Objectives: To lay stress upon the importance of adequate water and sanitation in the prevention of cholera in Guinea. Methods: The data on deaths and cases of cholera in Guinea from 2000 to 2011 were downloaded from ...Objectives: To lay stress upon the importance of adequate water and sanitation in the prevention of cholera in Guinea. Methods: The data on deaths and cases of cholera in Guinea from 2000 to 2011 were downloaded from the WHO Official website. The data on deaths and cases of cholera outbreak which occurred in Guinea from 02 February to 15 October 2012 were collected from the Guinean Ministry of Public Health. The cholera index case is confirmed by a laboratory test. Cholera cases were defined as individuals over one year old who had had watery stools with or without vomiting. Cholera incidence and case fatality rates between different areas of cholera occurrence in the country over time were computed. Results: Over the overall 12-year period (2000-2012), the case fatality rate showed a somewhat sign of slight rising trend when the incidence rates increased rapidly. During the seven consecutive years of cholera outbreaks in Guinea, between 2003 and 2009, the most affected areas were Conakry, Dubreka, Coyah, Boffa, Forécariah, Guékédou, Dalaba and Télimélé. In 2012, Cholera outbreak resulted in an incidence rate of 23.23 per 10,000 population and a case fatality ratio (CFR) of approximately 1.8%. Cases and deaths were reported in 12 prefectures out of 34: Conakry, Coyah, Forecariah, Fria, Boffa, Dubréka, Boké, Mamou, Kindia, Kankan, Kerouané and Dabola. Conclusion: Cholera is an important health problem in Guinea. Any earnest attempts to improve water and sanitation alongside with promotion of good hygienic practices will likely ward off the threat of cholera in the country.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
Birds’behavioral response to brood parasitism can be influenced not only by evolution but also by context and individual experience.This could include nest sanitation,in which birds remove debris from their nests.Ult...Birds’behavioral response to brood parasitism can be influenced not only by evolution but also by context and individual experience.This could include nest sanitation,in which birds remove debris from their nests.Ultimately,nest sanitation behavior might be an evolutionary precursor to the rejection of parasitic eggs.Proximately,the context or experience of performing nest sanitation behavior might increase the detection or prime the removal of parasitic eggs,but evidence to date is limited.We tested incubation-stage nests of herring gulls Larus argentatus to ask whether nest sanitation increased parasitic egg rejection.In an initial set of 160 single-object experiments,small,red,blocky objects were usually rejected(18 of 20 nests),whereas life-sized,3D-printed herring gull eggs were not rejected whether red(0 of 20)or the olive-tan base color of herring gull eggs(0 of 20).Next,we simultaneously presented a red,3D-printed gull egg and a small,red block.These nests exhibited frequent nest sanitation(small,red block removed at 40 of 48 nests),but egg rejection remained uncommon(5 of those 40)and not significantly different from control nests(5 of 49)which received the parasitic egg but not the priming object.Thus,performance of nest sanitation did not shape individuals’responses to parasitism.Interestingly,parents were more likely to reject the parasitic egg when they were present as we approached the nest to add the experimental objects.Depending on the underlying mechanism,this could also be a case of experience creating variation in responses to parasitism.展开更多
Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demon...Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demonstrated in the treatment of concentrated black water and kitchen waste. The highest methane production of 48 L/person/day was achieved at the hydraulic retention time（HRT） of 7 days, while the other measures of performance at the HRT of 8.3 days were better than at the HRT of 7 or 10 days, achieving a methane production of 43 L/person/day, removal of total chemical oxygen demand（TCOD）of 89%, removal of soluble chemical oxygen demand（SCOD） of 92%, and conversion of chemical oxygen demand（COD） to methane of 71%. It is not recommended to decrease HRT lower than 7 days due to the instability of the initial period. The concentrations of volatile fatty acids（VFAs） in the IUSR were less than 10 mg/L, indicating that the anaerobic process was stable. Sludge bed development showed that sludge bed with high microbial activity was formed in the bottom and that the precipitation zone of effluents formed should preferably occupy 30% of the height of the IUSR. The effluents of the IUSR could be used for irrigation in agriculture in combination with a settling tank accompanied by disinfection to remove solids and pathogens.展开更多
Absence of wastewater and solid waste facilities impacts the quality of life of many people in developing countries. Implementation of these facilities will benefit public health, water quality, livelihoods and proper...Absence of wastewater and solid waste facilities impacts the quality of life of many people in developing countries. Implementation of these facilities will benefit public health, water quality, livelihoods and property value. Additional benefits may result from the potential recovery of valuable resources from wastewater and solid waste, such as compost, energy, phosphorus, plastics and paper. Improving water quality through implementation of wastewater and solid waste interventions requires, among others, an analysis of i) sources of pollution, ii) mitigating measures and resource recovery potentials and their effect on water quality and health, and iii) benefits and costs of interventions. We present an integrated approach to evaluate costs and benefits of domestic and industrial wastewater and solid waste interventions. To support a policy maker in formulating a cost and environmentally effective approach, we quantified the impact of these interventions on 1) water quality improvement, 2) resource recovery potential, and 3) monetized benefits versus costs. The integration of technical, hydrological, agronomical and socio-economic elements to derive these three tangible outputs in a joint approach is a novelty. The approach is demonstrated using the heavily polluted Indonesian Upper Citarum River in the Bandung region. Domestic interventions, applying simple (anaerobic filter) technologies, were economically most attractive with a benefit cost ratio (BCR) of 3.2, but could not reach target water quality standards. To approach the target water quality, both advanced domestic (nutrient removal systems) and industrial wastewater treatment interventions were required, leading to a BCR of 2. We showed that benefits from selling recovered resources represent here an additional driver for improving water quality and outweigh the additional costs for resource recovery facilities. While included benefits captured some of the major items, these may have been undervalued. Based on these findings, water quality interventions justify their costs and are socially and economically beneficial.展开更多
This research project investigates the current status of water supply, sanitation, and hygiene practices in Munshiganj District, Bangladesh. Data collection involved a structured questionnaire and a reconnaissance sur...This research project investigates the current status of water supply, sanitation, and hygiene practices in Munshiganj District, Bangladesh. Data collection involved a structured questionnaire and a reconnaissance survey. Findings reveal that 30% of individuals rely on surface water (hand-tube wells, rivers, and ponds), prioritized as canal > river > pond, while 70% depend on groundwater (subterranean electric motor, deep tube-well). Drinking water is generally sufficient, with 95% reporting adequacy throughout the year. About 45% use hand tube-well water, 28% use deep tube-well water, and 11% use supply tap water for various purposes. Bathing trends include underground water through electric motor > pond > hand tube-well water > river, while for cooking, the order is underground water through electric motor > pond > hand tube-well water > river. Toilet water supply ranks as supply tap water > hand tube-well water > deep tube-well water. Although sanitation awareness is high, some lack knowledge of good hygiene practices. After defecating, handwashing methods include soap, ash, soil, or water. Children’s waste disposal varies, with some discarding it in open areas. Approximately 40% suffer from diseases like Diarrhoea due to unsafe water, primarily affecting children and elders. Training exists, but a significant portion lacks sanitation education. Dry skin or exposure to cold water may cause temporary irritation. Local government involvement in sanitation efforts is less active compared to non-governmental organizations. Results emphasize the need to enhance community awareness of safe water supplies and sanitation practices. .展开更多
Wastewater treatment is a problem with much acuity in the city of Maradi in general, and particularly in the Communal District I of Maradi. It is for this reason that the present study was conducted which deals with w...Wastewater treatment is a problem with much acuity in the city of Maradi in general, and particularly in the Communal District I of Maradi. It is for this reason that the present study was conducted which deals with wastewater sanitation. The main objective of this study conducted through a survey is to investigate in the domestic wastewater sanitation in the Communal District I of Maradi city. Specifically, the study aims to estimate the amount of wastewater produced by households and to analyze the sanitation system at household and at district levels. The wastewater management practices in this district were assessed through a descriptive cross sectional study in which a total of 129 households were selected by sample distribution technique in the district neighborhoods and studied using interviewer and administered questionnaires at communal and household levels. The results of the study showed that the amount of domestic wastewater generated is quite large, about 32.27 m3 per person per day, and this comes from several sources including showers, laundry, dishwashing and income generating activities. The results also revealed that the unhealthy state of the Communal District I of Maradi is related to the absence of a wastewater treatment system, the methods and practices used in its management, and the population is also largely responsible for this unhealthy state and not willing to participate to a sanitation project.展开更多
Background: Environmental sanitation is a fundamental process that is a key public health intervention which is essential for social, economic and overall health development of communities. Objective: To determine Kno...Background: Environmental sanitation is a fundamental process that is a key public health intervention which is essential for social, economic and overall health development of communities. Objective: To determine Knowledge, Attitude and Practices of Environmental Sanitation in Semi-Urban Communities in Orlu, Imo State, Nigeria. Methods: A cross sectional descriptive design using a multistage random sampling technique to select 426 participants from households and business premises in semi-urban communities in Orlu Local Government Area of Imo State. Data was collected using a pretested, semi structured, interviewer administered questionnaire. Descriptive analyses were done with frequencies and summary statistics to assess the respondents’ knowledge, attitude and practices of environmental sanitation. Results: The results revealed that the mean age of the respondents’ was 37.0 ± 2.2 with a male to female ratio of 1:1.2. Despite high awareness about environmental sanitation (95.0%) reported among the respondents, proportion of them with good knowledge about environmental sanitation (22.9%), attitude (38.6%) and practice (20.8%) towards environmental sanitation was low. The mean quantity of waste generated per week per household or business premise was 14.1 ± 0.94 kg with a majority of the respondents (80.0%), not separating their waste before disposal. The commonest solid waste component generated was organic/perishable materials (74.8%) and the commonest disposal practice reported was open dumping (49.8%). Conclusion: A lot of attention is still required in the development of basic sanitation infrastructure and also, in the promotion of strategies or interventions that influence behavioural change towards environmental sanitation especially in developing countries like Nigeria.展开更多
In this study, a stratified survey sampling was used in order to broaden our knowledge on the management systems of household waste in the town of Kaya/Burkina Faso. Population study consists of households of the town...In this study, a stratified survey sampling was used in order to broaden our knowledge on the management systems of household waste in the town of Kaya/Burkina Faso. Population study consists of households of the town of Kaya. The sample size was fist determined using the sample size calculation formula. Then four (04) strata comprising the town of Kaya sectors that have a Health and Social Promotion Center (HSPC) have been considered. A random household selection method, used inside each stratum and a number of 468 households representative of the town’s population, was surveyed. We have addressed all solid and liquid waste management strategies in those four strata. For each stratum, waste disposal infrastructure, its management in the households and its impacts on the town’s environment and populations’ health were screened. Data collected are presented through descriptive statistics in mean of tables and graphs. Frequently reported diseases in the four HSPCs have been correlated with waste management and disposal methods in the town. Poor handling, evacuation and disposal of waste have numerous negatives impacts on the city’s environment such as proliferation of mosquitoes and flies, bad odors, visual pollution. These negatives impacts on the environment in turn have negatives impacts on the health of the city residents. Malaria appears the most encountered disease followed by Acute Respiratory Infection and Diarrhea. Suggestions aimed at improving waste management and the reduction of its deficiencies impacts on the health of the population has been made.展开更多
Availability of clean water and adequate sanitation facilities are of prime importance for limiting diarrheal diseases. We examined the spatial information on the groundwater quality and sanitation facilities of a vil...Availability of clean water and adequate sanitation facilities are of prime importance for limiting diarrheal diseases. We examined the spatial information on the groundwater quality and sanitation facilities of a village in southern India using Geographic Information System (GIS) tools. Place of residence, position of wells and latrines were mapped and well water samples were tested for microbial contamination (Total Coliform Counts (TCC), Fecal Coliform Counts (FCC) and Fecal Streptococcal Counts (FSC)). A well structured questionnaire was administered to 50 residents of the selected areas to elicit information on water collection, handling and storage. The location and distances of wells from latrines were determined using the Global Positioning System (GPS) device and a tape rule respectively. Data on 170 cases of various water-borne diseases were collected from primary health centers in the study area. Groundwater in the village was found to be microbiologically unfit for consumption. Analysis using direct observations supplemented by GIS maps revealed poor planning, design of the wells and improper siting of wells from latrines which were found to be the possible reasons of groundwater contamination. There was a significant difference in TCC between covered and uncovered wells (p < 0.01) but no significant differences were observed in the FCC, FSC and well covering. The mean distance (6.44 ± 2.37 m) of wells from the latrines in the study area was below the limit (15.24 m or 50 ft) set by United State Environmental Protection Agency (USEPA). TCC and FCC increased with a decrease in distance between the wells and latrines with a significance (p < 0.01). A moderate negative correlation (r = -0.593, r = -0.470) was ensued between the distance from latrine and coliform count. This study accentuates the need to set standards for the siting of wells from latrines and need for treatment.展开更多
Most water and sanitation projects in poor neighbourhood of urban Nigeria are executed through self-supply option. This is defined as an incremental improvement of WASH products e.g. water and sanitation structures by...Most water and sanitation projects in poor neighbourhood of urban Nigeria are executed through self-supply option. This is defined as an incremental improvement of WASH products e.g. water and sanitation structures by a household or small group of households which are financed by their own effort and investment. It is indeed a concept which complements conventional water supply and sanitation funded by government. The aim of this paper is, therefore, to investigate the extent of the use of innovative financing especially group saving approach to improve water and sanitation projects in Awka town, Nigeria. Towards achieving the aim, data were collected through questionnaires which were designed and administered on the respondents between January and April, 2016 and from other secondary sources. Data were analyzed using Principal Component Analysis and Component scores to establish the extent of the use of this option in the 9 component quarters of the town. Result shows that some quarters have perfected using the self-supply option while in others, it is yet to be widely accepted. It is finally recommended among others that the urban water policy as well as urban water safety plan should be revised to include the option as a way of improving domestic water supply and sanitation in the town.展开更多
文摘Objectives: To lay stress upon the importance of adequate water and sanitation in the prevention of cholera in Guinea. Methods: The data on deaths and cases of cholera in Guinea from 2000 to 2011 were downloaded from the WHO Official website. The data on deaths and cases of cholera outbreak which occurred in Guinea from 02 February to 15 October 2012 were collected from the Guinean Ministry of Public Health. The cholera index case is confirmed by a laboratory test. Cholera cases were defined as individuals over one year old who had had watery stools with or without vomiting. Cholera incidence and case fatality rates between different areas of cholera occurrence in the country over time were computed. Results: Over the overall 12-year period (2000-2012), the case fatality rate showed a somewhat sign of slight rising trend when the incidence rates increased rapidly. During the seven consecutive years of cholera outbreaks in Guinea, between 2003 and 2009, the most affected areas were Conakry, Dubreka, Coyah, Boffa, Forécariah, Guékédou, Dalaba and Télimélé. In 2012, Cholera outbreak resulted in an incidence rate of 23.23 per 10,000 population and a case fatality ratio (CFR) of approximately 1.8%. Cases and deaths were reported in 12 prefectures out of 34: Conakry, Coyah, Forecariah, Fria, Boffa, Dubréka, Boké, Mamou, Kindia, Kankan, Kerouané and Dabola. Conclusion: Cholera is an important health problem in Guinea. Any earnest attempts to improve water and sanitation alongside with promotion of good hygienic practices will likely ward off the threat of cholera in the country.
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.
基金supported by funds from the Arthur Vining Davis Foundation.
文摘Birds’behavioral response to brood parasitism can be influenced not only by evolution but also by context and individual experience.This could include nest sanitation,in which birds remove debris from their nests.Ultimately,nest sanitation behavior might be an evolutionary precursor to the rejection of parasitic eggs.Proximately,the context or experience of performing nest sanitation behavior might increase the detection or prime the removal of parasitic eggs,but evidence to date is limited.We tested incubation-stage nests of herring gulls Larus argentatus to ask whether nest sanitation increased parasitic egg rejection.In an initial set of 160 single-object experiments,small,red,blocky objects were usually rejected(18 of 20 nests),whereas life-sized,3D-printed herring gull eggs were not rejected whether red(0 of 20)or the olive-tan base color of herring gull eggs(0 of 20).Next,we simultaneously presented a red,3D-printed gull egg and a small,red block.These nests exhibited frequent nest sanitation(small,red block removed at 40 of 48 nests),but egg rejection remained uncommon(5 of those 40)and not significantly different from control nests(5 of 49)which received the parasitic egg but not the priming object.Thus,performance of nest sanitation did not shape individuals’responses to parasitism.Interestingly,parents were more likely to reject the parasitic egg when they were present as we approached the nest to add the experimental objects.Depending on the underlying mechanism,this could also be a case of experience creating variation in responses to parasitism.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China (No. 2011ZX07301-003)the National Key Research and Development Plan (No. 2016YFC0400806)
文摘Anaerobic treatment is the core technology for resource and energy recovery from source-separated domestic bio-wastes. The higher efficiency of an improved upflow solid reactor（IUSR） designed in this study was demonstrated in the treatment of concentrated black water and kitchen waste. The highest methane production of 48 L/person/day was achieved at the hydraulic retention time（HRT） of 7 days, while the other measures of performance at the HRT of 8.3 days were better than at the HRT of 7 or 10 days, achieving a methane production of 43 L/person/day, removal of total chemical oxygen demand（TCOD）of 89%, removal of soluble chemical oxygen demand（SCOD） of 92%, and conversion of chemical oxygen demand（COD） to methane of 71%. It is not recommended to decrease HRT lower than 7 days due to the instability of the initial period. The concentrations of volatile fatty acids（VFAs） in the IUSR were less than 10 mg/L, indicating that the anaerobic process was stable. Sludge bed development showed that sludge bed with high microbial activity was formed in the bottom and that the precipitation zone of effluents formed should preferably occupy 30% of the height of the IUSR. The effluents of the IUSR could be used for irrigation in agriculture in combination with a settling tank accompanied by disinfection to remove solids and pathogens.
文摘Absence of wastewater and solid waste facilities impacts the quality of life of many people in developing countries. Implementation of these facilities will benefit public health, water quality, livelihoods and property value. Additional benefits may result from the potential recovery of valuable resources from wastewater and solid waste, such as compost, energy, phosphorus, plastics and paper. Improving water quality through implementation of wastewater and solid waste interventions requires, among others, an analysis of i) sources of pollution, ii) mitigating measures and resource recovery potentials and their effect on water quality and health, and iii) benefits and costs of interventions. We present an integrated approach to evaluate costs and benefits of domestic and industrial wastewater and solid waste interventions. To support a policy maker in formulating a cost and environmentally effective approach, we quantified the impact of these interventions on 1) water quality improvement, 2) resource recovery potential, and 3) monetized benefits versus costs. The integration of technical, hydrological, agronomical and socio-economic elements to derive these three tangible outputs in a joint approach is a novelty. The approach is demonstrated using the heavily polluted Indonesian Upper Citarum River in the Bandung region. Domestic interventions, applying simple (anaerobic filter) technologies, were economically most attractive with a benefit cost ratio (BCR) of 3.2, but could not reach target water quality standards. To approach the target water quality, both advanced domestic (nutrient removal systems) and industrial wastewater treatment interventions were required, leading to a BCR of 2. We showed that benefits from selling recovered resources represent here an additional driver for improving water quality and outweigh the additional costs for resource recovery facilities. While included benefits captured some of the major items, these may have been undervalued. Based on these findings, water quality interventions justify their costs and are socially and economically beneficial.
文摘This research project investigates the current status of water supply, sanitation, and hygiene practices in Munshiganj District, Bangladesh. Data collection involved a structured questionnaire and a reconnaissance survey. Findings reveal that 30% of individuals rely on surface water (hand-tube wells, rivers, and ponds), prioritized as canal > river > pond, while 70% depend on groundwater (subterranean electric motor, deep tube-well). Drinking water is generally sufficient, with 95% reporting adequacy throughout the year. About 45% use hand tube-well water, 28% use deep tube-well water, and 11% use supply tap water for various purposes. Bathing trends include underground water through electric motor > pond > hand tube-well water > river, while for cooking, the order is underground water through electric motor > pond > hand tube-well water > river. Toilet water supply ranks as supply tap water > hand tube-well water > deep tube-well water. Although sanitation awareness is high, some lack knowledge of good hygiene practices. After defecating, handwashing methods include soap, ash, soil, or water. Children’s waste disposal varies, with some discarding it in open areas. Approximately 40% suffer from diseases like Diarrhoea due to unsafe water, primarily affecting children and elders. Training exists, but a significant portion lacks sanitation education. Dry skin or exposure to cold water may cause temporary irritation. Local government involvement in sanitation efforts is less active compared to non-governmental organizations. Results emphasize the need to enhance community awareness of safe water supplies and sanitation practices. .
文摘Wastewater treatment is a problem with much acuity in the city of Maradi in general, and particularly in the Communal District I of Maradi. It is for this reason that the present study was conducted which deals with wastewater sanitation. The main objective of this study conducted through a survey is to investigate in the domestic wastewater sanitation in the Communal District I of Maradi city. Specifically, the study aims to estimate the amount of wastewater produced by households and to analyze the sanitation system at household and at district levels. The wastewater management practices in this district were assessed through a descriptive cross sectional study in which a total of 129 households were selected by sample distribution technique in the district neighborhoods and studied using interviewer and administered questionnaires at communal and household levels. The results of the study showed that the amount of domestic wastewater generated is quite large, about 32.27 m3 per person per day, and this comes from several sources including showers, laundry, dishwashing and income generating activities. The results also revealed that the unhealthy state of the Communal District I of Maradi is related to the absence of a wastewater treatment system, the methods and practices used in its management, and the population is also largely responsible for this unhealthy state and not willing to participate to a sanitation project.
文摘Background: Environmental sanitation is a fundamental process that is a key public health intervention which is essential for social, economic and overall health development of communities. Objective: To determine Knowledge, Attitude and Practices of Environmental Sanitation in Semi-Urban Communities in Orlu, Imo State, Nigeria. Methods: A cross sectional descriptive design using a multistage random sampling technique to select 426 participants from households and business premises in semi-urban communities in Orlu Local Government Area of Imo State. Data was collected using a pretested, semi structured, interviewer administered questionnaire. Descriptive analyses were done with frequencies and summary statistics to assess the respondents’ knowledge, attitude and practices of environmental sanitation. Results: The results revealed that the mean age of the respondents’ was 37.0 ± 2.2 with a male to female ratio of 1:1.2. Despite high awareness about environmental sanitation (95.0%) reported among the respondents, proportion of them with good knowledge about environmental sanitation (22.9%), attitude (38.6%) and practice (20.8%) towards environmental sanitation was low. The mean quantity of waste generated per week per household or business premise was 14.1 ± 0.94 kg with a majority of the respondents (80.0%), not separating their waste before disposal. The commonest solid waste component generated was organic/perishable materials (74.8%) and the commonest disposal practice reported was open dumping (49.8%). Conclusion: A lot of attention is still required in the development of basic sanitation infrastructure and also, in the promotion of strategies or interventions that influence behavioural change towards environmental sanitation especially in developing countries like Nigeria.
文摘In this study, a stratified survey sampling was used in order to broaden our knowledge on the management systems of household waste in the town of Kaya/Burkina Faso. Population study consists of households of the town of Kaya. The sample size was fist determined using the sample size calculation formula. Then four (04) strata comprising the town of Kaya sectors that have a Health and Social Promotion Center (HSPC) have been considered. A random household selection method, used inside each stratum and a number of 468 households representative of the town’s population, was surveyed. We have addressed all solid and liquid waste management strategies in those four strata. For each stratum, waste disposal infrastructure, its management in the households and its impacts on the town’s environment and populations’ health were screened. Data collected are presented through descriptive statistics in mean of tables and graphs. Frequently reported diseases in the four HSPCs have been correlated with waste management and disposal methods in the town. Poor handling, evacuation and disposal of waste have numerous negatives impacts on the city’s environment such as proliferation of mosquitoes and flies, bad odors, visual pollution. These negatives impacts on the environment in turn have negatives impacts on the health of the city residents. Malaria appears the most encountered disease followed by Acute Respiratory Infection and Diarrhea. Suggestions aimed at improving waste management and the reduction of its deficiencies impacts on the health of the population has been made.
文摘Availability of clean water and adequate sanitation facilities are of prime importance for limiting diarrheal diseases. We examined the spatial information on the groundwater quality and sanitation facilities of a village in southern India using Geographic Information System (GIS) tools. Place of residence, position of wells and latrines were mapped and well water samples were tested for microbial contamination (Total Coliform Counts (TCC), Fecal Coliform Counts (FCC) and Fecal Streptococcal Counts (FSC)). A well structured questionnaire was administered to 50 residents of the selected areas to elicit information on water collection, handling and storage. The location and distances of wells from latrines were determined using the Global Positioning System (GPS) device and a tape rule respectively. Data on 170 cases of various water-borne diseases were collected from primary health centers in the study area. Groundwater in the village was found to be microbiologically unfit for consumption. Analysis using direct observations supplemented by GIS maps revealed poor planning, design of the wells and improper siting of wells from latrines which were found to be the possible reasons of groundwater contamination. There was a significant difference in TCC between covered and uncovered wells (p < 0.01) but no significant differences were observed in the FCC, FSC and well covering. The mean distance (6.44 ± 2.37 m) of wells from the latrines in the study area was below the limit (15.24 m or 50 ft) set by United State Environmental Protection Agency (USEPA). TCC and FCC increased with a decrease in distance between the wells and latrines with a significance (p < 0.01). A moderate negative correlation (r = -0.593, r = -0.470) was ensued between the distance from latrine and coliform count. This study accentuates the need to set standards for the siting of wells from latrines and need for treatment.
文摘Most water and sanitation projects in poor neighbourhood of urban Nigeria are executed through self-supply option. This is defined as an incremental improvement of WASH products e.g. water and sanitation structures by a household or small group of households which are financed by their own effort and investment. It is indeed a concept which complements conventional water supply and sanitation funded by government. The aim of this paper is, therefore, to investigate the extent of the use of innovative financing especially group saving approach to improve water and sanitation projects in Awka town, Nigeria. Towards achieving the aim, data were collected through questionnaires which were designed and administered on the respondents between January and April, 2016 and from other secondary sources. Data were analyzed using Principal Component Analysis and Component scores to establish the extent of the use of this option in the 9 component quarters of the town. Result shows that some quarters have perfected using the self-supply option while in others, it is yet to be widely accepted. It is finally recommended among others that the urban water policy as well as urban water safety plan should be revised to include the option as a way of improving domestic water supply and sanitation in the town.
