一体化生物膜技术处理滨海农村污水

对厌氧-3级好氧/缺氧生物膜工艺进行技术改进,并对改进后的"一体化生物膜技术"处理低碳氮比农村生活污水进行了实际应用。新工艺增设了回流泵(回流比2∶1),且厌氧段悬浮填料装填率由原来的15%提高到30%,3级好氧/缺氧段YDT型弹性立体填料装填率依次由原来的50%、40%、25%提高到70%、60%和40%。装置连续稳定运行12个月,平均进水量为18 m3/d,HRT为3.7 d,监测结果表明:对COD、BOD、NH3-N、TN、TP和SS平均去除率分别为75.6%、85.9%、86.7%、63.9%、69.3%和85.5%;出水COD、BOD、NH3-N、TN、TP和SS的平均浓度分别在34.9、8.9、3.4、9.9、0.9和6.9 mg/L以下。改进后出水BOD和TN的去除能力有较大提高,除TP外其他各项指标均达到了设计要求。     

Socio-economic research in support of climate policy development: Mistra's Research Program Clipore

Mistra's Climate Policy Research Program, Clipore, is one of the largest research programs directed to support international climate policy development, involving research groups in Sweden, Norway, United States and India. It has been running from 2004 to 2011 with a budget of more than 100 MSEK (15?M USD). The paper briefly describes the program and its outcomes in relation to climate policy development. Discussion focuses on how the program has been able to be in the front of and include the development of emissions trading systems in Europe and the United States and how the program has been able to follow and produce inputs to the agenda of the United Nations Framework Convention on Climate Change (UNFCCC). The paper also discusses how the program has managed to present its outcomes and maintain an active dialogue with the various stakeholders. The paper emphasises options and obstacles in the communication between science and policy.     

Kinetics of particulate organic matter removal as a response to bioflocculation in aerobic biofilm reactors.

Recent research has identified that the major fraction of chemical oxygen demand in domestic wastewaters is in particulate form. The research presented herein develops the kinetics of particle removal as a response to bioflocculation at the surface of aerobic biofilms. This study focuses on the removal of particles that are maintained in aqueous suspension after 30 minutes of gravity settling. It is helpful to consider the particulate organics removal process in biofilms as the sum of four steps, namely (1) external transport of the particles to the biofilm surface, (2) bioflocculation, (3) organic particulate hydrolysis, and (4) diffusion and reaction of the solubilized organics by the bacterial cells comprising the biofilm. Organic (native corn starch) and inorganic particle (Min-U-Sil 10 [U.S. Silica Company, Berkeley Springs, West Virginia]) suspensions, with micronutrients, were continuously fed to a rotating disc biofilm reactor to verify a first-order kinetic expression that has been used to describe bioflocculation and to demonstrate that bioflocculation is the primary particle removal mechanism. Extracellular polymeric substances were extracted and quantified to describe the role they play in the bioflocculation process.     

一株苯酚降解菌的筛选及降解动力学特性

利用富集驯化的培养方法,从首钢焦化厂废水处理系统中的二沉池出水中,分离筛选出一株能够高效降解苯酚的菌株B3对其16S rDNA序列进行分析,并选择Monod方程和Andrews方程分别研究该菌在不同苯酚浓度条件下的降酚动力学模式。结果表明,B3为蜡状芽孢杆菌(Bacillus cereus);苯酚浓度较低时,苯酚对菌株的生长基本不产生抑制作用,用Monod模型对B3降酚动力学过程进行拟合,其动力学参数V max=0.03 h-1,K s=25.53 mg/L;苯酚浓度较高时,按照Andrews模型对B3降酚动力学过程进行非线性最小二乘曲线拟合,其动力学参数V max=0.08 h-1,K s=147.52 mg/L,K i=384.96 mg/L。根据动力学方程,推论菌株B3降解对于浓度238.30 mg/L的苯酚具有最佳降解效果。     

Influence of nutritional status on some toxic and essential elements in the blood of women exposed to vehicular pollution in Ile-Ife, Nigeria

Blood levels of the elements Cu, Zn, Se, As, Cd, Hg, and Pb have been determined in 62 Nigerian women who were occupationally exposed to vehicular pollution. Mercury was determined using a direct mercury analyzer, while all the other elements were determined by an inductively coupled plasma mass spectrometer system. The mean values for all the toxic elements were all within the recommended desirable/tolerable limits, except for Se (0.44 μg/mL, compared with <0.2 μg/mL recommended by the WHO). More than 98 % of the subjects had blood selenium levels higher than this recommended limit. For As, Hg, and Pb, the corresponding figures of subjects with blood levels above the recommended limits were 4, 8, and 19.3 %, respectively. When the subjects were grouped according to their body mass indexes as normal, underweight, overweight, and obese, analysis of variance shows that mean blood levels of Cu, As, and, to some extent Hg were significantly different in the four nutritional status groups. Blood Hg level correlates significantly with blood As in all the groups, except in obese subjects. Also, a significant correlation between age and blood Hg was observed only in normal subjects and between age and blood Pb only in obese subjects. These results suggest that nutritional status could influence both elemental levels and the interactions between trace elements in the blood of female subjects. Nutrition is therefore a factor to consider in efforts to modify human susceptibility to toxic elements.     

Cooling suits, physiological response, and task performance in hot environments for the power industry.

Heat stress on workers working outdoors in the power industry may result in fatigue and deterioration in task performance. This research collected and analyzed data on task performance of workers working indoors and outdoors with and without a cooling suit. The task performance was compared on the basis of heart rate, oxygen consumption, tympanic temperature, subjective responses, productivity, and error rates. Based on One-Way Analysis Of Variance (ANOVA) results, a significantly lower estimated working oxygen consumption was observed (p < .001) when the cooling suit was worn. The productivity was higher while workers wore the cooling suit as compared to no cooling suit (p = .011) whereas the error rates were significantly lower (p < .001). Also a significantly lower self-reported discomfort was observed in the neck and shoulders while working wearing the cooling suit (p = .004). This study concluded that wearing a cooling suit while working outdoors was associated with physiological benefits as well as improved task performance of the study participants.     

Work status and organizational citizenship behavior: a field study of restaurant employees

This survey‐based field study of 257 service employees developed and tested a model of differences in the organizational citizenship behavior of full‐time and part‐time employees based on social exchange theory. Questionnaire data from matched pairs of employees and their supervisors demonstrated that part‐time employees exhibited less helping organizational citizenship behavior than full‐time employees, but there was no difference in their voice behavior. We also predicted that both preferred work status (an individual factor) and organizational culture (a contextual factor) would moderate the relationships between work status and citizenship. For helping, results demonstrated that preferred status mattered more to part‐time workers than to full‐time. For voice, preferred work status was equally important to part‐time and full‐time workers, such that voice was high only when actual status matched preferred status. Contrary to our expectations, work status made more of a difference in both helping and voice in less bureaucratic organizations. We discuss the implications of work status for social exchange relationships, differences in the social exchange costs and benefits of helping compared to voice, and ramifications of our findings for future research. Copyright © 2001 John Wiley & Sons, Ltd.     

Evaluating Habitat as a Surrogate for Population Viability Using a Spatially Explicit Population Model

Because data for conservation planning are always limited, surrogates are often substituted for intractable measurements such as species richness or population viability. We examined the ability of habitat quality to act as a surrogate for population performance for both Red-shouldered Hawks (Buteo lineatus) and Northern Goshawks (Accipiter gentilis). We compared simple measures of habitat quality to estimates of population growth rates obtained from a spatially explicit model of population dynamics. We found that habitat quality was a relatively poor predictor of simulated population growth rates for several reasons. First, a relatively small proportion of the potential habitat for each species served as population sources in our simulations--15% for Red-shouldered Hawks and 2% for Goshawks. Second, when habitat quality correctly predicted demographic sources on the landscape, it consistently underestimated the contribution of these areas to the population. In areas where habitat quality correctly anticipated the presence of demographic sinks, we found no useful quantitative relationship between the two measures. Our simulation model captured the influence of habitat quality on the hawk populations, but it also incorporated interactions between dispersing individuals and landscape patterns. Thus, the discrepancies we observed likely reflected the influence of forest fragmentation and the spatial arrangement of forest patches on the populations. We conclude that simple measures of habitat quality will often be poor surrogates for population persistence, but that spatially explicit population models can help inform the development of better indices.     

Development and case study of a science-based software platform to support policy making on air quality

This article describes the development and implementations of a novel software platform that supports real-time, science-based policy making on air quality through a user-friendly interface. The software, RSM-VAT, uses a response surface modeling (RSM) methodology and serves as a visualization and analysis tool (VAT) for three-dimensional air quality data obtained by atmospheric models. The software features a number of powerful and intuitive data visualization functions for illustrating the complex nonlinear relationship between emission reductions and air quality benefits. The case study of contiguous U.S. demonstrates that the enhanced RSM-VAT is capable of reproducing the air quality model results with Normalized Mean Bias < 2% and assisting in air quality policy making in near real time.