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02582 Prediction of unconfined compressive strength ofcement paste containing industrial wastes
15 Environment (pollution, health protection, safety) reactivation method, the adhesion form of potassium compounds in the polluted catalyst under the various gas conditions was evaluated by using a thermogravimetric analyser in which water vapour can feed. Additionally, the activity of the treated catalyst was also tested by a differential reactor. As a result, KOH changes to K2CO3 under a CO2 concentration of 25% or more. KOH becomes a solid-phase from the liquid-phase when it is changed into K2CO3. Therefore, the catalyst can not be reactive because K2CO3 chokes pores of the catalyst• However, the activity of the polluted catalyst is revived to 80% of the initial activity by controlling the gas species concentration, especially CO2. Moreover, the catalytic activity can be revived under a steam-carbon ratio of 2.0 or more. Based on the results obtained by these fundamental experiments, the reactivation methods of catalyst polluted are proposed as follows: (i) catalyst should be loaded more upstream in the anode; (ii) in order to reactivate the polluted catalyst, the DIRMCFC should maintain a steam-carbon ratio of 2.0 or more; (iii) gas conditions to activate the catalyst should be applied regularly.
04/02582 Prediction of unconfined compressive strength of cement paste containing industrial wastes Stegemann, J, A. and Buenfeld, N. R. Waste Management, 2003, 23, (4), 321-332. Neural network analysis was used to construct models of unconfined compressive strength (UCS) as a function of mix composition using existing data from literature studies of Portland cement containing real industrial wastes. The models were able to represent the known nonlinear dependency of UCS on curing time and water content, and generalized from the literature data to find relationships between UCS and quantities of five waste types. Substantial decreases in UCS were caused by all wastes; except for EAF dust, the effect was non-linear with the greatest decrease caused initially by approx. 12% plating sludge, 40% foundry dust, 58% other ash, and 72% MSWI fly ash by mass of dry product. It appears that the maximum waste additions used in modelling may approximate the practical limits of waste additions used in modelling may approximate the practical limits of waste addition to Portland cement, i.e., 50% plating sludge or EAF dust, 64% foundry dust, 92% other ash, and 85% MSWI fly ash by mass of dry product. The laboratory was found to be a key predictive variable and acted as a surrogate for laboratory-specific variables related to cement composition, strength and hardening class, product mixing and preparation details, laboratory conditions, and testing details. While the neural network modelling approach has been shown to be feasible, development of better models would require larger data sets with more complete information regarding laboratory-specific variables and waste composition.
04/02583 Public participation in environmental decisions: stakeholders, authorities and procedural justice Maguire, L. A. and Lind, E. A. Int. J. Global Environmental Issues, 2003, 3, (2), 133-148. This study analysed a stakeholder participation process undertaken by the North Carolina Division of Water Quality to see if the process satisfied elements of procedural justice: representation of relevant parties, voice, sound technical basis, fair treatment by authorities and absence of bias. The rushed timeframe for the process compromised several elements of procedural justice. Representation suffered from the absence of pre-process contact with potential participants. Toofrequent meetings prevented stakeholders from digesting complex technical information on water-quality impacts of excess nutrients. The Division of Water Quality dominated the function of the stakeholder groups by playing multiple roles, including convening meetings, providing technical information, drafting documents, and serving as liaison to the state legislature. Stakeholders acknowledged that the division's strong role was probably essential to making progress in such a short timeframe but worried that the result was biased in favour of division views.
04/02584 Recent advances in mercury removal technology at the National Energy Technology Laboratory O'Dowd, W. J. et al. Fuel Processing Technology, 2004, 85, (6-7), 533548. The in-house research effort on mercury studies at the National Energy Technology Laboratory is an integrated, multi-task approach, including experimentation at both the laboratory-scale and the pilot-scale, as well as a numerical modelling effort to aid in interpretation of pilot-scale results. In the laboratory-scale work, novel sorbents and techniques for the removal of mercury from flue gas are being investigated using a small packed-bed reactor. The reactor system is used to screen novel sorbents for their capability to remove mercury from gas streams. The capacities of these novel sorbents are determined as a function of gas composition and temperature and are compared to results with commercially available activated carbons. In the pilot-scale work, an existing pilot unit has been characterized with respect to the distribution and fate of hazardous air pollutants in flue gas, with an
360 Fuel and Energy Abstracts September 2004
emphasis on mercury. The pilot unit is a 500-1b/h (227-kg/h) pulverized coal-fired (PCFC) combustion system that includes a furnace, air preheater, spray dryer, ductwork and a pulse-jet fabric filter. The investigations with this unit have entailed evaluation of various activated carbons and novel sorbents, as well as comparisons of various sampling techniques for the determination of total and speciated forms of mercury. The impact of various parameters (temperature, sorbentto-mercury ratio, baghouse pressure drop) on the removal of mercury has been investigated. Additionally, a slipstream allows for the investigation of sorbent injection in a fly ash-free flue gas over a wide range of operating conditions, including residence time. A summary of the results for mercury measurement and control from the 500-1b/h (227-kg/h) PCFC combustion system will be presented, as well as the evaluation of methods for measurement of in-duct removals using the slipstream. Finally, a discussion of the numerical modelling effort will be given.
04•02585 Removal of unburned carbon from municipal solid waste fly ash by column flotation Huang, Y. et al. Waste Management, 2003, 23, (4), 307-313. Unburned carbon (UC) is the major source of organic contaminants in municipal solid waste (MSW) fly ash. So most organic contaminants can be removed by the removal of the UC from the MSW fly ash. This study first used a technique of column flotation to remove U C from MSW fly ash. The influences of column flotation parameters on the recovery efficiency of UC were systematically studied. It was found that the UC recovery efficiency was greatly influenced by the gas flow rate, pH value, collector kerosene's concentration and the types of fly ash. By optimizing the above parameters, 61.2% of the UC from MSW fly ash having 5.24% UC content was successfully removed. The removal mechanism was well accounted for the kinetic theory of column flotation and surface-chemistry theory. The results indicate that the Column flotation technique is effective in removing the U C from MSW fly ash, and show that there is a strong possibility for practical application of this technique in removing the organic contaminants from MSW fly ash.
04•02586 Solid state dehalogenation of PCBs in contaminated soil using NaBH4 Aresta, M. et al. Waste Management, 2003, 23, (4), 315-319. This work presents the results of an experimental study on the abatement of polychlorinated biphenyl (PCBs) in contaminated soil using a high-energy milling technique that promotes a reaction only by impact between milling bodies. A sample of soil from a controlled landfill was treated with powdered NaBH4 using two different hydride/ soil ratios (5 and 2.5% w/w). The efficiency of the dehalogenation/ hydrogenation reaction was studied as a function of the milling time (3.5 up to 30 h). After each run, the total PCBs content and the production of inorganic chloride were measured. The complete abatement was obtained with a starting PCBs concentration of about 2600 mg/kg. The residual PCBs concentration resulted to be <0.2 rag/ kg. The final products of the treatment were biphenyl and NaCl. Other toxic or hazardous organic by-products were not generated. Boron was found as boric acid.
04/02587 State responsibility and compensation for climate change damages - a legal and economic assessment Tol, R. S. J. and Verheyen, R. Energy Policy, 2004, 32, (9), 1109-1130. Customary international law has that countries may do each other no harm. A country violates this rule if an activity under its control does damage to another country, and if this is done on purpose or due to carelessness. Impacts of climate change fall under this rule, which is reinforced by many declarations and treaties, including the UNFCCC. Compensation for the harm done depends on many parameters, such as emission scenarios, climate change, climate change impacts and its accounting. The compensation paid by the OECD may run up to 4% of its GDP, far exceeding the costs of climate change to the OECD directly. However, the most crucial issues are, first, from when countries can be held responsible and, second, which emissions are acceptable and which careless. This may even be interpreted such that the countries of the OECD are entitled to compensation, rather than be obliged to pay. State responsibility could substantially change international climate policy.
04102588 Sustainable urban transportation: impact of mitigation strategies on local pollutants
CO 2
Yedla, S. and Parikh, J. K. Int. J. Environmental and Pollution, 2003, 19, (5), 475-482. This paper assesses COz mitigation strategies in Delhi and Mumbai against the dynamics of local pollutants. After testing against technoeconomic feasibility, compressed natural gas (CNG) technology, fourstroke two-wheelers and battery-operated vehicles (BOV) were selected as candidate options for Mumbai and Delhi. Multiple
04/02582 Prediction of unconfined compressive strength of cement paste containing industrial wastes Stegemann, J, A. and Buenfeld, N. R. Waste Management, 2003, 23, (4), 321-332. Neural network analysis was used to construct models of unconfined compressive strength (UCS) as a function of mix composition using existing data from literature studies of Portland cement containing real industrial wastes. The models were able to represent the known nonlinear dependency of UCS on curing time and water content, and generalized from the literature data to find relationships between UCS and quantities of five waste types. Substantial decreases in UCS were caused by all wastes; except for EAF dust, the effect was non-linear with the greatest decrease caused initially by approx. 12% plating sludge, 40% foundry dust, 58% other ash, and 72% MSWI fly ash by mass of dry product. It appears that the maximum waste additions used in modelling may approximate the practical limits of waste additions used in modelling may approximate the practical limits of waste addition to Portland cement, i.e., 50% plating sludge or EAF dust, 64% foundry dust, 92% other ash, and 85% MSWI fly ash by mass of dry product. The laboratory was found to be a key predictive variable and acted as a surrogate for laboratory-specific variables related to cement composition, strength and hardening class, product mixing and preparation details, laboratory conditions, and testing details. While the neural network modelling approach has been shown to be feasible, development of better models would require larger data sets with more complete information regarding laboratory-specific variables and waste composition.
04/02583 Public participation in environmental decisions: stakeholders, authorities and procedural justice Maguire, L. A. and Lind, E. A. Int. J. Global Environmental Issues, 2003, 3, (2), 133-148. This study analysed a stakeholder participation process undertaken by the North Carolina Division of Water Quality to see if the process satisfied elements of procedural justice: representation of relevant parties, voice, sound technical basis, fair treatment by authorities and absence of bias. The rushed timeframe for the process compromised several elements of procedural justice. Representation suffered from the absence of pre-process contact with potential participants. Toofrequent meetings prevented stakeholders from digesting complex technical information on water-quality impacts of excess nutrients. The Division of Water Quality dominated the function of the stakeholder groups by playing multiple roles, including convening meetings, providing technical information, drafting documents, and serving as liaison to the state legislature. Stakeholders acknowledged that the division's strong role was probably essential to making progress in such a short timeframe but worried that the result was biased in favour of division views.
04/02584 Recent advances in mercury removal technology at the National Energy Technology Laboratory O'Dowd, W. J. et al. Fuel Processing Technology, 2004, 85, (6-7), 533548. The in-house research effort on mercury studies at the National Energy Technology Laboratory is an integrated, multi-task approach, including experimentation at both the laboratory-scale and the pilot-scale, as well as a numerical modelling effort to aid in interpretation of pilot-scale results. In the laboratory-scale work, novel sorbents and techniques for the removal of mercury from flue gas are being investigated using a small packed-bed reactor. The reactor system is used to screen novel sorbents for their capability to remove mercury from gas streams. The capacities of these novel sorbents are determined as a function of gas composition and temperature and are compared to results with commercially available activated carbons. In the pilot-scale work, an existing pilot unit has been characterized with respect to the distribution and fate of hazardous air pollutants in flue gas, with an
360 Fuel and Energy Abstracts September 2004
emphasis on mercury. The pilot unit is a 500-1b/h (227-kg/h) pulverized coal-fired (PCFC) combustion system that includes a furnace, air preheater, spray dryer, ductwork and a pulse-jet fabric filter. The investigations with this unit have entailed evaluation of various activated carbons and novel sorbents, as well as comparisons of various sampling techniques for the determination of total and speciated forms of mercury. The impact of various parameters (temperature, sorbentto-mercury ratio, baghouse pressure drop) on the removal of mercury has been investigated. Additionally, a slipstream allows for the investigation of sorbent injection in a fly ash-free flue gas over a wide range of operating conditions, including residence time. A summary of the results for mercury measurement and control from the 500-1b/h (227-kg/h) PCFC combustion system will be presented, as well as the evaluation of methods for measurement of in-duct removals using the slipstream. Finally, a discussion of the numerical modelling effort will be given.
04•02585 Removal of unburned carbon from municipal solid waste fly ash by column flotation Huang, Y. et al. Waste Management, 2003, 23, (4), 307-313. Unburned carbon (UC) is the major source of organic contaminants in municipal solid waste (MSW) fly ash. So most organic contaminants can be removed by the removal of the UC from the MSW fly ash. This study first used a technique of column flotation to remove U C from MSW fly ash. The influences of column flotation parameters on the recovery efficiency of UC were systematically studied. It was found that the UC recovery efficiency was greatly influenced by the gas flow rate, pH value, collector kerosene's concentration and the types of fly ash. By optimizing the above parameters, 61.2% of the UC from MSW fly ash having 5.24% UC content was successfully removed. The removal mechanism was well accounted for the kinetic theory of column flotation and surface-chemistry theory. The results indicate that the Column flotation technique is effective in removing the U C from MSW fly ash, and show that there is a strong possibility for practical application of this technique in removing the organic contaminants from MSW fly ash.
04•02586 Solid state dehalogenation of PCBs in contaminated soil using NaBH4 Aresta, M. et al. Waste Management, 2003, 23, (4), 315-319. This work presents the results of an experimental study on the abatement of polychlorinated biphenyl (PCBs) in contaminated soil using a high-energy milling technique that promotes a reaction only by impact between milling bodies. A sample of soil from a controlled landfill was treated with powdered NaBH4 using two different hydride/ soil ratios (5 and 2.5% w/w). The efficiency of the dehalogenation/ hydrogenation reaction was studied as a function of the milling time (3.5 up to 30 h). After each run, the total PCBs content and the production of inorganic chloride were measured. The complete abatement was obtained with a starting PCBs concentration of about 2600 mg/kg. The residual PCBs concentration resulted to be <0.2 rag/ kg. The final products of the treatment were biphenyl and NaCl. Other toxic or hazardous organic by-products were not generated. Boron was found as boric acid.
04/02587 State responsibility and compensation for climate change damages - a legal and economic assessment Tol, R. S. J. and Verheyen, R. Energy Policy, 2004, 32, (9), 1109-1130. Customary international law has that countries may do each other no harm. A country violates this rule if an activity under its control does damage to another country, and if this is done on purpose or due to carelessness. Impacts of climate change fall under this rule, which is reinforced by many declarations and treaties, including the UNFCCC. Compensation for the harm done depends on many parameters, such as emission scenarios, climate change, climate change impacts and its accounting. The compensation paid by the OECD may run up to 4% of its GDP, far exceeding the costs of climate change to the OECD directly. However, the most crucial issues are, first, from when countries can be held responsible and, second, which emissions are acceptable and which careless. This may even be interpreted such that the countries of the OECD are entitled to compensation, rather than be obliged to pay. State responsibility could substantially change international climate policy.
04102588 Sustainable urban transportation: impact of mitigation strategies on local pollutants
CO 2
Yedla, S. and Parikh, J. K. Int. J. Environmental and Pollution, 2003, 19, (5), 475-482. This paper assesses COz mitigation strategies in Delhi and Mumbai against the dynamics of local pollutants. After testing against technoeconomic feasibility, compressed natural gas (CNG) technology, fourstroke two-wheelers and battery-operated vehicles (BOV) were selected as candidate options for Mumbai and Delhi. Multiple