A/DAT-IAT生物膜法处理高含盐废水

以含盐量为60 000mg/L(以NaCl计)的模拟工业废水为研究对象,利用A/DAT-IAT生物膜反应器,研究A/DAT-IAT工艺对投加悬浮填料后高含盐废水的处理,并以CODCr、NH4 -N、PO43--P等作为指标评价处理效果.试验结果表明,在总水力停留时间(HRT)为13 h、pH=7,5、25℃条件下,进水ρ(CODCr)、ρ(NH4 -N)和ρ(PO43--P)分别为907.4～1 210.0 mg/L、86.2～99.7 mg/L和3.6～5.1 mg/L.CODCr、NH4 -N和PO43--P的平均去除率分别为73.9%、38.6%和93.5%,平均出水SS为198 mg/L,其中CODCr和PO43--P的去除效果较好.研究表明,A/DAT-IAT生物膜法较其他活性污泥法有了较大的提高.     

Perfluorinated Surfactants in Surface and Drinking Waters (9 pp)

Background, Aim and Scope In this paper recent results are provided of an investigation on the discovery of 12 perfluorinated surfactants (PS) in different surface and drinking waters (Skutlarek et al. 2006 a, Skutlarek et al. 2006 b). In the last years, many studies have reported ubiquitous distribution of this group of perfluorinated chemicals, especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in the environment, particularly in wildlife animal and human samples (Giesy and Kannan 2001, Houde et al. 2006, Prevedouros et al. 2006). Perfluorinated surfactants (e.g. PFOS and PFOA) have shown different potentials for reproductory interference and carcinogenity in animal experiments as well as partly long half-lives in humans (Guruge et al. 2006, FSA UK 2006a, FSA UK 2006b, 3M 2005, OECD 2002, Yao and Zhong 2005). They possess compound-dependent extreme recalcitrance against microbiological and chemical degradation and, in addition, they show variable potentials for bioaccumulation in animals and humans (Houde et al. 2006). Materials and Methods: Surface and drinking water samples were collected from different sampling sites: - Surface waters: samples taken from the rivers Rhine, Ruhr, Moehne and some of their tributaries. Further samples were taken from the Rhine-Herne-Canal and the Wesel-Datteln-Canal. - Drinking waters: samples taken in public buildings of the Rhine-Ruhr area. After sample clean-up and concentration by solid-phase extraction, the perfluorinated surfactants were determined using HPLC-MS/MS. Results: All measured concentrations (sum of seven mainly detected components) in the Rhine river and its main tributaries (mouths) were determined below 100 ng/L. The Ruhr river (tributary of the Rhine) showed the highest concentration (94 ng/L), but with a completely different pattern of components (PFOA as major component), as compared with the other tributaries and the Rhine river. Further investigations along the Ruhr river showed remarkably high concentrations of PS in the upper reaches of the Ruhr river and the Moehne river (tributary of the Ruhr) (Ruhr: up to 446 ng/L, Moehne: up to 4385 ng/L). The maximum concentration of all drinking water samples taken in the Rhine-Ruhr area was determined at 598 ng/L with the major component PFOA (519 ng/L). Discussion: The surface water contaminations most likely stem from contaminated inorganic and organic waste materials (so-called 'Abfallgemisch'). This waste material was legally applied to several agricultural areas on the upper reaches of the Moehne. Perfluorinated surfactants could be detected in some suchlike soil samples. They contaminated the river and the reservoir belonging to it, likely by superficial run-off over several months or probably years. Downstream, dilution effects are held responsible for decreasing concentrations of PS in surface waters of the Moehne and the Ruhr river. In analogy to the surface water samples, PS (major component PFOA) can be determined in many drinking water samples of the Rhine-Ruhr area where the water supplies are mainly based on bank filtration and artificial recharge. Conclusions: The concentrations found in drinking waters decreased with the concentrations of the corresponding raw water samples along the flow direction of the Ruhr river (from east to west) and were not significantly different from surface water concentrations. This indicates that perfluorinated surfactants are at present not successfully removed by water treatment steps. Recommendations and Perspectives: Because of their different problematic properties (persistence, mobility, toxicity, bioaccumulation), the concentrations of specific perfluorinated surfactants and their precursors in drinking waters and food have to be minimised. Therefore, it is of utmost importance to take the initiative to establish suitable legal regulations (limitations/ban) concerning the production and use of these surfactants and their precursors. Furthermore, it is indispensable to protect water resources from these compounds. A discussion on appropriate limit values in drinking water and foodstuffs is urgently needed. Concerning the assumed soil contamination, the corresponding regulation (Bioabfall-Verordnung 1998 – Regulation on Organic Waste 1998) should be extended to allow the control of relevant organic pollutants.     

pp´DDT and pp´DDE Accumulation in a Food Chain of Lake Maggiore (Northern Italy): Testing Steady-State Condition

- DOI: http://dx.doi.org/10.1065/espr2006.01.010 Background, Aims and Scope Although pp'DDT usage was strongly limited or banned in most parts of the world during the last three or four decades, the parent compound, its homologues and their metabolites still occur at levels which might pose a risk for many ecosystem components. A case of DDT pollution of industrial origin was discovered in 1996 in Lake Maggiore, the second largest (212 km2) and deepest (370 m) lake in Italy, causing concern for wildlife and human health. The extensive monitoring of many biotic and abiotic compartments which followed from 1998 in order to assess the pollution level and its trend in time, provided a great availability of data referring to DDT contamination of the different fish species of the lake. In this study, the recent contamination levels in selected fish species were compared to those measured in 1998 to evaluate the temporal pollution trend of the lake and its natural recovery, given that no remediation measures were carried out on the contaminated soils and sediments in this time span. Moreover, a modelling approach to test the equilibrium condition between water and pelagic fish species was used. Analytical results of pp'DDT and pp'DDE concentrations in lake water were used as input data in the bioenergetic model by Connolly & Pedersen (1988) to calculate concentrations in two fish species and to compare the predicted and the measured contamination. Methods Sampling and analytical determination of DDT homologues in lake water: Five water sampling campaigns were carried out from May 2002 to February 2004 in three sampling sites of Lake Maggiore. Suspended and dissolved pollutants were determined separately. Quantitative DDT homologue analyses were performed by HRGC coupled with ECD detection by the external standard method. Single water extracts were put together in correspondence with the stratification zones of the water column inferred on the basis of the temperature profile to improve analytical sensitivity. Selection of fish data: Concentrations of DDT and DDE in fishes were selected from recent literature (CIPAIS 2003, 2004). Bioaccumulation model: The bioenergetic model proposed by Connolly & Pedersen (1988) was used to assess the bioaccumulation of pp'DDT and pp'DDE of Alosa fallax (landlocked shad) and Coregonus spp. (whitefish), selected among the different species as representative of a secondary consumer level. Results and Discussion The average concentrations of pp'DDT and pp'DDE in water to be used as input data in the bioenergetic model were obtained considering all the concentrations measured at the three sampling stations in the epylimnion where the fish species considered in this study spend most of their life. The resulting values were 0.05 and 0.16 ng/L for pp'DDT and pp'DDE, respectively. Average measured pp'DDT and pp'DDE concentrations in landlocked shad were 0.81 +/- 0.39 and 1.69 +/- 0.71 mg/kg lipids, respectively, and were 0.29 +/- 0.12 and 1.06 +/- 0.41 mg/kg lipids for the whitefish. Calculated and measured values turned out to be in quite good agreement for pp'DDT, while measured pp'DDE concentrations were higher than expected on the basis of the bioenergetic model in both species. Probably metabolic transformations of pp'DDT accumulated in fish tissues in the past are responsible for the observed differences between calculated and expected pp'DDE concentrations in fish. Conclusions Pelagic fishes of Lake Maggiore seem to maintain the DDT accumulated during their life time and the most efficient mechanism responsible for the fish population recoveries is probably their generation changes; for this reason, equilibrium models cannot be used until negligible pp'DDT concentrations are reached in fish tissues. Recommendations and Outlook The limit proposed for pp'DDT in water by the EU Directive 2000/60, which will come in force in 2008, is 0.2 ng/L, four times higher than the average concentration measured in Lake Maggiore waters. Nevertheless, concentrations measured in Lake Maggiore fish were very close and sometimes exceeded the Maximum residue limits (MRLs) settled by the Italian legislation for foods (0.1 mg/kg w.w. for fish containing 5–20% lipid). It seems, therefore, that the 'environmental quality standard' of 0.2 ng/L cannot guarantee the suitability of fish for human consumption.     

Quantitation of Hydroxyl Radicals from Photolysis of Fe(III)-Citrate Complexes in Aerobic Water (5 pp)

Background For their high photoreactivity, Fe(III)-carboxylate complexes are important sources of H2O2 for some atmospheric and surface waters. Citrate is one kind of carboxylate, which can form complexes with Fe(III). In our previous study, we have applied Fe(III)-citrate complexes to degrade and decolorize dyes in aqueous solutions both under UV light and sunlight. Results have shown that carboxylic acids can promote the photodegradation efficiency. It is indicated that the photolysis of Fe(III)-citrate complexes may cause the formation of some reactive species (e. g. H2O2 and ·OH). This work is attempted to quantify hydroxyl radicals generated in the aqueous solution containing Fe(III)-citrate complexes and to interpret the photoreactivity of Fe(III)-citrate complexes for degrading organic compounds. Methods By using benzene as the scavenger to produce phenol, the photogeneration of ·OH in the aqueous solution containing Fe (III)-citrate complexes was determined by HPLC. Results and Discussion In the aqueous solution containing 60.0/30.0 mM Fe(III)/citrate and 7.0 mM benzene at pH 3.0, 96.66 mM ·OH was produced after irradiation by a 250W metal halide light (l ≥ 313 nm) for 160 minutes. Effects of initial pH value and concentrations of Fe(III) and citrate on ·OH radical generation were all examined. The results show that the greatest photoproduction of ·OH in the aqueous solution (pH ranged from 3.0 to 7.0) was at pH 3.0. The photoproduction of ·OH increased with increasing Fe(III) or citrate concentrations. Conclusion In the aqueous solutions containing Fe(III)-citrate complexes, ·OH radicals were produced after irradiation by a 250W metal halide light. It can be concluded that Fe(III)-citrate complexes are important sources of ·OH radicals for some atmospheric and surface waters. Recommendations and Outlook It is believed that the photolysis of Fe(III)-citrate complexes in the presence of oxygen play an important role in producing ·OH both in atmospheric waters and surface water where high concentrations of ferric ions and citrate ions exist. The photoproduction of ·OH has a high oxidizing potential for the degradation of a wide variety of natural and anthropogenic organic and inorganic substances. We can use this method for toxic organic pollutants such as organic dyes and pesticides.     

泥石流-堰塞湖灾后应急救援决策研究——以甘肃文县“8·17”泥石流灾害为例

以甘肃文县2020年"8.17"泥石流灾害为例,开展泥石流-堰塞湖灾害灾后应急救援决策研究,探索性将该类灾害前期阶段应急救援决策总结为:灾情盲估预判-先期应急备灾-成因剖析-灾情宏观初判-应急救援决策等。研究结果表明:预判影响人口约10.8万人,预估需求帐篷约2.3万顶、饮用水约240 t/d,文县消防救援大队距离最近,附近有文县第一人民医院等8家医疗防疫力量,石鸡坝初级中学等10所学校可作为临时安置避难场所备选;受影响矿山企业5家,重要水库1座;泥石流淤积物堆积区约7.91×10~4 m~2,堰塞湖面积约1.06 km~2,淹没区约37.4×10~4 m~2,因灾受损民居51处、桥梁3处、电站1处、加油站1处及耕地10处,优选3条灾后救援生命线。     

厌氧-好氧活性污泥法处理高浓度甲醇废水

介绍了厌氧一好氧活性污泥法处理电管厂高浓度甲醇废水的动态试验结果。试验结果表明：该方法处理高浓度甲醇废水,可以克服甲醇废水厌氧处理容易酸化的问题．运行稳定．抗负荷冲击性强．处理效果良好。     

Abusive supervision and work behaviors: The mediating role of LMX

We investigated the mediating role of the leader–member exchange (LMX) in the association of abusive supervision and employee work behaviors (task performance and organizational citizenship behaviors toward the organization and individuals). Using data collected from 366 supervisor–subordinate dyads, we found that LMX fully mediated the negative effects of abusive supervision on all three work behaviors. In addition, we conducted a supplementary study on the basis of the data collected from 54 supervisor–subordinate dyads from a garment company, and we found that LMX mediated the relationship between abusive supervision and employee objective future performance with interactional justice controlled. Copyright © 2011 John Wiley & Sons, Ltd.     

富勒烯甘氨酸铜盐的制备及表征

以富勒烯和甘氨酸为原料合成富勒烯甘氨酸,再与硝酸铜反应得到富勒烯甘氨酸铜盐。通过单因素方法探讨了反应温度、反应时间、反应物物料比对目标物富勒烯甘氨酸铜盐中铜质量分数的影响。获得最佳工艺条件为:富勒烯甘氨酸和硝酸铜的摩尔比1∶5,反应时间2.0 h,反应温度35℃。此时富勒烯甘氨酸铜盐中铜质量分数为17.8%。同时用FT-IR、MS、元素分析及原子吸收等方法表征了产物的结构。用差热仪测试了富勒烯甘氨酸铜盐的热稳定性,表明产物具有良好的热稳定性。     

基于CFD的深水钻井溢油事故定量风险评估

针对深水钻井作业过程中的井喷溢油问题,基于计算流体力学(CFD)方法,通过UDF函数给定海流流剖面、波浪入口边界条件和海水静压分布情况,结合标准k-ε方程,采用VOF模型实现对油、气、水三相自由面的追踪,建立了溢油扩散事故数值仿真模型,评估深水条件下溢油扩散危害区域,研究海流流速、溢油量对原油扩散的影响。结果表明,海流流速和溢油量是原油扩散行为和危害区域分布范围的重要影响因素。     

生物滴滤池净化二氯甲烷废气的实验研究

在φ50mm生物滴滤池内进行了二氯甲烷废气净化的实验研究.由工厂活性污泥经驯化培养得到菌种,进一步接种、在填料表面挂膜,接种和挂膜约需30d.滴滤池内装填聚丙烯散堆填料,废气和循环液在滴滤池内逆流操作,循环液pH值为7.0±0.5,温度维持在28.5±2℃的条件下,生物膜系统能较好地适应进口浓度的变化.在气体空床停留时间为15.7s、二氯甲烷进口浓度为0.7～3.12g/m³的范围内,去除效率为72.0%～99.1%.滴滤池中的酸性环境对二氯甲烷的降解具有明显抑制作用.