<strong>Introduction:</strong> The present research paper aims at assessing the bacteriological water quality in households and at provisioning points, and so factors of water deterioration. <strong>...<strong>Introduction:</strong> The present research paper aims at assessing the bacteriological water quality in households and at provisioning points, and so factors of water deterioration. <strong>Method:</strong> a transverse study has been conducted during the period starting from 11 up to 28 October 2018 within 6 Health Zones (HZ) in Tshopo Province integrated in National Program of Schools and Sanitized Villages (NPSSV). Water samples have been collected within 300 reserves of households and 30 water provisioning and analysed points in order to find out water contamination factors. The frequencies and raw OR have been estimated at (p < 0.05) valued significative. <strong>Results:</strong> fecal coliforms (80% CI95: 75% - 85%) and total (97% CI95: 95% - 99%) were significantly present in water reserves and the presence of Escherichia coli were at about 27% (IC95 22% - 32%). These proportions were correspondingly at 63%, 90% and 10% at water provisioning. The fecal coliforms were the highest in water reserves of sanitized villages (p < 0.05) and Escherichia coli were at about three times higher in traditional sources (17% vs 6%). The duration of water conservation was around 48 hours and more (OR = 4.41;IC95: 1.92 - 10.11), water classification of sanitized risk “intermedium” and the recipients of conservation with bottleneck were associated with the presence of E.coli in water (p < 0.05). <strong>Conclusion: </strong>water from provisioning sources and household reserves are severely polluted and water quality is not good at consumption point and at provisioning point. The reinforcement of safety measures at water points, reduction of conservation length and hygienic water cleaning of storage water recipients are necessary to assure quality of water.展开更多
The long-standing use of portable toilet cubicles by residents of Shanghai’s narrow,labyrinthine alleys came to an end in September 2025 after the city largely finished building public toilets to make up their lack o...The long-standing use of portable toilet cubicles by residents of Shanghai’s narrow,labyrinthine alleys came to an end in September 2025 after the city largely finished building public toilets to make up their lack of sanitation facilities.The project,targeting 14,082 households,started last year.展开更多
This study examined the hygiene status of blueberry harvest containers cleaned/sanitized with various approaches.Each of four blueberry facilities in Georgia or Oregon was visited twice during the 2021 harvest season....This study examined the hygiene status of blueberry harvest containers cleaned/sanitized with various approaches.Each of four blueberry facilities in Georgia or Oregon was visited twice during the 2021 harvest season.Swab samples from used berry lugs(UL),cleaned/sanitized lugs(CL),used handpicking buckets(UB),and cleaned/sanitized buckets(CB)in Georgia(n=160)and from used berry flats(UF)and cleaned/sanitized flats(CF)as well as UB and CB in Oregon(n=160)were collected.The populations of total aerobes(TA),total yeasts and molds(YM),and total coliforms(TC),as well as the incidences of fecal coliforms(FC),and enterococci(EC)were determined.In Georgia,the UL and UB had significantly(P<0.05)higher TA and YM counts than their cleaned/sanitized counterparts.FC and EC were detected in 1.3%or 3.8%of the samples.In Oregon,UB had significantly higher mean YM and TC counts than CB.FC and EC were detected in 3.8%or 10.6%of the samples.Containers soaked in chlorinated water with manual washing/scrubbing seemed cleaner than those washed in a washing machine with un-chlorinated water.Chlorination of water in the washing machine after each use was,nevertheless,more effective than manual washing.展开更多
■INTRODUCTION A recent article by Holcomb et al.1 in Environment&Health offers a revealing look into how children in Maputo,Mozambique are exposed to enteric pathogenseven in households with improved sanitation.T...■INTRODUCTION A recent article by Holcomb et al.1 in Environment&Health offers a revealing look into how children in Maputo,Mozambique are exposed to enteric pathogenseven in households with improved sanitation.Their research questions the reliability of traditional fecal indicators and highlights a core issue in environmental health:invisible,routine exposure pathways that are difficult to capture with standard tools.展开更多
Nest sanitation is a ubiquitous behavior in birds and functions to remove foreign objects that accidentally have fallen into their nests. In avian brood parasitism, the host’s ability to recognize and reject parasiti...Nest sanitation is a ubiquitous behavior in birds and functions to remove foreign objects that accidentally have fallen into their nests. In avian brood parasitism, the host’s ability to recognize and reject parasitic eggs is a specific anti-parasitic behavior. Previous studies have shown that egg recognition may have evolved from nest sanitation behavior;however, few studies have offered evidence in support of this hypothesis. In the current study, we added one real white egg and one model egg to the nests of common tailorbirds (Orthotomus sutorius), the main host of plaintive cuckoos (Cacomantis merulinus), to explore the relationship between egg recognition ability in hosts and nest sanitation behavior. Results showed that common tailorbirds rejected both non-mimetic blue model eggs and mimetic white model eggs at a similar rate of 100%, but only rejected 16.1% of mimetic real white eggs. The egg rejection behavior of common tailorbirds towards both real and model eggs was consistent. However, when both blue model eggs and real white eggs were simultaneously added to their nests, the probability of rejecting the mimetic real white egg increased to 50%. The addition of blue model eggs not only increased the occurrence of nest sanitation behavior but also increased the ability to recognize and reject parasitic eggs. This suggests that nest sanitation may facilitate egg rejection in common tailorbird hosts.展开更多
Most studies exploring abilities of hosts to detect brood parasitism are based on detecting colour and/or pattern differences among parasitic and host eggs or nestlings,while only few were focused on size differences....Most studies exploring abilities of hosts to detect brood parasitism are based on detecting colour and/or pattern differences among parasitic and host eggs or nestlings,while only few were focused on size differences.True recognition and recognition by discordancy are used to explain cognitive mechanisms of host egg recognition;however,only a few studies have found that hosts use recognition by discordancy.This study investigated:1)whether egg and nestling recognitions in the Crested Myna(Acridotheres cristatellus) are based on size cues;2)whether the egg cognitive mechanism is recognition by discordancy based on size cues;and 3) whether the longer the experiment time,the higher the egg recognition rate.Our results showed that the Crested Myna uses egg or nestling size as a recognition cue while the egg and nestling colour and patterning are not associated with egg or nestling rejection,thus the cognitive mechanism of egg recognition in the Crested Myna is recognition by discordancy based on egg size cues.Furthermore,there is a rejection delay in time of egg rejection behaviour of the Crested Myna.Therefore,we suggest that the periodicity of egg rejection experiments could be appropriately extended,especially for species with relatively low egg recognition ability.展开更多
Sustainable sanitation is an approach for more ecological and sustainable water resources management. In this paper, we proposed one of the new integrated waste treatment systems： an ＂sustainable sanitation system＂...Sustainable sanitation is an approach for more ecological and sustainable water resources management. In this paper, we proposed one of the new integrated waste treatment systems： an ＂sustainable sanitation system＂ that includes separation of the black water from water system by a non-flushing toilet （bio-toilet）, and a gray water treatment based on a biological and ecological concept. Sustainable sanitation system also converts the domestic waste to soil conditioners and fertilizers, for farmland use. As one of the case studies, Environmentally Symbiotic Housing in which people actually live using the bio-toilet for the black water treatment and the household wastewater treatment facility for the gray water was introduced. The availability of this system was investigated by analyzing the sawdust used in the bio-toilet and the quality of the effluent in the household wastewater treatment facility. As the result, the water content of the sawdust did not exceed 60% in any of the sampling points and the BOD and COD of the effluent of the household wastewater treatment facility were below 10 and 20 mg/L respectively, due to the low loading. Compared to the pollution load on the water environment created by the conventional system, it was found that the effluent of the house has a lower load than the tertiary treatment and the volume of the water consumption is 75% of the conventional system.展开更多
As compared to conventional diesel heavy-duty vehicles,natural gas vehicles have been proved to be more eco-friendly due to their lower production of greenhouse gas and pollu-tant emissions,which are causing enormous ...As compared to conventional diesel heavy-duty vehicles,natural gas vehicles have been proved to be more eco-friendly due to their lower production of greenhouse gas and pollu-tant emissions,which are causing enormous adverse effects on global warming and air pol-lution.However,natural gas vehicles were rarely studied before,especially through on-road measurements.In this study,a portable emission measurement system(PEMS)was em-ployed to investigate the real-world emissions of nitrogen oxides(NO_(x))(nitrogen monoxide(NO),nitrogen dioxide(NO_(2))),total hydrocarbons(THC),carbon monoxide(CO),and carbon dioxide(CO_(2))from two liquified natural gas(LNG)China V heavy-duty cleaning sanitation trucks with different weight.Associated with the more aggressive driving behaviors,the ve-hicle with lower weight exhibited higher CO_(2)(3%)but lower NO_(x)(48.3%)(NO_(2)(78.2%)and NO(29.4%)),CO(44.8%),and THC(3.7%)emission factors.Aggressive driving behaviors were also favorable to the production of THC,especially those in the medium-speed range but sig-nificantly negative to the production of CO and NO_(2),especially those in the low-speed range with high engine load.In particular,the emission rate ratio of NO_(2)/NO decreased with the increase of speed/scaled tractive power in different speed ranges.展开更多
Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows the...Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows them to identify the parasitic eggs, so that egg discrimination behavior may have evolved from nest sanitation behavior. However, whether nest sanitation behavior could improve egg rejection in cuckoo hosts was inconclusive.Methods: In this study, we investigated the relationship between nest sanitation and egg discrimination behavior in a potential cuckoo host, the Brown-breasted Bulbul(Pycnonotus xanthorrhous) with two experimental groups. In the first group, we added a blue, non-mimetic egg to the nest of the host, while in the second group we added a blue, non-mimetic egg and a peanut half-shell.Results: The results showed that in the first group, the probability of rejecting the non-mimetic eggs was 53.8%(n = 26 nests). In comparison, all of the Brown-breasted Bulbuls in the second group were able to rapidly remove the peanut shells from the nest, but only 52.6%(n = 19 nests) rejected the non-mimetic eggs. The rejection rates of the non-mimetic eggs in both experimental groups were not significantly different.Conclusions: Our study indicated that nest sanitation behavior of Brown-breasted Bulbuls did not influence their egg recognition and that egg discrimination ability of Brown-breasted Bulbuls was not directly related to nest sanitation behavior.展开更多
Objective:To find out the prevalence of intestinal parasites among primary school population(the most vulnerable group) in rural and urban areas in south Jordan.Methods:During a medical civic action in the south of Jo...Objective:To find out the prevalence of intestinal parasites among primary school population(the most vulnerable group) in rural and urban areas in south Jordan.Methods:During a medical civic action in the south of Jordan in summer 2000,stool specimens were collected from 2400 primary school children,aged from 6-12 years,and examined for the detection of intestinal parasitic infection from both urban(1 100 samples) and rural(1 300 samples) areas in south Jordan.Results:The results indicated that the overall prevalence of intestinal parasitic infection was 28.5%.It was more in rural(33.2%) than in urban(23.0%) areas,but no sex difference was found.As regard to the type of infection,Giardia lamblia was the commonest intestinal protozoa, with a rate of 42.6%,while Enterobious vermicularis was the commonest helminth recorded in our study with a rate of 5.9%.Conclusions:Health education by health and school authorities is recommended,particular attention should be paid to repairing the sewage disposal system as well as water supply,which acts as main source of water pollution.展开更多
Chlorine-based sanitizers have seen wide spread use in food sanitation. The reaction of chlorine species with organic matter is a concern for two reasons. Available chlorine can be “used up” by organic compounds res...Chlorine-based sanitizers have seen wide spread use in food sanitation. The reaction of chlorine species with organic matter is a concern for two reasons. Available chlorine can be “used up” by organic compounds resulting in a lower amount of chlorine available for disinfection. Another concern is that some forms of chlorine can react with some organic compounds to form toxic halogenated disinfection byproducts（DBPs）. Many studies have been conducted to evaluate the role of hypochlorous acid（HOCl） and hypochlorite ion（OCl–） in the production of DBPs with a particular interest in the production of trihalomethanes（THMs） and haloacetic acids（HAAs）. Since most of the chlorine reactions are pH dependent, pH is found to have a significant effect on the formation of chlorine DBPs. In many cases, the concentration of THMs decreases and HAAs increases as pH decreases. pH also plays an important role in the determination of the type and amount of DBPs formed, with lower, more acidic, pHs resulting in the formation of less chloroform. This review summarizes the information from the literature on the role of chlorine-based sanitizers as affected by pH in the formation of different types of DBPs. Alternative novel strategies to minimize the formation of DBPs are also discussed.展开更多
Poor wastewater management coupled with lack of sanitation facilities has aggravated the sanitation challenges in developing countries.?This study was aimed at providing information on the current state of sanitation ...Poor wastewater management coupled with lack of sanitation facilities has aggravated the sanitation challenges in developing countries.?This study was aimed at providing information on the current state of sanitation in Cotonou City through surveys. The most common sanitation facilities in the city were septic tanks, latrines and soakaway pits. Mechanical desulging was mainly used (94%) for desludging latrines and septic tanks with a frequency of less than once a year for 73% of the houses;manual desludging was most common for soakaway pits. 84% of sullage generated is disposed without treatment. The only existing stabilization pond plant, managed by a private company SIBEAU, is overloaded;the effluent is poor (up to 2250mg/l BOD5) and does not meet any quality standards. 96% of survey respondents recognise that the sanitation situation in the city is not good;it has to be improved by providing an appropriate and sustainable sanitation management system.展开更多
The vacuum sanitation is the safe and sound disposal approach of human excreta under the specific environments like flights, high speed trains and submarines. However, the propulsive force of current systems is not ad...The vacuum sanitation is the safe and sound disposal approach of human excreta under the specific environments like flights, high speed trains and submarines. However, the propulsive force of current systems is not adjustable and the energy consumption does not adapt to the real time sewerage requirement. Therefore, it is important to study the sewerage force adjustment to improve the energy efficiency. This paper proposes an energy conservation design in vacuum sanitation systems with pneumatic ejector circuits. The sewerage force is controlled by changing the systematic vacuum degree according to the amount of the excreta. In particular, the amount of the excreta is tested by liquid level sensor and mass sensor. According to the amount of the excreta, the relationship between the excreta amount and the sewerage force is studied to provide proper propulsive force. In the other aspect, to provide variable vacuum degrees for different sanitation requirements, the suction and discharge system is designed with pneumatic vacuum ejector. On the basis of the static flow-rate characteristics and the vacuum generation model, the pressure response in the ejector circuit is studied by using the static flow rate characteristics of the ejector and air status equation. The relationship is obtained between supplied compressed air and systematic vacuum degree. When the compressed air is supplied to the ejector continuously, the systematic vacuum degree increases until the vacuum degree reaches the extreme value. Therefore, the variable systematic vacuum degree is obtained by controlling the compressed air supply of the ejector. To verify the effect of energy conservation, experiments are carried out in the artificial excreta collection, and the variable vacuum-degree design saves more than 30% of the energy supply. The energy conservation is realized effectively in the new vacuum sanitation systems with good application prospect. The proposed technology provides technological support for the energy conservation of vacuum sanitation systems.展开更多
文摘<strong>Introduction:</strong> The present research paper aims at assessing the bacteriological water quality in households and at provisioning points, and so factors of water deterioration. <strong>Method:</strong> a transverse study has been conducted during the period starting from 11 up to 28 October 2018 within 6 Health Zones (HZ) in Tshopo Province integrated in National Program of Schools and Sanitized Villages (NPSSV). Water samples have been collected within 300 reserves of households and 30 water provisioning and analysed points in order to find out water contamination factors. The frequencies and raw OR have been estimated at (p < 0.05) valued significative. <strong>Results:</strong> fecal coliforms (80% CI95: 75% - 85%) and total (97% CI95: 95% - 99%) were significantly present in water reserves and the presence of Escherichia coli were at about 27% (IC95 22% - 32%). These proportions were correspondingly at 63%, 90% and 10% at water provisioning. The fecal coliforms were the highest in water reserves of sanitized villages (p < 0.05) and Escherichia coli were at about three times higher in traditional sources (17% vs 6%). The duration of water conservation was around 48 hours and more (OR = 4.41;IC95: 1.92 - 10.11), water classification of sanitized risk “intermedium” and the recipients of conservation with bottleneck were associated with the presence of E.coli in water (p < 0.05). <strong>Conclusion: </strong>water from provisioning sources and household reserves are severely polluted and water quality is not good at consumption point and at provisioning point. The reinforcement of safety measures at water points, reduction of conservation length and hygienic water cleaning of storage water recipients are necessary to assure quality of water.
文摘The long-standing use of portable toilet cubicles by residents of Shanghai’s narrow,labyrinthine alleys came to an end in September 2025 after the city largely finished building public toilets to make up their lack of sanitation facilities.The project,targeting 14,082 households,started last year.
文摘This study examined the hygiene status of blueberry harvest containers cleaned/sanitized with various approaches.Each of four blueberry facilities in Georgia or Oregon was visited twice during the 2021 harvest season.Swab samples from used berry lugs(UL),cleaned/sanitized lugs(CL),used handpicking buckets(UB),and cleaned/sanitized buckets(CB)in Georgia(n=160)and from used berry flats(UF)and cleaned/sanitized flats(CF)as well as UB and CB in Oregon(n=160)were collected.The populations of total aerobes(TA),total yeasts and molds(YM),and total coliforms(TC),as well as the incidences of fecal coliforms(FC),and enterococci(EC)were determined.In Georgia,the UL and UB had significantly(P<0.05)higher TA and YM counts than their cleaned/sanitized counterparts.FC and EC were detected in 1.3%or 3.8%of the samples.In Oregon,UB had significantly higher mean YM and TC counts than CB.FC and EC were detected in 3.8%or 10.6%of the samples.Containers soaked in chlorinated water with manual washing/scrubbing seemed cleaner than those washed in a washing machine with un-chlorinated water.Chlorination of water in the washing machine after each use was,nevertheless,more effective than manual washing.
文摘■INTRODUCTION A recent article by Holcomb et al.1 in Environment&Health offers a revealing look into how children in Maputo,Mozambique are exposed to enteric pathogenseven in households with improved sanitation.Their research questions the reliability of traditional fecal indicators and highlights a core issue in environmental health:invisible,routine exposure pathways that are difficult to capture with standard tools.
基金supported by the National Natural Science Foundation of China(31672303 to C.C.Y.,and 31472013,31772453 and 31970427 to W.L.)
文摘Nest sanitation is a ubiquitous behavior in birds and functions to remove foreign objects that accidentally have fallen into their nests. In avian brood parasitism, the host’s ability to recognize and reject parasitic eggs is a specific anti-parasitic behavior. Previous studies have shown that egg recognition may have evolved from nest sanitation behavior;however, few studies have offered evidence in support of this hypothesis. In the current study, we added one real white egg and one model egg to the nests of common tailorbirds (Orthotomus sutorius), the main host of plaintive cuckoos (Cacomantis merulinus), to explore the relationship between egg recognition ability in hosts and nest sanitation behavior. Results showed that common tailorbirds rejected both non-mimetic blue model eggs and mimetic white model eggs at a similar rate of 100%, but only rejected 16.1% of mimetic real white eggs. The egg rejection behavior of common tailorbirds towards both real and model eggs was consistent. However, when both blue model eggs and real white eggs were simultaneously added to their nests, the probability of rejecting the mimetic real white egg increased to 50%. The addition of blue model eggs not only increased the occurrence of nest sanitation behavior but also increased the ability to recognize and reject parasitic eggs. This suggests that nest sanitation may facilitate egg rejection in common tailorbird hosts.
基金supported by the National Natural Science Foundation of China (No.31970427 and 32270526 to WL)supported by the specific research fund of The Innovation Platform for Academicians of Hainan Province
文摘Most studies exploring abilities of hosts to detect brood parasitism are based on detecting colour and/or pattern differences among parasitic and host eggs or nestlings,while only few were focused on size differences.True recognition and recognition by discordancy are used to explain cognitive mechanisms of host egg recognition;however,only a few studies have found that hosts use recognition by discordancy.This study investigated:1)whether egg and nestling recognitions in the Crested Myna(Acridotheres cristatellus) are based on size cues;2)whether the egg cognitive mechanism is recognition by discordancy based on size cues;and 3) whether the longer the experiment time,the higher the egg recognition rate.Our results showed that the Crested Myna uses egg or nestling size as a recognition cue while the egg and nestling colour and patterning are not associated with egg or nestling rejection,thus the cognitive mechanism of egg recognition in the Crested Myna is recognition by discordancy based on egg size cues.Furthermore,there is a rejection delay in time of egg rejection behaviour of the Crested Myna.Therefore,we suggest that the periodicity of egg rejection experiments could be appropriately extended,especially for species with relatively low egg recognition ability.
文摘Sustainable sanitation is an approach for more ecological and sustainable water resources management. In this paper, we proposed one of the new integrated waste treatment systems： an ＂sustainable sanitation system＂ that includes separation of the black water from water system by a non-flushing toilet （bio-toilet）, and a gray water treatment based on a biological and ecological concept. Sustainable sanitation system also converts the domestic waste to soil conditioners and fertilizers, for farmland use. As one of the case studies, Environmentally Symbiotic Housing in which people actually live using the bio-toilet for the black water treatment and the household wastewater treatment facility for the gray water was introduced. The availability of this system was investigated by analyzing the sawdust used in the bio-toilet and the quality of the effluent in the household wastewater treatment facility. As the result, the water content of the sawdust did not exceed 60% in any of the sampling points and the BOD and COD of the effluent of the household wastewater treatment facility were below 10 and 20 mg/L respectively, due to the low loading. Compared to the pollution load on the water environment created by the conventional system, it was found that the effluent of the house has a lower load than the tertiary treatment and the volume of the water consumption is 75% of the conventional system.
基金This work was supported by the National Key Research and Development Project(No.2016YFC0201004)the National Natural Science Foundation of China(No.42005108)the Science and Technological Fund of Anhui Province for Outstanding Youth(No.1808085J19).
文摘As compared to conventional diesel heavy-duty vehicles,natural gas vehicles have been proved to be more eco-friendly due to their lower production of greenhouse gas and pollu-tant emissions,which are causing enormous adverse effects on global warming and air pol-lution.However,natural gas vehicles were rarely studied before,especially through on-road measurements.In this study,a portable emission measurement system(PEMS)was em-ployed to investigate the real-world emissions of nitrogen oxides(NO_(x))(nitrogen monoxide(NO),nitrogen dioxide(NO_(2))),total hydrocarbons(THC),carbon monoxide(CO),and carbon dioxide(CO_(2))from two liquified natural gas(LNG)China V heavy-duty cleaning sanitation trucks with different weight.Associated with the more aggressive driving behaviors,the ve-hicle with lower weight exhibited higher CO_(2)(3%)but lower NO_(x)(48.3%)(NO_(2)(78.2%)and NO(29.4%)),CO(44.8%),and THC(3.7%)emission factors.Aggressive driving behaviors were also favorable to the production of THC,especially those in the medium-speed range but sig-nificantly negative to the production of CO and NO_(2),especially those in the low-speed range with high engine load.In particular,the emission rate ratio of NO_(2)/NO decreased with the increase of speed/scaled tractive power in different speed ranges.
基金supported by the National Natural Science Foundation of China(Nos.31672303 to CY,31472013 and 31772453 to WL)
文摘Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows them to identify the parasitic eggs, so that egg discrimination behavior may have evolved from nest sanitation behavior. However, whether nest sanitation behavior could improve egg rejection in cuckoo hosts was inconclusive.Methods: In this study, we investigated the relationship between nest sanitation and egg discrimination behavior in a potential cuckoo host, the Brown-breasted Bulbul(Pycnonotus xanthorrhous) with two experimental groups. In the first group, we added a blue, non-mimetic egg to the nest of the host, while in the second group we added a blue, non-mimetic egg and a peanut half-shell.Results: The results showed that in the first group, the probability of rejecting the non-mimetic eggs was 53.8%(n = 26 nests). In comparison, all of the Brown-breasted Bulbuls in the second group were able to rapidly remove the peanut shells from the nest, but only 52.6%(n = 19 nests) rejected the non-mimetic eggs. The rejection rates of the non-mimetic eggs in both experimental groups were not significantly different.Conclusions: Our study indicated that nest sanitation behavior of Brown-breasted Bulbuls did not influence their egg recognition and that egg discrimination ability of Brown-breasted Bulbuls was not directly related to nest sanitation behavior.
文摘Objective:To find out the prevalence of intestinal parasites among primary school population(the most vulnerable group) in rural and urban areas in south Jordan.Methods:During a medical civic action in the south of Jordan in summer 2000,stool specimens were collected from 2400 primary school children,aged from 6-12 years,and examined for the detection of intestinal parasitic infection from both urban(1 100 samples) and rural(1 300 samples) areas in south Jordan.Results:The results indicated that the overall prevalence of intestinal parasitic infection was 28.5%.It was more in rural(33.2%) than in urban(23.0%) areas,but no sex difference was found.As regard to the type of infection,Giardia lamblia was the commonest intestinal protozoa, with a rate of 42.6%,while Enterobious vermicularis was the commonest helminth recorded in our study with a rate of 5.9%.Conclusions:Health education by health and school authorities is recommended,particular attention should be paid to repairing the sewage disposal system as well as water supply,which acts as main source of water pollution.
文摘Chlorine-based sanitizers have seen wide spread use in food sanitation. The reaction of chlorine species with organic matter is a concern for two reasons. Available chlorine can be “used up” by organic compounds resulting in a lower amount of chlorine available for disinfection. Another concern is that some forms of chlorine can react with some organic compounds to form toxic halogenated disinfection byproducts（DBPs）. Many studies have been conducted to evaluate the role of hypochlorous acid（HOCl） and hypochlorite ion（OCl–） in the production of DBPs with a particular interest in the production of trihalomethanes（THMs） and haloacetic acids（HAAs）. Since most of the chlorine reactions are pH dependent, pH is found to have a significant effect on the formation of chlorine DBPs. In many cases, the concentration of THMs decreases and HAAs increases as pH decreases. pH also plays an important role in the determination of the type and amount of DBPs formed, with lower, more acidic, pHs resulting in the formation of less chloroform. This review summarizes the information from the literature on the role of chlorine-based sanitizers as affected by pH in the formation of different types of DBPs. Alternative novel strategies to minimize the formation of DBPs are also discussed.
文摘Poor wastewater management coupled with lack of sanitation facilities has aggravated the sanitation challenges in developing countries.?This study was aimed at providing information on the current state of sanitation in Cotonou City through surveys. The most common sanitation facilities in the city were septic tanks, latrines and soakaway pits. Mechanical desulging was mainly used (94%) for desludging latrines and septic tanks with a frequency of less than once a year for 73% of the houses;manual desludging was most common for soakaway pits. 84% of sullage generated is disposed without treatment. The only existing stabilization pond plant, managed by a private company SIBEAU, is overloaded;the effluent is poor (up to 2250mg/l BOD5) and does not meet any quality standards. 96% of survey respondents recognise that the sanitation situation in the city is not good;it has to be improved by providing an appropriate and sustainable sanitation management system.
基金supported by Doctor Innovation Fund of Nanjing University of Science and Technology of China(Grant No. 20080407)Joint-PhD Program of China Scholarship Council(Grant No.2008104777)
文摘The vacuum sanitation is the safe and sound disposal approach of human excreta under the specific environments like flights, high speed trains and submarines. However, the propulsive force of current systems is not adjustable and the energy consumption does not adapt to the real time sewerage requirement. Therefore, it is important to study the sewerage force adjustment to improve the energy efficiency. This paper proposes an energy conservation design in vacuum sanitation systems with pneumatic ejector circuits. The sewerage force is controlled by changing the systematic vacuum degree according to the amount of the excreta. In particular, the amount of the excreta is tested by liquid level sensor and mass sensor. According to the amount of the excreta, the relationship between the excreta amount and the sewerage force is studied to provide proper propulsive force. In the other aspect, to provide variable vacuum degrees for different sanitation requirements, the suction and discharge system is designed with pneumatic vacuum ejector. On the basis of the static flow-rate characteristics and the vacuum generation model, the pressure response in the ejector circuit is studied by using the static flow rate characteristics of the ejector and air status equation. The relationship is obtained between supplied compressed air and systematic vacuum degree. When the compressed air is supplied to the ejector continuously, the systematic vacuum degree increases until the vacuum degree reaches the extreme value. Therefore, the variable systematic vacuum degree is obtained by controlling the compressed air supply of the ejector. To verify the effect of energy conservation, experiments are carried out in the artificial excreta collection, and the variable vacuum-degree design saves more than 30% of the energy supply. The energy conservation is realized effectively in the new vacuum sanitation systems with good application prospect. The proposed technology provides technological support for the energy conservation of vacuum sanitation systems.
