To investigate the potential use of two Japanese regional clayey soils, named Ariake clay and Akaboku soil, as soil barrier materials, a series of laboratory diffusion tests are presented. Using an available computer ...To investigate the potential use of two Japanese regional clayey soils, named Ariake clay and Akaboku soil, as soil barrier materials, a series of laboratory diffusion tests are presented. Using an available computer program Pollute V6.3, the effective diffusion coefficients of K^＋ of the soils were back-calculated from the diffusion tests. It is found that the Ariake clay has a larger effective diffusion coefficient than the Akaboku soil, indicating that the Ariake clay may provide a better diffusion barrier. A comparison of the effective diffusion coefficients between the single-salt solution condition and the multi-salt solution condition indicates that soils have higher effective diffusion coefficients under the former condition. It is suggested to use miscible solution close to landfill leachates for determining effective diffusion coefficients of specified chemical species for a practical design.展开更多
The presence of a thatch layer in established pastures could reduce the contact between broiler litter and soil, thus increasing the potential for surface runoff contamination with litter P. We conducted a laboratory ...The presence of a thatch layer in established pastures could reduce the contact between broiler litter and soil, thus increasing the potential for surface runoff contamination with litter P. We conducted a laboratory study to evaluate the effect of a thatch layer on the dynamics of water-soluble P in undisturbed cores taken from a pasture. Cores with and without a thatch layer received a surface application of broiler litter (5 thm-2) and were incubated at 25 oC for 56 d. The result showed that on the soil surface the contents of water soluble-P (39 kghm-2) of the cores with the thatch layer was higher than that (20 kghm-2) of the cores without the thatch layer. Therefore on well-established pastures fertilized with broiler litter, the presence of a thatch layer might lead to high concentrations of water-soluble P on the soil surface.展开更多
Proper solid waste disposal is an important socioeconomic concern for all developing countries.Municipalities have their own policies,individual approaches and methods to manage the solid wastes.They consider wastelan...Proper solid waste disposal is an important socioeconomic concern for all developing countries.Municipalities have their own policies,individual approaches and methods to manage the solid wastes.They consider wastelands outside the urban area as the best suitable for the solid waste disposal.Such improper site selection will create morphological changes that lead to environmental hazards in the urban and its surrounding areas.In this research,the site selection for urban solid waste disposal in the Coimbatore district used geographical information system(GIS)and multi-criteria decision analysis(MCDA).Thematic layers of lineament density,landuse/landcover,population density,groundwater depth,drainage density,slope,soil texture,geology and geomorphology were considered as primary criteria and weights for criteria,and sub-criteria were assigned by MCDA analysis.The resultant weight score was validated by consistency ratio so that the efficiency of the selected criteria was justified.The overlay analysis in GIS environment provides 17 potential zones in Coimbatore district,among which,four suitable sites were screened and refined with the help of field investigation and visual interpretation of satellite image.The result of landfill suitability map shows the effectiveness of the proposed method.展开更多
Central composite design (CCD), the most popular design ofresponse surface methodology (RSM), was employed to investigate theeffect of total organic carbon (TOC) ratio of high molecular weightorganic matter (HMW) to l...Central composite design (CCD), the most popular design ofresponse surface methodology (RSM), was employed to investigate theeffect of total organic carbon (TOC) ratio of high molecular weightorganic matter (HMW) to low molecular weight organic matter (LMW),the LMW strength and molar ratio of hydrogen peroxide to ferrous ionon landfill leachate treatment by Fenton process. Based on theexperimental data, a response surface quadratic model in terms ofactual factors was obtained through analysis of variance (ANOVA).展开更多
Surface mining operations extract a large quantity of waste material,which is generally disposed into a dump area.This waste can cause a series of environmental problems ranging from landscape deterioration to acidic ...Surface mining operations extract a large quantity of waste material,which is generally disposed into a dump area.This waste can cause a series of environmental problems ranging from landscape deterioration to acidic water generation and water pollution.Therefore,mine waste management is a significant task in mining operations.As known,in strip mining,the overburden is not transported to waste dumps but disposed directly into adjacent strip which was mined out.This concept can be adapted for mine planning of relatively horizontal deposits through a mixed integer programming(MIP)model.The main idea behind this work is that,in one pit,production voids created in early year of mining are used for waste landfilling in late years of production.In other words,in addition to external dumping,a landfilling option within the same pit is proposed for mine design optimization.The problem is formulated as maximization of the net present value(NPV)of the mining project under the constraints of access,landfill waste handling,mining and processing capacities.A case study using a data set was carried out to see the performance of the proposed approach.The findings showed that this approach could be used in waste management incorporating a landfilling option into mine planning.As a result,material handling costs decrease,and environmental compliance increases due to less external waste quantity.展开更多
According to the structural characteristics of hazardous waste landfill, a new model based on the finite element method （FEM） is developed. The detection layer is considered as a sealed space and it is assumed that ...According to the structural characteristics of hazardous waste landfill, a new model based on the finite element method （FEM） is developed. The detection layer is considered as a sealed space and it is assumed that total current flows through the leak for the high resistivity of geomembrane liner. The leak current is regarded as a positive point current ＋I and the other current source is -I. Electrical potential of an arbitrary point in detection layer satisfies Poisson equation. Experiments for detecting leaks in liner were carried out. Excellent agreement between experimental data and simulated model data validates the new model. Parametric curves for a single leak show that with optimum selection of field survey parameters leaks can be detected effectively. For multiple leaks, the simulated results indicate that they are detectable when leak separation is larger than measurement spacing.展开更多
文摘To investigate the potential use of two Japanese regional clayey soils, named Ariake clay and Akaboku soil, as soil barrier materials, a series of laboratory diffusion tests are presented. Using an available computer program Pollute V6.3, the effective diffusion coefficients of K^＋ of the soils were back-calculated from the diffusion tests. It is found that the Ariake clay has a larger effective diffusion coefficient than the Akaboku soil, indicating that the Ariake clay may provide a better diffusion barrier. A comparison of the effective diffusion coefficients between the single-salt solution condition and the multi-salt solution condition indicates that soils have higher effective diffusion coefficients under the former condition. It is suggested to use miscible solution close to landfill leachates for determining effective diffusion coefficients of specified chemical species for a practical design.
文摘The presence of a thatch layer in established pastures could reduce the contact between broiler litter and soil, thus increasing the potential for surface runoff contamination with litter P. We conducted a laboratory study to evaluate the effect of a thatch layer on the dynamics of water-soluble P in undisturbed cores taken from a pasture. Cores with and without a thatch layer received a surface application of broiler litter (5 thm-2) and were incubated at 25 oC for 56 d. The result showed that on the soil surface the contents of water soluble-P (39 kghm-2) of the cores with the thatch layer was higher than that (20 kghm-2) of the cores without the thatch layer. Therefore on well-established pastures fertilized with broiler litter, the presence of a thatch layer might lead to high concentrations of water-soluble P on the soil surface.
文摘Proper solid waste disposal is an important socioeconomic concern for all developing countries.Municipalities have their own policies,individual approaches and methods to manage the solid wastes.They consider wastelands outside the urban area as the best suitable for the solid waste disposal.Such improper site selection will create morphological changes that lead to environmental hazards in the urban and its surrounding areas.In this research,the site selection for urban solid waste disposal in the Coimbatore district used geographical information system(GIS)and multi-criteria decision analysis(MCDA).Thematic layers of lineament density,landuse/landcover,population density,groundwater depth,drainage density,slope,soil texture,geology and geomorphology were considered as primary criteria and weights for criteria,and sub-criteria were assigned by MCDA analysis.The resultant weight score was validated by consistency ratio so that the efficiency of the selected criteria was justified.The overlay analysis in GIS environment provides 17 potential zones in Coimbatore district,among which,four suitable sites were screened and refined with the help of field investigation and visual interpretation of satellite image.The result of landfill suitability map shows the effectiveness of the proposed method.
基金Supported by the Delaware Solid Waste Authority, Dover DE, USA and China Scholarship Council (No. 97842039).
文摘Central composite design (CCD), the most popular design ofresponse surface methodology (RSM), was employed to investigate theeffect of total organic carbon (TOC) ratio of high molecular weightorganic matter (HMW) to low molecular weight organic matter (LMW),the LMW strength and molar ratio of hydrogen peroxide to ferrous ionon landfill leachate treatment by Fenton process. Based on theexperimental data, a response surface quadratic model in terms ofactual factors was obtained through analysis of variance (ANOVA).
文摘Surface mining operations extract a large quantity of waste material,which is generally disposed into a dump area.This waste can cause a series of environmental problems ranging from landscape deterioration to acidic water generation and water pollution.Therefore,mine waste management is a significant task in mining operations.As known,in strip mining,the overburden is not transported to waste dumps but disposed directly into adjacent strip which was mined out.This concept can be adapted for mine planning of relatively horizontal deposits through a mixed integer programming(MIP)model.The main idea behind this work is that,in one pit,production voids created in early year of mining are used for waste landfilling in late years of production.In other words,in addition to external dumping,a landfilling option within the same pit is proposed for mine design optimization.The problem is formulated as maximization of the net present value(NPV)of the mining project under the constraints of access,landfill waste handling,mining and processing capacities.A case study using a data set was carried out to see the performance of the proposed approach.The findings showed that this approach could be used in waste management incorporating a landfilling option into mine planning.As a result,material handling costs decrease,and environmental compliance increases due to less external waste quantity.
基金Project supported by the National High-Technology Research and Development Program of China(Grant No.2001AA644010)
文摘According to the structural characteristics of hazardous waste landfill, a new model based on the finite element method （FEM） is developed. The detection layer is considered as a sealed space and it is assumed that total current flows through the leak for the high resistivity of geomembrane liner. The leak current is regarded as a positive point current ＋I and the other current source is -I. Electrical potential of an arbitrary point in detection layer satisfies Poisson equation. Experiments for detecting leaks in liner were carried out. Excellent agreement between experimental data and simulated model data validates the new model. Parametric curves for a single leak show that with optimum selection of field survey parameters leaks can be detected effectively. For multiple leaks, the simulated results indicate that they are detectable when leak separation is larger than measurement spacing.
