Behaviour of pathogenic E. coli and Salmonella enteritidis in small domestic sewage treatment apparatus (“Johkasou”)

2001 ◽  
Vol 43 (12) ◽  
pp. 191-193 ◽  
Author(s):  
M. Kaneko ◽  
T. Nambu ◽  
M. Tokoro

“Johkasou” is a small sewage treatment apparatus commonly used in Japan which can effectively treat domestic wastewater in places where a public sewage system is difficult to supply. The behaviour of enterohaemorrhagic E. coli 0157 and Salmonella enteritidis in a “Johkasou” was studied. Their reduction rates depended significantly on the water temperature in the “Johkasou” with minimal decrease in numbers at 10°C within 48 h. The reduction rates increased at 20°C and 30°C where 4 log reduction could be expected. The reduction rates were influenced by the BOD of the solutions that contained the pathogens with the lower the BOD the higher the reduction rate. The reduction rates were about the same between both pathogens. The result showed that it was necessary to disinfect the effluent as some pathogens can pass through the apparatus when some users of the apparatus excrete pathogens.

2002 ◽  
Vol 65 (8) ◽  
pp. 1215-1220 ◽  
Author(s):  
CHIA-MIN LIN ◽  
SARAH S. MOON ◽  
MICHAEL P. DOYLE ◽  
KAY H. McWATTERS

Iceberg lettuce is a major component in vegetable salad and has been associated with many outbreaks of foodborne illnesses. In this study, several combinations of lactic acid and hydrogen peroxide were tested to obtain effective antibacterial activity without adverse effects on sensory characteristics. A five-strain mixture of Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis, and Listeria monocytogenes was inoculated separately onto fresh-cut lettuce leaves, which were later treated with 1.5% lactic acid plus 1.5% hydrogen peroxide (H2O2) at 40°C for 15 min, 1.5% lactic acid plus 2% H2O2 at 22°C for 5 min, and 2% H2O2 at 50°C for 60 or 90 s. Control lettuce leaves were treated with deionized water under the same conditions. A 4-log reduction was obtained for lettuce treated with the combinations of lactic acid and H2O2 for E. coli O157:H7 and Salmonella Enteritidis, and a 3-log reduction was obtained for L. monocytogenes. However, the sensory characteristics of lettuce were compromised by these treatments. The treatment of lettuce leaves with 2% H2O2 at 50°C was effective not only in reducing pathogenic bacteria but also in maintaining good sensory quality for up to 15 days. A ≤4-log reduction of E. coli O157:H7 and Salmonella Enteritidis was achieved with the 2% H2O2 treatment, whereas a 3-log reduction of L. monocytogenes was obtained. There was no significant difference (P > 0.05) between pathogen population reductions obtained with 2% H2O2 with 60- and 90-s exposure times. Hydrogen peroxide residue was undetectable (the minimum level of sensitivity was 2 ppm) on lettuce surfaces after the treated lettuce was rinsed with cold water and centrifuged with a salad spinner. Hence, the treatment of lettuce with 2% H2O2 at 50°C for 60 s is effective in initially reducing substantial populations of foodborne pathogens and maintaining high product quality.


1986 ◽  
Vol 18 (7-8) ◽  
pp. 209-216 ◽  
Author(s):  
Y. Inamori ◽  
R. Sudo ◽  
T. Goda

The purpose of this study was to assess the applicability of the anaerobic biofilter process to treat low strength organic wastewater such as domestic sewage. It was found that when the influent BOD was approximately 200 mg/l, water temperature and BOD loading, under a hydraulic retention time (HRT) of 30 hrs, were 20°C and 0.2 kg/m3.day respectively, a BOD removal of at least 70% was attained, and the ratio of sludge produced to BOD removed in the anaerobic biofilter was as low as 0.1. Furthermore it was also found that 75% of nitrogen (N) could be removed in the anaerobic-aerobic biofilter process when the circulation ratio was more than 1:2.


2011 ◽  
Vol 71-78 ◽  
pp. 4765-4769
Author(s):  
Ying Li ◽  
Jing Zhou

According to the biodegradability of wastewater and better adaptability of biological treatment processes, and advantages of using biological contact oxidation process to treat sewage, biological contact oxidation method was used to study the removal conditions of domestic sewage treatment in high latitude area, and a set of experimental device of biological contact oxidation method applied in treating domestic sewage in low temperature was designed, to solve the serious pollution of domestic wastewater and its higher treatment cost in high latitude area.


2020 ◽  
Vol 10 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Yerabham Praveenkumarreddy ◽  
Masato Akiba ◽  
Keerthi Siri Guruge ◽  
Keshava Balakrishna ◽  
Kalwaje Eshwara Vandana ◽  
...  

Abstract Antibiotics received by sewage treatment plants may be the causative factor in spreading antibiotic resistance bacteria in the aquatic environment. The current study investigates the distribution of antimicrobial-resistant Escherichia coli (E. coli) in four sewage treatment plants (STPs) in South India receiving hospital and domestic wastewater in different proportions. A total of 221 E. coli isolates were checked for antimicrobial resistance against 16 antimicrobials. Among the antimicrobials tested, ampicillin (AMP) and cefazolin (CFZ) showed resistance between 20% and 90%, nalidixic acid (NAL) and ciprofloxacin (CIP) showed resistance between 15% and 75% and chloramphenicol (CHL) showed resistance between 2% and 20%. Based on the observations, there is no significant difference between the wastewater inlet and outlet, suggesting that treatment process was not effective in reducing the resistance. In conclusion, the trends of antimicrobial resistance pattern show that the levels of resistance were slightly higher in hospital wastewater than domestic wastewater. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.


1993 ◽  
Vol 27 (1) ◽  
pp. 51-57 ◽  
Author(s):  
T. Watanabe ◽  
K. Kuniyasu ◽  
H. Ohmori

In order to prevent water pollution and satisfy the demands for flush toilets in regions where a public sewerage system has not been in service, some on-site small scale domestic wastewater treatment processes called GAPPEI JOHKASOU have been developed to treat black water and gray water together in an individual house. Prior to its technical development, the characteristics of wastewater discharged from individual houses should be measured. The possibility of application of anaerobic filter is examined for processing organic wastewater at low concentration like in domestic wastewater, and an anaerobic filteris successfully developed to lengthen the sludge removal interval, since the flow rate of wastewater from individual houses is characterized by a large variation. It is difficult to serve the centralized treatment systems in many regions. Thus, a small GAPPEI JOHKASOU has been developed and propagated for by individual houses in such regions.


2019 ◽  
Vol 64 (3) ◽  
pp. 328-339
Author(s):  
Yuhang Cai ◽  
Asad A. Zaidi ◽  
Peiqi Sun ◽  
Yue Shi ◽  
Kun Zhang ◽  
...  

Design of ship sewage treatment systems that not only satisfy the use of small space on board but also meets International Maritime Organisation (IMO) latest emission standards is still a challenging problem for ship industry. This study provides a comparative disquisition between two different MBR reactors i.e, air-lift multilevel circulation membrane reactor (AMCMBR) and anaerobic/anoxic/aerobic membrane reactor (AOA-MBR) for domestic sewage treatment. The influence of pollutants volume loading rate (VLR) and C/N on effluent chemical oxygen demand (COD), ammonium nitrogen (NH4+-N) and TN for marine domestic sewage was analyzed. The results revealed that AMCMBR showed better removal efficiencies for COD and TN than AOA-MBR. The volume of AMCMBR was only half of the AOA-MBR. In addition, high average value of mixed liquor volatile suspended solids (MLVSS)/mixed liquid suspended solids (MLSS) (i.e. 0.75) of AMCMBR indicated high biomass and good pollutants removal achieved by this reactor. An interesting phenomenon was found in the study regarding Urease activity for the two reactors. Urease activity for AMCMBR in different working conditions all exceeded AOA-MBR and there exist no clear difference of NR activities between AMCMBR and AOA-MBR except for low C/N ratio (i.e. 6 and 4). This phenomenon proved that AMCMBR has a greater performance for treating ship domestic wastewater.


2016 ◽  
Vol 74 (6) ◽  
pp. 1492-1498 ◽  
Author(s):  
Bin Ji ◽  
Taoyuan Wei ◽  
Wei Chen ◽  
Jie Fan ◽  
Jian Wang ◽  
...  

A sequencing batch biofilm filter (SBBF) was applied to treat domestic sewage. The bioreactor consisted of fibrous filler in the upper part and ceramsite filter media in the lower part. The impacts of the most important factors including dissolved oxygen (DO), water temperature and hydraulic retention time (HRT) were evaluated on contaminants removal during the operation of the SBBF. Changes in DO (1.5–4.0 mg/L) and water temperature (2–30 °C) had little effect on the removal of chemical oxygen demand (COD), but had a greater impact on the removal of total nitrogen (TN) and NH4+-N. Changes in HRT (8–14 h) had little effect on the removal of COD, but had a greater impact on the removal of TN, NH4+-N and total phosphorus. The optimal operating parameters for the SBBF were as follows: DO of 2–3 mg/L, water temperature above 10 °C, and HRT of 10–13 h. Furthermore, a simple kinetic model was developed, reflecting the relationship between COD and HRT.


2013 ◽  
Vol 395-396 ◽  
pp. 1248-1252
Author(s):  
Xiang Wei Sun ◽  
Shan Quan Jiang ◽  
Yun Cheng Xie

Simulative wastewater was treated by a biofilm with soft filling and biological filter processing, the removal rate of COD /TN/NH4+-N and TP were discussed at different C/N ratio. The combined processing of biofilm and biological filter was studied. The results showed that the removal rate of COD is 80%. Biofilm had highly treatment efficiency and biological filter processing needed lower energy at low organic loading. The combined processing showed that the removal rate of COD and NH4+-N is more than 80% and 65% respectively. It will help for further study of domestic sewage treatment.


2003 ◽  
Vol 66 (10) ◽  
pp. 1822-1831 ◽  
Author(s):  
NORITOSHI KITAMOTO ◽  
YOJI KATO ◽  
TAKASHI OHNAKA ◽  
MASAHARU YOKOTA ◽  
TOMOYUKI TANAKA ◽  
...  

In this study, the bactericidal effects of Japanese alkaline foods on food-poisoning bacteria were evaluated. Konjac is an alkaline food soaked in calcinated calcium (the pH of konjac fluid ranges from 11.42 to 12.53). Konjac fluids completely inactivated Escherichia coli, enterohemorrhagic E. coli O157:H7 and E. coli O26:H9, Salmonella Enteritidis, Vibrio parahemolyticus, and Staphylococcus aureus. The initial level of 6 log CFU/ml dramatically decreased after incubation with konjac fluid, and no viable gram-negative bacterium cells could be detected within 1 to 2 days and no viable S. aureus cells could be detected within 3 to 5 days. On the other hand, treatment with konjac fluid was also effective in reducing levels of spore-forming bacteria (Bacillus subtilis, Bacillus cereus, Clostridium perfringens, and Clostridium botulinum type E and type A). At least a 4-log reduction of spore-forming bacteria was obtained in konjac fluid within 7 to 14 days. Vegetative cells were more susceptible to konjac fluid than spores were. When the initial cell count was 6 log CFU/ml, a few surviving spores remained for 60 to 90 days, but no spores could be detected after 120 days. When the initial count of spore-forming bacteria was 3 to 4 log CFU/ml, the cells considered vegetative were completely inactivated within 1 to 3 days. Repeated treatment with konjac fluid caused complete inactivation of spores in less than 1 to 3 days. Our studies indicate that konjac fluid, which has a long history of use in food, will control food-poisoning bacterial contamination during the production or preservation of konjac and other foods and has a preventive effect on bacteria that can cause severe disease at uniquely low levels.


2003 ◽  
Vol 48 (2) ◽  
pp. 81-87 ◽  
Author(s):  
R.J. Davies-Colley ◽  
R.J. Craggs ◽  
J.W. Nagels

“Advanced” pond systems (APS) have the potential for improving treatment, including disinfection, over conventional WSPs. Disinfection in a pilot scale APS at Ngatea, New Zealand was studied. This system comprises a high-rate algal pond (HRP) that optimises growth of settleable colonial green algae, followed by an algal settling pond (ASP) that removes much of the nutrients and solids as non-noxious algal sludge, and then a maturation pond (MP) for effluent polishing. Monitoring of this pilot-scale system over 2 years showed excellent overall removal of E. coli (average of 2000-fold reduction), with approximately 1 log removal in each of the three stages. Experiments in the pilot scale HRP suggest that most E. coli removal in this stage is inactivation by sunlight exposure, but with an important contribution from continuous dark processes. Preliminary experiments on the pilot scale algal settling pond (APS) suggest the combined effect of sedimentation of bacteria and sunlight disinfection of the (clarified) supernatant water.


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