scholarly journals Elimination of enteric indicators and pathogenic bacteria in secondary effluents and lake water by solar disinfection (SODIS)

2013 ◽  
Vol 3 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Adel A. S. AL-Gheethi ◽  
I. Norli ◽  
Mohd Omar Ab. Kadir
Keyword(s):  
Lake Water ◽  
Membrane Filtration ◽  
Pathogenic Bacteria ◽  
Fecal Coliforms ◽  
Secondary Effluent ◽  
Salmonella Spp ◽  
Solar Disinfection ◽  
Pet Bottles ◽  
Colony Forming Units ◽  
Secondary Effluents

The reduction of enteric indicators (fecal coliforms (FC) and Enterococcus faecalis) and elimination of pathogenic bacteria (Salmonella spp. and Staphylococcus aureus) in the secondary effluents and lake water by solar disinfection (SODIS) was studied in this article. FC, E. faecalis, Salmonella spp. and S. aureus were isolated and enumerated using membrane filtration techniques after SODIS of samples inside transparent polyethylene terephthalate (PET) bottles for 1, 2, 3, 4, 5, 6, 7 and 8 h. The results show that SODIS can reduce numbers of FC, Salmonella spp. and S. aureus by more than 4 log10 colony forming units (CFU)/100 mL after 6 h. However, regrowth of these bacteria was observed after the incubation of the treated samples at 37 °C for 24 h, whereas SODIS for 8 h would eliminate pathogenic bacteria and no regrowth would be observed in these samples as determined by an absence and presence technique using enrichment medium. E. faecalis was not eliminated in the secondary effluents and lake water by SODIS, but this bacterium was reduced to less than detection limits (1 CFU/100 mL) when the treated secondary effluent samples were stored for 16 days at room temperature. The elimination of pathogenic bacteria and reduction of enteric indicators resulted in undetectable levels using SODIS for secondary effluents and lake water.

scholarly journals Bioaugmentation process of secondary effluents for reduction of pathogens, heavy metals and antibiotics

2016 ◽  
Vol 14 (5) ◽  
pp. 780-795 ◽  
Author(s):  
A. A. Al-Gheethi ◽  
R. M. S. R. Mohamed ◽  
A. N. Efaq ◽  
I. Norli ◽  
Abdullah Abd Halid ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Pathogenic Bacteria ◽  
Treatment Process ◽  
Subtilis Strain ◽  
Secondary Effluent ◽  
Salmonella Spp ◽  
Secondary Effluents ◽  
Removal Of Heavy Metals ◽  
Us Epa ◽  
Faecal Indicators

The study probed into reducing faecal indicators and pathogenic bacteria, heavy metals and β-lactam antibiotics, from four types of secondary effluents by bioaugmentation process, which was conducted with Bacillus subtilis strain at 45 °C. As a result, faecal indicators and pathogenic bacteria were reduced due to the effect of thermal treatment process (45 °C), while the removal of heavy metals and β-lactam antibiotics was performed through the functions of bioaccumulation and biodegradation processes of B. subtilis. Faecal coliform met the guidelines outlined by WHO and US EPA standards after 4 and 16 days, respectively. Salmonella spp. and Staphylococcus aureus were reduced to below the detection limits without renewed growth in the final effluents determined by using a culture-based method. Furthermore, 13.5% and 56.1% of cephalexin had been removed, respectively, from secondary effluents containing 1 g of cephalexin L−1 (secondary effluent 3), as well as 1 g of cephalexin L−1 and 10 mg of Ni2+ L−1 (secondary effluent 4) after 16 days. The treatment process, eventually, successfully removed 96.6% and 66.3% of Ni2+ ions from the secondary effluents containing 10 mg of Ni2+ L−1 (secondary effluent 2) and E4, respectively. The bioaugmentation process improved the quality of secondary effluents.

Survival of Pathogenic Bacteria in Pesticide Solutions and on Treated Tomato Plants

2005 ◽  
Vol 68 (2) ◽  
pp. 296-304 ◽  
Author(s):  
TIFFANY T. Y. GUAN ◽  
GREGORY BLANK ◽  
RICHARD A. HOLLEY
Keyword(s):  
Membrane Filtration ◽  
Salmonella Enteritidis ◽  
Pathogenic Bacteria ◽  
Incubation Temperature ◽  
Bacterial Survival ◽  
Salmonella Spp ◽  
Tomato Plants ◽  
Sterile Saline ◽  
E Coli ◽  
Pesticide Formulations

The ability of Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Shigella to survive or grow in pesticide solutions (Ambush 240EC, Benlate T-N-G, Bravo 500, Botran 75WP, Captan 80WDG, Parasol, and Vendex 50W) used by the horticultural industry was examined. In the laboratory, individual cultures were inoculated at 4 log CFU/ml in pesticides diluted with sterile saline to the lowest recommended spray concentrations. During 21°C incubation for ≤96 h, bacterial survivors in the samples and a control consisting of saline were enumerated either by agar surface plating or hydrophobic grid membrane filtration. Most formulations tested were somewhat inhibitory to the pathogenic bacteria. All inoculated bacteria survived or grew in Bravo 500. Among bacteria tested, Salmonella spp. were best able to survive and Listeria spp. were least able to survive in pesticide solutions. When the incubation temperature or pesticide concentration was increased, survival of Salmonella varied depending on the type of formulation. In the field, when a bacterial cocktail containing E. coli O157:H7 and Salmonella Enteritidis was added to Bravo 500 at 6 log CFU/ml, both organisms were recovered from leaves and fruit skins of sprayed tomato plants after the recommended 1 day-to-harvest interval. E. coli and Salmonella survived longer on tomato leaves when sprayed in saline (at least 26 and 56 days, respectively) than when sprayed in Bravo 500 (>45 h and <15 days, respectively). While Salmonella serovars Typhimurium and Heidelberg grew in the fungicide Bravo, and Enteritidis grew in the insecticide Vendex within 96 h at 21°C in the laboratory, pathogen growth in other pesticide formulations did not occur. Higher temperature (≤30°C) or doubling pesticide concentrations had either no or a negative effect on Salmonella Heidelberg survival. Use of unexpired pesticide formulations may have contributed to the reduced bacterial survival and growth found in the laboratory and during the field trials with Bravo.

scholarly journals Comparison of Membrane Filtration and Replica Plate Technique to Detect Fecal Coliform

2018 ◽  
Vol 17 (2) ◽  
pp. 25-31 ◽  
Author(s):  
Bikram Gautam ◽  
Rameshwar Adhikari
Keyword(s):  
Fecal Coliform ◽  
Membrane Filtration ◽  
Pearson Correlation ◽  
Total Coliform ◽  
Fecal Coliforms ◽  
Kathmandu Valley ◽  
Local Market ◽  
Extrinsic Factors ◽  
Colony Forming Units ◽  
Routine Basis

Introduction: Membrane filtration (MF) is one of the widely used technique on a routine basis. On the other hand, replica plate (RP) technique can be used to transfer existing bacterial colonies in two plates which even allows pinpointing the original colony. The aim of this study is to comparatively detect the cfu/100 mL of fecal coliform using membrane filtration and replica plate techniques.Methods: In the study, a total of 25 bottled water were selected from the local market in Kathmandu valley. The total coliform count was detected using MF, while fecal coliform was detected using both MF and RP technique.Results: It was found that the average cfu/100 mL for total coliform, fecal coliform (MF) and fecal coliform (RP) were 143.38, 49.82 and 51.00 respectively. Pearson correlation coefficient calculated between total coliform and fecal coliform (MF), total coliform and fecal coliform (RP), fecal coliform (MF) and fecal coliform (RP) were found to be 0.695, 0.733 and 0.990 respectively; implying a positive correlation Conclusions: It has been demonstrated that intrinsic and extrinsic factors influence colony forming units. Furthermore, RP is a more sensitive method for screening fecal coliforms although both MF and RP can be efficiently used.

scholarly journals Comparative microbiological analysis of four different sea fishes collected from local market in Dhaka Metropolis

Food Research ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 161-165 ◽  
Author(s):  
Ifra Tun Nur ◽  
Amatun Nur Mou ◽  
Umme Habiba
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Fecal Coliforms ◽  
Local Market ◽  
Microbiological Analysis ◽  
Salmonella Spp ◽  
Fish Samples ◽  
The Status ◽  
Raw Fish ◽  
Frozen Fish

The present investigation attempted to evaluate the existence and survival of spoilage microorganisms in four common sea fishes (Poma, Rupchanda, Koral and Tuna) available in Bangladesh and to determine the effects of cooking temperature to optimize the growth of fish microflora. Moreover, the status of fish in frozen condition after cooking was also studied. A total 4 categories of sea fishes were collected from the local shops in Dhaka city. Raw, cooked and frozen fish samples were analyzed for the existence of pathogenic bacteria through the conventional cultural techniques and the confirmative biochemical identification procedures. Total viable bacteria were present in all four fish samples in raw, cooked and frozen condition up to 6 log CFU/mL. Most of the raw fish samples were found to harbor a huge population of microorganisms up to 5 log CFU/mL including the fecal coliforms. Several specific bacterial species like E. coli, Klebsiella spp., Salmonella spp., Shigella spp., Staphylococcus spp., Pseudomonas spp. and Vibrio spp. were present in raw samples. However, the microbial load reduced from the fish after cooking and the status was static in frozen condition. Thus, the incidence of fecal coliforms in raw fish may be considered as a serious threat to the public health upon consumption of such fishes.

Field Tests of the Solar Water Detoxification SOLWATER Reactor in Los Pereyra, Tucumán, Argentina

2006 ◽  
Vol 129 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Christian Navntoft ◽  
Paula Araujo ◽  
Marta I. Litter ◽  
María C. Apella ◽  
Diego Fernández ◽  
...  
Keyword(s):  
Membrane Filtration ◽  
Field Tests ◽  
Fecal Coliforms ◽  
Shallow Aquifer ◽  
Time Intervals ◽  
Filtration Method ◽  
Feed Tank ◽  
Cultivable Bacteria ◽  
Colony Forming Units ◽  
In Series

The SOLWATER reactor prototype is composed of two tubes containing a supported heterogeneous photocatalyst (Ahlstrom© paper impregnated with titanium dioxide), and two tubes containing a supported photosensitizer (designed and provided by G. Orellana, Universidad Complutense, Madrid, Spain). The tubes are placed on a CPC collector and run in series. Electricity is provided by a solar panel, and the recirculation rate is ca13Lmin−1. Total volume in the feed tank plus tubes is 20L. The reactor was designed and constructed by the consortium of a European research project whose objective is on the development of a fully autonomous solar reactor system to purify drinking water in remote locations of developing countries. The prototype was placed in the yard of a shanty house in Los Pereyra, Tucumán, Argentina. Water to feed the reactor is taken from the shallow aquifer through an open well. This water is contaminated with high counts of coliforms and Enterococcus faecalis. It also contains widely variable levels of Pseudomonas aeruginosa. The chemical composition of the water shows high levels of natural organic matter and of various inorganic pollutants. The reactor has been running since February 22, 2005. This paper presents the results collected in three months of operation. Around 4hr operation on a sunny day, and 5-6hr on a cloudy day are required to totally destroy fecal coliforms and Ent. faecalis. Even 24h after the experiment is concluded, no cultivable bacteria are seen by the membrane filtration method (measured colony forming units after 24hr=0). On the other hand, a small number of total coliforms remain (a few percent or less of the original count) at the end of some of the latest experiments. Possible explanations for this result are the drop in ambient temperature, the decrease in solar irradiance, and the exhaustion of the catalyst and sensitizer. P. aeruginosa is much more resistant, and only partial destruction is observed in those time intervals. The evolution of chemical parameters is also presented and discussed.

Roof-harvested rainwater for potable purposes: application of solar disinfection (SODIS) and limitations

2009 ◽  
Vol 60 (2) ◽  
pp. 419-431 ◽  
Author(s):  
Muhammad Tahir Amin ◽  
Mooyoung Han
Keyword(s):  
Synergistic Effects ◽  
Weather Conditions ◽  
Reaction Rate Constant ◽  
Microbial Inactivation ◽  
Fecal Coliforms ◽  
Indicator Organisms ◽  
Solar Disinfection ◽  
Pet Bottles ◽  
Initial Ph ◽  
Plate Counts

Efficiency of solar disinfection (SODIS) was evaluated for the potability of rainwater in view of the increasing water and energy crises especially in developing countries. Rainwater samples were collected from an underground storage tank in 2 L polyethylene terephthalate (PET) bottles and SODIS efficiency was evaluated at different weather conditions. For optimizing SODIS, PET bottles with different backing surfaces to enhance the optical and thermal effects of SODIS were used and different physicochemical parameters were selected and evaluated along with microbial re-growth observations and calculating microbial decay constants. Total and fecal coliforms were used along with Escherichia Coli and Heterotrophic Plate Counts (HPC) as basic microbial and indicator organisms of water quality. For irradiance less than 600 W/m2, reflective type PET bottles were best types while for radiations greater than 700 W/m2, absorptive type PET bottles offered best solution due to the synergistic effects of both thermal and UV radiations. Microbial inactivation did not improve significantly by changing the initial pH and turbidity values but optimum SODIS efficiency is achieved for rainwater with acidic pH and low initial turbidity values by keeping air-spaced PET bottles in undisturbed conditions. Microbial re-growth occurred after one day only at higher turbidity values and with basic pH values. First-order reaction rate constant was in accordance with recent findings for TC but contradicted with previous researches for E. coli. No microbial parameter met drinking water guidelines even under strong experimental weather conditions rendering SODIS ineffective for complete disinfection and hence needed more exposure time or stronger sunlight radiations. With maximum possible storage of rainwater, however, and by using some means for accelerating SODIS process, rainwater can be disinfected and used for potable purposes.

scholarly journals ANTIMICROBIAL EFFICACY OF SOLAR DISINFECTION OF SELECTED DRINKING WELL WATER IN BENIN CITY, NIGERIA

2021 ◽  
Vol 2 (1) ◽  
pp. 16-25
Author(s):  
S. K. Adebiyi ◽  
E. Emoresele ◽  
M. J. Ogbonnaya
Keyword(s):  
Antibiotic Susceptibility ◽  
Fecal Coliforms ◽  
Antimicrobial Efficacy ◽  
Most Probable Number ◽  
Well Water ◽  
Fecal Indicators ◽  
Probable Number ◽  
Solar Disinfection ◽  
Benin City ◽  
Pet Bottles

Solar Disinfection (SODIS) has been identified as a relatively cheap method of purifying water against pathogens, therefore providing potable drinking water, an essential component upon which living systems and the human body depends. In this study, the antimicrobial efficacy of solar disinfection of drinking well water was studied. A total of thirty (30) wells was randomly sampled from six (6) local government areas in Benin City, based on accessibility and communal usage. The well water was sampled using transparent 1L polyethylene terephthalate (PET) bottles. Standard microbiological and biochemical test procedures were performed to enumerate, isolate, characterize and identify the isolates to genus level. Antibiotic susceptibility of the isolate was also ascertained. Coliform test was conducted and counts expressed in Most Probable Number (MPN). The study revealed that Staphylococcus sp., Micrococcus sp., and Klebsiella sp. and, Penicillium sp., Fusarium sp. and Candida sp. were the most prevalent heterotrophic bacteria and fungi isolates in the study area in addition to fecal indicators (Escherichia coli and Fecal streptococci) with 83.33% occurrences respectively. The study also revealed that the overall percentage elimination of the identified isolates was recorded as 42.11%, while the percentage elimination of fecal indicators identified was 50%. It was observed that SODIS was very efficacious with a percentage reduction of above 95% for all identified isolates. It was also observed that SODIS is slightly more bactericidal as compared to its being fungicidal. From the study, it could not be ascertained with certainty whether or not, exposure to SODIS alters a microbial pathogens’ antibiotic susceptibility. The use of SODIS did not completely eliminate all the fecal coliforms found in the studied well water, therefore making it unfit for drinking with regards to WHO recommendation. Consequently, the study recommends the use of SODIS only in conjunction with other water purification methods to ensure potability.

APPLICATION OF MICROFILTRATION AND ULTRAFILTRATION FOR REUSING TREATED WASTEWATER; AS A SOLUTION TO EASE IRAN’S WATER SHORTAGE PROBLEMS

2015 ◽  
Vol 11 (6) ◽  
pp. 3662-3668
Author(s):  
Leila Babaei ◽  
A. Torabian ◽  
B. Aminzadeh
Keyword(s):  
Removal Efficiency ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Water Shortage ◽  
Fecal Coliforms ◽  
Treated Wastewater ◽  
Secondary Effluent ◽  
Allowable Level ◽  
Ozone Injection

Water shortage is a big problem in the Middle East. This paper investigates the possibility of reusing municipal wastewater by membrane filtration for non-potable consumption. The wastewater used for tests in this study was secondary effluent discharged from the secondary sedimentation pond of Ekbatan wastewater treatment plant in Tehran. These tests on reusing wastewater involved four main processes. Results showed that the best process was that ozone injection before MF and UF with COD removal efficiency of approximately 78 percent. In this case, removal efficiency of turbidity and TSS were 100 percent; additionally, traces of total and fecal Coliforms were completely removed. In the membrane processes, removal efficiency of TKN was about 40 percent. The removal efficiency of TP in all processes was about 7 percent, while it increased to 14 percent in the hybrid treatment. It can be concluded that all of further purification processes failed to achieve total phosphorus (TP) standards and thus in order to eliminate TP and reach allowable level, further researches are needed.<w:LsdException Locked="false" Priority="73" SemiHidden="false" UnhideWhenUsed="false" Name="Color

Direct Detection of Enteropathogenic Bacteria in Estuarine Water Using Nucleic Acid Probes

1991 ◽  
Vol 24 (2) ◽  
pp. 261-266 ◽  
Author(s):  
Ivor T. Knight ◽  
Jocelyne DiRuggiero ◽  
Rita R. Colwell
Keyword(s):  
Water Samples ◽  
Pathogenic Bacteria ◽  
Direct Detection ◽  
Specific Gene ◽  
Estuarine Water ◽  
Indicator Organisms ◽  
Salmonella Spp ◽  
Dna And Rna ◽  
Enteropathogenic Bacteria ◽  
Highly Sensitive Detection

Direct detection and enumeration of pathogenic bacteria, rather than indicator organisms, in aquatic environments is desirable but hindered by the difficulties of culturing and identifying specific pathogens from these environments. We have developed a method for concentrating bacteria from water samples and extracting their DNA and RNA for use as targets for pathogen-specific gene probes. The method has been used to detect and enumerate Salmonella spp. in estuarine water samples. The probe binds Salmonella DNA quantitatively, making it possible to estimate relative amounts of target in each sample. Salmonella spp. were detected in samples which yielded no Salmonella spp. using culturing. Since the probe method does not require culturing the target organism, both culturable and non-culturable forms are detected. We have also used polymerase chain reaction to amplify a region of the enterotoxin gene in enterotoxigenic Escherichiacoli and Vibriocholerae (ltx and ctx, respectively). The amplified products are then identified with ctx and ltx probes, making specific, highly sensitive detection possible.

Viruses and Water: Problems, Detection, and Control

1993 ◽  
Vol 27 (7-8) ◽  
pp. 127-133 ◽  
Author(s):  
H. Dizer ◽  
J. Dürkop ◽  
A. Grohmann ◽  
H. Kopecka ◽  
J. M. López-Pila
Keyword(s):  
Drinking Water ◽  
Surface Waters ◽  
Membrane Filtration ◽  
Wastewater Treatment Plants ◽  
Health Hazard ◽  
Primary Source ◽  
Detection Methods ◽  
Secondary Effluent ◽  
Naturally Occurring ◽  
Water Problems

Secondary effluent of wastewater treatment plants contains a high number of viruses and other pathogens, which pose a health risk to the population, (especially when receiv ng waters are used for bathing and swimming, or for growing shellfish. In areas with a high density of population, where drinking water supply is dependent on surface waters and contaminated rivers are the primary source of drinking water, failure of the filtration or of the disinfection step, or of any other “barriers” supposed to warrant safe potable water, will increase the risk of health hazard for the consumer. We have compared the efficiency of viral elimination in secondary effluent by flocculation, uv rradiation and membrane filtration taking naturally occurring, or additionally seeded f2 phages, as indicator for viruses. Flocculation decreased the number of phages present in secondary effluent by more than two logs. If combined with uv irradiation, the elimination reached five additional logs. Membrane filtration eliminated essentially all naturally occurring phages. Improvement of the quality of surface waters calls for a refinement of detection methods for viruses. We have found that the polymerase chain reaction (PCR) might be used for detecting viruses in surface waters.

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