Combined influence of food level and inoculation density on competition between <Emphasis Type="Italic">Anuraeopsis fissa</Emphasis> and <Emphasis Type="Italic">Brachionus patulus</Emphasis> or <Emphasis Type="Italic">Brachionus macracanthus</Emphasis> (Rotifera: Brachionidae)

We tested separately the effect of two taxonomically related rotifers (B. patulus and B. macracanthus) on the population dynamics of another species (A. fissa) at low (0.5 ×10 ⁶) and high food levels (1.5 × 10⁶ cells/ml of Chlorella vulgaris) using different inoculation densities (0–100%). We also quantified the impact of A. fissa on the two brachionid species. Regardless of the presence of the competing species, an increase in the availability of food led to increase in the abundances of the three rotifers. The population growth of B. patulus, B. macracanthus, or A. fissa was affected negatively when cultured together with another species. An increase in the initial density of any one of the competing species became advantageous to maintain a certain population size. At a low algal food level, B. patulus was able to suppress A. fissa more strongly than B. macracanthus. On the other hand, at a high food level, B. macracanthus suppressed the population of A. fissa more strongly than B. patulus. Peak population densities for A. fissa varied from about 150 to 1000 ind./ml, depending on food density and the presence of competitors. The rate of population increase (r) of A. fissa, B. patulus, and B. macracanthus increased with an increase in food availability but decreased with increasing initial density of the competitor. Both Brachionus spp. experienced negative growth rates in the presence of A. fissa, especially at a high initial density of the latter. Published in Russian in Ekologiya, 2007, Vol. 38, No. 5, pp. 381–390. The article was submitted by the authors in English.     

国内外含油污泥的处理现状分析

在石油开采及生产加工过程中要产生大量的废弃含油污泥,这些污泥不经处理直接排入环境将严重危害环境的安全以及人类的健康.因此,国内外正积极采取各种应对措施,希望能缓解含油污泥带来的危害.综述了国内外含油污泥的处理技术现状,并展望了含油污泥处理技术的发展方向.     

STREAM DISCHARGE PREDICTION VIA A GRID BASED SOIL WATER ROUTING WITH PADDY FIELDS1

ABSTRACT: A grid based daily hydrologic model for a watershed with paddy fields was developed to predict the stream discharge. ASCII formatted elevation, soil, and land use data supported by the GRASS Geographic Information System are used to generate distributed results such as surface runoff and subsurface flow, soil water content, and evapotranspiration. The model uses a single flow path algorithm and simulates a water balance at each grid element. A linear reservoir assumption was used to predict subsurface runoff components. The model was applied to a 75.6 km² watershed located in the middle of South Korea, and observed stream flow hydrographs from 1995 and 1996 were compared to model predictions. The stream flow predictions of 1995 and 1996 generally agreed with the observed flow, resulting in a Nash‐Sutcliffe efficiency R² of 0.60 and 0.62, respectively. The hydraulic conductivity for percolating water through the saturated layer affected baseflow generation. The levee height of the paddy influenced the time and magnitude of the surface runoff, depending on irrigation management. The model will be used for making low flow management decisions by evaluating the role of each land use to stream flow, especially in case of paddy decrease by gradual urbanization of a watershed.     

浅谈安全文化

20世纪80年代,我国劳动保护界的学者和专家提出了安全文化的理念, 提出了劳动保护科学体系的构想,1992 年建立了相应的学科。20世纪末,我国一批学者又提出了安全、减灾、环境科学交叉融合的大安全科学技术体系,针对传统安全理念开展了企业安全文化、大众安全文化、社区安全文化等理论研究。为我国安全科学奠定了理论基础, 并不断完善和拓展了我国安全科学技术学科的建设。     

油田作业废水高效处理技术中试研究

文章根据新疆油田作业废水特征及油田地处干旱区的地理特点,结合国内外含聚合物污水处理的技术现状,以及油田连续生产稳定运行的要求,在含油污水处理技术的基础上,开展了作业废水处理关键技术研究和工艺优化,采用了"隔油—絮凝气浮—深层过滤"技术。中试试验结果表明:处理后废水COD_(Cr)、石油类、SS可分别由680 mg/L、98.6 mg/L、56.2 mg/L降至98.8 mg/L、5.4 mg/L、4.5 mg/L,去除率分别为85.5%、94.5%、92.0%。     

Effect of fertilizer application on ammonia emission and concentration levels of ammonium, nitrate, and nitrite ions in a rice field

The concentrations of ammonium NH4+, nitrate NO3-, and nitrite NO2- ions were recorded along with ammonia (NH(3)) emission from a fertilized rice field located in the Kwangju province in South Korea over a period of 4 months (June to October 2006). The highest magnitude of NH(3) flux was 20,754 microg m(-2) h(-1), while the average flux value over the entire sampling period was 2,395 microg m(-2) h(-1). The highest ionic concentrations were 1.67, 0.44, and 0.71 ppm for NH4+, NO3-, and NO2- ions, respectively. Possible effects of soil pH on NH(3) fluxes were detected, as they concurrently exhibited a gradual and periodic change during the sampling period. Positive correlations existed between concentrations of NH4+ and NO2- ions and the soil pH. Positive correlations also existed between NH(3) emission flux and ambient (and water) temperatures. Results indicated that fertilizer application to rice can lead to significant emission of NH(3) along with NH4+ and NO3- ions.     

黑河下游额济纳河流域生态环境现状及发展趋势

本文通过资料和监测数据阐述了2006—2011年黑河下游额济纳河流域生态环境现状及其变化趋势。土地覆盖监测数据结果表明,截至2011年额济纳河流域绿洲面积达3232km^2,水域湿地面积达118km^2,额济纳绿洲植被覆盖度总体呈增加趋势,局部地区增加显著,而个别地区植被呈缓慢退化。水资源调查数据说明。额济纳河流域绿洲的维持和恢复仍取决于黑河水的补给量,近几年黑河水在额济纳境内的进入量基本能维持额济纳现有绿洲规模。     

The 210Po and 210Pb levels in surface sediment samples in the Izmir Bay (Aegean Sea-Turkey)

Bottom sediments reflect in general the relative contamination of a sea area. Therefore, a great deal of monitoring work has been dedicated to the analysis of bottom sediments. Izmir Bay is a very important pollution centre in Turkish Aegean coast region due to a densely populated community, industrial complex and maritime transportation, and there are many streams flowing into the bay that pass through a number of industrial and agricultural areas. It had received the majority of domestic and industrial wastewaters until the wastewater treatment plant was constructed. It is well known that sediments play an important role as reservoirs of a fraction of the pollution in aquatic systems. Therefore, sediment samples were collected monthly from three stations which are located in the inner part of the bay during the period January to December 2003. Temporal variations and seasonal changes on their ²¹⁰Po and ²¹⁰Pb contents were examined, and the activity concentrations of ²¹⁰Po and ²¹⁰Pb were found to vary from 43±6 to 132±12 and 27±5 to 91±9 Bq kg^???1 dry wt, respectively. The highest values of those natural radionuclides were measured at Kar??yaka Station because of the current systems of the bay. Seasonally, the ²¹⁰Pb levels were found to increase during the winter time for all the stations.     

The carajas iron ore project: The strategy of a third world state- owned enterprise in a depressed market

This paper describes how the Carajas iron ore project was set up in February 1985 at a time of deep recession in the iron ore and steel industries. Development of the project was met with much criticism, mainly from North American steel makers, who argued that the project would only be successful through the support of a Third World government, highly dependent on foreign exchange, without any consideration being given to its economic feasibility or to the fundamentals of the market. The authors explain why the World Bank took the step of setting up the project and how its development can be partly explained by the interests of the Japanese and European steel makers. The role of the Brazilian government is explained and the authors conclude that the relatively low rate of investment anticipated by the project will be overshadowed by the high gains in foreign exchange.     

Advancing the use of an innovative cleanup technology: Case study of Lasagna™

Originated from a recognized need for significantly more effective technologies for soil cleanup, the Lasagna^TM project provides an interesting case study in which industry, government, and academia successfully collaborated to rapidly advance the technology from the laboratory to the field. Called Lasagna^TM because of its layered configurations, the technology combines electrically induced contaminant transport in soils, treatment in place, and geotechnical methods to achieve completely in situ clean-up of contaminated soils. Experiences with respect to the partnership, the development of technology and its current commercialization status are described.