Detection of perfluorooctane surfactants in Great Lakes water

Widespread use of perfluorooctane surfactants has led to ubiquitous presence of these chemicals in biological tissues. While perfluorooctane surfactants have been measured in blood and liver tissue samples of fish, birds, and mammals in the Great Lakes region, data for the aqueous concentrations of these compounds in the Great Lakes or other ambient waters is lacking. Sixteen Great Lakes water samples were analyzed for eight perfluorooctane surfactants. The monitored perfluorooctane surfactants were quantitatively determined using single quadrupole HPLC/MS and qualitatively confirmed using ion trap MS/MS. Additionally, PFOS was quantitatively confirmed using triple quadrupole LC/MS/MS. Concentrations of PFOS and PFOA in the two lakes ranged from 21-70 and 27-50 ng/L, respectively. Analysis also showed the presence of PFOS precursors, N-EtFOSAA (range of 4.2-11 ng/L) and FOSA (range of 0.6-1.3 ng/L), in all samples above the LOQ. PFOSulfinate, another precursor, was identified at six of eight locations with a concentration range, when present, of <2.2-17 ng/L. Other PFOS precursors, N-EtFOSE, PFOSAA, and N-EtFOSA were not observed at any of the sampling locations. These are the first reported concentrations of perfluorooctane surfactants in Great Lakes water and the first report of PFOS precursors in any water body.     

Mass budget of perfluorooctane surfactants in Lake Ontario

Perfluorooctane surfactants have been reported in biota, water, and air samples worldwide. Despite these reports, the main environmental sources of these compounds remain undefined. To address this gap in knowledge, an annual lake-wide mass budget of eight perfluorooctane surfactants was developed for Lake Ontario. To determine the atmospheric contribution to the mass budget, over-the-lake gas-phase air concentrations for N-EtFOSE and N-EtFOSA and particulate-phase air concentrations for PFOS in any air sample are reported for the first time, with mean concentrations when present of 0.5+/-0.32 (N-EtFOSE gas-phase), 1.1+/-0.9 (N-EtFOSA gas-phase), and 6.4+/-3.3 (PFOS particulate-phase) pg/m3. The mass budget finds inflow from Lake Erie (14 361+/-4489 kg sigma perfluorooctane surfactants) and wastewater discharge (1762+/-2697 kg sigma perfluorooctane surfactants) to be the major sources, while outflow through the St. Lawrence River is the dominant loss mechanism (22,727+/-7060 kg/year sigma perfluorooctane surfactants). Using the mass budget data, the steady state and measured mean concentrations in the lake water are the same at the 95% confidence level.     

Mass loading and fate of perfluoroalkyl surfactants in wastewater treatment plants

Wastewater treatment plants have recently been identified as a significant pathway for the introduction of perfluoroalkyl surfactants (PASs) to natural waters. In this study, we measured concentrations and fate of several PASs in six wastewater treatment plants (WWTPs) in New York State. We also monitored and measured matrix effects (ionization suppression and enhancement) by postcolumn infusion and standard additions. Concentrations of perfluorooctanoate (PFOA) in effluents of the six WWTPs ranged from 58 to 1050 ng/L. Perfluorooctanesulfonate (PFOS) was also ubiquitous in effluents of these WWTPs, albeit at much lower concentrations (3-68 ng/L). Two of these WWTPs employed identical treatment processes, with similar hydraulic retentions, but differed only in that Plant B treated domestic and commercial waste, whereas Plant A had an additional industrial influence. We found that this industrial influence resulted in significantly greater mass flows of all of the PASs analyzed. Primary treatment was found to have no effect on the mass flows of PASs. Secondary treatment by activated sludge in Plant A significantly increased (p < 0.05) the mass flows of PFOS, PFOA, perfluorononanoate (PFNA), perfluorodecanoate (PFDA), and perfluoroundecanoate (PFUnDA). However, in Plant B, only the mass flow of PFOA was significantly increased. The observed increase in mass flow of several PASs may have resulted from biodegradation of precursor compounds such as fluorotelomer alcohols, which is supported by significant correlations in the mass flow of PFOA/PFNA and PFDA/PFUnDA. Furthermore, the masses of PFDA and PFUnDA were significantly correlated only after the secondary treatment. In Plant A, concentrations of odd-number PFCAs were greater than those of even-number PFCAs, and concentration decreased with increasing chain length (from C8 to C12). A different pattern was observed in sludge samples, in which the dominance of PFOA decreased, and PFDA and PFUnDA increased, suggesting preferential partitioning of longer-chain PFCAs to sludge.     

Urban wastewater treatment by a nutrient film technique system with a valuable commercial plant species (Chrysanthemum cinerariaefolium Trev.)

Urban wastewater causes rapid eutrophication of natural waters and requires treatment before discharge. This is expensive and produces huge quantities of sludge. In the European Community, it will no longer be lawful to dispose of this sludge as landfill after 2005 (European Directive 91/271/CEE of May 21, 1991). Wastewater treatment by the Chrysanthemum cinerariaefolium plants in horizontal flow was investigated using the nutrient film technique (NFT), a widely used hydroponic system in the commercial greenhouse industry. After a 48 h plant treatment, the purification efficiency was 95%, 91%, and 99% with respect to suspended solids (SS), biochemical oxygen demand (BOD5), and chemical oxygen demand (COD), and the elimination of nutrients (total nitrogen and total phosphorus) varied between 40% and 80%. SS and thus indirectly BOD5 and COD were removed by filtration and adsorption; the solids trapped in the root systems were then decomposed and mineralized. The system with 25 plants purified 30 L of wastewater in 48 h. One-hundred people communities wastewater could be treated with a 6 m2 area of production. Pyrethrin contents and chlorophyll a fluorescence of plants grown on raw urban waters were not significantly different from those grown on a standard nutrient solution.     

Removal of oxide nanoparticles in a model wastewater treatment plant: influence of agglomeration and surfactants on clearing efficiency

The rapidly increasing production of engineered nanoparticles has created a demand for particle removal from industrial and communal wastewater streams. Efficient removal is particularly important in view of increasing long-term persistence and evidence for considerable ecotoxicity of specific nanoparticles. The present work investigates the use of a model wastewater treatment plant for removal of oxide nanoparticles. While a majority of the nanoparticles could be captured through adhesion to clearing sludge, a significant fraction of the engineered nanoparticles escaped the wastewater plant's clearing system, and up to 6 wt % of the model compound cerium oxide was found in the exit stream of the model plant. Our study demonstrates a significant influence of surface charge and the addition of dispersion stabilizing surfactants as routinely used in the preparation of nanoparticle derived products. A detailed investigation on the agglomeration of oxide nanoparticles in wastewater streams revealed a high stabilization of the particles against clearance (adsorption on the bacteria from the sludge). This unexpected finding suggests a need to investigate nanoparticle clearance in more detail and demonstrates the complex interactions between dissolved species and the nanoparticles within the continuously changing environment of the clearing sludge.     

印染废水处理中的自控系统

阐述一种PLC和上位机两级控制结构的自动化控制系统在印染废水处理工艺中的应用.整套控制系统由上位机系统,可编程序控制器系统(PLC),I/0柜,就地操作箱,一次仪表和电源系统等组成,重点介绍了该系统的性能,处理污水工艺的方式以及该系统的特点.     

烟草商业企业精益物流评价体系研究

为科学评价烟草商业企业精益物流水平,本研究以平衡记分卡为基础,从物流成本、客户服务、运行管理和学习创新四个方面构建了精益物流评价指标体系。以前三项代表物流运营水平(L-Level),以最后一项代表精益改善能力(S-Skill),结合二维构面图理论,构建了L-S 二维分类评价模型。依据评价结果在L-S 平面上的投影分布,将商业企业精益状态进行分类,进而分析企业精益管理所处的阶段和潜在的问题,为企业管理决策提供依据。      

The effects on product of a hot water pasteurizing treatment applied routinely in a commercial beef carcass dressing process

The effects of a pasteurizing treatment on the microbiological condition and the appearance of carcasses, routine in a commercial carcass dressing process, were examined. Beef carcass sides were pasteurized with water at 85°C. During 2-h periods, all sides from the dressing process were treated for 8, 9, 10, 11 or 12 s. During each period, microbiological samples were obtained by swabbing five randomly selected sides before and five others after the treatment, with a single sample being obtained from 25 treated and 25 untreated sides from each treatment time. All treatments similarly reduced the log mean numbers of total aerobic counts by about 1 log unit, but the reductions in the log total numbers of coliforms orEscherichia coli recovered from 25 samples increased with increasing treatment time, to >2 log units with treatment times of 11 or 12 s. Cooling of the sides did not obviously reduce the numbers of total aerobic bacteria on beef sides, but there were small reductions in the numbers of coliforms and E. coli on both treated and untreated sides. After cooling, sides treated routinely for 10 s yielded total aerobic counts at log mean numbers of about 2 log cfu cm⁻², and coliforms and E. coli at log total numbers of <2 and <1 log cfu 2500 cm⁻², respectively. After the carcass breaking process, loin primal cuts and manufacturing beef from such sides yielded total aerobic counts at log mean numbers of about 3 and about 4 log cfu cm⁻², respectively; coliform counts at log total numbers of about 3 and about 4 log cfu 2500 cm⁻², respectively; and E. coli counts at log total numbers >2 log cfu 2500 cm⁻²; which indicated that product was contaminated from improperly cleaned equipment during the carcass breaking process. When sides treated for 10 s with water that had previously been used to treat 120 or more sides were compared after cooling with untreated sides from the same carcasses, the appearances of treated sides were judged to be less desirable than those of the untreated sides because of the less desirable appearance of the fat tissue on the treated sides. However, the mean differences between untreated and treated sides for overall appearance and the appearance of fat tissue were only 0·45 and 0·46 assessment units, respectively, for assessments on a seven-point scale. The small adverse effect of the pasteurizing treatment on the appearance of beef carcass sides apparently did not affect the value of the meat. Thus, the data indicated that, in commercial practice, pasteurizing treatment times should be set by reference to reductions in numbers of E. coli rather than of total aerobic counts, to assure the maximum possible reduction in the number of enteric pathogens; that protein suspended in the circulating water of pasteurizing equipment will accumulate to levels that affect the appearance of carcass fat, unless the water is changed at appropriate intervals or actions are taken to remove the protein from the water or carcass surfaces; and that pasteurizing of carcasses alone is inadequate for assuring the safety of meat when recontamination of product with enteric organisms occurs during the carcass-breaking process.     

Effects of long-term wastewater application on chemical properties and phosphorus adsorption capacity in soils of a wastewater land treatment system

The buildup of phosphorus (P) in the soil is a major factor limiting the operating life of a wastewater land treatment system. In this study, we evaluated changes of chemical properties, P profiles, and adsorption isotherms in the soils of a Muskegon wastewater land treatment system, which has received wastewater for approximately 30 years. It was found that the pH in the 15-cm topsoil increased from approximately 5-6 in 1973 to approximately 7.4-7.8 in 2003; a large amount of salt (e.g., Ca, Mg) in wastewater was adsorbed by the soil; the soil Al content (either exchangeable or oxalate extractable) decreased, while the oxalate-extractable Fe content remained at the same level. Ca-bound P accounted for > or = 70% of the total P adsorbed in the soil. The soil P adsorption capacity increased and was positively correlated with the concentration of exchangeable Ca in the soil. A higher concentration of exchangeable Ca was found in the 15-cm topsoil, where a higher total organic carbon was present. More P was accumulated in the upper soil than in the deeper soil. The adsorption of Ca in wastewater by the soil may extend the life expectancy of the Muskegon land treatment system.     

造纸污水光催化处理及过程控制系统

在用GC-MS方法分析广州某二次纤维造纸厂各工段污水成分的基础上,利用自制的纳米TiO2胶体分别光催化处理二次纤维造纸混合污水及经过SBR生化处理后的造纸污水;利用金卤灯模拟太阳光,进行了太阳光光催化处理造纸污水的研究;并设计了间歇式光催化处理造纸污水系统及其自动控制系统。研究表明,光催化氧化法处理污水,尤其是造纸过程产生的含有大量木质素、有机氯酚高分子化合物的污水,效果显著。     

Sterols and anionic surfactants in urban aerosol: emissions from wastewater treatment plants in relation to background concentrations

Aerosol particles that are emitted from aeration tanks of wastewater treatment plants (WWTPs) can be enriched with environmentally relevant wastewater constituents. In this study, aerosol particles were sampled simultaneously at the pre-aeration tank of a municipal WWTP and at two urban locations approximately 1 km away from the WWTP to evaluate the significance of these aerosol emissions. Moreover, aerosol particles were sampled at a small wastewater irrigation facility and at a rural site. In aerosol particles and wastewater, six sterols (cholesterol, coprostanol, campesterol, beta-sitosterol, stigmasterol, stigmastanol) and anionic surfactants (expressed in terms of methylene blue active substances, MBAS) were quantified. The results showed significantly higher concentrations of sterols and MBAS at the WWTP than atthe urban locations. At the WWTP, average concentrations of cholesterol (848 +/- 321 pg m(-3)), coprostanol (1132 +/- 565 pg m(-3)), and MBAS (132 +/- 43 ng m(-3)) in aerosol were approximately twice as high. This can be attributed to emissions from the treatment tank. Coprostanol, a unique tracer for wastewater, was detected only occasionally at the urban locations. The results of this study show that the aeration of wastewater is a continuously operating local source for organic compounds in aerosol. The wastewater irrigation facility was a minor source of aerosol-bound sterols (coprostanol, 287 +/- 218 pg m(-3)) and anionic surfactants (64 +/- 32 ng m(-3)). Except for coprostanol, all compounds were also present in samples of rural aerosol.     

Antimicrobial effects of a commercial fermentation product on fresh-cut onions

The antimicrobial effects of a commercial fermentation product (CFP) added to fresh-cut onions was assessed. Diced onions without treatment were packed in sealed and vented single-pinhole polyethylene bags, which served as controls. Treated and control samples were then stored at 4 and 7°C. Changes in the microbial loads including total aerobic bacteria, yeasts and molds, and coliforms were determined. Quality parameters including O(2)-CO(2) concentration, pH, soluble solids, and conductivity were also evaluated following 0, 3, 7, 10, 14, and 18 days of storage. After 10 days of storage at 4°C, CFP-treated samples had significantly lower microbial loads (P < 0.001), and aerobic plate counts, yeast and mold counts, and coliform counts were lower by 2.5, 3.2, and 1.4 log, respectively, compared with the controls. The addition of 0.5 or 1% CFP maintained the shelf life of fresh-cut onions for up to 14 and 18 days, respectively, compared with 10 days for the control. In addition, it was determined that storage temperature played an important role in maintaining the quality of fresh-cut onions. Significant (P ≤ 0.05) differences in microbial loads and product quality were found between 4 and 7°C in all treatments.     

工业废水处理中pH值的自动控制系统

设计了一套适用于工业废水pH值的自动控制系统,该系统结构简单、控制效果良好,可提高废水处理的pH值自动控制能力,处理效率高,还能改善排放水质量.     

Carbamazepine and its metabolites in wastewater and in biosolids in a municipal wastewater treatment plant

Pharmaceutically active compounds (PhACs) are discharged into the environment from domestic wastewater treatment plants (WWTPs). In this study, we determined the distribution of the anti-epileptic drug, carbamazepine (CBZ), and its major metabolites and caffeine in both aqueous and solid phases through different treatment processes of a WWTP. A method was developed to extract samples of biosolids using pressurized liquid extraction (PLE), coupled with cleanup of extracts using solid-phase extraction. Samples of biosolids and wastewater were analyzed for caffeine and CBZ and five of its metabolites, 10,11-dihydro-10,11-epoxycarbamazepine (CBZ-EP), 11-dihydro-10,11-epoxycarbamazepine (CBZ-DiOH), 2-hydroxycarbamazepine (CBZ-20H), 3-hydroxycarbamazepine (CBZ-30H), and 10,11-dihydro-10-hydroxycarbamazepine (CBZ-100H). The analytes were quantified using liquid chromatography-electrospray ionization tandem mass spectrometry. The recoveries of the analytes were 82.1-91.3% from raw biosolids and 80.1-92.4% from treated biosolids, and the limits of detection were 0.06-0.50 and 0.06-0.40 microg/kg on a wet weight basis for raw and treated biosolids, respectively. The behavior of carbamazepine and its metabolites, together with caffeine as a marker of domestic inputs, was investigated in the WWTP for the City of Peterborough, ON, Canada, which utilizes secondary sewage treatment technologies. CBZ, CBZ-2OH, CBZ-30H, and CBZ-DiOH were detected at concentrations of 69.6, 1.9, 1.6, and 7.5 microg/kg (dry weight), respectively, in untreated biosolids and at concentrations of 258.1, 3.4, 4.3, and 15.4 microg/kg (dry weight), respectively, in treated biosolids. However, CBZ-EP and CBZ-100H were not detected in any of the biosolid samples. CBZ and its five metabolites were detected in all wastewater samples collected from four different stages of treatment. The results showed that 29% of the carbamazepine was removed from the aqueous phase during treatment in the WWTP, while the metabolites were not effectively removed. Concentrations of caffeine were reduced by 99.9% in the aqueous phase, which appeared to be due primarily to degradation. Caffeine was also detected at concentrations of 165.8 and 7.6 microg/kg (dry weight) in raw and treated biosolids, respectively. Because of differences in hydrophobicity, CBZ is the primary analyte in biosolids, while CBZ-DiOH is the primary analyte in the aqueous phase of the wastewater. A mass balance calculation showed that the majority of CBZ and its metabolites exist in the aqueous phase (i.e., wastewater), ratherthan in the biosolids, 78 g of CBZ and its metabolites enters the Peterborough WWTP daily, and 91 g is discharged from the WWTP daily in the combined suspended solids and aqueous phases of the wastewater. The calculated daily inputs into the WWTP are somewhat less than the inputs of 192 g estimated from Canadian annual sales data for CBZ.     

Evaluation of surfactants for use in the spray treatment of iron chlorosis in citrus trees

Wetting and stomatal penetration of plant leaves by spray solutions can be obtained when the surface tension of the spray solution is sufficiently low. Low surface tension fluorocarbon and silicone-based surfactants were active at lower concentrations and were found to be less harmful to plant cell membranes than a comparable carbohydrate-based surfactant. A silicone-based surfactant greatly increased the efficiency of iron solutions sprayed onto chlorotic citrus trees.     

污水厌氧处理过程DCS控制系统设计

在对典型的污水厌氧处理工艺分析的基础上,设计了一套基于西门子PCS7开发平台的污水厌氧处理过程DCS控制系统。采用专家前馈＋反馈控制来调节调制池污水pH值,采用比值算法来控制营养物质投加量。     

Emission and control of nitrous oxide from a biological wastewater treatment system with intermittent aeration

Nitrous oxide (N2O) can be emitted as a by-product of the process of nitrogen removal from wastewater. Two methods of complete denitrification and media application were studied in lab-scale intermittent aeration reactors fed with domestic wastewater to refine methods of controlling the N2O emission rate. A study on cyclic patterns showed that the highest N2O emission rate was at the beginning of the aerobic phase rather than the anoxic phase. This was probably because the nitrifying bacteria had accumulated nitrite nitrogen (NO2-) under low DO conditions. Methanol as an external carbon source was added during the anoxic phase to reduce nitrate nitrogen (NO3-) when denitrification was completed. The N2O emission rates in both the aerobic and anoxic phases were significantly influenced by residual NO3-, increasing monotonically as the concentration of NO3- in the reactor increased. Over 95% of average N2O emissions in both the aerobic and anoxic phases were prevented when methanol was added. The biofilm reactor showed similar patterns to those of the non-biofilm reactor in track behavior, but the former was more effective in the reduction of N2O emissions.     

基于专家系统的APMP制浆废水好氧处理控制系统

为解决APMP制浆废水好氧处理中溶解氧控制过程的严重非线性、时间延迟等问题,以S7-400PLC的APMP制浆废水好氧处理DCS控制系统为例,将前馈专家控制、PID控制、专家反馈控制算法结合起来对曝气池内的溶解氧含量进行控制,根据不同阶段所表现出来的不同特性即溶解氧偏差的实时变化采取不同的专家控制策略,从而使溶解氧浓度保持在要求范围内,获得理想控制效果.     

Fate of coliphage in a wastewater treatment process

The fate of coliphage in a wastewater treatment plant in the central part of Japan was investigated from March to December 2001. A relative abundance of coliphage, 1000-10,000 PFU/ml determined with three different Escherichia coli strains, was detected in the influent. But, no remarkable seasonal change in the phage concentration in the influent was observed during the ten-month test period. Almost ten times higher coliphage concentration was detected by the F+ E. coli strain than by the other two F- strains. The RNA phage was more stable than the DNA phage against aerobic treatment using activated sludge. Most of the phages in the influent and primary settling tank were detected as suspended forms. Anaerobic-aerobic treatment enhanced adsorption of the phage by the solid particles. Almost no phage was detected in the effluent. Aerobic treatment using activated sludge and/or the addition of flocculants such as PAC was effective for the removal of coliphage, an index of enteric viral pollution.