge (CAS) municipal wastewater treatment ranged from 37% for BTri to insignificant removal for 4-TTri. In laboratory batch tests 5-TTri was mineralized completely and 4-TTri was mineralized to only 25%. This different behavior of the three benzotriazoles was confirmed by following the triazoles through a partially closed water cycle, into bank filtrate used for drinking water production, where BTri (0.1 microg/L) and 4-TTri (0.03 microg/ L) but no 5-TTri were detected after a travel time of several months. The environmental half-life appears to increase from 5-TTri over BTri to 4-TTri. Treatment of municipal wastewater by a lab-scale membrane bioreactor (MBR) instead of CAS improved the removal of BTri and 5-TTri but could not avoid their discharge. Almost complete removal was achieved by ozonation of the treatment plant effluent with 1 mg O3/mg DOC.     

Oxidation of pharmaceuticals during ozonation of municipal wastewater effluents: a pilot study

To reduce the release of pharmaceuticals and endocrine disruptors into the aquatic environment or to remove them from wastewater intended for direct or indirect reuse, the application of advanced wastewater treatment may be required. In the present study, municipal wastewater effluents were treated with ozone (O3) in a pilot-scale plant consisting of two bubble columns. The investigated effluents, which varied in suspended solids concentrations, comprised an effluent of conventional activated sludge treatment (CAS), the same effluent dosed with 15 mg of TSS L(-1) of activated sludge (CAS + SS), and the effluent of a membrane bioreactor pilot plant (MBR). Selected classes of pharmaceuticals were spiked in the wastewater at realistic levels ranging from 0.5 to 5 microg L(-1). Samples taken at the inlet and the outlet of the pilot plant were analyzed with liquid chromatography (LC)-electrospray tandem mass spectrometry (MS). Macrolide and sulfonamide antibiotics, estrogens, and the acidic pharmaceuticals diclofenac, naproxen, and indomethacin were oxidized by more than 90-99% for O3 doses > or = 2 mg L(-1) in all effluents. X-ray contrast media and a few acidic pharmaceuticals were only partly oxidized, but no significant differences were observed among the three effluents. These results show that many pharmaceuticals present in wastewater can be efficiently oxidized with O3 and that suspended solids have only a minor influence on the oxidation efficiency of nonsorbing micropollutants.     

Enantiomeric profiling of chiral drugs in wastewater and receiving waters

The aim of this paper is to discuss the enantiomer-specific fate of chiral drugs during wastewater treatment and in receiving waters. Several chiral drugs were studied: amphetamine-like drugs of abuse (amphetamine, methamphetamine, MDMA, MDA), ephedrines (ephedrine and pseudoephedrine), antidepressant venlafaxine, and beta-blocker atenolol. A monitoring program was undertaken in 7 WWTPs (utilizing mainly activated sludge and trickling filters technologies) and at 6 sampling points in receiving waters over the period of 9 months. The results revealed the enantiomer-specific fate of all studied drugs during both wastewater treatment and in the aqueous environment. The extent of stereoselectivity depended on several parameters including: type of chiral drug (high stereoselectivity was recorded for atenolol and MDMA), treatment technology used (activated sludge showed higher stereoselectivity than trickling filters), and season (higher stereoselectivity was observed in the aqueous environment over the spring/summer time).     

西南少数民族服饰纹样的精神显现

 从西南少数民族服饰纹样的象征性寓意出发,通过分析纹样图案与自然、宗教以及历史文化之间的内在联系,将其所蕴含的精神体现归纳为:天人合一境界、宗教寓意以及本民族的文化历史3类。针对现代服装设计中存在的服饰纹样误用缺陷指出,只有真正理解和发掘少数民族服饰纹样的精神内涵,才能传承其文化精髓,不断从传统的服饰纹样中获得设计灵感和主题,从而使现代服装具有最为珍贵的内在神韵,在国际舞台上散发出中国文化的独特魅力。     

Factual analysis of granule flotation in brewery wastewater treatment plants by the fluorescence in situ hybridization method

The factors that change the microbial distribution and consequently the flotation of brewery granules were investigated using laboratory-scale upflow anaerobic sludge blanket (UASB) reactors and the fluorescence in situ hybridization (FISH) method. The startup operations of laboratory-scale UASB reactors fed with acetate-based synthetic wastewater, in which the loading rate was maintained at 0.1 gCOD/gVSS/d (Run 1) and increased in a stepwise manner from 0.1 gCOD/gVSS/d to 1.0 gCOD/gVSS/d (Run 2), generated methanogen colonies near the granule surface, while the overloading operation at 1.0 gCOD/gVSS/d from the startup (Run 3) resulted in the formation of methanogen colonies deep in the granules. In each run, a proportion of the granules floated when overloaded at 2.0 gCOD/gVSS/d and circulation was stopped. The ratio of floating granules increased as the methanogen-growing region increased. On the other hand, the Bacteria layer on the granule surface, which is also considered as a possible cause of granule flotation, was not formed by the inflow of other organic acids such as propionate and lactate. Glucose caused formation of a 5-microm-thick surface Bacteria layer, but the granules were still resistant to flotation. Interfusing of air under glucose feeding caused the formation of a Bacteria layer over 50 microm thick leading to granule flotation.     

Microbial ecology of nitrifying bacteria in wastewater treatment process examined by fluorescence in situ hybridization

The microbial ecology of nitrifying bacteria in various types of wastewater treatment processes and the dynamic response of the microbial ecology in biofilms were investigated using fluorescence in situ hybridization (FISH) with 16S rRNA-targeted oligonucleotide probes. Nitrifying bacteria were found to exhibit various organizational forms under different conditions of substrate composition and concentration. Ammonia-oxidizing bacteria were dominant in ammonia-rich inorganic wastewater, while heterotrophic bacteria and ammonia-oxidizing bacteria were localized at different positions in the biofilm in organic wastewater. The dynamics of the microbial ecology in the biofilm with regard to the spatial distribution of ammonia-oxidizing bacteria and heterotrophic bacteria caused by a gradual change in substrate composition was successfully monitored by FISH analysis.     

Applications of fluorescence spectroscopy for predicting percent wastewater in an urban stream

Dissolved organic carbon (DOC) is a significant organic carbon reservoir in many ecosystems, and its characteristics and sources determine many aspects of ecosystem health and water quality. Fluorescence spectroscopy methods can quantify and characterize the subset of the DOC pool that can absorb and re-emit electromagnetic energy as fluorescence and thus provide a rapid technique for environmental monitoring of DOC in lakes and rivers. Using high resolution fluorescence techniques, we characterized DOC in the Tualatin River watershed near Portland, Oregon, and identified fluorescence parameters associated with effluent from two wastewater treatment plants and samples from sites within and outside the urban region. Using a variety of statistical approaches, we developed and validated a multivariate linear regression model to predict the amount of wastewater in the river as a function of the relative abundance of specific fluorescence excitation/emission pairs. The model was tested with independent data and predicts the percentage of wastewater in a sample within 80% confidence. Model results can be used to develop in situ instrumentation, inform monitoring programs, and develop additional water quality indicators for aquatic systems.     

Microbial analyses by fluorescence in situ hybridization of well-settled granular sludge in brewery wastewater treatment plants

The characteristics of granular sludge from full-scale upflow anaerobic sludge blanket reactors used for the treatment of brewery wastewater were investigated. Fluorescence in situ hybridization (FISH) analyses of settled granules from a reactor that had been treating brewery wastewater stably at COD removal rates of over 90% for more than 6 months showed that a methanogen of the genus Methanosaeta was predominant near the granule surface and that Bacteria were not abundant. The center of the granules was composed of dead or resting cells, or both, which were used as a support for active archaeal and bacterial cells near the surface. Periodic analysis of granules from full-scale plants showed that granules containing methanogens deep within them tended to float. Granules with a Bacteria layer on the surface also tended to float. On the basis of these findings, well-settled granules are considered to have methanogens that develop near the granule surface so that the gases generated during methane fermentation are readily released.     

Decolorization, cytotoxicity, and genotoxicity reduction during a combined ozonation/fungal treatment of dye-contaminated wastewater

In view of compliance with increasingly stringent environmental legislation imposed by regional, national, and supranational (e.g., European Union) authorities, innovative environmental technologies for the treatment of dye-contaminated effluents are necessary in the color industry. In this study, effluents of an industrial dye producer were subjected to distinct treatment trains following an initial qualitative characterization. The effectiveness of ozonation and a treatment using white rot fungi (WRF) and their enzymes were compared with respect to parameters such as residual color, toxicity on human cells, and genotoxicity. A combined ozonation/WRF process was also investigated. The effluent exhibited significant toxicity that was reduced by only 10% through ozonation, whereas the fungal treatment achieved a 35% reduction. A combined treatment (ozone/WRF) caused an abatement of the toxicity by more than 70%. In addition, the initial genotoxicity of the effluent was still present after the ozone treatment, while it was completely removed through the fungal treatment.     

Detection of multiple hormonal activities in wastewater effluents and surface water, using a panel of steroid receptor CALUX bioassays

It is generally known that there are compounds present in the aquatic environment that can disturb endocrine processes, for example via interaction with the endogenous hormone receptors. Most research so far has focused on compounds that bind to the estrogen and/or androgen receptor, but ligands for other hormone receptors might also be present. In this study, a newly completed panel of human cell derived CALUX reporter gene bioassays was utilized to test water extracts for estrogen (ER), as well as androgen (AR), progesterone (PR), and glucocorticoid (GR) receptor mediated transactivation activity. Effluents from industry, hospital, and municipal sewage treatment plants, as well as tap water and different sources of surface water were tested. The CALUX reporter gene panel showed high sensitivity and specificity to known agonists, enabling discrimination between different receptor based endocrine responses present in the aquatic environment. Our results clearly showed the presence of agonistic activity on the ER, as well as on the AR, PR, and GR in the raw and wastewater and surface water extracts. However, no hormone receptor-mediated transactivation was detected in the drinking water or in the blank water. The levels of estrogenic activity were 0.2-0.5 ng E2-equiv/L for surface water and 0.4-1.0 ng E2-equiv/L for municipal effluents, which was consistent with previous studies. Surprisingly, the other hormonal activities were found to be present in similar or much higher levels. Most notably, glucocorticoid-like activity was detected in all samples, at surprisingly high levels ranging from 0.39-1.3 ng Dex-equiv/L in surface water and 11-243 ng Dex-equiv/L in effluents. When regarding the fact that dexamethasone in the GR CALUX bioassay is a factor 12 more potent than the natural hormone cortisol, results expressed as cortisol equivalents would range up to 2900 ng cortisol equiv/L. Further studies are needed to establish the identity of the active compounds and to understand the significance of the level of activities with regard to human and ecotoxicological risks.     

臭氧及电化学氧化处理制革生化尾水比较研究

结合臭氧氧化和电化学氧化两项高级氧化处理技术对制革生化尾水进行研究。试验过程中臭氧最佳作用参数为投加量30mg／L,pH=7,时间30min;电解最佳作用参数为电流密度75A／m^2,pH=7,电解时间15min．且使用钛基Ru-Ir-Sn阳极效果最好。研究发现：二者对废水色度去除效果均可达90％以上,对COD削减则存在去除极限,削减率低于50％。臭氧氧化可将生化性由0．023调至0．180,电化学氧化则可以将生化性调至0．410。臭氧氧化对类蛋白有机物的去除效果较好,类腐殖质有机物则残留较多;电化学氧化则相反,对类腐殖质去除较为彻底,类蛋白有机物则残留较多。     

Structure-reactivity of naphthenic acids in the ozonation process

Large volumes of oil sands process-affected water (OSPW) are produced in northern Alberta by the surface mining oil sands industry. Naphthenic acids (NAs) are a complex mixture of persistent organic acids that are believed to contribute to the toxicity of OSPW. In situ microbial biodegradation strategies are slow and not effective at eliminating chronic aquatic toxicity, thus there is a need to examine alternative remediation techniques. NAs with multiple rings and alkyl branching are most recalcitrant to microbial biodegradation, but here we hypothesized that these same structural features may lead to preferential degradation in the ozonation process. Total NA degradation increased with increasing pH for commercial NA solutions, suggesting a hydroxyl radical mechanism and that naturally alkaline OSPW would unlikely require pH adjustment prior to treatment. For commercial NAs and OSPW, NAs with more rings and more carbon (and more H atoms) were depleted most rapidly in the process. Relative rate measurements with binary mixtures of model NA compounds not only confirmed this structure reactivity but also indicated that alkyl branching patterns were an additional factor determining NA reactivity. The results demonstrate that ozonation is complementary to microbial biodegradation, and the process remains a promising water reclamation strategy for the oil sands industry.     

染料废水的臭氧／纳米氧化铁催化氧化脱色

采用臭氧/纳米氧化铁催化氧化技术对活性染料废水进行脱色处理.以硅藻土为载体,采用浸渍-沉淀方法负载水合铁氧化物,以110℃烘干和290℃焙烧样品制备催化剂,并与硅藻土原土及双氧水进行臭氧催化氧化对比试验.结果表明,硅藻土负载纳米铁氧化物对臭氧氧化染料废水具有良好的催化性能,其催化效果比双氧水好;其中又以烘干样品的性能优于焙烧样品,经过6 min氧化,色度去除率可达95%以上;天然硅藻土的催化性能较差,总体脱色效果较单独臭氧氧化效果差.     

Degradation kinetics of tomato juice quality parameters by ozonation

Tomato juice samples were ozonated with control variables of ozone concentration (1.6–7.8 %w/w) and treatment time (0–10 min). Effects of ozone processing variables on quality parameters of pH, ^oBrix, titratable acidity (TA), cloud value, non-enzymatic browning, colour values ( L *, a *, and b *) and ascorbic acid (AA) content were determined. No significant changes ( P  > 0.05) in pH, ^oBrix, TA, cloud value and Non enzymatic browning (NEB) ( P  ≤ 0.05) were found with ozonation. L *, a * and b * colour values were significantly affected by ozone concentration and treatment time. A significant reduction of AA (96 %) was observed at an ozone concentration of 7.8%w/w and a treatment time of 10 min. Results presented in this study indicate that visual colour and nutritional quality is significantly affected during ozone processing. Thus, the effects of ozonation on the nutritional properties of tomato juice should be considered by processors prior to its adoption as a preservation technique.     

Thresholds for the effects of pesticides on invertebrate communities and leaf breakdown in stream ecosystems

We compiled data from eight field studies conducted between 1998 and 2010 in Europe, Siberia, and Australia to derive thresholds for the effects of pesticides on macroinvertebrate communities and the ecosystem function leaf breakdown. Dose-response models for the relationship of pesticide toxicity with the abundance of sensitive macroinvertebrate taxa showed significant differences to reference sites at 1/1000 to 1/10,000 of the median acute effect concentration (EC50) for Daphnia magna, depending on the model specification and whether forested upstream sections were present. Hence, the analysis revealed effects well below the threshold of 1/100 of the EC50 for D. magna incorporated in the European Union Uniform Principles (UP) for registration of single pesticides. Moreover, the abundances of sensitive macroinvertebrates in the communities were reduced by 27% to 61% at concentrations related to 1/100 of the EC50 for D. magna. The invertebrate leaf breakdown rate was positively linearly related to the abundance of pesticide-sensitive macroinvertebrate species in the communities, though only for two of the three countries examined. We argue that the low effect thresholds observed were not mainly because of an underestimation of field exposure or confounding factors. From the results gathered we derive that the UP threshold for single pesticides based on D. magna is not protective for field communities subject to multiple stressors, pesticide mixtures, and repeated exposures and that risk mitigation measures, such as forested landscape patches, can alleviate effects of pesticides.     

Degradation of aflatoxins in peanut kernels/flour by gaseous ozonation and mild heat treatment

Aflatoxins occur naturally in many agricultural crops causing health hazards and economic losses. Despite improved handling, processing and storage, they remain a problem in the peanut industry. Therefore, new ways to detoxify contaminated products are needed to limit economic/health impacts and add value to the peanut industry. The study was conducted (1) to evaluate the effectiveness of ozonation and mild heat in breaking down aflatoxins in peanut kernels and flour, and (2) to quantify aflatoxin destruction compared with untreated samples. Peanut samples were inoculated with known concentrations of aflatoxins B1, B2, G1 and G2. Samples were subjected to gaseous ozonation and under various temperatures (25, 50, 75°C) and exposure times (5, 10, 15 min). Ozonated and non-ozonated samples were extracted in acetonitrile/water, derivatized in a Kobra cell and quantified by high-performance liquid chromatography. Ozonation efficiency increased with higher temperatures and longer treatment times. Regardless of treatment combinations, aflatoxins B1 and G1 exhibited the highest degradation levels. Higher levels of toxin degradation were achieved in peanut kernels than in flour. The temperature effect lessened as the exposure time increased, suggesting that ozonation at room temperature for 10-15 min could yield degradation levels similar to those achieved at higher temperatures while being more economical.