scholarly journals Diarrhoea prevention in Bolivia through point-of-use water treatment and safe storage: a promising new strategy

1999 ◽  
Vol 122 (1) ◽  
pp. 83-90 ◽  
Author(s):  
R. E. QUICK ◽  
L. V. VENCZEL ◽  
E. D. MINTZ ◽  
L. SOLETO ◽  
J. APARICIO ◽  
...  
Keyword(s):  
Water Quality ◽  
Community Education ◽  
Water Disinfection ◽  
E Coli ◽  
Safe Storage ◽  
Point Of Use ◽  
Quality Testing ◽  
New Strategy ◽  
Diarrhoea Prevention ◽  
And Control

A novel water quality intervention that consists of point-of-use water disinfection, safe storage and community education was field tested in Bolivia. A total of 127 households in two periurban communities were randomized into intervention and control groups, surveyed and the intervention was distributed. Monthly water quality testing and weekly diarrhoea surveillance were conducted. Over a 5-month period, intervention households had 44% fewer diarrhoea episodes than control households (P=0·002). Infants <1 year old (P=0·05) and children 5–14 years old (P=0·01) in intervention households had significantly less diarrhoea than control children. Campylobacter was less commonly isolated from intervention than control patients (P=0·02). Stored water in intervention households was less contaminated with Escherichia coli than stored water in control households (P<0·0001). Intervention households exhibited less E. coli contamination of stored water and less diarrhoea than control households. This promising new strategy may have broad applicability for waterborne disease prevention.

The effect of type of water supply on water quality in a developing community in South Africa

1997 ◽  
Vol 35 (11-12) ◽  
pp. 35-40 ◽  
Author(s):  
B. Genthe ◽  
N. Strauss ◽  
J. Seager ◽  
C. Vundule ◽  
F. Maforah ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
E Coli ◽  
Guideline Values ◽  
Developing Communities ◽  
Quality Guideline ◽  
And Control ◽  
The Relationship

Efforts to provide water to developing communities in South Africa have resulted in various types of water supplies being used. This study examined the relationship between the type of water supply and the quality of water used. Source (communal taps, private outdoor and indoor taps) and point-of-use water samples were examined for heterotrophic plate counts (HPC), total and faecal coliforms, E. coli, and coliphages. Ten percent of samples were also analysed for enteric viruses, Giardia and Cryptosporidium. Approximately 320 households were included in a case-control study. In addition, a cross-sectional study was conducted. Both studies examined the relationship between different types of water facilities and diarrhoea among pre-school children. The source water was of good microbial quality, but water quality was found to have deteriorated significantly after handling and storage in both case and control households, exceeding drinking water quality guideline values by 1-6 orders of magnitude. Coliphage counts were low for all water samples tested. Enteric viruses and Cryptosporidium oocysts were not detected. Giardia cysts were detected on one occasion in case and control in-house samples. Comparisons of whether in-house water, after handling and storage, complied with water quality guideline values demonstrated households using communal taps to have significantly poorer quality than households using private outdoor or indoor taps for HPC and E. coli (χ2 = 14.9, P = 0.001; χ2 = 6.6, P = 0.04 respectively). A similar trend (although not statistically significant) was observed for the other microbial indicators. The cross-sectional study demonstrated an apparent decrease in health risk associated with private outdoor taps in comparison to communal taps. This study suggests that a private outdoor tap is the minimum level of water supply in order to ensure the supply of safe water to developing communities.

scholarly journals Managed Aquifer Recharge at a Farm Level: Evaluating the Performance of Direct Well Recharge Structures

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1069 ◽  
Author(s):  
Prahlad Soni ◽  
Yogita Dashora ◽  
Basant Maheshwari ◽  
Peter Dillon ◽  
Pradeep Singh ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Levels ◽  
Water Supplies ◽  
E Coli ◽  
Significant Difference ◽  
Dug Wells ◽  
And Control ◽  
Dug Well ◽  
Recharge Structures

A field study evaluated the performance of direct well recharge structures (DWRS) in order to harvest and filter farm runoff and its discharge into open dug wells to augment groundwater recharge. This was undertaken between 2016 and 2018 using a total of 11 wells in the Dharta watershed, situated in a semi-arid hardrock region of Udaipur district, Rajasthan, India. The depth to water level in each DWRS well was monitored weekly for 1 to 3 years before and after the DWRS was established, and water samples were taken for water quality analysis (pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, fluoride, and Escherichia coli) before and during the monsoon period. For each DWRS well, two control wells in close proximity were also monitored and sampled. Five of the DWRS established in 2018 also had flow meters installed in order to measure discharge from the filter to the well. The volume of water recharged through DWRS into individual wells during the 2018 monsoon ranged from 2 to 176 m3 per well. Although the mean rise in water levels over the monsoon was higher in DWRS wells than in nearby control wells, the difference was not significant. Values of pH, EC, TDS, and F decreased in DWRS and control wells as each monsoon progressed, whereas the turbidity of wells with DWRS increased slightly. There was no significant difference between DWRS and control wells for pH, EC/TDS, turbidity, or fluoride. The presence of E. coli in DWRS wells was higher than in control wells, however, E. coli exceeded drinking water guidelines in all sampled wells. On the basis of this study, it is recommended that rural runoff should not be admitted to wells that are used for, or close to, wells used for drinking water supplies, even though salinity and fluoride concentrations may be reduced. For this study, none of the 11 DWRS wells produced sufficient additional recharge to potentially increase dry season irrigation supplies to justify expenditure on DWRS. This even applies to the DWRS well adjacent to a small ephemeral stream that had a significantly larger catchment area than those drawing on farmers’ fields alone. An important and unexpected finding of this study was that no sampled open dug well met drinking water standards. This has led to a shift in local priorities to implement well-head water quality protection measures for wells used for drinking water supplies. It is recommended that parapet walls be built around the perimeter of such dug wells, as well as having covers be installed.

scholarly journals Effect of single and combined exposures to UV-C and UV-A LEDs on the inactivation of Klebsiella pneumoniae and Escherichia coli in water disinfection

2021 ◽  
Author(s):  
María-Angélica Galezzo ◽  
Manuel Rodríguez Susa
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Water Disinfection ◽  
Dark Repair ◽  
Light Emitting ◽  
E Coli ◽  
Point Of Use ◽  
Combined Exposures ◽  
Uv Leds ◽  
Uv C

Abstract A system consisting of one UV-A (365 nm) and two UV-C (265 nm) light-emitting diodes (LEDs) was built to evaluate the effect of single and combined exposures to UV-A and UV-C LEDs on Klebsiella pneumoniae and Escherichia coli inactivation and subsequent reactivation. The dose was measured by actinometry using potassium ferrioxalate. Of laboratory prepared samples, 10 mL were irradiated for 20, 30, 45, 60 and 90 s. Logarithmic inactivation and percentages of photoreactivation and dark repair were calculated. E. coli and K. pneumoniae were reduced by more than 7 and 4 logs, respectively, at a dose of 21.5 mJ cm−2 using UV-C. No positive synergistic effect on the inactivation of the two bacteria was observed when using a simultaneous combination of UV-C and UV-A, probably due to a reactivation of the bacteria in the presence of UV-A light, which was not observed in irradiated samples under an individual exposure of 265 nm. For E. coli under 265 nm, the percentage of photoreactivation amounted to 10%, 3 h after irradiation. The results of this study demonstrated the capacity to inactivate E. coli and K. pneumoniae up to a considerable level and provide information for the application of UV LEDs in point-of-use systems.

scholarly journals Fast Disinfection ofEscherichia coliBacteria Using Carbon Nanotubes Interaction with Microwave Radiation

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Samer M. Al-Hakami ◽  
Amjad B. Khalil ◽  
Tahar Laoui ◽  
Muataz Ali Atieh
Keyword(s):  
Carbon Nanotubes ◽  
Microwave Radiation ◽  
Pathogenic Bacteria ◽  
Removal Rate ◽  
Water Disinfection ◽  
E Coli ◽  
Point Of Use ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Fischer Esterification

Water disinfection has attracted the attention of scientists worldwide due to water scarcity. The most significant challenges are determining how to achieve proper disinfection without producing harmful byproducts obtained usually using conventional chemical disinfectants and developing new point-of-use methods for the removal and inactivation of waterborne pathogens. The removal of contaminants and reuse of the treated water would provide significant reductions in cost, time, liabilities, and labour to the industry and result in improved environmental stewardship. The present study demonstrates a new approach for the removal ofEscherichia coli(E. coli) from water using as-produced and modified/functionalized carbon nanotubes (CNTs) with 1-octadecanol groups (C18) under the effect of microwave irradiation. Scanning/transmission electron microscopy, thermogravimetric analysis, and FTIR spectroscopy were used to characterise the morphological/structural and thermal properties of CNTs. The 1-octadecanol (C18) functional group was attached to the surface of CNTs via Fischer esterification. The produced CNTs were tested for their efficiency in destroying the pathogenic bacteria (E. coli) in water with and without the effect of microwave radiation. A low removal rate (3–5%) of (E. coli) bacteria was obtained when CNTs alone were used, indicating that CNTs did not cause bacterial cellular death. When combined with microwave radiation, the unmodified CNTs were able to remove up to 98% of bacteria from water, while a higher removal of bacteria (up to 100%) was achieved when CNTs-C18was used under the same conditions.

scholarly journals Demonstration and evaluation of germicidal UV-LEDs for point-of-use water disinfection

2010 ◽  
Vol 8 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Christie Chatterley ◽  
Karl Linden
Keyword(s):  
Uv Irradiation ◽  
Uv Light ◽  
Low Pressure ◽  
Water Disinfection ◽  
Light Emitting ◽  
E Coli ◽  
Point Of Use ◽  
One Year ◽  
Uv Lamps ◽  
Uv Leds

Ultraviolet (UV) irradiation is a common disinfection option for water treatment in the developed world. There are a few systems installed in developing countries for point-of-use treatment, but the low-pressure mercury lamps currently used as the UV irradiation source have a number of sustainability issues including a fragile envelope, a lifetime of approximately one year, and they contain mercury. UV light emitting diodes (LEDs) may offer solutions to many of the sustainability issues presented by current UV systems. LEDs are small, efficient, have long lifetimes, and do not contain mercury. Germicidal UV LEDs emitting at 265 nm were evaluated for inactivation of E. coli in water and compared to conventional low-pressure UV lamps. Both systems provided an equivalent level of treatment. A UV-LED prototype was developed and evaluated as a proof-of-concept of this technology for a point-of-use disinfection option, and the economics of UV-LEDs were evaluated.

Development and evaluation of a small scale water disinfection system

2016 ◽  
Vol 6 (3) ◽  
pp. 389-400 ◽  
Author(s):  
Dorcas Alfa ◽  
Sudesh Rathilal ◽  
V. L. Pillay ◽  
Kumnandi Pikwa ◽  
Martha N. Chollom
Keyword(s):  
Rural Areas ◽  
Water Disinfection ◽  
Woven Fabric ◽  
Small Scale ◽  
E Coli ◽  
Point Of Use ◽  
Quality Of Water ◽  
Two Factors ◽  
Gravity Driven ◽  
High Turbidity

Provision of microbiologically safe drinking water for people living in the rural areas of developing countries remains a major challenge to date. A simple gravity-driven membrane point of use system was developed based on woven fabric microfiltration (WFMF) membranes. The WFMF is a loose type of membrane (0.45 μm). However, complete disinfection is not achieved with the WFMF, hence it was incorporated with two disinfectants. This study aimed to combine the WFMF with two disinfectants (WaterGuard and bromochlor tablets) to bring the water to the accepted quality for drinking. Four different types of water were sourced, considering two factors: E. coli and turbidity content. The WFMF demonstrated excellent filtration performance by producing permeates with turbidity less than 1 NTU for feed turbidity ranging between 10 and 200 NTU. There was 95–99.8% E. coli removal for raw feeds with influent E. coli ranging between 500 and 44,500 CFU/100 mL. Total disinfection was achieved with both disinfectants; however, the effectiveness of the chemical disinfectants in E. coli removal was affected by the quality of water to be disinfected. The study showed that turbidity plays a major role in disinfection performances by increasing chlorine demand on water sources with high turbidity levels.

scholarly journals Implementasi Higiene Sanitasi pada RPH Kategori I sebagai Syarat Produksi Daging Sehat

2021 ◽  
Vol 9 (3) ◽  
pp. 138-143
Author(s):  
M. Fitri ◽  
H. Nuraini ◽  
R. Priyanto ◽  
Y. C. Endrawati
Keyword(s):  
Water Quality ◽  
Quality Assurance ◽  
Assessment Method ◽  
Personal Hygiene ◽  
Plate Count ◽  
E Coli ◽  
A Value ◽  
Total Plate Count ◽  
Sanitation And Hygiene ◽  
Quality Testing

Abbatoirs have to produce meat that complied requisite of safety, healthy, wholeness and halal. Animalorigin product have to requisite basic safety product which implementated of hygine sanitation asproduction processed. The research aim was to evaluate implementation of hygine sanitation systemon 1st categrory abbatoir at Bogor Regency to complied safety and quality assurance of product.Observations on the implementation of hygienic sanitation were carried out using an evaluation matrixof the suitability of physical requirements with the criterion parameter assessment method based onthe Regulation of the Minister of Agriculture Number 13/2010. The best suitability value (NK) of 3 wasobtained on the environmental hygiene indicator and the absence of the use of chemicals, while theother sanitation hygiene indicators were worth 2 (less appropriate). The results of testing on meat forthe content of Salmonella sp. is negative and the Total Plate Count test is between 7.1 x 103 - 5.2 x 104cfu/g below the SNI threshold (1.0 x 106 cfu/g). The test for E. coli in meat was above the threshold ofsuspected contamination from the water used. Validation of hygiene sanitation practices was carried outby means of Colliform swabs on knives, palms hand and clothing of officers. Colliform swab test of theofficer’s palm hand, which is 5.4 x 102 cfu/g, shows a value above the allowable threshold. The results ofthe evaluation of the application of sanitation and hygiene in the abattoir are quite good but still needimprovement. Priority improvements are the equipment of cleaning facilities, water quality testing andimprovement of personal hygiene understanding.

On-Surface Radical Oligomerisation: A New Approach to STM Tip-Induced Reactions

2018 ◽  
Author(s):  
Gaolei Zhan ◽  
Younes Makoudi ◽  
Judicael Jeannoutot ◽  
Simon Lamare ◽  
Michel Féron ◽  
...  
Keyword(s):  
Sample Surface ◽  
Scanning Tunnelling Microscope ◽  
Transfer Event ◽  
New Approach ◽  
The Past ◽  
Organic Nanostructures ◽  
Scanning Tunnelling ◽  
New Strategy ◽  
Surface Fabrication ◽  
And Control

Over the past decade, on-surface fabrication of organic nanostructures has been widely investigated for the development of molecular electronic devices, nanomachines, and new materials. Here, we introduce a new strategy to obtain alkyl oligomers in a controlled manner using on-surface radical oligomerisations that are triggered by the electrons/holes between the sample surface and the tip of a scanning tunnelling microscope. The resulting radical-mediated mechanism is substantiated by a detailed theoretical study. This electron transfer event only occurs when <i>V</i><sub>s</sub> < -3 V or <i>V</i><sub>s</sub> > + 3 V and allows access to reactive radical species under exceptionally mild conditions. This transfer can effectively ‘switch on’ a sequence leading to formation of oligomers of defined size distribution due to the on-surface confinement of reactive species. Our approach enables new ways to initiate and control radical oligomerisations with tunnelling electrons, leading to molecularly precise nanofabrication.

STUDI PERBANDINGAN KUALITAS AIR BERSIH DALAM KAITANYA DENGAN AKTIVITAS MASYARAKAT DI SEKITAR SUMBER AIR PADA DESA WAINITU, BATUMERAH, AMAHUSU, DAN HALONG

2017 ◽  
Vol 13 (2) ◽  
pp. 111-119
Author(s):  
Lela Uyara ◽  
Pieter Kunu ◽  
Silwanus M Talakua
Keyword(s):  
Water Quality ◽  
Quality Standard ◽  
Total Coliform ◽  
Quality Analysis ◽  
Clean Water ◽  
Water Quality Analysis ◽  
E Coli ◽  
Microbiological Parameters ◽  
Standard Quality

The study aims to determine the quality of clean water in the villages of Wainitu, Batumerah, Amahusu and Halong by comparing the result of water quality analysis with water quality standard. Water quality analysis includes Physiscal, Chemical, and Microbiological parameters. This research uses descriptive method, this method describes systematics, accurate about facts and characteristic of the quality of clean water of each research location. The results showed that the source of clean water in the village of Batumerah did not meet the standard of clean water quality standards indicated by the number of E. coli and the high total coliform.  Keywords: standard quality of clean water, water quality, Wainitu, Batumerah, Amahusu and Halong villages   ABSTRAK Penelitian yang bertujuan untuk menetapkan kualitas air bersih di Desa Wainitu, Batumerah, Amahusu dan Halong, dengan membandingkan hasil analisis kualitas air dengan standar baku mutu air bersih. Analisis kualitas air meliputi parameter fisika, kimia dan mikrobiologi. Penelitian ini menggunakan metode deskriptif; metode ini menggambarkan sicara sistematis, akurat, fakta dan karakteristik mengenai kualitas air bersih di masing-masing lokasi penelitian. Hasil penelitian menunjukkan bahwa sumber air bersih di Desa Batumerah tidak memenuhi standar baku mutu air bersih yang ditunjukkan oleh jumlah E. coli dan total Koliform yang tinggi. Kata Kunci: baku mutu air bersih, Desa Wainitu, Batumerah, Amahusu dan Halong, kualitas air

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.

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