Report: transboundary hazardous waste management. part II: performance auditing of treatment facilities in importing countries.

Before implementing the self-monitoring model programme of the Basel Convention in the Asia, Taiwan has conducted a comprehensive 4-year follow-up project to visit the governmental authorities and waste-disposal facilities in the countries that import waste from Taiwan. A total of nine treatment facilities, six of which are reported in this paper, and the five countries where the plants are located were visited in 2001-2002. France, Belgium and Finland primarily handled polychlorinated biphenyl capacitors, steel mill dust and metal waste. The United States accepted metal sludge, mainly electroplating sludge, from Taiwan. Waste printed circuit boards, waste wires and cables, and a mixture of waste metals and electronics were the major items exported to China. Relatively speaking, most treatment plants for hazardous waste paid close attention to environmental management, such as pollution control and monitoring, site zoning, system management regarding occupational safety and hygiene, data management, permits application, and image promotion. Under the tight restrictions formulated by the central environment agency, waste treatment plants in China managed the environmental issues seriously. For example, one of the treatment plants had ISO 14001 certification. It is believed that with continuous implementation of regulations, more improvement is foreseeable. Meanwhile, Taiwan and China should also continuously enhance their collaboration regarding the transboundary management of hazardous waste.     

Introduction of a recycling system for sustainable municipal solid waste management: a case study on the greater Banjul area of the Gambia

This research proposes for the introduction of a recycling system in the Gambia to enhance sustainable municipal solid waste management. Poor infrastructures, coupled with inadequate resources and lack of funding, work against the optimization of a MSW disposal service. In the authors’ view, authorities in charge of waste management need to change not only behaviors, but modernize their processes. Recycling technology is a key part of the solution. A model has been developed which suggest the involvement of stakeholders to achieve meaningful sustainable MSWM. This can be achieved by recognizing the role of the informal sector through community-based organizations, Non-Governmental Organizations (NGOs), and the private sector. The open dump approach is leading to severe environmental consequences as the groundwater and soil within the dump is been contaminated. In this study, an integrated municipal solid waste management approach was developed with a model to help achieve sustainable municipal solid waste management. Resource recovery, not waste disposal, must be the ultimate goal with clearly defined end user markets so that the recovery loop is complete. Mandatory sorting of waste at household level would help greatly in making recycling activity successful.     

整装催化转化器中CO氧化的数值模拟

研究整装催化转化器中CO氧化的起燃过程.建立了起燃过程数学模型,通过数值计算,分析和讨论了起燃过程中温度的变化,气流性质和催化剂性质各种参数对转化器起燃性能的影响.结果表明,在起燃过程中,壁温峰值的位置逐渐向催化剂入口处移动;固相导热系数在反应点火前后对壁温峰值位置的影响不同;增大CO浓度、增大气体流速、降低气体温度会延迟催化剂的起燃;缩短催化剂长度、增大孔密度有利于起燃.参数分析有助于反应器的设计和建模.     

基站动力环境集中监控系统的雷电防护

雷击是造成电子产品损坏的主要自然灾害,本文在对基站动力环境监控系统雷电危害的特点进行分析的基础上,对基站动力环境监控系统雷电危害的引入途径进行了深入的分析,提出了相应的防护措施。     

澜沧铅矿井下有毒有害气体测评与控制

通过对井下作业点空气中CO、SO2、H2S、NO2和CO2等有毒有害气体的测定,将测定结果与进行比较,发现澜沧铅矿井下部分作业地点空气中CO、NO2和CO2浓度超过规定标准.根据分析、评价的结果,结合该矿实际情况,提出了控制井下有毒有害气体、改善井下空气质量的通风排毒等技术措施,以及防止井下有毒有害气体中毒的管理和个体防护措施.通过实施这些措施,使澜沧铅矿井下有毒有害气体得到了有效控制,其浓度达到了规定的要求.     

Arsenic, cadmium, and lead in California cropland soils: role of phosphate and micronutrient fertilizers

Phosphate and micronutrient fertilizers contain potentially harmful trace elements, such as arsenic (As), cadmium (Cd), and lead (Pb). We investigated if application of these fertilizer increases the As, Cd, and Pb concentrations of the receiving soils. More than 1000 soil samples were collected in seven major vegetable production regions across California. Benchmark soils (no or low fertilizer input) sampled in 1967 and re-sampled in 2001 served as a baseline. Soils were analyzed for total concentrations of As, Cd, Pb, P, and Zn. The P and Zn concentrations of the soils were indicators of P fertilizer and micronutrient inputs, respectively. Results showed that the concentrations of these elements in the vegetable production fields in some production areas of California had been shifted upward. Principal component analysis and cluster analysis showed that the seven production areas could be sorted into three categories: (i) enrichment of As, Cd, and Pb, which was associated with the enrichment of P and Zn in one of the seven areas surveyed; (ii) enrichment of As, which was associated with enrichment of Zn in two of the seven areas surveyed; and (iii) no remarkable correlation between enrichment of As, Cd, and Pb and enrichment of P and Zn in the other four areas surveyed.     

An economic evaluation on the purification and storage of waste hydrogen for the use of fuel cell scooters

Safe and reliable metal hydride canisters (MHCs) for the use of hydrogen storage at low pressure can be applied to supply small fuel cell vehicles or scooters with hydrogen fuel. However, greater cost-effectiveness of hydrogen gas is obviously necessary to the successful promotion of hydrogen fuel cell scooters in the market. In this study, we use the net present value (NPV) method to evaluate the feasibility of an investment project on the supply of purified hydrogen in a pulp company at Hualien, Taiwan. The purified hydrogen can be separated from waste hydrogen by using pressure swing adsorption (PSA) technology and then be stored in MHCs. Under some assumptions of improved parameters about hydrogen production cost and hydrogen gas price, the discounted payback period of hydrogen purification and storage project in our study can be less than 10 years and the unit cost of hydrogen gas can be close to the price of gasoline. Moreover, the unit cost of hydrogen gas in our study can be lower than the cost from other sources of hydrogen.     

Siting and Routing Assessment for Solid Waste Management Under Uncertainty Using the Grey Mini-Max Regret Criterion

Solid waste management (SWM) is at the forefront of environmental concerns in the Lower Rio Grande Valley (LRGV), South Texas. The complexity in SWM drives area decision makers to look for innovative and forward-looking solutions to address various waste management options. In decision analysis, it is not uncommon for decision makers to go by an option that may minimize the maximum regret when some determinant factors are vague, ambiguous, or unclear. This article presents an innovative optimization model using the grey mini-max regret (GMMR) integer programming algorithm to outline an optimal regional coordination of solid waste routing and possible landfill/incinerator construction under an uncertain environment. The LRGV is an ideal location to apply the GMMR model for SWM planning because of its constant urban expansion, dwindling landfill space, and insufficient data availability signifying the planning uncertainty combined with vagueness in decision-making. The results give local decision makers hedged sets of options that consider various forms of systematic and event-based uncertainty. By extending the dimension of decision-making, this may lead to identifying a variety of beneficial solutions with efficient waste routing and facility siting for the time frame of 2005 through 2010 in LRGV. The results show the ability of the GMMR model to open insightful scenario planning that can handle situational and data-driven uncertainty in a way that was previously unavailable. Research findings also indicate that the large capital investment of incineration facilities makes such an option less competitive among municipal options for landfills. It is evident that the investment from a municipal standpoint is out of the question, but possible public–private partnerships may alleviate this obstacle.