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.

Inactivation of Microorganisms in Cloudy Ginkgo (Ginkgo biloba Linn.) Juice by Pulsed Electric Fields

2007 ◽  
Vol 13 (2) ◽  
pp. 83-90 ◽  
Author(s):  
H. Zhang ◽  
Z. Wang ◽  
R.-J. Yang ◽  
S.-Y. Xu
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Fields ◽  
Treatment Time ◽  
Synergistic Effects ◽  
Pulsed Electric Fields ◽  
Bath Temperature ◽  
Microbial Inactivation ◽  
Plate Counts

Pulsed electric fields (PEF) were applied to neutral ginkgo cloudy juice to study the influence of the electric field strength, the treatment time and temperature on microbial inactivation. The results showed that microbial inactivation increased with the electric field strength, the treatment time and temperature. PEF treatment caused 3.39 and 4.44-log cycles reduction of coliforms and total plate counts, respectively, when pulse duration was 3 μs, the electric field strength 30 kV/cm, the treatment time 520 μs and the water bath temperature 15°C. Under the same conditions, the microbial shelf life of ginkgo cloudy juice was extended to 24 days at 4°C and 18 days at room temperature. A 3.7-log cycles reduction of the total yeast and mould counts was obtained by applying 390 μs of 30 kV/cm at 15°C.Yeast and mould cells were less resistant to PEF process than bacteria cells. The effect of heat generated during the PEF treatment was limited on microbial inactivation. Temperature and the induced heat by PEF had synergistic effects to microbial inactivation in cloudy ginkgo juice.

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 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.

Campylobacter in waterborne epidemics in Finland

2004 ◽  
Vol 4 (2) ◽  
pp. 39-45 ◽  
Author(s):  
M.-L. Hänninen ◽  
R. Kärenlampi
Keyword(s):  
Campylobacter Jejuni ◽  
Causative Agent ◽  
Water Samples ◽  
Fecal Coliforms ◽  
Risk Level ◽  
Source Water ◽  
Indicator Organisms ◽  
Faecal Contamination ◽  
E Coli ◽  
July August September

The sources for drinking water in Finland are surface water, groundwater or artificially recharged groundwater. There are approximately 1400 groundwater plants in Finland that are microbiologically at a high risk level because in most cases they do not use any disinfection treatment. Campylobacter jejuni has caused waterborne epidemics in several countries. Since the middle of the 1980s, C. jejuni has been identified as the causative agent in several waterborne outbreaks in Finland. Between 1998 and 2001, C. jejuni or C. upsaliensis caused seven reported waterborne epidemics. In these epidemics approximately 4000 people acquired the illness. Most of the outbreaks occurred in July, August , September or October. In four of them source water and net water samples were analysed for total coliforms or fecal coliforms, E. coli and campylobacters. We showed that large volumes of water samples in studies of indicator organisms (up to 5000 ml) and campylobacters (4000–20,000 ml) increased the possibility to identify faecal contamination and to detect the causative agent from suspected sources.

Water Quality of Swimming Pools in Jerusalem

1993 ◽  
Vol 27 (7-8) ◽  
pp. 287-294 ◽  
Author(s):  
S. Lerman ◽  
O. Lev ◽  
A. Adin ◽  
E. Katzenelson
Keyword(s):  
Water Quality ◽  
Fecal Coliforms ◽  
Pathogenic Microorganisms ◽  
Swimming Pools ◽  
Indicator Organisms ◽  
Indicator Microorganisms ◽  
E Coli ◽  
Safe Water ◽  
Indirect Information

The Israel Ministry of Health is now revising its regulations for the assurance of safe water quality in public swimming pools. Since it is not possible to monitor each of the pathogenic microorganisms, it is often recommended to monitor indicator bacteria which provide indirect information on the water quality in the swimming pool. Three indicator microorganisms are often recommended: coliform counts (total coliforms, fecal coliforms or E. Coli), staphylococcus aureus and pseudomonas aeruginosa. A four year survey of the water quality of swimming pools in the Jerusalem District was conducted in order to determine whether the monitoring of all three indicators is necessary to assure safe water quality or is it sufficient to monitor only a single microorganism. A statistical analysis, conducted by using several different statistical techniques, reveals that the populations of the three indicator organisms are significantly interdependent but the correlations between each pair of these indicators are not sufficient to base a prediction of any of the organisms based on the measurements of the others. Therefore, it is concluded that monitoring of all three indicators should be recommended in order to provide an adequate picture of the water quality in swimming pools.

Microbiological Quality of Fresh Blue Crabmeat, Clams and Oysters

1983 ◽  
Vol 46 (11) ◽  
pp. 978-981 ◽  
Author(s):  
B. A. WENTZ ◽  
A. P. DURAN ◽  
A. SWARTZENTRUBER ◽  
A. H. SCHWAB ◽  
R. B. READ
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Microbiological Quality ◽  
Fecal Coliforms ◽  
Geometric Means ◽  
Colony Forming Units ◽  
Plate Counts ◽  
The Mean ◽  
Eastern Oysters

The microbiological quality of fresh blue crabmeat, soft- and hardshell clams and shucked Eastern oysters was determined at the retail (crabmeat, oysters) and wholesale (clams) levels. Geometric means of aerobic plate counts incubated at 35°C were: blue crabmeat 140,000 colony-forming units (CFU)/g, hardshell clams, 950 CFU/g, softshell clams 680 CFU/g and shucked Eastern oysters 390,000 CFU/g. Coliform geometric means ranged from 3,6/100 g for hardshell clams to 21/g for blue crabmeat. Means for fecal coliforms or Escherichia coli ranged from <3/100 g for clams to 27/100 g for oysters, The mean Staphylococcus aureus count in blue crabmeat was 10/g.

scholarly journals Investigation on microbial inactivation and urea decomposition in human urine during thermal storage

2017 ◽  
Vol 7 (3) ◽  
pp. 378-386 ◽  
Author(s):  
Xiaoqin Zhou ◽  
Yajie Li ◽  
Zifu Li ◽  
Yue Xi ◽  
Sayed Mohammad Nazim Uddin ◽  
...  
Keyword(s):  
Human Urine ◽  
Storage Condition ◽  
Microbial Inactivation ◽  
Fecal Coliforms ◽  
World Health ◽  
Large Space ◽  
Potential Health ◽  
Health Organization ◽  
Urea Decomposition ◽  
Storage Temperatures

The World Health Organization suggests storing human urine for at least 6 months at 20 °C prior to application as fertilizer to reduce the potential health risks from pathogenic organisms. Such a storage condition for human urine, however, not only requires a long period of time and large space but also ignores the risk of nitrogen losses. In this study, human urine underwent thermal treatment during storage to improve disinfection and to inhibit urea hydrolysis. Microbial indicators such as Escherichia coli and fecal coliforms and the concentration of ammonia/ammonium were investigated in urine samples that were stored at 60 °C and 70 °C. Both the inactivation of indicators and decomposition of urea improved under storage temperatures of 60 °C and 70 °C compared with storage under ambient temperature. Therefore, human urine is recommended to be stored at 70 °C for 7 days for hygienic and stabilization purposes. Under this storage condition, pH is maintained below 8.0 and ammonia/ammonium content is maintained at approximately 800 mg/L.

Occurrence and die-off of indicator organisms in the sediment in two constructed wetlands

2001 ◽  
Vol 44 (11-12) ◽  
pp. 223-230 ◽  
Author(s):  
T.A. Stentström ◽  
A. Carlander
Keyword(s):  
Constructed Wetlands ◽  
Municipal Wastewater ◽  
Full Scale ◽  
Water Phase ◽  
Fecal Coliforms ◽  
Main Concern ◽  
Particle Removal ◽  
Stormwater Treatment ◽  
Indicator Organisms ◽  
Factors Affecting

The interest in constructed wetlands for municipal wastewater and stormwater treatment has recently increased but data for the reduction efficiency of indicator organisms are often restricted to the water phase. In a full-scale wastewater wetland in Sweden fecal coliforms and enterococci were reduced by 97-99.9% and coliphages by approximately 70%. The factors affecting the reduction are however less well understood. In two full-scale wetlands, for stormwater and wastewater treatment, an assessment has been done of the particle associated fraction of indicator organisms. No significant differences in the particle-associated numbers were seen between the inlet and the outlet of the wetlands, but the amounts of sedimenting particles varied between the two sites. In the stormwater wetland the amount of sedimenting particles at the outlet was 3% of the amount at the inlet, while the wastewater wetland had much lower particle removal efficiency. The reduction of suspended particles seems to be the main factor for bacterial elimination from the water phase, governed by vegetation and design. In the sediment, survival of presumptive E.coli, fecal enterococci, Clostridium and coliphages were long with T90-values of 27, 27, 252 and 370 days, respectively. The organisms can however be reintroduced by resuspension. Viruses in the water phase may be of main concern for a risk assessment of receiving waters.

The relationship between three potential pathogens and pollution indicator organisms in Nova Scotian coastal waters

1983 ◽  
Vol 29 (10) ◽  
pp. 1261-1269 ◽  
Author(s):  
W. J. Robertson ◽  
R. S. Tobin
Keyword(s):  
Membrane Filtration ◽  
Indicator Bacteria ◽  
Fecal Coliforms ◽  
Most Probable Number ◽  
Indicator Organisms ◽  
Fecal Indicator ◽  
Filtration Method ◽  
Probable Number ◽  
Pollution Indicator ◽  
Nova Scotian

Fifteen stations, in two estuaries, along the Northumberland Strait of Nova Scotia were examined between June and September 1981 for a relationship between the concentrations of commonly monitored fecal indicator bacteria and the potential pathogens Candida albicans, Pseudomonas aeruginosa, and Vibrio parahaemolyticus. Increased densities of these three organisms were usually associated with high densities of indicator bacteria. Whereas C. albicans and P. aeruginosa occur in human fecal wastes, V. parahaemolyticus is indigenous to the marine environment and positively responds to elevated nutrient levels in sewage. There is also some evidence that these bacteria survive as long or longer in marine waters than the common indicator bacteria. While membrane-filtration techniques for the enumeration of C. albicans and P. aeruginosa proved satisfactory, a V. parahaemolyticus membrane-filtration method lacked specificity and was supplemented by a most-probable-number method. In marine recreational and shellfish waters, these three organisms could complement fecal coliforms and fecal streptococci as indicators of human fecal contamination.

Distribution of Coliphages in Various Foods

1986 ◽  
Vol 49 (12) ◽  
pp. 944-951 ◽  
Author(s):  
J. E. KENNEDY ◽  
C. I. WEI ◽  
J. L. OBLINGER
Keyword(s):  
Escherichia Coli ◽  
Food Samples ◽  
Fecal Coliforms ◽  
Bacterial Indicators ◽  
Processed Meats ◽  
E Coli ◽  
Plate Counts ◽  
The Relationship

The distribution of coliphages in various foods and the relationship between the incidences of coliphages and bacterial indicators were investigated. A total of 120 food samples comprising twelve products and including fresh meats, shellfish, vegetables and processed meats, were analyzed for indigenous coliphages using Escherichia coli hosts C, C-3000 and B. Bacterial analyses included enumeration of E. coli, fecal coliforms and coliforms, as well as aerobic plate counts and Salmonella analyses. Coliphages were detected (≥10 PFU/100 g) in 56% of samples and eleven of twelve products. Coliphages, E. coli, fecal coliforms and coliforms were recovered at a level of at least 30 organisms per 100 g in 43, 43, 68 and 81% of samples, with overall mean recoveries of 13, 19, 93 and 4300 organisms/100 g, respectively. Highest and lowest recoveries of coliphages and E. coli were from fresh meats and vacuum-packaged processed meats, respectively. Significant nonparametric correlations between coliphages, E. coli, fecal coliforms and coliforms were found among all food samples.

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