scholarly journals Fabrication of potable and eco-friendly solar disinfection (sodis) unit and its performance analysis

2021 ◽  
Vol 8 (1) ◽  
pp. 41-50
Author(s):  
Malavika J P ◽  
Shobana C
Keyword(s):  
Drinking Water ◽  
Solar Energy ◽  
Water Samples ◽  
Polluted Water ◽  
Contaminated Water ◽  
Treated Water ◽  
Solar Disinfection ◽  
E Coli ◽  
Pet Bottles ◽  
Disinfection Unit

Solar disinfection (SODIS) is a technique, which involves utilization of solar energy to make safe drinking water from biologically contaminated water. In the conventional SODIS method, the PET bottles are filled with polluted water and exposed to the sunlight for a certain period depending upon the local weather conditions. However much more effective disinfection system is needed to overcome the problems of inefficient utilization of available solar energy and the health risk posed by treating the water using chemicals during the purification process.  Hence, the present work aims in designing a portable solar disinfection unit that can efficiently use solar energy by manually adjusting the unit according to sunlight availability. Along with it, incorporation of the additional eco-friendly unit with water purifying plants Vetiveria zizanioides (Vetiver) and Hemidesmus indicus (Nannari) is done to achieve high efficiency in producing potable water from biologically contaminated water. The contaminated water samples treated in the solar disinfection unit and eco-friendly water purifying unit are analyzed for the presence of total coliforms and E-coli by using the Most probable Number method and P/A analysis, respectively. A reduction in 99.74% of total coliform count and absence of E-coli was observed in the treated water samples.  The physicochemical analysis was carried out to ensure the suitability of treated water for consumption and the results revealed a notable reduction in the parameters, and all the parameters came under the permissible range of IS drinking water characteristics. The designed system can be used to disinfect the contaminated water sample most efficiently, thereby making the water suitable for consumption.

scholarly journals Effectiveness of solar disinfection for household water treatment: an experimental and modeling study

2021 ◽  
Author(s):  
Md. Rezaul Karim ◽  
Md. Habibur Rahman Bejoy Khan ◽  
Md. Abu-Sa-Ad Akash ◽  
Shahriar Shams
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Low Cost ◽  
Weibull Model ◽  
Bacterial Inactivation ◽  
Household Water Treatment ◽  
Treated Water ◽  
Solar Disinfection ◽  
Pet Bottles ◽  
Household Water

Abstract Solar disinfection (SODIS) is a simple and low-cost household water treatment (HWT) option used for disinfection of drinking water. In this study, the bacterial inactivation potential of SODIS was evaluated under the solar irradiance observed in different seasons in Bangladesh according to WHO evaluation protocol of HWT, and the SODIS experiments were conducted for both transmissive and reflective reactors using PET bottles and plastic bags. In summer, log reduction value (LRV) more than 5 was observed for the transmissive PET reactors for 6 to 8 hr exposure to sunlight and the treated water complied with the microbial standard of zero colony forming units/100 mL in drinking water. In monsoon and winter, LRV > 4 can be achieved for 16 hr and 8 hr exposure to sunlight, respectively, using reflective reactors. The plastic bag was found to be more effective than PET. A safe exposure time was estimated from the Weibull model to be maintained for SODIS application to achieve 4.0 LRV and also to prevent the re-growth of microorganisms in the treated water. A significant re-growth of microorganisms was observed in the treated water, thus SODIS with other HWT processes can be recommended for use in communities with an unsafe drinking water supply.

scholarly journals Bacteria Detection and Differentiation Using Impedance Flow Cytometry

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3496 ◽  
Author(s):  
Casper Clausen ◽  
Maria Dimaki ◽  
Christian Bertelsen ◽  
Gustav Skands ◽  
Romen Rodriguez-Trujillo ◽  
...  
Keyword(s):  
Drinking Water ◽  
Real Time ◽  
Electrical Response ◽  
Solid Particles ◽  
Electrical Impedance Spectroscopy ◽  
Contaminated Water ◽  
E Coli ◽  
Two Samples ◽  
Microbiological Control ◽  
Frequency Phase

Monitoring of bacteria concentrations is of great importance in drinking water management. Continuous real-time monitoring enables better microbiological control of the water and helps prevent contaminated water from reaching the households. We have developed a microfluidic sensor with the potential to accurately assess bacteria levels in drinking water in real-time. Multi frequency electrical impedance spectroscopy is used to monitor a liquid sample, while it is continuously passed through the sensor. We investigate three aspects of this sensor: First we show that the sensor is able to differentiate Escherichia coli (Gram-negative) bacteria from solid particles (polystyrene beads) based on an electrical response in the high frequency phase and individually enumerate the two samples. Next, we demonstrate the sensor’s ability to measure the bacteria concentration by comparing the results to those obtained by the traditional CFU counting method. Last, we show the sensor’s potential to distinguish between different bacteria types by detecting different signatures for S. aureus and E. coli mixed in the same sample. Our investigations show that the sensor has the potential to be extremely effective at detecting sudden bacterial contaminations found in drinking water, and eventually also identify them.

scholarly journals Development of an Internal Control for Evaluation and Standardization of a Quantitative PCR Assay for Detection of Helicobacter pylori in Drinking Water

2007 ◽  
Vol 73 (22) ◽  
pp. 7380-7387 ◽  
Author(s):  
Keya Sen ◽  
Nancy A. Schable ◽  
Dennis J. Lye
Keyword(s):  
Helicobacter Pylori ◽  
Drinking Water ◽  
Quantitative Pcr ◽  
Water Samples ◽  
Sodium Thiosulfate ◽  
Qpcr Assay ◽  
E Coli ◽  
H Pylori ◽  
Labeled Probe ◽  
Treated Drinking Water

ABSTRACT Due to metabolic and morphological changes that can prevent Helicobacter pylori cells in water from growing on conventional media, an H. pylori-specific TaqMan quantitative PCR (qPCR) assay was developed that uses a 6-carboxyfluorescein-labeled probe (A. E. McDaniels, L. Wymer, C. Rankin, and R. Haugland, Water Res. 39:4808-4816, 2005). However, proper internal controls are needed to provide an accurate estimate of low numbers of H. pylori in drinking water. In this study, the 135-bp amplicon described by McDaniels et al. was modified at the probe binding region, using PCR mutagenesis. The fragment was incorporated into a single-copy plasmid to serve as a PCR-positive control and cloned into Escherichia coli to serve as a matrix spike. It was shown to have a detection limit of five copies, using a VIC dye-labeled probe. A DNA extraction kit was optimized that allowed sampling of an entire liter of water. Water samples spiked with the recombinant E. coli cells were shown to behave like H. pylori cells in the qPCR assay. The recombinant E. coli cells were optimized to be used at 10 cells/liter of water, where they were shown not to compete with 5 to 3,000 cells of H. pylori in a duplex qPCR assay. Four treated drinking water samples spiked with H. pylori (100 cells) demonstrated similar cycle threshold values if the chlorine disinfectant was first neutralized by sodium thiosulfate.

Application of a molecular method for the detection of group A rotaviruses in raw and treated water

2004 ◽  
Vol 50 (1) ◽  
pp. 223-228 ◽  
Author(s):  
W.B. van Zyl ◽  
P.J. Williams ◽  
W.O.K. Grabow ◽  
M.B. Taylor
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Viral Gastroenteritis ◽  
Treated Water ◽  
Source Of Infection ◽  
Drinking Waters ◽  
Group A Rotaviruses ◽  
Group A ◽  
Treated Drinking Water ◽  
Drinking Water Samples

Group A human rotaviruses (HRVs) are the most important aetiological agents of acute viral gastroenteritis in infants and young children in both developing and industrialised countries. Rotaviruses are resistant to many chemical disinfectants and reportedly survive well in treated tapwater and sewage. In this study a group A specific reverse transcriptase-polymerase chain reaction (RT-PCR) followed by a nested-PCR was applied for the detection of HRVs in raw and treated drinking-water samples drawn at a water reclamation plant. For a period of two years (July 2000 to June 2002), borehole, raw and treated drinking-water samples were collected weekly. Viruses were recovered from the water samples using a glass wool adsorption-elution technique followed by secondary concentration using precipitation with polyethylene glycol. In the first year of the study group A HRVs were detected in 11% sewage samples, 8% partially treated waters and 5% final treated drinking waters. The results of the second year of the study showed the presence of group A HRVs in 11% sewage and untreated surface water samples, 15% partially treated water and 6.5% final treated drinking waters. No HRVs were detected in the water samples from the boreholes. The presence of group A HRVs in treated drinking-water samples suggested that this water could be a potential source of infection to consumers. The data also implied that either the water treatment did not remove HRVs or the treated water was contaminated post-treatment.

scholarly journals Borehole water: a potential health risk to rural communities in South Africa

2018 ◽  
Vol 19 (1) ◽  
pp. 128-136 ◽  
Author(s):  
S. Taonameso ◽  
L. S. Mudau ◽  
A. N. Traoré ◽  
N. Potgieter
Keyword(s):  
Drinking Water ◽  
Rural Communities ◽  
Water Samples ◽  
Rural Areas ◽  
Total Coliform ◽  
Water Sources ◽  
Potential Health ◽  
Point Mapping ◽  
E Coli ◽  
Mapping Tool

Abstract Sporadic outbreaks of diarrhoea in children in the Vhembe rural areas could be an indication of contamination in drinking water sources. In areas where improved water sources are used, not all rural households experience the benefits of these improved water sources. Water samples were collected from boreholes in three wards in the Vhembe District to determine microbiological risks over a 5-month period. A Water Point Mapping tool was used to indicate the borehole distribution. Water samples were taken from each functional borehole and analysed for total coliform and Escherichia coli counts, electrical conductivity, pH and temperature. A multiplex PCR protocol was used for identification of pathogenic E. coli. A total of 125 boreholes were identified of which only 12 were functional. Seven boreholes tested positive for total coliforms and E. coli counts. Four boreholes (33.3%) tested positive for diarrhoeagenic E. coli. Fifty-eight percent (58%) of water samples were without health risks, 17% were low risk and 25% could cause infection according to the South African water quality standards. This study indicated the importance of the role of the Municipalities and the maintenance plans that need to ensure that all boreholes are functional and provide safe drinking water to the rural communities.

scholarly journals Analysis of heavy metals and coliform in samples of drinking water collected from municipal ward offices of western suburbs of Mumbai, India

2014 ◽  
Vol 15 (1&2) ◽  
pp. 99-107
Author(s):  
G.V Zodape
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Water Samples ◽  
Fecal Contamination ◽  
E Coli ◽  
Metallic Sheen ◽  
Differential Medium ◽  
Drinking Water Samples

14 drinking water samples were collected from Vile Parle to Dadar of Suburban’s of (P-South ward offices of B.M.C (Bombay Municipal Corporation) Mumbai in the month from June to December 2012. The samples of drinking-water were analyzed for Cu, Zn, Mn, Fe, As, Cr, Ni, Pb, Cd and Hg. From the results so obtained, the contamination due to heavy metals – Zn (3.115 ppm and 7.816 ppm), Mn (3.115 ppm and 7.426 ppm), Fe (1.124 ppm and 2.872 ppm), As (0.011 ppm to 0.091 ppm), Cr (0.188 ppm and 0.998 ppm ), Pb (1.587 ppm and 4.56 ppm) and Cd (0.011 ppm and 0.051 ppm ) was found to be high whereas the contamination due to Cu (0.012 ppm and 0.313 ppm), Ni (0.126 ppm and 0.774 ppm), were found below the acceptable limits and no Hg was detected in the samples of drinking-water. In the present work, MacConkey Broth was used as a differential medium for detection and enumeration of coliforms from a wide variety water samples. The presence of positive doubtful presumptive test immediately suggests that the water is non potable (i.e., both acid and gas develops in a tube after 48 hours incubation). Confirmation suggests that there is fecal contamination in the water under investigation and hence it is non potable. All the fourteen samples (streaked from positive Ma cConkey broth tubes) were found to be contaminated with E. coli, which was further confirmed by the presence of colonies with green metallic sheen observed under a microscope confirmed that the said samples were contaminated with E. coli - the major indicator of fecal contamination.

scholarly journals A Breakthrough in Water Purification Using an Oligodynamic Metal and Moringa Oleifera Seed

2018 ◽  
Author(s):  
Alakaparampil Joseph Varkey
Keyword(s):  
Drinking Water ◽  
Water Purification ◽  
Water Samples ◽  
Moringa Oleifera ◽  
Technical Assistance ◽  
Cost Effective ◽  
Power Source ◽  
Raw Water ◽  
Treated Water ◽  
Moringa Oleifera Seed

A simple, efficient and stand-alone method for purification of river water using moringa seed powder and copper is discussed. Coagulant property of the seed powder clears turbid raw water and the oligodynamic activity of copper completely destroys E.coli bacteria. Both raw and treated water samples were tested for contaminants to verify the efficacy of the system. Treated water has turbidity in the range 3 NTU - 5 NTU and non-detected (< 1 MPN/100 mL) E.coli count making it suitable for drinking. The technique is very cost effective and can be practiced anywhere using locally available materials. It does not require a power source or any technical assistance. Being a stand-alone system the technique exceptionally useful in providing drinking water as an immediate solution in disaster areas affected by cyclone or floods.

scholarly journals Arsenic Removal from Contaminated Water Using Natural Adsorbents: A Review

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1407
Author(s):  
Kanfolo Franck Herve YEO ◽  
Chaokun Li ◽  
Hui Zhang ◽  
Jin Chen ◽  
Wendong Wang ◽  
...  
Keyword(s):  
Drinking Water ◽  
Ion Exchange ◽  
Flow Rate ◽  
Contact Time ◽  
Arsenic Removal ◽  
Polluted Water ◽  
Contaminated Water ◽  
Natural Materials ◽  
The Past ◽  
Natural Adsorbents

More than 170 million individuals have been influenced by arsenic (As) because of the ingestion of As-polluted groundwater. The presence of As in water bodies, particularly groundwater, has been found to become a widespread issue in the past few decades. Because arsenic causes extreme wellbeing impacts, even at a low concentration in drinking water, the innovations of As removal from contaminated water are of significant importance. Traditional strategies, for example, reverse osmosis, ion exchange, and electro-dialysis are generally utilized for the remediation of As-polluted water; however, the high cost and/or sludge production restricts their application in less-developed areas. The utilization of adsorbents acquired from natural materials has been explored as an alternative for the costly techniques for As removal. This paper aims to review the past and current developments in using naturals adsorbents or modified natural materials for arsenic removal and show the different parameters, which may influence the As removal effectiveness of the natural adsorbent, such as contact time, adsorbent dosage, flow rate, pH, reusability, temperature, and influence of others ions.

scholarly journals Sanitary Status and Occurrence of Some Water-Borne Pathogens in Well and Surface Waters of Panhauya Community and Ahmadu Bello University Farm, Zaria

2020 ◽  
Vol 5 (2) ◽  
pp. 138-147
Author(s):  
S. L. Afegbua ◽  
Keyword(s):  
Drinking Water ◽  
Surface Waters ◽  
Water Samples ◽  
Universal Access ◽  
Microbiological Quality ◽  
Health Concern ◽  
Salmonella Spp ◽  
Open Defecation ◽  
E Coli ◽  
Water Borne

The Sustainable Development Goal on sanitation aims to achieve universal access to good health, affordable drinking water, sanitation and an end to open defeacation by 2030. The recent ranking of Nigeria as first globally for open defecation is of public and environmental health concern. This study assessed the sanitary condition and the microbiological quality of well and surface waters of Panhauya community and Ahmadu Bello University farm, Zaria, and the antibiogram of the bacterial isolates.. Based on the WHO criteria, the sanitary inspection showed that 16.7%, 54.2%, 25% and 4.2% of the water sampling points had a very high, high, intermediate and low risk of contamination respectively. Occurrence of Escherichia coli, Giardia lamblia, Entamoeba histolytica, Pseudomonas aeruginosa, Salmonella spp and Vibrio cholerae in water samples from Panhuaya community was 87.5%, 75%, 68.8%, 50%, 25% and 12.5% respectively. In ABU farm Shika, the occurrence was; E. coli (75%), E. histolytica (63%), G. lamblia and Salmonella spp. All E. coli isolates exhibited high multidrug resistance to antibiotics screened with a MAR index of 0.3-0.8. The drinking water sources in Panhuaya and ABU farm were unsafe and the presence of these pathogens in the water samples may be attributed to a number of factors including poor sanitation, manure application and open defecation practice. This indicates a public health risk to the residents and emphasises the need for safe water supplies sanitation and antibiotic stewardship. Keywords: Well water; surface water; sanitary inspection; open defecation; water-borne pathogens; Zaria.

scholarly journals Oligodynamic Action of Silver, Copper and Brass on Enteric Bacteria Isolated from Water of Kathmandu Valley

1970 ◽  
Vol 10 ◽  
pp. 189-193 ◽  
Author(s):  
Rajani Shrestha ◽  
Dev Raj Joshi ◽  
Jyotsna Gopali ◽  
Sujan Piya
Keyword(s):  
Drinking Water ◽  
Agar Medium ◽  
Enteric Bacteria ◽  
Holding Time ◽  
Broth Culture ◽  
Contaminated Water ◽  
Gram Negative ◽  
E Coli ◽  
Nutrient Agar Medium ◽  
Shigella Spp

Traditionally certain metal pots are used to store drinking water in order to ensure safety. A study was conducted with the aim of evaluating the effect of oligodynamic metals such as copper, silver and brass against enteric gram negative drinking water isolates such as Salmonella paratyphi, Shigella spp., E. coli (MDR), E. coli, Vibrio cholerae and Klebsiella during September 2007 to January 2008. The test was carried out by preparing broth of the respective microorganisms followed with contaminating autoclaved distilled water with 1% (by volume) of the prepared broth culture and incubating the contaminated water in the respective metal pots up to 48 h (holding time). Reduction in the microbial load was assessed by pour plating the water content in the metal pots on Nutrient agar medium in every 0, 4th, 8th, 12th, 24th and 48th h of incubation (holding time). Among three test pots, copper pot showed the maximum bactericidal action compared to silver and brass pots towards most of the enteric gram negative bacterial isolates of water. Complete inhibition of tested organism was recorded within 4 to 48 hours of holding time. This study suggested the promotion of use of water pots made of oligodynamic metals such as silver and copper, and alloy such as brass to control the gram negative enteric pathogens in drinking water.Key words: Oligodynamic action; Heavy metals; Enteric bacteriaDOI: 10.3126/njst.v10i0.2959Nepal Journal of Science and Technology Vol. 10, 2009 Page: 189-193   

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