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
This study aimed at investigating the causes of floods in Numan Town with particular reference to the 2012 floods. Three residential areas： Gangare, Gwadda Mallam and Green Village were selected for the study. Hydrol...This study aimed at investigating the causes of floods in Numan Town with particular reference to the 2012 floods. Three residential areas： Gangare, Gwadda Mallam and Green Village were selected for the study. Hydrological, SRTM （shuttle radar topography mission） digital elevation model, secondary and primary data were utilized. A total of 180 questionnaires were administered to the residents in equal proportion using systematic random sampling. ArcGIS 10.0 and Excel were used for the analysis. The study revealed that the major causes of flood in the area include discharge of water from the Lagdo dam in Cameroon and Kiri dam in Adamawa State. Others include heavy rainfall, topography, and lack of adherence to development control provisions which resulted in construction of residential areas on flood plains. Many of the residents do not have legal title to their plots and this constitutes a very serious constraint to provision of drainages and solid waste disposal services. To ameliorate the devastating effects of floods, the study recommends relocation of residents of flood prone areas, provision of solid waste management services, and construction of more drainages. In addition, the town planning authorities and community leaders should collaborate to ensure that houses are built in flood plains.展开更多
Based on the situation that the trade of manufactured goods takes the main position in Shandong Province,this paper identifies Shandong industrial pollutant discharge by three indices,which are industrial effluent dis...Based on the situation that the trade of manufactured goods takes the main position in Shandong Province,this paper identifies Shandong industrial pollutant discharge by three indices,which are industrial effluent discharge,industrial SO2 emission,and solid waste disposal.Furthermore,it conducts an empirical analysis of the trade terms of pollution content transfer on nine identified industrial sectors.The conclusion is that the increase in industrial effluent discharge,industrial SO2 emission,and solid waste disposal has paralleled the growth of the GDP in Shandong.The rapid economic growth brings obvious negative impact on the environment.Compared with that in 1998,the increase in the pollution content of exports in 2007 indicated that more environmental costs were generated with the economic development in Shandong.There is a need for optimization of foreign trade structure in Shandong,especially the need for increasing import of the pollution intensive products and decreasing the export of the pollution intensive products.The research on the relationship between manufactured goods trade and the environmental impact will make a contribution to the adjustment of foreign trade and environmental policies.展开更多
The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansi...The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansion must be considered from the geotechnical engineering point of view, for which purpose, it is necessary to understand the geotechnical properties of the MSW in the landfill, some of whose physical properties were measured by common geotechnical tests, such as those on unit weight, water content, organic matter content, specific gravity, coefficient of permeability, compressibility, etc. The mechanical properties were studied by direct shear test, triaxial compression test, and static and dynamic penetration tests. Some strength parameters for engineering analysis were obtained.展开更多
An experimental study of the treatment of plastic-contained Japanese MSW （municipal solid waste） employing 1 ton capacity hydrothermal reactor to produce chlorine-free solid fuel has been performed. The system appli...An experimental study of the treatment of plastic-contained Japanese MSW （municipal solid waste） employing 1 ton capacity hydrothermal reactor to produce chlorine-free solid fuel has been performed. The system applies medium-pressure saturated steam at about 2 MPa in a stirred reactor for certain holding period. It was shown that the products exhibited organic chlorine conversion into inorganic chlorine, which can then be water washed. To obtain an optimal operating condition, the temperature and holding period was integrated into one parameter called RS （reaction severity）. It was found that to convert 75% organic chlorine in the MSW, the optimum RS number correlates to an operating temperature of about 225℃ and holding period of 90 min, or 235 ℃ for 60 min. Since hydrothermal treatment is a batch process, a shorter holding period is preferable to increase the number of batches and indirectly increase its processing capacity.展开更多
The rapid increase in population in Thika has led to increase in municipal solid waste generation, which has posed challenges in the waste disposal and management. This study was carried out to quantify and characteri...The rapid increase in population in Thika has led to increase in municipal solid waste generation, which has posed challenges in the waste disposal and management. This study was carried out to quantify and characterize the waste generated within Thika municipality. Six months data （between March 2014 and August 2014） of waste stream at the dumpsite was reviewed and analyzed. The survey indicated that 66.95% ± 0.34% of the total waste dumped originated from the municipal council ofThika （MCT）. It constitutes of domestic, commercial and institutional waste. 33.05% is industrial waste. Sixty eight percent （68%） of the waste consisted primarily of four components： paper, plastic, organics and food. Food accounted for 15.51% ± 0.95%, paper 18.31% ± 1.7%, plastics 17.89% ± 0.81% and organics other than food 16.51% ±1.01%, respectively obtained at 95% confidence level. Each of the components has some level of recovery. Some of the reusable and recyclable materials were being recovered, food waste had the highest recovery rate of 23% ± 1.7% and was used as animal feed, while plastic （soft plastic） 17% ± 0.93% was sold to recyclers. Recovery of materials for recycling and composting was estimated at 10.21 tonnes or 11.35% of daily generation, leaving 76.44 tonnes per day that can be converted into useful energy. The study shows waste in this dumpsite can be exploited to by converting it to energy thus a good solution for waste management.展开更多
By making the use of the processes which includes separating trash and solid materials from the wastewater-ammonia stripping tower-UASB-biological oxidation pond, we have treated the wastewater which comes from the sw...By making the use of the processes which includes separating trash and solid materials from the wastewater-ammonia stripping tower-UASB-biological oxidation pond, we have treated the wastewater which comes from the swine factory. The treated wastewater can meet the primary standard of The People＇s Republic of China based on sewage discharge standards and the wastewater treatment project design contract （GBl8596-2001）, and the effluent will be used as irrigation-water. We introduce this project including the quality of influent and effluent and the flow scheme, the statement of every part, the investment and the effect, etc. The operation indicated that this process has many merits such as the stability in operation-effect and the convenience in management. So it will provide some help for the similar wastewater treatment.展开更多
This article reviews the literature on thermochemical processing of municipal solid waste as the final disposal in Brazil, explores recent publications in the field of solid waste generated, its origin, characteristic...This article reviews the literature on thermochemical processing of municipal solid waste as the final disposal in Brazil, explores recent publications in the field of solid waste generated, its origin, characteristics and removal mechanisms currently employed, in the same way, available technologies for the thermochemical treatment of MSW with an emphasis on gasification and clean technology are evaluated, highlighting the current technical and reported in the literature in order to identify indicators of efficiency and flexibility of the technology. From the review it is concluded that gasification is a technically feasible option for the thermochemical conversion of municipal solid waste and subsequent power generation, besides being a technology that meets the applicable emission limits. Some of the main advantages of gasification of municipal solid waste are： （a） the sharp reduction in the waste mass （about 70-80%） and volume （approximately 80-90%）; （b） the drastic reduction in land use, 1：3000; （c） destruction of organic pollutants and other halogenated hydrocarbons; （d） concentration and immobilisation of inorganic contaminants so that they can be used effectively and safely removed; （e） use recyclables, such as ferrous metals, ferrous ash and slag materials; （f） reducing emissions of greenhouse gases by anaerobic decomposition of organic waste and （g） power generation.展开更多
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This study aimed at investigating the causes of floods in Numan Town with particular reference to the 2012 floods. Three residential areas： Gangare, Gwadda Mallam and Green Village were selected for the study. Hydrological, SRTM （shuttle radar topography mission） digital elevation model, secondary and primary data were utilized. A total of 180 questionnaires were administered to the residents in equal proportion using systematic random sampling. ArcGIS 10.0 and Excel were used for the analysis. The study revealed that the major causes of flood in the area include discharge of water from the Lagdo dam in Cameroon and Kiri dam in Adamawa State. Others include heavy rainfall, topography, and lack of adherence to development control provisions which resulted in construction of residential areas on flood plains. Many of the residents do not have legal title to their plots and this constitutes a very serious constraint to provision of drainages and solid waste disposal services. To ameliorate the devastating effects of floods, the study recommends relocation of residents of flood prone areas, provision of solid waste management services, and construction of more drainages. In addition, the town planning authorities and community leaders should collaborate to ensure that houses are built in flood plains.
文摘Based on the situation that the trade of manufactured goods takes the main position in Shandong Province,this paper identifies Shandong industrial pollutant discharge by three indices,which are industrial effluent discharge,industrial SO2 emission,and solid waste disposal.Furthermore,it conducts an empirical analysis of the trade terms of pollution content transfer on nine identified industrial sectors.The conclusion is that the increase in industrial effluent discharge,industrial SO2 emission,and solid waste disposal has paralleled the growth of the GDP in Shandong.The rapid economic growth brings obvious negative impact on the environment.Compared with that in 1998,the increase in the pollution content of exports in 2007 indicated that more environmental costs were generated with the economic development in Shandong.There is a need for optimization of foreign trade structure in Shandong,especially the need for increasing import of the pollution intensive products and decreasing the export of the pollution intensive products.The research on the relationship between manufactured goods trade and the environmental impact will make a contribution to the adjustment of foreign trade and environmental policies.
文摘The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansion must be considered from the geotechnical engineering point of view, for which purpose, it is necessary to understand the geotechnical properties of the MSW in the landfill, some of whose physical properties were measured by common geotechnical tests, such as those on unit weight, water content, organic matter content, specific gravity, coefficient of permeability, compressibility, etc. The mechanical properties were studied by direct shear test, triaxial compression test, and static and dynamic penetration tests. Some strength parameters for engineering analysis were obtained.
文摘An experimental study of the treatment of plastic-contained Japanese MSW （municipal solid waste） employing 1 ton capacity hydrothermal reactor to produce chlorine-free solid fuel has been performed. The system applies medium-pressure saturated steam at about 2 MPa in a stirred reactor for certain holding period. It was shown that the products exhibited organic chlorine conversion into inorganic chlorine, which can then be water washed. To obtain an optimal operating condition, the temperature and holding period was integrated into one parameter called RS （reaction severity）. It was found that to convert 75% organic chlorine in the MSW, the optimum RS number correlates to an operating temperature of about 225℃ and holding period of 90 min, or 235 ℃ for 60 min. Since hydrothermal treatment is a batch process, a shorter holding period is preferable to increase the number of batches and indirectly increase its processing capacity.
文摘The rapid increase in population in Thika has led to increase in municipal solid waste generation, which has posed challenges in the waste disposal and management. This study was carried out to quantify and characterize the waste generated within Thika municipality. Six months data （between March 2014 and August 2014） of waste stream at the dumpsite was reviewed and analyzed. The survey indicated that 66.95% ± 0.34% of the total waste dumped originated from the municipal council ofThika （MCT）. It constitutes of domestic, commercial and institutional waste. 33.05% is industrial waste. Sixty eight percent （68%） of the waste consisted primarily of four components： paper, plastic, organics and food. Food accounted for 15.51% ± 0.95%, paper 18.31% ± 1.7%, plastics 17.89% ± 0.81% and organics other than food 16.51% ±1.01%, respectively obtained at 95% confidence level. Each of the components has some level of recovery. Some of the reusable and recyclable materials were being recovered, food waste had the highest recovery rate of 23% ± 1.7% and was used as animal feed, while plastic （soft plastic） 17% ± 0.93% was sold to recyclers. Recovery of materials for recycling and composting was estimated at 10.21 tonnes or 11.35% of daily generation, leaving 76.44 tonnes per day that can be converted into useful energy. The study shows waste in this dumpsite can be exploited to by converting it to energy thus a good solution for waste management.
文摘By making the use of the processes which includes separating trash and solid materials from the wastewater-ammonia stripping tower-UASB-biological oxidation pond, we have treated the wastewater which comes from the swine factory. The treated wastewater can meet the primary standard of The People＇s Republic of China based on sewage discharge standards and the wastewater treatment project design contract （GBl8596-2001）, and the effluent will be used as irrigation-water. We introduce this project including the quality of influent and effluent and the flow scheme, the statement of every part, the investment and the effect, etc. The operation indicated that this process has many merits such as the stability in operation-effect and the convenience in management. So it will provide some help for the similar wastewater treatment.
文摘This article reviews the literature on thermochemical processing of municipal solid waste as the final disposal in Brazil, explores recent publications in the field of solid waste generated, its origin, characteristics and removal mechanisms currently employed, in the same way, available technologies for the thermochemical treatment of MSW with an emphasis on gasification and clean technology are evaluated, highlighting the current technical and reported in the literature in order to identify indicators of efficiency and flexibility of the technology. From the review it is concluded that gasification is a technically feasible option for the thermochemical conversion of municipal solid waste and subsequent power generation, besides being a technology that meets the applicable emission limits. Some of the main advantages of gasification of municipal solid waste are： （a） the sharp reduction in the waste mass （about 70-80%） and volume （approximately 80-90%）; （b） the drastic reduction in land use, 1：3000; （c） destruction of organic pollutants and other halogenated hydrocarbons; （d） concentration and immobilisation of inorganic contaminants so that they can be used effectively and safely removed; （e） use recyclables, such as ferrous metals, ferrous ash and slag materials; （f） reducing emissions of greenhouse gases by anaerobic decomposition of organic waste and （g） power generation.
