The high moisture content （80%） in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification （S/S） alternative for the sludge was developed,...The high moisture content （80%） in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification （S/S） alternative for the sludge was developed, using calcined aluminum salts （AS） as solidifier, and CaCl 2 , Na 2 SO 4 and CaSO 4 as accelerators, to enhance the mechanical compressibility making the landfill operation possible. The properties of the resultant matrixes were determined in terms of moisture contents, unconfined compressive strength, products of hydration, and toxicity characteristics. The results showed that AS exhibited a moderate pozzolanic activity, and the mortar AS 0 obtained with 5% AS and 10% CaSO 4 of AS by weight presented a moisture contents below 50%–60% and a compressive strength of （51.32 ± 2.9） kPa after 5–7 days of curing time, meeting the minimum requirement for sanitary landfill. The use of CaSO 4 obviously improved the S/S performance, causing higher strength level. X-ray diffraction, scanning electron microscopy and thermogravimetry- differential scanning calorimetry investigations revealed that a large amount of hydrates （viz., gismondine and CaCO 3 ） were present in solidified sludge, leading to the depletion of evaporable water and the enhancement of the strength. In addition, the toxicity characteristic leaching procedure （TCLP） and horizontal vibration （HJ 557-2009） leaching test were conducted to evaluate their environmental compatibility. It was found that the solidified products conformed to the toxicity characteristic criteria in China and could be safely disposed of in a sanitary landfill.展开更多
Introduction: Pesticides are currently an essential component of agricultural production techniques for controlling pests and weeds. In Burkina Faso, non-compliance with good practice in the use of pesticides poses a ...Introduction: Pesticides are currently an essential component of agricultural production techniques for controlling pests and weeds. In Burkina Faso, non-compliance with good practice in the use of pesticides poses a real health problem for the population. This study examines the health risks associated with pesticide management in rice-growing areas. Material and Methods: A field survey was conducted in Bama, involving farmers, focusing on their socio-demographic characteristics, pesticide usage, and health effects. Cholinesterase levels were measured in subsample of farmers using a portable device. Data were analysed using Microsoft Excel, calculating means and percentages for various practices. Health consultations, protection methods, and pesticide management were studied. Erythrocyte acetylcholinesterase activity was compared before and after treatment. Data were categorised into classes based on inhibition levels, and correlation analyses determined relationships between variables such as age, years of experience, and cholinesterase activity. Results: The results indicate that rice cultivation is mainly carried out by a fairly young population, with nearly 63% being under the age of 50. Common poor practices in pesticide use include improper storage and reuse of leftover pesticides. Seven types of pesticides were identified, including organophosphates such as glyphosate, which was used in 26.7% of cases. This organophosphate has resulted in class B poisoning, causing a 30% - 50% reduction in erythrocyte cholinesterase activity. The health effects of pesticide use are felt by agricultural farmers through various symptoms of poisoning. Conclusion: To reduce the occurrence of pesticide poisoning, it is essential to launch information and awareness campaigns among the population and farmers to promote safe practices in pesticide use in Bama, Burkina Faso.展开更多
The quality of infant flours used during the weaning age is of great importance in that it conditions the nutritional health of infants and young children. This study aimed to assess the nutritional and sanitary quali...The quality of infant flours used during the weaning age is of great importance in that it conditions the nutritional health of infants and young children. This study aimed to assess the nutritional and sanitary quality of infant flours produced in the city of Ouagadougou. This was a cross-sectional study including 11 out of 25 infant flour production units that gave their consent to partake in the study. In total, 25 infant flour samples have been collected from July to September 2021. The physicochemical and microbiological parameters were determined according to standard methods. The ANOVA analysis of variance showed significant differences between the means of the physico-chemical and the means of the microbiological parameters respectively. The results showed that 60% of proteins and 80% of lipid and total carbohydrate contents were below the authorised limits. The energy values were below the authorised limit in 88% of the cases. All instant infant flours had microbiological loads compliant with Burkinabè standards. As for infant flour to be cooked, 63.64% and 81.82% had satisfactory numbers of total coliforms and faecal coliforms respectively. Staphylococcus aureus and Escherichia coli were detected in these samples with 86.36% of infant formulae having results below the recommended limit. These results show that the infant flours produced in Ouagadougou were somehow of acceptable quality. However, there is a need to improve the formulae for macronutrient contents, energy values and sanitary quality to comply with the recommendations.展开更多
The present study aims at studying relationships between various environmental factors andplant performance on a completed sanitary landfill. Three sites were chosen for comparison: an on-sitelow landfill gas region w...The present study aims at studying relationships between various environmental factors andplant performance on a completed sanitary landfill. Three sites were chosen for comparison: an on-sitelow landfill gas region with a rich vegetation growth (Site L) , an on-site high landfill gas region with apoor vegetation growth (Site H), an off site control region (Site N) which located close to the GinDrinkers' Bay landfill. In Site H, where the levels of methane and carbon dioxide were higher, growth oftrees, shrubs and climbing plants are adversely affected, but not herbs and grasses. Analysis of correla-tion coefficient indicated that carbon dioxide and methane showed a negative correlation with the growth oftrees and shrubs. In Site H, the higher levels of conductivity, Kjeldah-N, Ammonium-N, and variousheavy metals, such as Mn were also exerted their adverse effect on plant growth. Trees tolerant to land-fill gas , e. g. Acacia confusa . would be a better choice for planting on sanitary landfills , in addition to theuse of shallow-rooted trees. Grasses and herbs are less susceptible to landfill gas due to their shallow-rootsystems. Hydroseeding of grasses would ensure a better plant coverage in areas with a moderate level oflandfill gas. Installation of a ventilation system might be needed for areas with a high level of landfill gas.展开更多
Background: Food safety is an integral part of food security. It refers to the protection of the food supply against risks of microbial, chemical and physical origin at every stage of the food chain. The study aimed t...Background: Food safety is an integral part of food security. It refers to the protection of the food supply against risks of microbial, chemical and physical origin at every stage of the food chain. The study aimed to investigate the sanitary quality of meals served in the canteens and vicinity of the Lagoon Mother and Child University Hospital Centre (CHU-MEL) and National Hospital and University Centre Hubert Koutoukou Maga (CNHU-HKM) of Cotonou. Methods: It was a cross-sectional with a data collection period from 16 March to 22 April 2021. There were 32 vendors surveyed and 40 meals sampled for microbiological examination. We collected data on the vendors’ socio-demographic characteristics, working environment, health status, knowledge and food hygiene practices. Results: About 83% of the meals contained pathogenic microorganisms. All meals had a temperature from 4°C to 60°C called the “danger zone”. The level of knowledge about food hygiene was low in 65.7% of the vendors. About 47% had poor personal and clothing hygiene, food storage and service practices. Conclusion: These results show that the meals sold in the CHU-MEL and CNHU-HKM could present a health risk for the consumer. There is a need for improvement of the sanitary quality of the meals delivered in the canteens and vicinity of these hospitals.展开更多
The menstrual cycle is always considered as a big nightmare by many women. This research aims to make this process smooth and safe by developing natural sanitary pads which are used to absorb and retain menstrual bloo...The menstrual cycle is always considered as a big nightmare by many women. This research aims to make this process smooth and safe by developing natural sanitary pads which are used to absorb and retain menstrual blood from the body. Some existing sanitary pads contain 90% plastics made of non-woven polypropylene/polyethylene sheets, super absorbent polymers, and polyethylene back sheets that will take up to 600 - 800 years to decompose. So, biodegradable sanitary pads using natural fibers are the best alternative to eliminate the pads which contain non-biodegradable materials. In this research, nonwoven bamboo will be used as the top layer, nonwoven cotton will be used as the second layer, the absorbent core is to be made by the combination of kenaf and chitosan fibers as the third layer, cotton as the fourth layer, and cornstarch-based bioplastic sheets as the bottom layer. These biodegradable natural materials will change the menstrual process into a healthy one as well as create a robust ecological community.展开更多
Although a lot of research has focused on energy recovery and recycling of valuable materials from wastes to reduce loads on landfills,landfilling is still an inseparable part of solid waste management.Since landfills...Although a lot of research has focused on energy recovery and recycling of valuable materials from wastes to reduce loads on landfills,landfilling is still an inseparable part of solid waste management.Since landfills potentially pose a risk to human health and the surrounding environment,landfill site selection is an important endeavor that has to be carried out with great care.Choosing a suitable location for landfills depends on several factors and is a complicated procedure.In this paper,a comprehensive review of landfill site selection methods,with an emphasis on multi criteria decision making(multiple criteria decision analysis)has been presented.Assessments indicate that the most frequently used methods are weighted linear combination(WLC),ordered weighted averaging(OWA),analytic hierarchy process(AHP),fuzzy analytic hierarchy process(F-AHP),TODIM,fuzzy TODIM,analytic network process(ANP),fuzzy-analytic network process(F-ANP),and grey systems theory,each of which is discussed.The most widely used factors for selecting a landfill site are groundwater depth,surface water vicinity,elevation,land slope,soil permeability,soil stability,flooding susceptibility,lithology and stratification,faults,land use type,nearby settlements and urbanization,cultural and protected site vicinity,wind direction,roads,railways,proximity to building materials,pipelines and powerlines,and proximity to airports.展开更多
基金supported by the Science and Technol- ogy Commission of Shanghai Municipality (No. 08DZ 1202802, 09DZ 1204105)
文摘The high moisture content （80%） in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification （S/S） alternative for the sludge was developed, using calcined aluminum salts （AS） as solidifier, and CaCl 2 , Na 2 SO 4 and CaSO 4 as accelerators, to enhance the mechanical compressibility making the landfill operation possible. The properties of the resultant matrixes were determined in terms of moisture contents, unconfined compressive strength, products of hydration, and toxicity characteristics. The results showed that AS exhibited a moderate pozzolanic activity, and the mortar AS 0 obtained with 5% AS and 10% CaSO 4 of AS by weight presented a moisture contents below 50%–60% and a compressive strength of （51.32 ± 2.9） kPa after 5–7 days of curing time, meeting the minimum requirement for sanitary landfill. The use of CaSO 4 obviously improved the S/S performance, causing higher strength level. X-ray diffraction, scanning electron microscopy and thermogravimetry- differential scanning calorimetry investigations revealed that a large amount of hydrates （viz., gismondine and CaCO 3 ） were present in solidified sludge, leading to the depletion of evaporable water and the enhancement of the strength. In addition, the toxicity characteristic leaching procedure （TCLP） and horizontal vibration （HJ 557-2009） leaching test were conducted to evaluate their environmental compatibility. It was found that the solidified products conformed to the toxicity characteristic criteria in China and could be safely disposed of in a sanitary landfill.
文摘Introduction: Pesticides are currently an essential component of agricultural production techniques for controlling pests and weeds. In Burkina Faso, non-compliance with good practice in the use of pesticides poses a real health problem for the population. This study examines the health risks associated with pesticide management in rice-growing areas. Material and Methods: A field survey was conducted in Bama, involving farmers, focusing on their socio-demographic characteristics, pesticide usage, and health effects. Cholinesterase levels were measured in subsample of farmers using a portable device. Data were analysed using Microsoft Excel, calculating means and percentages for various practices. Health consultations, protection methods, and pesticide management were studied. Erythrocyte acetylcholinesterase activity was compared before and after treatment. Data were categorised into classes based on inhibition levels, and correlation analyses determined relationships between variables such as age, years of experience, and cholinesterase activity. Results: The results indicate that rice cultivation is mainly carried out by a fairly young population, with nearly 63% being under the age of 50. Common poor practices in pesticide use include improper storage and reuse of leftover pesticides. Seven types of pesticides were identified, including organophosphates such as glyphosate, which was used in 26.7% of cases. This organophosphate has resulted in class B poisoning, causing a 30% - 50% reduction in erythrocyte cholinesterase activity. The health effects of pesticide use are felt by agricultural farmers through various symptoms of poisoning. Conclusion: To reduce the occurrence of pesticide poisoning, it is essential to launch information and awareness campaigns among the population and farmers to promote safe practices in pesticide use in Bama, Burkina Faso.
文摘The quality of infant flours used during the weaning age is of great importance in that it conditions the nutritional health of infants and young children. This study aimed to assess the nutritional and sanitary quality of infant flours produced in the city of Ouagadougou. This was a cross-sectional study including 11 out of 25 infant flour production units that gave their consent to partake in the study. In total, 25 infant flour samples have been collected from July to September 2021. The physicochemical and microbiological parameters were determined according to standard methods. The ANOVA analysis of variance showed significant differences between the means of the physico-chemical and the means of the microbiological parameters respectively. The results showed that 60% of proteins and 80% of lipid and total carbohydrate contents were below the authorised limits. The energy values were below the authorised limit in 88% of the cases. All instant infant flours had microbiological loads compliant with Burkinabè standards. As for infant flour to be cooked, 63.64% and 81.82% had satisfactory numbers of total coliforms and faecal coliforms respectively. Staphylococcus aureus and Escherichia coli were detected in these samples with 86.36% of infant formulae having results below the recommended limit. These results show that the infant flours produced in Ouagadougou were somehow of acceptable quality. However, there is a need to improve the formulae for macronutrient contents, energy values and sanitary quality to comply with the recommendations.
文摘The present study aims at studying relationships between various environmental factors andplant performance on a completed sanitary landfill. Three sites were chosen for comparison: an on-sitelow landfill gas region with a rich vegetation growth (Site L) , an on-site high landfill gas region with apoor vegetation growth (Site H), an off site control region (Site N) which located close to the GinDrinkers' Bay landfill. In Site H, where the levels of methane and carbon dioxide were higher, growth oftrees, shrubs and climbing plants are adversely affected, but not herbs and grasses. Analysis of correla-tion coefficient indicated that carbon dioxide and methane showed a negative correlation with the growth oftrees and shrubs. In Site H, the higher levels of conductivity, Kjeldah-N, Ammonium-N, and variousheavy metals, such as Mn were also exerted their adverse effect on plant growth. Trees tolerant to land-fill gas , e. g. Acacia confusa . would be a better choice for planting on sanitary landfills , in addition to theuse of shallow-rooted trees. Grasses and herbs are less susceptible to landfill gas due to their shallow-rootsystems. Hydroseeding of grasses would ensure a better plant coverage in areas with a moderate level oflandfill gas. Installation of a ventilation system might be needed for areas with a high level of landfill gas.
文摘Background: Food safety is an integral part of food security. It refers to the protection of the food supply against risks of microbial, chemical and physical origin at every stage of the food chain. The study aimed to investigate the sanitary quality of meals served in the canteens and vicinity of the Lagoon Mother and Child University Hospital Centre (CHU-MEL) and National Hospital and University Centre Hubert Koutoukou Maga (CNHU-HKM) of Cotonou. Methods: It was a cross-sectional with a data collection period from 16 March to 22 April 2021. There were 32 vendors surveyed and 40 meals sampled for microbiological examination. We collected data on the vendors’ socio-demographic characteristics, working environment, health status, knowledge and food hygiene practices. Results: About 83% of the meals contained pathogenic microorganisms. All meals had a temperature from 4°C to 60°C called the “danger zone”. The level of knowledge about food hygiene was low in 65.7% of the vendors. About 47% had poor personal and clothing hygiene, food storage and service practices. Conclusion: These results show that the meals sold in the CHU-MEL and CNHU-HKM could present a health risk for the consumer. There is a need for improvement of the sanitary quality of the meals delivered in the canteens and vicinity of these hospitals.
文摘The menstrual cycle is always considered as a big nightmare by many women. This research aims to make this process smooth and safe by developing natural sanitary pads which are used to absorb and retain menstrual blood from the body. Some existing sanitary pads contain 90% plastics made of non-woven polypropylene/polyethylene sheets, super absorbent polymers, and polyethylene back sheets that will take up to 600 - 800 years to decompose. So, biodegradable sanitary pads using natural fibers are the best alternative to eliminate the pads which contain non-biodegradable materials. In this research, nonwoven bamboo will be used as the top layer, nonwoven cotton will be used as the second layer, the absorbent core is to be made by the combination of kenaf and chitosan fibers as the third layer, cotton as the fourth layer, and cornstarch-based bioplastic sheets as the bottom layer. These biodegradable natural materials will change the menstrual process into a healthy one as well as create a robust ecological community.
文摘Although a lot of research has focused on energy recovery and recycling of valuable materials from wastes to reduce loads on landfills,landfilling is still an inseparable part of solid waste management.Since landfills potentially pose a risk to human health and the surrounding environment,landfill site selection is an important endeavor that has to be carried out with great care.Choosing a suitable location for landfills depends on several factors and is a complicated procedure.In this paper,a comprehensive review of landfill site selection methods,with an emphasis on multi criteria decision making(multiple criteria decision analysis)has been presented.Assessments indicate that the most frequently used methods are weighted linear combination(WLC),ordered weighted averaging(OWA),analytic hierarchy process(AHP),fuzzy analytic hierarchy process(F-AHP),TODIM,fuzzy TODIM,analytic network process(ANP),fuzzy-analytic network process(F-ANP),and grey systems theory,each of which is discussed.The most widely used factors for selecting a landfill site are groundwater depth,surface water vicinity,elevation,land slope,soil permeability,soil stability,flooding susceptibility,lithology and stratification,faults,land use type,nearby settlements and urbanization,cultural and protected site vicinity,wind direction,roads,railways,proximity to building materials,pipelines and powerlines,and proximity to airports.
