<span style="font-family:Verdana;">We are confronting a new threat in the prevalence of antibiotic-resistant bacteria followed by epidemic spread in aquatic environments in metropolitan areas because d...<span style="font-family:Verdana;">We are confronting a new threat in the prevalence of antibiotic-resistant bacteria followed by epidemic spread in aquatic environments in metropolitan areas because damage from river floods is increasing remarkably in Japan due to global extreme weather. The sewer penetration rate is about 100% in Tokyo and reclaimed water from sewage treatment plants accounts for over 50% of all water in both the down- and mid-stream areas of local rivers. The water quality of these rivers, which contain microflora, seems to be seriously affected by reclaimed water. In this study, we collected water samples on July 17, 2018 and examined the behavior of antibiotic-resistant fecal coliforms in the stream of a sewage treatment plant in Tokyo. Extended-spectrum </span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-lactamase (ESBL)</span><span style="font-family:Verdana;">-producing fecal coliforms with encoding genes were found;the CTX-M-1, CTX-M-9, TEM, and SHV groups were found to have survived in the final effluent to the river after sterilization with sodium hypochlorite.展开更多
Through investigating ten recreational marine beaches in China, we aimed to detect the occurrence of human enteric viruses in coastal bathing beaches and find a correlationship, if any, between the presence of enteric...Through investigating ten recreational marine beaches in China, we aimed to detect the occurrence of human enteric viruses in coastal bathing beaches and find a correlationship, if any, between the presence of enteric viruses in surface seawater and the concentrations of fecal coliforms, the conventional indicator of fecal pollution. In this study, twenty seawater samples were assayed for fecal coliforms and human pathogenic enteric viruses (hepatitis A viruses, rotaviruses, polioviruses) analysis. Enteric viruses were detected by RT-PCR, in 20 sample sites, 5%, 40%, 40% were positive for the presence of human hepatitis A viruses, rotaviruses, polioviruses, respectively. Seven of 20 sites are suffering from severe fecal contamination, based on traditional plate counts of fecal coliform outnumbering the established thresholds for recreation. Additionally, statistical analysis presented that no correlation was found between bacterial indicators and viruses in surface seawaters. The data confirmed that indicator bacteria in water are not reflective of the presence of enteric viruses in marine waters. Thus, current recreational water quality standards of both bacterial and viral indices should be reevaluated.展开更多
Fecal Coliform Bacteria (FCB) of marine waters was monitored in Luoyuan Bay from January, 2003 to December, 2005. The results showed that number of FCB in marine water samples ranged from no detection ( 〈2 cfu/100...Fecal Coliform Bacteria (FCB) of marine waters was monitored in Luoyuan Bay from January, 2003 to December, 2005. The results showed that number of FCB in marine water samples ranged from no detection ( 〈2 cfu/100 mL) to 540 cfu/100 mL in Luoyuan Bay. Values of FCB during August to October were significantly higher than those during January to April during three year period. Monthly changes of FCB values at each year period were mainly due to monthly precipitation. In addition, compared with FCB values in difference sample sites, values of FCB in Bay-heed were significantly higher than those in middle of bay and Bay-mouth, Luoyuan Bay. However, values of FCB in Bay-mouth were significantly less than those in middle of bay. The ratios to the par of FCB in 2003, 2004, and 2005 years were 100%, 98.0%, and 97.9%, respectively. Therefore, we considered that the pollution of FCB of surface marine water in Luoyuan Bay was not serious.展开更多
Introduction: This study was carried out to assess the quality of sheep meat sold to consumers in Saaba municipality. Methods: A preliminary survey consisted of assessing hygiene and sampling meat in butchers’ stores...Introduction: This study was carried out to assess the quality of sheep meat sold to consumers in Saaba municipality. Methods: A preliminary survey consisted of assessing hygiene and sampling meat in butchers’ stores. To achieve this, 100 sales outlets were surveyed for their hygiene conditions. 25 mutton meat samples were sampled in the three villages in Saaba district and analyzed using conventional microbiological techniques. The analysis consisted of determining the microbiological characteristics. Results: According to the results of this study, 100% of the butchers surveyed were men of the region. Among these men, 13% had secondary education, 46% had primary education and 41% were illiterate. Of the 100 retail outlets visited, 96% of the sellers were unaware of the hygiene rules and the dangers of microorganisms. The microbiological analysis of the samples revealed that 100% of the meat was of unsatisfactory microbiological quality. The average contamination rate by total aerobic mesophilic flora, total coliforms, Staphylococcus aureus and yeasts and molds was 8.93 × 106, 3.12 × 105, 3.69 × 106, and 6.74 × 103 CFU/g respectively. No Salmonella strain was detected in any of the samples analyzed. Conclusion: Our results pointed out the unsatisfactory safety quality of the sheep meat sold in the sheep meat and good hygiene practices.展开更多
In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed...In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.展开更多
Background: The high doses of zinc oxide(Zn O) administered orally to piglets for the prevention of diarrhea and increase of growth rate can contaminate pig farms and the surrounding environment. Therefore, there is a...Background: The high doses of zinc oxide(Zn O) administered orally to piglets for the prevention of diarrhea and increase of growth rate can contaminate pig farms and the surrounding environment. Therefore, there is a need to find a replacement of high doses of dietary Zn O with an equally effective alternative. In the present study, the effect of two formulations of zinc phosphate-based nanoparticles(Zn A and Zn C NPs) on growth performance,intestinal microbiota, antioxidant status, and intestinal and liver morphology was evaluated. A total of 100 weaned piglets were randomly divided into 10 equal groups with the base diet(control) or the base diet supplemented with Zn A, Zn C, or Zn O at concentrations 500, 1000, and 2000 mg Zn per kilogram of diet. Supplements were given to animals for 10 days. Fecal samples were collected on day 0, 5, 10 and 20. At the end of the treatment(day 10),three piglets from each group were sacrificed and analyzed.Results: Comparing to that of control, the significantly higher piglet weight gain was observed in all piglet groups fed with Zn A(P < 0.05). Differences in the total aerobic bacteria and coliform counts in piglet feces after NPs supplementation compared to that of control and Zn O groups were also found(P < 0.05). The majority of aerobic culturable bacteria from the feces represented Escherichia(28.57–47.62%), Enterococcus(3.85–35.71%), and Streptococcus(3.70–42.31%) spp. A total of 542 Escherichia coli isolates were screened for the virulence genes STa,STb, Stx2, F4, and F18. The substantial occurrence of E. coli virulence factors was found on day 5, mainly in fimbrillary antigen and thermostable toxins, except for piglets fed by Zn C. Zn treatment decreased Zn blood levels in piglets fed with Zn O and Zn A(500 mg/kg) and increased in Zn C(2000 mg/kg) compared to that of control(P < 0.05). The antioxidant status of piglets was affected only by Zn A. While some changes in the liver and the intestinal morphology of piglets with NPs were observed, none were serious as reflected by the normal health status and increased weigh gain performance.Conclusions: Our results indicate that Zn A NPs have a positive effect on the piglet growth performance even at the lowest concentration. The prevalence of E. coli virulence factors was lowest in pigs supplemented with Zn C.Zinc phosphate-based nanoparticles may be an effective alternative to Zn O.展开更多
Fecal microorganisms, which are indicators or pathogens, have an optimum growth in the specific conditions of the internal environment animal or human. Therefore, when issued by a host, they result in sudden and drast...Fecal microorganisms, which are indicators or pathogens, have an optimum growth in the specific conditions of the internal environment animal or human. Therefore, when issued by a host, they result in sudden and drastic changes in the environment. This study aims at bacteriological characterization of the effluent from the provincial hospital in Sidi Kacem. And it shows that the effluent from the hospital contributing to non-regulatory standards ultimately reaches the environment (river wadi floor, animal, vegetable...). The results of bacteriological analyses (Total Coliforms, Fecal Coliforms) about sewage from the provincial hospital depending on the day of rest and work in the city of Sidi Kacem are presented with means respectively 557 × 104 and 328 × 104 in the rest and working days 555 × 104, 342 × 104 and the much higher maximum working days from the day of rest are 64 × 105 and 42 × 105. The results obtained show that the rate of bacteria (CT-CF) exceeds standards recommended by CNS (1994) and WHO (1996, 1997). These results have adverse effects on human life, animal, environment and ecosystem in general.展开更多
In 2014 we began the first systematic study of water quality, specifically fecal contamination of drinking water in the Khumbu Valley, Sagarmatha National Park (SNP, Mt. Everest region), Nepal. Our goal was to identif...In 2014 we began the first systematic study of water quality, specifically fecal contamination of drinking water in the Khumbu Valley, Sagarmatha National Park (SNP, Mt. Everest region), Nepal. Our goal was to identify coliform bacteria and E. coli in drinking water and groundwater-fed springs to generate a data set that will function as a base for potable water supplies and further monitoring. Sampling occurred in May (pre-monsoon summer) and early November (post-monsoon early winter) 2014. Sample sites were selected based on proximity to villages and primary use as a drinking water source. Overall, the data presented a predictable correlation between fecal contamination and both elevation and increasing population/tourist traffic. Drinking water within the study area met current World Health Organization drinking water standards for the physical properties of temperature (2.8°C - 13°C), pH (5.27 - 7.24), conductivity (14.5 - 133 mS) and TDS (7.24 - 65.5 ppm). Samples from the more populated, lower altitude areas had higher levels of E. coli. Samples collected and analyzed in May (pre-monsoon summer) had a higher level of E. coli and coliform bacteria than samples collected in November (post-monsoon early winter) suggesting a seasonal dependence overlaid on the population signature. Surface water typically had higher E. coli values than groundwater-fed springs. Temperature, total dissolved solids and conductivity generally decreased with increasing elevation, whereas pH increased with increasing elevation. There appears to be significant presence of fecal contamination of water sources due to a combination of tourism, elevation and seasons.展开更多
<span style="font-family:Verdana;">Rural communities in sub</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span>...<span style="font-family:Verdana;">Rural communities in sub</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span><span style="font-family:Verdana;">Saharan Africa (SSA) are always faced with the challenge of securing safe water for beneficial uses. Most communities lack a centralized water supply system and, thus, each residence utilizes the treatment method that they can afford. This study evaluated three treatment methods for drinking water in the Njala University and Mokonde communities in southern Sierra Leone. In the perceived natural treatment, residents in the Mokonde community believe that groundwater has been purified by the soil media and, hence, does not require further treatment. In the conventional treatment, the Njala University Water Works use sand filtration and chlorine disinfection to treat water from the Taia River. The third treatment method, first flush diversion, was introduced by Njala University researchers in 2014. We studied the populations of coliform bacteria and </span><i><span style="font-family:Verdana;">E. coli</span></i><span style="font-family:Verdana;"> in untreated and treated water samples to determine if each of the treatment methods supported the beneficial use of drinking. This study concludes that the natural filtration does not remove pathogens in the well water. Even though the first flush and conventional treatments were efficient in reducing microbial populations in the water, the World Health Organization’s 100% removal guideline was not achieved most of the time. Therefore, all three treatment methods did not support the beneficial use of drinking. Further treatment was needed to render the water potable.展开更多
Water and its importance cannot be understated.Its greatest value lies in its ability and capacity to provide biological and environmental services.Water quality is an essential parameter to be studied when the overal...Water and its importance cannot be understated.Its greatest value lies in its ability and capacity to provide biological and environmental services.Water quality is an essential parameter to be studied when the overall focus is sustainable development keeping mankind at a focal point.The study assessed the water quality and its suitability for drinking purposes in most areas of Padada Watershed.In this study,nine identified sampling points were analyzed for different physico-chemical parameters such as turbidity,BOD(Biological Oxygen Demand),TSS(Total Solid Suspended),fecal coliform,pH,temperature,DO(Dissolved Oxygen),and SC(Specific Conductivity).Results found turbidity range from 0.74-19.7 NTU;BOD range from 0.04-2.2 mg/L;TSS range from 1-411 mg/L;fecal coliform range from<1.8-160,000 MPN/100mL.The temperature value ranges from 24.8-31.9°C;pH value ranges from 7.05-7.92;SC ranges from 119.7-551μS/cm while DO range from 4.87-8.14 mg/L.Moreover,the results revealed that most sampling sites exceeded the permissible limits.The highest concentration of fecal coliform indicates contamination which may cause possible human health infection.Thus,the water of Padada River Watershed is not potable for drinking and it is recommended to take beneficial steps to prevent adverse health effects to the community.展开更多
The dynamics of the composition and antibiotic resistance of the fecal coliform bacteria(FCB)in a typical wastewater treatment plant(WWTP)were investigated concerning the seasonal changes.Results showed that WWTP coul...The dynamics of the composition and antibiotic resistance of the fecal coliform bacteria(FCB)in a typical wastewater treatment plant(WWTP)were investigated concerning the seasonal changes.Results showed that WWTP could remove the FCB concentration by 3∼5 logs within the effluent of 10^(4)∼10^(5)CFU/L,but the antibiotic resistant rate of FCB species increased significantly after WWTP.The dominant FCB changed from Escherichia coli in the influent(∼73.0%)to Klebsiella pneumoniae in the effluent(∼53.3%)after WWTP,where the Escherichia coli was removed the most,while Klebsiella pneumoniae was the most persistent.The secondary tank removed the most of FCB(by 3∼4 logs)compared to other processes,but increased all the concerned antibiotic resistant rate.The potential super bugs of FCB community showing resistance to all the target antibiotics were selected in the biological treatment unit of WWTP.The FCB showed the highest multiple antibiotic resistance(92.9%)in total which even increased to 100%in the effluent.Klebsiella has the highest antibiotic resistant rate in FCB,with a multiple antibiotic resistance rate of 98.4%.These indicated that the Klebsiella pneumoniae not just Escherichia coli should be specially emphasized after WWTP concerning the health risk associated with FCB community.展开更多
文摘<span style="font-family:Verdana;">We are confronting a new threat in the prevalence of antibiotic-resistant bacteria followed by epidemic spread in aquatic environments in metropolitan areas because damage from river floods is increasing remarkably in Japan due to global extreme weather. The sewer penetration rate is about 100% in Tokyo and reclaimed water from sewage treatment plants accounts for over 50% of all water in both the down- and mid-stream areas of local rivers. The water quality of these rivers, which contain microflora, seems to be seriously affected by reclaimed water. In this study, we collected water samples on July 17, 2018 and examined the behavior of antibiotic-resistant fecal coliforms in the stream of a sewage treatment plant in Tokyo. Extended-spectrum </span><i><span style="font-family:Verdana;">β</span></i><span style="font-family:Verdana;">-lactamase (ESBL)</span><span style="font-family:Verdana;">-producing fecal coliforms with encoding genes were found;the CTX-M-1, CTX-M-9, TEM, and SHV groups were found to have survived in the final effluent to the river after sterilization with sodium hypochlorite.
基金provided by the National High Technology Research and Development Program("863"Program)of China,grant no.2006AA09Z162the National Key Scientific and Technological Project,grant no.908-01-ZH3
文摘Through investigating ten recreational marine beaches in China, we aimed to detect the occurrence of human enteric viruses in coastal bathing beaches and find a correlationship, if any, between the presence of enteric viruses in surface seawater and the concentrations of fecal coliforms, the conventional indicator of fecal pollution. In this study, twenty seawater samples were assayed for fecal coliforms and human pathogenic enteric viruses (hepatitis A viruses, rotaviruses, polioviruses) analysis. Enteric viruses were detected by RT-PCR, in 20 sample sites, 5%, 40%, 40% were positive for the presence of human hepatitis A viruses, rotaviruses, polioviruses, respectively. Seven of 20 sites are suffering from severe fecal contamination, based on traditional plate counts of fecal coliform outnumbering the established thresholds for recreation. Additionally, statistical analysis presented that no correlation was found between bacterial indicators and viruses in surface seawaters. The data confirmed that indicator bacteria in water are not reflective of the presence of enteric viruses in marine waters. Thus, current recreational water quality standards of both bacterial and viral indices should be reevaluated.
文摘Fecal Coliform Bacteria (FCB) of marine waters was monitored in Luoyuan Bay from January, 2003 to December, 2005. The results showed that number of FCB in marine water samples ranged from no detection ( 〈2 cfu/100 mL) to 540 cfu/100 mL in Luoyuan Bay. Values of FCB during August to October were significantly higher than those during January to April during three year period. Monthly changes of FCB values at each year period were mainly due to monthly precipitation. In addition, compared with FCB values in difference sample sites, values of FCB in Bay-heed were significantly higher than those in middle of bay and Bay-mouth, Luoyuan Bay. However, values of FCB in Bay-mouth were significantly less than those in middle of bay. The ratios to the par of FCB in 2003, 2004, and 2005 years were 100%, 98.0%, and 97.9%, respectively. Therefore, we considered that the pollution of FCB of surface marine water in Luoyuan Bay was not serious.
文摘Introduction: This study was carried out to assess the quality of sheep meat sold to consumers in Saaba municipality. Methods: A preliminary survey consisted of assessing hygiene and sampling meat in butchers’ stores. To achieve this, 100 sales outlets were surveyed for their hygiene conditions. 25 mutton meat samples were sampled in the three villages in Saaba district and analyzed using conventional microbiological techniques. The analysis consisted of determining the microbiological characteristics. Results: According to the results of this study, 100% of the butchers surveyed were men of the region. Among these men, 13% had secondary education, 46% had primary education and 41% were illiterate. Of the 100 retail outlets visited, 96% of the sellers were unaware of the hygiene rules and the dangers of microorganisms. The microbiological analysis of the samples revealed that 100% of the meat was of unsatisfactory microbiological quality. The average contamination rate by total aerobic mesophilic flora, total coliforms, Staphylococcus aureus and yeasts and molds was 8.93 × 106, 3.12 × 105, 3.69 × 106, and 6.74 × 103 CFU/g respectively. No Salmonella strain was detected in any of the samples analyzed. Conclusion: Our results pointed out the unsatisfactory safety quality of the sheep meat sold in the sheep meat and good hygiene practices.
文摘In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.
基金Financial support from NAZV QK1720349 “Nanoparticles zinc as an alternative to antibiotics in pigs”ERDF “Multidisciplinary research to increase application potential of nanomaterials in agricultural practice”(No.CZ.02.1.01/0.0/0.0/16_025/0007314)+1 种基金also supported by Internal Grant Agency of Mendel University in Brno(AF-IGA2019-TP006)by CEITEC 2020 (LQ1601)。
文摘Background: The high doses of zinc oxide(Zn O) administered orally to piglets for the prevention of diarrhea and increase of growth rate can contaminate pig farms and the surrounding environment. Therefore, there is a need to find a replacement of high doses of dietary Zn O with an equally effective alternative. In the present study, the effect of two formulations of zinc phosphate-based nanoparticles(Zn A and Zn C NPs) on growth performance,intestinal microbiota, antioxidant status, and intestinal and liver morphology was evaluated. A total of 100 weaned piglets were randomly divided into 10 equal groups with the base diet(control) or the base diet supplemented with Zn A, Zn C, or Zn O at concentrations 500, 1000, and 2000 mg Zn per kilogram of diet. Supplements were given to animals for 10 days. Fecal samples were collected on day 0, 5, 10 and 20. At the end of the treatment(day 10),three piglets from each group were sacrificed and analyzed.Results: Comparing to that of control, the significantly higher piglet weight gain was observed in all piglet groups fed with Zn A(P < 0.05). Differences in the total aerobic bacteria and coliform counts in piglet feces after NPs supplementation compared to that of control and Zn O groups were also found(P < 0.05). The majority of aerobic culturable bacteria from the feces represented Escherichia(28.57–47.62%), Enterococcus(3.85–35.71%), and Streptococcus(3.70–42.31%) spp. A total of 542 Escherichia coli isolates were screened for the virulence genes STa,STb, Stx2, F4, and F18. The substantial occurrence of E. coli virulence factors was found on day 5, mainly in fimbrillary antigen and thermostable toxins, except for piglets fed by Zn C. Zn treatment decreased Zn blood levels in piglets fed with Zn O and Zn A(500 mg/kg) and increased in Zn C(2000 mg/kg) compared to that of control(P < 0.05). The antioxidant status of piglets was affected only by Zn A. While some changes in the liver and the intestinal morphology of piglets with NPs were observed, none were serious as reflected by the normal health status and increased weigh gain performance.Conclusions: Our results indicate that Zn A NPs have a positive effect on the piglet growth performance even at the lowest concentration. The prevalence of E. coli virulence factors was lowest in pigs supplemented with Zn C.Zinc phosphate-based nanoparticles may be an effective alternative to Zn O.
文摘Fecal microorganisms, which are indicators or pathogens, have an optimum growth in the specific conditions of the internal environment animal or human. Therefore, when issued by a host, they result in sudden and drastic changes in the environment. This study aims at bacteriological characterization of the effluent from the provincial hospital in Sidi Kacem. And it shows that the effluent from the hospital contributing to non-regulatory standards ultimately reaches the environment (river wadi floor, animal, vegetable...). The results of bacteriological analyses (Total Coliforms, Fecal Coliforms) about sewage from the provincial hospital depending on the day of rest and work in the city of Sidi Kacem are presented with means respectively 557 × 104 and 328 × 104 in the rest and working days 555 × 104, 342 × 104 and the much higher maximum working days from the day of rest are 64 × 105 and 42 × 105. The results obtained show that the rate of bacteria (CT-CF) exceeds standards recommended by CNS (1994) and WHO (1996, 1997). These results have adverse effects on human life, animal, environment and ecosystem in general.
文摘In 2014 we began the first systematic study of water quality, specifically fecal contamination of drinking water in the Khumbu Valley, Sagarmatha National Park (SNP, Mt. Everest region), Nepal. Our goal was to identify coliform bacteria and E. coli in drinking water and groundwater-fed springs to generate a data set that will function as a base for potable water supplies and further monitoring. Sampling occurred in May (pre-monsoon summer) and early November (post-monsoon early winter) 2014. Sample sites were selected based on proximity to villages and primary use as a drinking water source. Overall, the data presented a predictable correlation between fecal contamination and both elevation and increasing population/tourist traffic. Drinking water within the study area met current World Health Organization drinking water standards for the physical properties of temperature (2.8°C - 13°C), pH (5.27 - 7.24), conductivity (14.5 - 133 mS) and TDS (7.24 - 65.5 ppm). Samples from the more populated, lower altitude areas had higher levels of E. coli. Samples collected and analyzed in May (pre-monsoon summer) had a higher level of E. coli and coliform bacteria than samples collected in November (post-monsoon early winter) suggesting a seasonal dependence overlaid on the population signature. Surface water typically had higher E. coli values than groundwater-fed springs. Temperature, total dissolved solids and conductivity generally decreased with increasing elevation, whereas pH increased with increasing elevation. There appears to be significant presence of fecal contamination of water sources due to a combination of tourism, elevation and seasons.
文摘<span style="font-family:Verdana;">Rural communities in sub</span><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span><span style="font-family:Verdana;">Saharan Africa (SSA) are always faced with the challenge of securing safe water for beneficial uses. Most communities lack a centralized water supply system and, thus, each residence utilizes the treatment method that they can afford. This study evaluated three treatment methods for drinking water in the Njala University and Mokonde communities in southern Sierra Leone. In the perceived natural treatment, residents in the Mokonde community believe that groundwater has been purified by the soil media and, hence, does not require further treatment. In the conventional treatment, the Njala University Water Works use sand filtration and chlorine disinfection to treat water from the Taia River. The third treatment method, first flush diversion, was introduced by Njala University researchers in 2014. We studied the populations of coliform bacteria and </span><i><span style="font-family:Verdana;">E. coli</span></i><span style="font-family:Verdana;"> in untreated and treated water samples to determine if each of the treatment methods supported the beneficial use of drinking. This study concludes that the natural filtration does not remove pathogens in the well water. Even though the first flush and conventional treatments were efficient in reducing microbial populations in the water, the World Health Organization’s 100% removal guideline was not achieved most of the time. Therefore, all three treatment methods did not support the beneficial use of drinking. Further treatment was needed to render the water potable.
文摘Water and its importance cannot be understated.Its greatest value lies in its ability and capacity to provide biological and environmental services.Water quality is an essential parameter to be studied when the overall focus is sustainable development keeping mankind at a focal point.The study assessed the water quality and its suitability for drinking purposes in most areas of Padada Watershed.In this study,nine identified sampling points were analyzed for different physico-chemical parameters such as turbidity,BOD(Biological Oxygen Demand),TSS(Total Solid Suspended),fecal coliform,pH,temperature,DO(Dissolved Oxygen),and SC(Specific Conductivity).Results found turbidity range from 0.74-19.7 NTU;BOD range from 0.04-2.2 mg/L;TSS range from 1-411 mg/L;fecal coliform range from<1.8-160,000 MPN/100mL.The temperature value ranges from 24.8-31.9°C;pH value ranges from 7.05-7.92;SC ranges from 119.7-551μS/cm while DO range from 4.87-8.14 mg/L.Moreover,the results revealed that most sampling sites exceeded the permissible limits.The highest concentration of fecal coliform indicates contamination which may cause possible human health infection.Thus,the water of Padada River Watershed is not potable for drinking and it is recommended to take beneficial steps to prevent adverse health effects to the community.
基金supported by the Guangxi Key Research and Development Program(No.AB21196036)the Major science and Technology Project of Nanning(No.20213121)the State Key Joint Laboratory of Environmental Simulation and Pollution Control of China(No.22Z02ESPCR).
文摘The dynamics of the composition and antibiotic resistance of the fecal coliform bacteria(FCB)in a typical wastewater treatment plant(WWTP)were investigated concerning the seasonal changes.Results showed that WWTP could remove the FCB concentration by 3∼5 logs within the effluent of 10^(4)∼10^(5)CFU/L,but the antibiotic resistant rate of FCB species increased significantly after WWTP.The dominant FCB changed from Escherichia coli in the influent(∼73.0%)to Klebsiella pneumoniae in the effluent(∼53.3%)after WWTP,where the Escherichia coli was removed the most,while Klebsiella pneumoniae was the most persistent.The secondary tank removed the most of FCB(by 3∼4 logs)compared to other processes,but increased all the concerned antibiotic resistant rate.The potential super bugs of FCB community showing resistance to all the target antibiotics were selected in the biological treatment unit of WWTP.The FCB showed the highest multiple antibiotic resistance(92.9%)in total which even increased to 100%in the effluent.Klebsiella has the highest antibiotic resistant rate in FCB,with a multiple antibiotic resistance rate of 98.4%.These indicated that the Klebsiella pneumoniae not just Escherichia coli should be specially emphasized after WWTP concerning the health risk associated with FCB community.