Uptake of Cd, Cu, Ni and Zn by the Water Hyacinth, Eichhornia Crassipes (Mart.) Solms from Pulverised Fuel Ash (PFA) Leachates and Slurries

The main solid waste product from coal-fired power stations is pulverised fuel ash (PFA), which can be enriched in toxic elements. Disposal of PFA by dry (in landfills) or wet (by slurrying) disposal methods can release these elements into the environment. Thereafter, the contaminants can be taken up by biota such as Eichhornia crassipes, a common aquatic plant, which has the ability to accumulate elements from water. This study investigates the uptake of Cd, Cu, Ni and Zn by E. crassipes grown in leachates and slurries prepared from two different PFA samples. PFA samples were obtained from Indraprastha Power Station (IPP Stn.) in New Delhi, India and the Ratcliffe-on-Soar Power Station in the UK. E. crassipes grown in PFA leachates and slurries at 1:5 and 1:50 solid:liquid (PFA:deionised water) ratios show that the plant has a very high accumulation capacity for Cd, Cu, Ni and Zn from both leachates and slurries and the uptake of these metals is stronger in the roots than in the tops of the plant. Metal accumulation, as shown by the accumulation factor (AF) values, is higher from both leachates and slurries for plants grown in the 1:50 (PFA:DIW) ratios than in the 1:5 ratios, initial metal concentrations being higher in the 1:5 ratios than in the 1:50 ratios. Lower metal accumulation in the plants grown in slurries than in leachates is related to the high turbidity of growth medium in slurries resulting in ash particles adhering to the root surfaces thus reducing the surface area of metal absorption. Eichhornia plants are able to reduce the pH of all leachates, especially the highly alkaline Ratcliffe leachates to near neutral conditions. Accumulation of Cd and Zn by the plant is higher from the lower pH IPP leachates than the Ratcliffe leachates, indicating that these metals are more soluble and bioavailable in the acidic medium. However, accumulation of Cu and Ni is independent of the pH of the leachates, indicating that other factors, such as metal species, presence of complexing agents in the growth solutions, and effects of competing metal ions may be contributory factors towards the metal uptake and accumulation by the plant.     

输变电建设项目环境管理中存在问题及对策探讨

阐述了输变电建设项目在环境标准、技术规范、公众参与及竣工环保验收等方面存在的问题,并针对这些方面提出了建议。     

Optimal planning of co-firing alternative fuels with coal in a power plant by grey nonlinear mixed integer programming model

Energy supply and use is of fundamental importance to society. Although the interactions between energy and environment were originally local in character, they have now widened to cover regional and global issues, such as acid rain and the greenhouse effect. It is for this reason that there is a need for covering the direct and indirect economic and environmental impacts of energy acquisition, transport, production and use. In this paper, particular attention is directed to ways of resolving conflict between economic and environmental goals by encouraging a power plant to consider co-firing biomass and refuse-derived fuel (RDF) with coal simultaneously. It aims at reducing the emission level of sulfur dioxide (SO(2)) in an uncertain environment, using the power plant in Michigan City, Indiana as an example. To assess the uncertainty by a comparative way both deterministic and grey nonlinear mixed integer programming (MIP) models were developed to minimize the net operating cost with respect to possible fuel combinations. It aims at generating the optimal portfolio of alternative fuels while maintaining the same electricity generation simultaneously. To ease the solution procedure stepwise relaxation algorithm was developed for solving the grey nonlinear MIP model. Breakeven alternative fuel value can be identified in the post-optimization stage for decision-making. Research findings show that the inclusion of RDF does not exhibit comparative advantage in terms of the net cost, albeit relatively lower air pollution impact. Yet it can be sustained by a charge system, subsidy program, or emission credit as the price of coal increases over time.     

Diffusion of Policy Discourse into Rural Spheres Through Co-Management of State Forestlands: Two Cases from West Java,Indonesia

In the context of state forestland management in tropical regions, the implementation of a co-management approach has been widely advocated in order to include the voices of local people and accommodate their interests in management decision-making. Most co-management literatures, however, underestimate the significance of statutory authority held by state to control forestlands and resources. By clarifying the implications of state ownership of forestland, this article aims to critically examine co-management processes with reference to Foucault's notion of power and subject. Case studies were conducted at two co-management pilot sites in Gunung Halimun-Salak National Park, West Java, Indonesia. Findings demonstrate that co-management processes actually materialize shared decision-making arrangements between state forest bureaucracy and rural people through the application of equity approaches, such as deliberation, negotiation, and experimentation. At the same time, these processes can also function to diffuse state policy discourse in rural spheres, which makes rural subjects who accept and practice the policy discourse. The research also reveals that the diffusion process is complex and does not necessarily make a durable subject unless they are pertinently organized. The results of this research indicate that co-management of state forestlands is a double-edged process for local people who risk becoming a proxy of state bureaucracy in the implementation of state policy. Proponents of co-management should, therefore, critically examine whether new institutional arrangements, which are developed through co-management, truly reflect values and needs of local people and assist them to develop a pertinent subject to deal with it.     

企业供电系统安全可靠运行的探讨与实践

介绍了金川公司内部供电系统的概况,对供电系统的故障、事故类型及原因进行了简要分析,对降低故障率、减少一般事故、杜绝重大事故和人身伤亡事故的对策进行了探讨和实践。从企业的人──机──环境的角度提出：①依靠科技进步,提高系统装备安全可靠性;②加强管理,使员工具有较强的安全意识和行为。这两点是供电系统安全可靠运行的两个同等重要条件。     

应用分段烟羽模式估算秦山核电厂(二期)设计基准事故概率后果

采用天气取样技术和分段烟羽模式估算了秦山核电厂二期工程一旦发生设计基准事故，在半径８０ｋｍ评价区内可能造成的事故概率后果。天气取样采用分层取样技术，根据秦山二期厂址百米气象铁塔一年逐时气象观测数据取。持续时间长达３０天的事故释放采用分段烟羽模式由５个不同持续时间，不同释放量的烟段模拟；应用有效扩散参数概念以描述大气稳定度变化对扩散参数的影响，扩散参数采用厂址实测值。     

混凝微滤法处理制革废水

对混凝微滤法处理制革废水进行了试验研究,通过大量试验,确定了最佳工艺条件。在最优控制的基础上,制革废水经混凝沉淀－微滤处理后,COD,BOD5,SS和色度的去除率分别为80%,87%,89%和92%左右,处理后废水可达到排放标准或回用于制革工艺。结果表明,在较低温度下,用硫酸亚铁作混凝剂仍能较好地完成混凝沉淀,验证了硫酸亚铁的低温混凝效果。因此,该工艺值得在北方寒冷地区大力推广。      

功率超声应用于有机污染物降解的研究概况

功率超声是一项降解有机污染物的新型技术。本文介绍了功率超声降解有机污染物的原理：声空化理论及功率超声降解过程中导致有机物分解的三个主要机理,即高温热解机理、OH自由基氧化机理以及超临界水氧化机理。并系统地介绍了挥发性及难挥发性有机物应用功率超声降解时,在不同降解机理影响下的处理效果。文章同时介绍了影响超声降解的一些重要的物理、化学因素。最后提到目前超声降解存在的问题和发展前景。     

城区电力设施电磁影响与低频段电磁环境频谱

通过对电力设施电磁环境影响的形成机理、特征分析,对照低频段电磁环境频谱,分析论述城市区域中电力设施对电磁环境的影响特征以及在频谱中的反映和贡献。本文结论有助于掌握城市区域低频电磁环境的主要影响源,以支撑电磁环境监管。     

220kV输电线路导线不同排列方式下电磁环境影响分析

从220 kV高压架空输电线路工程的导线不同排列方式入手,分析不同导线排列方式下输电线路产生的电磁环境影响,通过对相同电压等级的同塔四回路输电线在导线水平排列和垂直排列两种方式下对周围电磁环境影响的比较分析,探讨此两种导线排列方式对周围环境的影响程度。同时,通过预测输电线路在导线相同排列方式下不同相序布置时对周围环境的影响,对今后的高压输电线路架线方式从减小环境影响角度考虑提出建议。