不同填料对近海域污染水体中磷的吸附效果研究

采用不同废弃物制成磷吸附填料来去除受污染水体中的磷。考察了水泥块、红砖、煤渣、海蛎壳及火山岩5种废弃物对近海域污染水体中磷的吸附性能,并对其机理进行解析。结果表明,水泥块有较大的比表面积,具有较高的除磷潜能,但其孔隙率较小,易被堵塞;而红砖块具有较大的孔隙率,可改善水力条件。在无盐度和盐度为30‰条件下,考察了填料除磷效果,结果表明,5种填料对磷的去除效果排序为:水泥块>煤渣>红砖>火山岩>海蛎壳;其中水泥块和煤渣的除磷效率分别达99.37%、99.0%和97.3%、94.6%,盐度对其除磷有较小的抑制作用;水泥块用作除磷填料最佳HRT为0.5 d,出水磷浓度达Ⅴ类地表水水质标准。     

Cultural values of natural resources among the San people neighbouring Kgalagadi Transfrontier Park,South Africa

Globally, cultural values of natural resources are increasingly recognised as important for local natural resource management and conservation in and beyond parks. The tendency has been to focus on the direct-use rather than the cultural values and importance of natural resources. The cultural values underlying natural resources (directly or indirectly used) and various natural resource-based activities, and the implications for conservation, remain little explored. Drawing from household surveys, in-depth qualitative interviews, observations and secondary data, we explore the cultural significance of natural resources and different land-use practices among the San people bordering Kgalagadi Transfrontier Park in South Africa. Our findings illustrate that though cultural values are inextricably linked to resource use, they are not recognised by all community members. Further, cultural values arise from a diverse and sometimes conflicting array of values that punctuate individuals' lifestyles. A better understanding of context-specific cultural settings and the linkages between the cultural and material dimensions of resource use can lead to the development of interventions that can ensure effective conservation of both natural resources and culture.     

Building urban gas process safety management (UG-PSM) system: Based on root cause analysis with 160 urban gas accidents in China

Urban safety is significantly impacted by the complexity of urban gas accidents. Although China has put forward the goal of “zero fatalities in accidents” for urban gas, unfortunately, the root causes of the unsound safety culture and imperfect safety management system of urban gas enterprises remain unresolved. Therefore, statistical analysis and 24Model analysis of 160 urban gas accidents in mainland China were performed to investigate the proximate causes of the accidents and the current situation of urban gas safety. The CCPS's risk-based process safety elements were used to identify potential deficiencies in the current urban gas process safety management (UG-PSM). During the analysis, it was observed that insufficient implementation of concealed danger investigation and rectification accounted for 76%, which is the primary proximate cause of urban gas accidents. Stakeholder outreach is the most under-represented competency in urban gas safety management. Based on the results, a novel framework for the UG-PSM system was constructed, and the theory of urban gas safety management was further improved. Furthermore, we evaluated the matching degree between UG-PSM elements and the existing measures of the government, urban gas associations, third-party organizations, and urban gas enterprises. Finally, we analyzed the feasibility, challenges, and development directions of the UG-PSM system. This study establishes a foundation for researchers and practitioners in the future research and practice of urban gas process safety and provides theoretical guidance for preventing high-incidence accidents of urban gas in China.     

Development and initial validation of an Aviation Safety Climate Scale

PROBLEM: A need was identified for a consistent set of safety climate factors to provide a basis for aviation industry benchmarking. METHOD: Six broad safety climate themes were identified from the literature and consultations with industry safety experts. Items representing each of the themes were prepared and administered to 940 Australian commercial pilots. RESULTS: Data from half of the sample (N=468) were used in an exploratory factor analysis that produced a 3-factor model of Management commitment and communication, Safety training and equipment, and Maintenance. A confirmatory factor analysis on the remaining half of the sample showed the 3-factor model to be an adequate fit to the data. DISCUSSION: The results of this study have produced a scale of safety climate for aviation that is both reliable and valid. IMPACT ON INDUSTRY: This study developed a tool to assess the level of perceived safety climate, specifically of pilots, but may also, with minor modifications, be used to assess other groups' perceptions of safety climate.     

关于大学文化对城市文化推动引领作用的思考——以秦皇岛市为例

城市文化以其地域性、多元性和开放性为自身繁荣奠定了基础,也不可避免地为其推陈出新带来弊端。大学文化以其继承性、创新性和先进性等特点,并通过培养和输送大批高素质人才、提供智力与技术支持、广泛开展文化交流等途径,发挥其对城市文化的推动、引领作用。     

An investigation of occupational subgroups with respect to patient safety culture

There are varying views about the consistency of safety culture across a given organisation or industrial sector: some view it as homogeneous, whereas others have suggested the presence of sub-cultures that vary according to the work group or worksite. This paper reports on a study in which job characteristics and safety climate ratings from a sample of British community pharmacists (N = 860) were subjected to a cluster analysis, with the aim of identifying whether discrete groups can be identified on the basis of these ratings. A four-cluster solution was obtained from the analysis. Examination of quantitative and qualitative data from each cluster led to them being identified as: (i) the disenfranchising pharmacy; (ii) the perilous pharmacy; (iii) the safety-focused pharmacy; (iv) the challenging pharmacy. On the basis of the data obtained, safety culture appears to have both characteristics generic to all community pharmacies and characteristics specific to each cluster, with a number of social and organisational factors influencing the culture in any one setting. Implications for the modelling and assessment of safety culture are discussed.     

Removal,adsorption and desorption of pentachlorophenol (PCP) by filamentous fungi: Rhizopusarrhizus and Cunninghamella elegans in batch system

PCP was, and in some countries still is, one of the most frequently used fungicides and pesticides, specially in wood preservation. The extensive use is correlated with contamination of water and soil and it is detected in several compartments of the food chain.

Some Micromycetes are able to adsorb and degrade PCP, with two mechanisms involved: biosorption (including both adsorption and absorption) and biodegradation.

Our work is focused on the biosorption alone and biodegradation‐biosorption of PCP by respectively denatured and living R.arrhizus and C.elegans fungi.

Living fungi are cultivated in batch system and denaturation is obtained by drying (70°C) and grinding the fungi to a calibrated powder (200–400 μm). Kinetic studies are performed with 10 mg/1 PCP initial concentration. Adsorption capacity is measured at equilibrium concentration as high as about 400 mg/1 PCP.

The results show that: PCP adsorption, for the two fungi, follows a two steps process. R. arrhizus dead and living biomasses are able to bind respectively, 75 and 55% of a 10 mg/1 PCP initial concentration in 1 hour contact time and then 75 and 100% in 96 hours. For C.elegans, 70 and 28% in 1 hour and in 96 hours 70 and 90%, respectively.

The PCP binding by living fungi is higher than non living ones, but with a slower rate.

The maximum PCP adsorption capacity is about 24 mg/g of R.arrhizus dried biomasses and 16 mg/g for C.elegans ones, in 48 hours contact time. Isotherm curves follow the Langmuir model.

Desorption studies with methanol (to reuse biomasses) shows that it is a rapid phenomenon (about 100% in 24 hours for the two fungi).

An industrial and economical process to depollute contaminated water by PCP is possible by using cheap fungal by‐products from fermentation industries.     

The metabolism of neonicotinoid insecticide thiamethoxam by soil enrichment cultures,and the bacterial diversity and plant growth‐promoting properties of the cultured isolates

A soil enrichment culture (SEC) rapidly degraded 96% of 200 mg L^?1 neonicotinoid insecticide thiamethoxam (TMX) in MSM broth within 30 d; therefore, its metabolic pathway of TMX, bacterial diversity and plant growth‐promoting rhizobacteria (PGPR) activities of the cultured isolates were studied. The SEC transformed TMX via the nitro reduction pathway to form nitrso, urea metabolites and via cleavage of the oxadiazine cycle to form a new metabolite, hydroxyl CLO‐tri. In addition, 16S rRNA gene‐denaturing gradient gel electrophoresis analysis revealed that uncultured rhizobacteria are predominant in the SEC broth and that 77.8% of the identified bacteria belonged to uncultured bacteria. A total of 31 cultured bacterial strains including six genera (Achromobacter, Agromyces, Ensifer, Mesorhizobium, Microbacterium and Pseudoxanthomonas) were isolated from the SEC broth. The 12 strains of Ensifer adhaerens have the ability to degrade TMX. All six selected bacteria showed PGPR activities. E. adhaerens TMX‐23 and Agromyces mediolanus TMX‐25 produced indole‐3‐acetic acid, whereas E. adhaerens TMX‐23 and Mesorhizobium alhagi TMX‐36 are N₂‐fixing bacteria. The six‐isolated microbes were tolerant to 200 mg L^?1 TMX, and the growth of E. adhaerens was significantly enhanced by TMX, whereas that of Achromobacter sp. TMX‐5 and Microbacterium sp.TMX‐6 were enhanced slightly. The present study will help to explain the fate of TMX in the environment and its microbial degradation mechanism, as well as to facilitate future investigations of the mechanism through which TMX enhances plant vigor.     

Hematological and histopathological changes in silver catfish Rhamdia quelen (Siluriformes) exposed to clomazone herbicide in the Madre River,Santa Catarina State,Southern Brazil

This study evaluated the influence of the clomazone herbicide (2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone) contamination on the hematological parameters and histological changes in gills and liver of silver catfish (Rhamdia quelen) from Madre River, Santa Catarina State, Southern Brazil. Fish were collected between March 2010 and January 2012 at two different sites of the Madre River, one site receiving residual water (contaminated site) from rice culture (n = 49) and another that do not receive residual water (reference site) (n = 48). The herbicide clomazone analysis detected 3.40 ± 1.70 μg/L in the contaminated site and 1.1 ± 0.33 μg/L in the reference site. Fish from contaminated site showed increased (P < 0.05) number of monocytes suggesting the possible defense response as a result of chronic exposure to clomazone. On the other hand, no difference was found in the hematocrit percentage, red blood cell count, total thrombocyte number, white blood cell count, lymphocytes, and neutrophils number. Fish from both sites showed histopathological changes in gills and liver, possibly caused by chronic exposure to contamination. The influence of herbicide sub doses on fish health is also discussed.     

ANAEROBIC TREATMENT OF ATRAZINE BEARING WASTEWATER

Performance of mixed microbial anaerobic culture in treating synthetic wastewater with high Chemical Oxygen Demand (COD) and varying atrazine concentration was studied. Performance of hybrid reactors with wood charcoal as adsorbent, with a dose of 10 g/l and 40 g/l, along with the microbial mass was also studied. All the reactors were operated in sequential mode with Hydraulic Retention Time (HRT) of 5 days. In all the cases, COD removal after 5 days was found to be above 81%. Initial COD was above 1000 mg/l. From a hybrid reactor COD removal after 2 days was observed to be 90%. Atrazine reduction after 5 days by microbial mass alone was 43.8%, 40% and 33.2% with an initial concentration of 0.5, 1.0 and 2.0 mg/l respectively. MLSS on all the cases were almost same. Increasing MLSS concentration by about 2 fold did not increase the atrazine removal efficiency significantly. Maximum atrazine removal was observed to be 64% from the hybrid reactor with 10 g/l of wood charcoal and 69.4% from the reactor with 40 g/l of wood charcoal. Atrazine removal from the hybrid reactors after 15 days were observed to be 35.7% and 38.7%, which showed that the higher dose of wood charcoal in hybrid reactor did not improve the atrazine removal efficiency significantly. Specific methanogenic activity test showed no inhibitory effect of atrazine on methane producing bacteria. The performance of anaerobic microorganisms in removing atrazine with no external carbon source and inorganic nitrogen source was studied in batch mode. With an initial concentration of 1.0 mg/l, reduction of atrazine by the anaerobic microorganisms in absence of external carbon source after 35 days was observed to be 61.8% where as in absence of external carbon and inorganic nitrogen source the reduction was only 44.2% after 150 days. Volatilization loss of atrazine was observed to be insignificant.