At Kuwana illegal dumping site in Japan, where hazardous waste was illegally dumped, groundwater was severely contaminated by Volatile Organic Compounds (VOCs). Groundwater was already remedied by conducting Pump-and-...At Kuwana illegal dumping site in Japan, where hazardous waste was illegally dumped, groundwater was severely contaminated by Volatile Organic Compounds (VOCs). Groundwater was already remedied by conducting Pump-and-Treat (P&T) after containment of all the waste by vertical slurry walls from 2002 to 2007. However, 1,4-dioxane was detected in both waste and groundwater outside of slurry walls after it was newly added into Japan environmental standards in late 2009, which suggested that the walls did not contain 1,4-dioxane completely. Our previous study developed a model to predict the 1,4-dioxane distribution in groundwater after the previous remediation at the site. In this study, numerical simulation was applied for remediation planning at the site based on the concept of Verified Follow Up (VF-UP) that had been proposed as a new approach to complete remediation effectively with consideration of future risks. The amount of waste to be removed and pumping plans were discussed by numerical simulation to achieve the remedial objective in which 1,4-dioxane in groundwater outside of walls is remedied within 10 years and 1,4-dioxane spreading throughout the walls is prevented in the case where a portion of waste is remained. Firstly, the amount of waste to be removed considering pumping plans for P&T was determined by scenario analysis. As a result, at least two-third of waste should be removed by combining with P&T. However, if the waste is remained, future risks of 1,4-dioxane spreading through the slurry walls may occur. Our simulation suggested that groundwater within the remaining waste must be pumped up at least 20 m3/d for containment of 1,4-dioxane within the remaining waste. In conclusion, our numerical simulation determined the amount of waste to be removed and the pumping plans for P&T to achieve the remedial objective effectively considering future risks based on the concept of VF-UP.展开更多
Wastewater treatment plants and solid dump sites act as potential reservoirs of highly resistant bacterial strains. This study presents information on the patterns of antimicrobial resistance among pathogenic bacteria...Wastewater treatment plants and solid dump sites act as potential reservoirs of highly resistant bacterial strains. This study presents information on the patterns of antimicrobial resistance among pathogenic bacteria in the sewage treatment plants and solid dump site in Nairobi County, Kenya. We employed standard microbiological methods to isolate and identify bacteria from these selected sites. Members of Escherichia, Klebsiella, Serratia, Shigella, Pseudomonas, Citrobacter spp, Enterobacter, Salmonella, Staphylococcus, Bacillus, Yersinia, Vibro cholera, Providencia, Morganella and Proteus spp were isolated. Escherichia and Klebsiella recorded the highest occurrence at 13.9% and 10.3% in wastewater. Shigella, Serratia Citrobacterfreundii, Pseudomonas, Staphylococcus, Escherichia and Klebsiella recorded the highest level of occurrence at 15.1%, 14.1%, 12%, 11%, 10.4%, 10.3%, and 8.3% in dumpsite respectively. Drug sensitivity using the Disc diffusion method showed that Ampicillin, Ceftazidime, Cefotaxime, Amoxicillin, and Cefepime had the highest levels of inactivity at (68.5%, 89.5%), (64.2%, 87%), (54.5%, 80.2%), (52%, 74%) and (49.1%, 72.4%) respectively while Levofloxacin and Gentamicin showed the smallest level of antibiotic resistance at (4.8%, 4.7%) and (4.2%, 2.6%) in both sites. Members of Escherichia, Klebsiella, Proteus vulgaris, Salmonella, Pseudomonas, Shigella and Serratia showed the highest level of ESBLs production at 28.9%, 18.4%, 15.8%, 10.5%, 7.9%, 7.9%, 7.9% and 7.9% in the wastewater whereas Shigella, Escherichia, Serratia, Pseudomonas, Klebsiella, and Proteus vulgaris showed the highest level ESBLs production at 45.5%, 10.9%, 9.1%, 9.1%, 7.3% and 7.3% from the dump site. All the antibiotics tested except for Gentamicin, Chloramphenicol and Ciprofloxacin differed significantly in terms of resistance levels (p < 0.05). The study concluded that, wastewater treatment plant and dump sites bear heavy burdens of potentially virulent resistant bacterial strains which may constitute major public health hazards to scavengers and those living near these sites. There is need therefore to educate people on the use of appropriate protective materials and the settlement patterns of individuals and communities near these sites.展开更多
Dumping areas represent a stable hazard. To clarify the formation mechanism of dumping piles on dumping area stability, an investigation in open pit mine was performed. Moreover, experiments with gravel were conducted...Dumping areas represent a stable hazard. To clarify the formation mechanism of dumping piles on dumping area stability, an investigation in open pit mine was performed. Moreover, experiments with gravel were conducted based on the research site conditions. The geological conditions, dumping operation, and waste particle size distribution were investigated in the Heidaigou open pit mine. Particle size distribution, dumping height, dumping volume, and floor inclination were varied to examine their effects on a single pile formation. The design of blasting can be modified to make the particle size of waste smaller. The volume of the bucket does not have a pronounced effect on dumping pile repose angle, capacity of dumping pile, and dumping area stability. The smaller the floor inclination, the better it is. Two measures are proposed to increase the kinetic force of friction between waste material and floor surface. The interval distance, dumping volume and dumping height were also varied to examine the interaction between the formations of multiple piles. The dumping width should be decided through optimization efficiency of bulldozer and dumping device in bucket wheel excavator-belt-stacker dumping operation and dragline dumping operation. Moreover, the volume of the bucket does not have a pronounced interaction effect. In the dumping operation, the work amount of bulldozer decreases as dumping pile increases. The design of the dumping operation must consider the total efficiency of ground leveling operation and forming dumping the area.展开更多
Municipal solid waste open dump site operation is an important element of waste management in Nigeria, both today and in the future. Dump site fires are common occurrences in the study area. The contribution of?munici...Municipal solid waste open dump site operation is an important element of waste management in Nigeria, both today and in the future. Dump site fires are common occurrences in the study area. The contribution of?municipal solid waste dump site fires to atmospheric pollution in the Niger Delta, Nigeria has been assessed experimentally. Five (5) municipal solid waste dump sites where fire incidence is a frequent and regular occurrence were chosen for the study. At each of the identified municipal solid waste dump site, eight (8) air quality monitoring parameters, suspended particulate matter (SPM10), nitrogen dioxide (NO2), carbon dioxide (CO2), carbon monoxide (CO), sulphur dioxide (SO2), methane (CH4), ammonia (NH3) and Hydrogen sulphide (H2S) were determined using a series of hand held air quality monitoring equipment. Results indicate the levels of SPM ranged between 773 and 801 μg/m3 and the levels of CO ranged between 133.7 and 141.6 ppm. The levels of CO2 ranged between 401 ppm and 404.5 ppm while that of NO2 ranged between 21.0 ppm and 27.3 ppm. The levels of SO2 ranged between 27.7 ppm and 37.1 ppm while that of NH3 ranged from 14.7 to 19.5 ppm. The levels of methane in the study area ranged between 2310 ppm and 2771 ppm and within the?vicinity of dump site fires H2S concentration ranges from 3.4 to 7.7 ppm. Levels of SPM, CO, CO2, and CH4 within the vicinity of the dump site fires were above regulatory limits. Dump site fires in the study area could threaten the health of anyone especially the dump site workers that are regularly exposed to the thick smoke and can be implicated in climate change debate. There is a need to develop better practices with regard to municipal solid waste open dump site operation and emission control.展开更多
The study looked at the levels of polycyclic aromatic hydrocarbons (PAHs) in leachates from a solid waste disposal site and an effluent from an oil refinery in some water bodies around Accra. Sixteen (PAHs) were extra...The study looked at the levels of polycyclic aromatic hydrocarbons (PAHs) in leachates from a solid waste disposal site and an effluent from an oil refinery in some water bodies around Accra. Sixteen (PAHs) were extracted simultaneously by solid phase and analysis by gas chromatograph. The results of this study gener-ally demonstrated that there were elevated levels of PAHs in the water sample of the Densu River, Chemu, Korle and Kpeshi Lagoons. The average concentration of PAHs in the water ranged from 0.000 of many of the PAHs to 0.552µg/L, for Acenapththene to 11.399µg/L for Benzo (ghi) perylene of the Chemu Lagoon, 0.00µg/L for Benzo (a) Pyrene to 8.800µg/L for Benzo (ghi) perylene (Korle Lagoon) and 0.052µg/L for Pyrene to 4.703ug/L for Acenaphthylene of the Kpeshi Lagoon and 0.00µg/L for pyrene to Acenaphthylene 2.926µg/L of the Weija Dam. Concentrations ranging from below detection level to 14.587µg/L were also recorded at the Oblogo solid waste dump and it’s environ. The Weija dam supply over two million gallons of portable water daily to the people of Accra and the levels of the PAH determined is worrying, as a result, the Oblogoh disposal site ought to be re-located to avert any possible epidemic.展开更多
This study compared the physicochemical parameters and heavy metal levels in soil samples from selected anthropogenic sites within Enugu metropolis, Enugu State, Nigeria using standard analytical methods. Soil samples...This study compared the physicochemical parameters and heavy metal levels in soil samples from selected anthropogenic sites within Enugu metropolis, Enugu State, Nigeria using standard analytical methods. Soil samples at depths (0 - 20 cm) and (20 - 40 cm) were collected from waste dump sites, metal scrap dumps, fuel filling stations and auto-mechanic workshops and analyzed for physicochemical characteristics and heavy metal levels. Atomic absorption spectrophotometer was used for heavy metal determination while conventional analytical methods were employed for physicochemical parameters evaluation of the soil samples. At soil depths 0 - 20 cm and 20 - 40 cm the respective mean range of pH, electrical conductivity, organic matter and organic carbon contents in the soil samples were, 6.33 - 6.74, 101.46 - 123.21 <em>μ</em>S/cm, 6.41% - 8.35% and 13.73% - 16.14% for auto-mechanic workshops;6.92 - 7.43, 56.46 - 60.02 <em>μ</em>S/cm, 1.53% - 2.20% and 11.93% - 12.60% for fuel filling stations;7.14 - 7.84, 70.81 - 77.71 <em>μ</em>S/cm, 3.81% - 4.12% and 8.57% - 9.24% for metal scrap dumps;6.54 - 6.81, 94.40 - 100.71 <em>μ</em>S/cm, 8.83% - 10.75% and 18.26% - 20.81% for waste dump sites. The pH of the top soil samples from auto-mechanical workshop was below the WHO recommended limits for agricultural purposes. The physic-chemical characteristics of the soil samples decreased with soil depths indicating therefore that anthropogenic activities greatly influence the soil characteristics at the top soils than the sub-soils. The electrical conductivity values of top and sub-soil samples from the studied auto-mechanical workshops were above the recommended limits. At soil depths 0 - 20 cm and 20 - 40 cm, the respective mean range of Zn, Pb and Cd in the soil samples were 17.29 - 19.16 <em>μ</em>g/g, 0.704 - 0.96 <em>μ</em>g/g and 0.26 - 0.33 <em>μ</em>g/g for auto-mechanic workshops;4.13 - 4.88 <em>μ</em>g/g, 0.21 - 0.32 <em>μ</em>g/g and 0.03 - 0.11 <em>μ</em>g/g for fuel filling stations;30.02 - 36.11 <em>μ</em>g/g, 0.43 - 0.48 <em>μ</em>g/g and 0.15 - 0.19 <em>μ</em>g/g for metal scrap dumps;9.30 - 10.84 <em>μ</em>g/g, 0.53 - 0.60 <em>μ</em>g/g and 0.38 - 0.45 <em>μ</em>g/g for waste dump sites. The mean levels of Pb in soil samples from mechanic workshops and waste dump sites were above the recommended permissible limits for agricultural purposes. The study therefore indicated that these sites (auto-mechanic workshops and waste dump sites) could be major sources of Pb pollution to nearby farmlands, streams and the general environment. Plants grown on or around these sites may not produce high yields and could be severely contaminated with heavy metals which portend health danger to food consumers within the environment.展开更多
文摘At Kuwana illegal dumping site in Japan, where hazardous waste was illegally dumped, groundwater was severely contaminated by Volatile Organic Compounds (VOCs). Groundwater was already remedied by conducting Pump-and-Treat (P&T) after containment of all the waste by vertical slurry walls from 2002 to 2007. However, 1,4-dioxane was detected in both waste and groundwater outside of slurry walls after it was newly added into Japan environmental standards in late 2009, which suggested that the walls did not contain 1,4-dioxane completely. Our previous study developed a model to predict the 1,4-dioxane distribution in groundwater after the previous remediation at the site. In this study, numerical simulation was applied for remediation planning at the site based on the concept of Verified Follow Up (VF-UP) that had been proposed as a new approach to complete remediation effectively with consideration of future risks. The amount of waste to be removed and pumping plans were discussed by numerical simulation to achieve the remedial objective in which 1,4-dioxane in groundwater outside of walls is remedied within 10 years and 1,4-dioxane spreading throughout the walls is prevented in the case where a portion of waste is remained. Firstly, the amount of waste to be removed considering pumping plans for P&T was determined by scenario analysis. As a result, at least two-third of waste should be removed by combining with P&T. However, if the waste is remained, future risks of 1,4-dioxane spreading through the slurry walls may occur. Our simulation suggested that groundwater within the remaining waste must be pumped up at least 20 m3/d for containment of 1,4-dioxane within the remaining waste. In conclusion, our numerical simulation determined the amount of waste to be removed and the pumping plans for P&T to achieve the remedial objective effectively considering future risks based on the concept of VF-UP.
文摘Wastewater treatment plants and solid dump sites act as potential reservoirs of highly resistant bacterial strains. This study presents information on the patterns of antimicrobial resistance among pathogenic bacteria in the sewage treatment plants and solid dump site in Nairobi County, Kenya. We employed standard microbiological methods to isolate and identify bacteria from these selected sites. Members of Escherichia, Klebsiella, Serratia, Shigella, Pseudomonas, Citrobacter spp, Enterobacter, Salmonella, Staphylococcus, Bacillus, Yersinia, Vibro cholera, Providencia, Morganella and Proteus spp were isolated. Escherichia and Klebsiella recorded the highest occurrence at 13.9% and 10.3% in wastewater. Shigella, Serratia Citrobacterfreundii, Pseudomonas, Staphylococcus, Escherichia and Klebsiella recorded the highest level of occurrence at 15.1%, 14.1%, 12%, 11%, 10.4%, 10.3%, and 8.3% in dumpsite respectively. Drug sensitivity using the Disc diffusion method showed that Ampicillin, Ceftazidime, Cefotaxime, Amoxicillin, and Cefepime had the highest levels of inactivity at (68.5%, 89.5%), (64.2%, 87%), (54.5%, 80.2%), (52%, 74%) and (49.1%, 72.4%) respectively while Levofloxacin and Gentamicin showed the smallest level of antibiotic resistance at (4.8%, 4.7%) and (4.2%, 2.6%) in both sites. Members of Escherichia, Klebsiella, Proteus vulgaris, Salmonella, Pseudomonas, Shigella and Serratia showed the highest level of ESBLs production at 28.9%, 18.4%, 15.8%, 10.5%, 7.9%, 7.9%, 7.9% and 7.9% in the wastewater whereas Shigella, Escherichia, Serratia, Pseudomonas, Klebsiella, and Proteus vulgaris showed the highest level ESBLs production at 45.5%, 10.9%, 9.1%, 9.1%, 7.3% and 7.3% from the dump site. All the antibiotics tested except for Gentamicin, Chloramphenicol and Ciprofloxacin differed significantly in terms of resistance levels (p < 0.05). The study concluded that, wastewater treatment plant and dump sites bear heavy burdens of potentially virulent resistant bacterial strains which may constitute major public health hazards to scavengers and those living near these sites. There is need therefore to educate people on the use of appropriate protective materials and the settlement patterns of individuals and communities near these sites.
文摘Dumping areas represent a stable hazard. To clarify the formation mechanism of dumping piles on dumping area stability, an investigation in open pit mine was performed. Moreover, experiments with gravel were conducted based on the research site conditions. The geological conditions, dumping operation, and waste particle size distribution were investigated in the Heidaigou open pit mine. Particle size distribution, dumping height, dumping volume, and floor inclination were varied to examine their effects on a single pile formation. The design of blasting can be modified to make the particle size of waste smaller. The volume of the bucket does not have a pronounced effect on dumping pile repose angle, capacity of dumping pile, and dumping area stability. The smaller the floor inclination, the better it is. Two measures are proposed to increase the kinetic force of friction between waste material and floor surface. The interval distance, dumping volume and dumping height were also varied to examine the interaction between the formations of multiple piles. The dumping width should be decided through optimization efficiency of bulldozer and dumping device in bucket wheel excavator-belt-stacker dumping operation and dragline dumping operation. Moreover, the volume of the bucket does not have a pronounced interaction effect. In the dumping operation, the work amount of bulldozer decreases as dumping pile increases. The design of the dumping operation must consider the total efficiency of ground leveling operation and forming dumping the area.
文摘Municipal solid waste open dump site operation is an important element of waste management in Nigeria, both today and in the future. Dump site fires are common occurrences in the study area. The contribution of?municipal solid waste dump site fires to atmospheric pollution in the Niger Delta, Nigeria has been assessed experimentally. Five (5) municipal solid waste dump sites where fire incidence is a frequent and regular occurrence were chosen for the study. At each of the identified municipal solid waste dump site, eight (8) air quality monitoring parameters, suspended particulate matter (SPM10), nitrogen dioxide (NO2), carbon dioxide (CO2), carbon monoxide (CO), sulphur dioxide (SO2), methane (CH4), ammonia (NH3) and Hydrogen sulphide (H2S) were determined using a series of hand held air quality monitoring equipment. Results indicate the levels of SPM ranged between 773 and 801 μg/m3 and the levels of CO ranged between 133.7 and 141.6 ppm. The levels of CO2 ranged between 401 ppm and 404.5 ppm while that of NO2 ranged between 21.0 ppm and 27.3 ppm. The levels of SO2 ranged between 27.7 ppm and 37.1 ppm while that of NH3 ranged from 14.7 to 19.5 ppm. The levels of methane in the study area ranged between 2310 ppm and 2771 ppm and within the?vicinity of dump site fires H2S concentration ranges from 3.4 to 7.7 ppm. Levels of SPM, CO, CO2, and CH4 within the vicinity of the dump site fires were above regulatory limits. Dump site fires in the study area could threaten the health of anyone especially the dump site workers that are regularly exposed to the thick smoke and can be implicated in climate change debate. There is a need to develop better practices with regard to municipal solid waste open dump site operation and emission control.
文摘The study looked at the levels of polycyclic aromatic hydrocarbons (PAHs) in leachates from a solid waste disposal site and an effluent from an oil refinery in some water bodies around Accra. Sixteen (PAHs) were extracted simultaneously by solid phase and analysis by gas chromatograph. The results of this study gener-ally demonstrated that there were elevated levels of PAHs in the water sample of the Densu River, Chemu, Korle and Kpeshi Lagoons. The average concentration of PAHs in the water ranged from 0.000 of many of the PAHs to 0.552µg/L, for Acenapththene to 11.399µg/L for Benzo (ghi) perylene of the Chemu Lagoon, 0.00µg/L for Benzo (a) Pyrene to 8.800µg/L for Benzo (ghi) perylene (Korle Lagoon) and 0.052µg/L for Pyrene to 4.703ug/L for Acenaphthylene of the Kpeshi Lagoon and 0.00µg/L for pyrene to Acenaphthylene 2.926µg/L of the Weija Dam. Concentrations ranging from below detection level to 14.587µg/L were also recorded at the Oblogo solid waste dump and it’s environ. The Weija dam supply over two million gallons of portable water daily to the people of Accra and the levels of the PAH determined is worrying, as a result, the Oblogoh disposal site ought to be re-located to avert any possible epidemic.
文摘This study compared the physicochemical parameters and heavy metal levels in soil samples from selected anthropogenic sites within Enugu metropolis, Enugu State, Nigeria using standard analytical methods. Soil samples at depths (0 - 20 cm) and (20 - 40 cm) were collected from waste dump sites, metal scrap dumps, fuel filling stations and auto-mechanic workshops and analyzed for physicochemical characteristics and heavy metal levels. Atomic absorption spectrophotometer was used for heavy metal determination while conventional analytical methods were employed for physicochemical parameters evaluation of the soil samples. At soil depths 0 - 20 cm and 20 - 40 cm the respective mean range of pH, electrical conductivity, organic matter and organic carbon contents in the soil samples were, 6.33 - 6.74, 101.46 - 123.21 <em>μ</em>S/cm, 6.41% - 8.35% and 13.73% - 16.14% for auto-mechanic workshops;6.92 - 7.43, 56.46 - 60.02 <em>μ</em>S/cm, 1.53% - 2.20% and 11.93% - 12.60% for fuel filling stations;7.14 - 7.84, 70.81 - 77.71 <em>μ</em>S/cm, 3.81% - 4.12% and 8.57% - 9.24% for metal scrap dumps;6.54 - 6.81, 94.40 - 100.71 <em>μ</em>S/cm, 8.83% - 10.75% and 18.26% - 20.81% for waste dump sites. The pH of the top soil samples from auto-mechanical workshop was below the WHO recommended limits for agricultural purposes. The physic-chemical characteristics of the soil samples decreased with soil depths indicating therefore that anthropogenic activities greatly influence the soil characteristics at the top soils than the sub-soils. The electrical conductivity values of top and sub-soil samples from the studied auto-mechanical workshops were above the recommended limits. At soil depths 0 - 20 cm and 20 - 40 cm, the respective mean range of Zn, Pb and Cd in the soil samples were 17.29 - 19.16 <em>μ</em>g/g, 0.704 - 0.96 <em>μ</em>g/g and 0.26 - 0.33 <em>μ</em>g/g for auto-mechanic workshops;4.13 - 4.88 <em>μ</em>g/g, 0.21 - 0.32 <em>μ</em>g/g and 0.03 - 0.11 <em>μ</em>g/g for fuel filling stations;30.02 - 36.11 <em>μ</em>g/g, 0.43 - 0.48 <em>μ</em>g/g and 0.15 - 0.19 <em>μ</em>g/g for metal scrap dumps;9.30 - 10.84 <em>μ</em>g/g, 0.53 - 0.60 <em>μ</em>g/g and 0.38 - 0.45 <em>μ</em>g/g for waste dump sites. The mean levels of Pb in soil samples from mechanic workshops and waste dump sites were above the recommended permissible limits for agricultural purposes. The study therefore indicated that these sites (auto-mechanic workshops and waste dump sites) could be major sources of Pb pollution to nearby farmlands, streams and the general environment. Plants grown on or around these sites may not produce high yields and could be severely contaminated with heavy metals which portend health danger to food consumers within the environment.
