Observed half-lives of 3H, 90Sr and 137Cs in hydrosphere in the Vltava River basin (Bohemia)

A near field study was set up to follow the effects of the Temelin nuclear power plant construction. Reference levels of artificial radionuclides were monitored in the Vltava River upper course and its tributaries in the period 1990-2001. Monitoring continued even after the waste water release startup during the pilot operation in 2002. The assessment of the (90)Sr and (137)Cs concentrations histories in ground water, river bottom sediments and fish showed a decreasing trend. This trend was not influenced by the nuclear power plant pilot operation. In the case of tritium, trend of increasing concentration had been already observed since the pilot operation startup. The monitoring of changes in concentrations of artificial and natural radionuclides in influenced and uninfluenced profiles will be maintained to assess the possible influence of the operation of the Temelin nuclear power plant.     

Noise annoyance responses of middle school pupils and teachers

The present survey study had three aims: (1) to compare pupils’ and teachers’ annoyance responses to classroom noise, (2) to compare females and males responses and (3) to test annoyance models that fitted both pupils and teachers. The study included 207 pupils, aged 13–14 years, and 166 teachers, aged 21–65 years. Both pupils and teachers rated chatter as the most disturbing noise source in the classroom. In line with predictions, the teachers experienced themselves as more sensitive to noise, had poorer hearing status, and reported more intense stress symptoms than the pupils. Contrary to expectations, the teachers were more annoyed and they perceived the noise to be more unpredictable than the pupils did. The control items showed a mixed pattern. There were no overall differences between females and males annoyance responses, but females reported having more stress symptoms than males. A conceptual model was tested with structural equation models, where noise sensitivity mediated the relationship between hearing status and annoyance, which in turn affected stress symptoms. Control and predictability were tested as moderators of the relations between stress symptoms and annoyance. The data fit the conceptual model reasonable well when both samples were included in the same test.     

WATER QUALITY IN THE PAWTUXET RIVER: METAL MONITORING AND GEOCHEMISTRY1

ABSTRACT: The Pawtuxet River flows from a relatively rural area through some of the more highly industrialized sections of Rhode Island. During its journey, the river receives many municipal, industrial, and ground water sources of metal constituents. The present report is the first in a two part series in which the water quality of this urban river was evaluated by a chemical monitoring study of the sources, transport mechanisms, and fate of cadmium, chromium, copper, lead, and nickel in the river. The second paper will use the chemical data to derive and calibrate a steady-state water quality model for this river. The metal concentrations In the river tended to increase from the headwaters to the mouth with river stations nearest to point source outfalls showing elevated values. In some sections of the river, levels of a few of the metals could not be explained by the point sources; and other inputs, including sediment resuspension, axe proposed to make up this apparent unbalance. The ability of a municipal secondary treatment plant to remove metals was demonstrated, and the tie-in of the effluent from a major chemical company to the plant did not cause any observable deterioration in treatment efficiency.     

Understanding resident satisfaction with involvement in highway planning: in-depth interviews during a highway planning process in the Netherlands

This study investigates resident satisfaction with provided involvement activities during highway planning processes, with particular attention given to the planned Southern Ring Road highway project in Groningen, the Netherlands. In-depth interviews with 38 residents living in the project area reveal important themes contributing to satisfaction. Satisfaction with passive information activities is motivated by the extent to which information addresses concerns, but (dis)trust in government and other information sources also plays a role. For residents preferring to obtain additional information, perceived access to such information and the extent to which it reduces concerns are also important to satisfaction. Finally, for residents who would rather participate actively, satisfaction is motivated by their perceived access to participation activities and the sense of being heard. Study results show how residents’ evaluations of the themes underpinning involvement satisfaction are based on their perceptions of actual project team activities and contextual factors.     

A fuzzy expert system for soil characterization

As soil is a natural resource not always renewable, the risk characterization of contaminated soils is an issue of great interest. Artificial Intelligence (AI), based on Decision Support Systems (DSSs), has been developed for a wide range of applications in contaminated soil management. Decision trees have already shown to be easy to interpret and able to treat large scale applications. Fuzzy logic gives an improvement in the perturbations and the variance of the training data, due to the elasticity of fuzzy set formalism. In this study, we have developed a classificatory tool applied to characterize contaminated soil in function of human and environmental risks. Knowledge engineering for constructing the Soil Risk Characterization Decision Support System (SRC-DSS) involves three stages: knowledge acquisition, conceptual design and system implementation. A total of 26 parameters were divided into three groups to facilitate the configuration of the expert system: source attributes, transfer vector attributes, and local properties. Sixteen case studies were evaluated with the SRC-DSS. In comparison with other techniques, the results of the current study have shown that SRC-DDS is an excellent tool to classify and characterize soils according to the associated risk.     

Wet peroxide degradation of atrazine

The high temperature (150-200 degrees C), high pressure (3.0-6.0 MPa) degradation of atrazine in aqueous solution has been studied. Under these extreme conditions atrazine steadily hydrolyses in the absence of oxidising agents. Additionally, oxygen partial pressure has been shown not to affect atrazine degradation rates. In no case mineralisation of the parent compound was observed. The addition of the free radical generator hydrogen peroxide to the reaction media significantly enhanced the depletion rate of atrazine. Moreover, partial mineralisation of the organics was observed when hydrogen peroxide was used. Again, oxygen presence did not influence the efficiency of the promoted reaction. Consecutive injections of hydrogen peroxide throughout the reaction period brought the total carbon content conversion to a maximum of 65-70% after 40 min of treatment (suggesting the total conversion of atrazine to cyanuric acid). Toxicity of the effluent measured in a luminometer decreased from 93% up to 23% of inhibition percentage. The process has been simulated by means of a semi-empirical model.     

Using fugacity to predict volatile emissions from layered materials with a clay/polymer diffusion barrier

Structural insulated panels (SIPs) have significant environmental and energy advantages. However, the tight structure that results may cause degraded indoor air quality and the potential release of volatile organic compounds (VOCs) from these layered materials must be considered. A physically based model for predicting VOC emissions from multi-layer materials is described. Fugacity is used to eliminate the concentration discontinuities at the interface between layers. This avoids an obstacle associated with numerically simulating mass transfer in composite materials. The numerical model is verified for a double-layer system by comparing predicted concentrations to those obtained with a previously published analytical model. In addition, hexanal emissions from multi-layer SIPs are simulated to demonstrate the usefulness of the fugacity approach. Finally, the multi-layer model is used to investigate the impact that clay/polyurethane nanocomposite diffusion barriers can have on VOC emissions. Indoor gas-phase concentrations can be greatly reduced with a barrier layer on the surface, thereby minimizing the environmental impact of SIPs.     

浮游植物和水质表征:从瑞典梅拉伦、哈马伦、韦特恩和维纳恩湖等大湖泊中获得的经验

自20世纪60年代以来,瑞典梅拉伦湖、哈马伦湖、韦特恩湖和维纳恩湖等大湖泊的浮游植物和环境变量一直处于监测之下.20世纪70年代政府出台了一些减少磷和工业废品排放的措施,于是水体磷的含量降低了90%～95%,结果大多数污染湖盆磷的浓度减少了一半.体现在浮游植物群落的变化是夏季蓝藻细菌、春季硅藻和隐鞭毛藻的生物量迅速降低,另一个反应是藻华期变短,生长季节的物种丰富度和生物量均匀度增加,浮游植物群落内物种数量和组成发生变化.此外,大湖泊物种丰富度相应与湖泊的特征有关.本文对湖泊中有毒蓝藻细菌的发生作了介绍,结合哈马伦湖和梅拉伦湖的藻华,确定在13～0.1 μg/L之间的微藻素最大和最小值;给出利用浮游植物作为监测指标确定水质量变化的基本框架,并提出了评价标准.