scholarly journals Assessment of a low-cost, point-of-use, ultraviolet water disinfection technology

2007 ◽  
Vol 6 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Sarah A. Brownell ◽  
Alicia R. Chakrabarti ◽  
Forest M. Kaser ◽  
Lloyd G. Connelly ◽  
Rachel L. Peletz ◽  
...  
Keyword(s):  
Rural Communities ◽  
Residence Time ◽  
Low Cost ◽  
Plug Flow ◽  
Field Studies ◽  
Water Disinfection ◽  
Galvanized Steel ◽  
Hydraulic Residence Time ◽  
Biological Assays ◽  
Point Of Use

We describe a point-of-use (POU) ultraviolet (UV) disinfection technology, the UV Tube, which can be made with locally available resources around the world for under $50 US. Laboratory and field studies were conducted to characterize the UV Tube's performance when treating a flowrate of 5 L/min. Based on biological assays with MS2 coliphage, the UV Tube delivered an average fluence of 900±80 J/m2 (95% CI) in water with an absorption coefficient of 0.01 cm−1. The residence time distribution in the UV Tube was characterized as plug flow with dispersion (Peclet Number = 19.7) and a mean hydraulic residence time of 36 s. Undesirable compounds were leached or produced from UV Tubes constructed with unlined ABS, PVC, or a galvanized steel liner. Lining the PVC pipe with stainless steel, however, prevented production of regulated halogenated organics. A small field study in two rural communities in Baja California Sur demonstrated that the UV Tube reduced E. coli concentrations to less than 1/100 ml in 65 out of 70 samples. Based on these results, we conclude that the UV Tube is a promising technology for treating household drinking water at the point of use.

scholarly journals Robust immobilization of anionic silver nanoparticles on cellulose filter paper toward a low-cost point-of-use water disinfection system with improved anti-biofouling properties

RSC Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 4873-4882
Author(s):  
Gongyan Liu ◽  
Ruiquan Yu ◽  
Jing Jiang ◽  
Zhuang Ding ◽  
Jing Ma ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Filter Paper ◽  
Low Cost ◽  
Water Disinfection ◽  
Point Of Use ◽  
Cellulose Filter

Point-of-use water disinfection by GA@AgNPs-LA-FP.

scholarly journals Implementation of point-of-use water treatment methods in a rural Tanzanian community: a case study

2020 ◽  
Vol 10 (4) ◽  
pp. 1012-1018
Author(s):  
T. M. Ngasala ◽  
S. J. Masten ◽  
C. Cohen ◽  
D. Ravitz ◽  
E. J. Mwita
Keyword(s):  
Water Treatment ◽  
Rural Communities ◽  
Water Samples ◽  
Cost Effective ◽  
Ease Of Use ◽  
Water Disinfection ◽  
Coliform Bacteria ◽  
Treatment Methods ◽  
Point Of Use ◽  
Household Water

Abstract This study was conducted in an agro-pastoral community in Northern Tanzania, where water sources are contaminated, and point-of-use water treatment is rarely used. The objectives of the study were to determine the quality of drinking water at the household level and to assess the perception and attitude towards the treatment methods that were introduced to community members. The three treatment methods evaluated were chlorine tablets, silver-infused ceramic tablets, and solar water disinfection (SODIS). These methods were selected due to their availability, ease of use, cost, and effectiveness in water with high levels of coliform bacteria. Each home within the study area was provided with one of three treatment methods. The use, performance, and acceptability of the new water treatment methods were assessed over a three-week period. Prior to the introduction of the methods, 40% of households reported that they treated water regularly. However, 80% of the household water samples tested positive for Escherichia coli. After introducing the new methods, 60% of households increased their water consumption, and all water samples tested negative for E. coli during the final week of testing. The work demonstrates the need to provide access to cost-effective household water treatment methods, especially in rural communities that lack access to potable water.

scholarly journals Factors involved in sustained use of point-of-use water disinfection methods: a field study from Flores Island, Indonesia

2014 ◽  
Vol 12 (3) ◽  
pp. 573-583 ◽  
Author(s):  
E. Roma ◽  
T. Bond ◽  
P. Jeffrey
Keyword(s):  
Water Treatment ◽  
Low Cost ◽  
Qualitative Evaluation ◽  
Ease Of Use ◽  
Water Disinfection ◽  
Cross Sectional ◽  
Household Water Treatment ◽  
Implementation Phase ◽  
Point Of Use ◽  
Sustained Use

Many scientific studies have suggested that point-of-use water treatment can improve water quality and reduce the risk of infectious diseases. Despite the ease of use and relatively low cost of such methods, experience shows the potential benefits derived from provision of such systems depend on recipients' acceptance of the technology and its sustained use. To date, few contributions have addressed the problem of user experience in the post-implementation phase. This can diagnose challenges, which undermine system longevity and its sustained use. A qualitative evaluation of two household water treatment systems, solar disinfection (SODIS) and chlorine tablets (Aquatabs), in three villages was conducted by using a diagnostic tool focusing on technology performance and experience. Cross-sectional surveys and in-depth interviews were used to investigate perceptions of involved stakeholders (users, implementers and local government). Results prove that economic and functional factors were significant in using SODIS, whilst perceptions of economic, taste and odour components were important in Aquatabs use. Conclusions relate to closing the gap between factors that technology implementers and users perceive as key to the sustained deployment of point-of-use disinfection technologies.

scholarly journals Assessing point-of-use ultraviolet disinfection for safe water in urban developing communities

2014 ◽  
Vol 12 (4) ◽  
pp. 663-669 ◽  
Author(s):  
Christina K. Barstow ◽  
Aaron D. Dotson ◽  
Karl G. Linden
Keyword(s):  
Pathogenic Bacteria ◽  
Flow Reactor ◽  
Low Cost ◽  
Plug Flow ◽  
Field Testing ◽  
Low Flow ◽  
Health Concern ◽  
Log Reduction ◽  
Point Of Use ◽  
Developing Communities

Residents of urban developing communities often have a tap in their home providing treated and sometimes filtered water but its microbial quality cannot be guaranteed. Point-of-use (POU) disinfection systems can provide safe drinking water to the millions who lack access to clean water in urban communities. While many POU systems exist, there are several concerns that can lead to low user acceptability, including low flow rate, taste and odor issues, high cost, recontamination, and ineffectiveness at treating common pathogens. An ultraviolet (UV) POU system was constructed utilizing developing community-appropriate materials and simple construction techniques based around an inexpensive low-wattage, low pressure UV bulb. The system was tested at the bench scale to characterize its hydrodynamic properties and microbial disinfection efficacy. Hydraulically the system most closely resembled a plug flow reactor with minor short-circuiting. The system was challenge tested and validated for a UV fluence of 50 mJ/cm2 and greater, over varying flow rates and UV transmittances, corresponding to a greater than 4 log reduction of most pathogenic bacteria, viruses, and protozoa of public health concern. This study presents the designed system and testing results to demonstrate the potential architecture of a low-cost, open-source UV system for further prototyping and field-testing.

scholarly journals Fabricación de un Concentrador Solar Parabólico Compuesto (CPC) para desinfección de agua de consumo en Comunidades Rurales

2019 ◽  
pp. 13-19
Author(s):  
José Alejandro Muñoz-Hernandez ◽  
Teresa Hernández-Ortiz ◽  
Moisés Montiel-González ◽  
Iván Salgado-Transito
Keyword(s):  
Rural Communities ◽  
Hydraulic System ◽  
Low Cost ◽  
Galvanized Steel ◽  
Industrial Processes ◽  
Average Amount ◽  
Glass Tubes ◽  
Main Components ◽  
Outside Diameter ◽  
Selection Of

This paper presents the selection of supply materials and describes the manufacturing process of a solar compound parabolic solar concentrator (CPC) to disinfect drinking water for consumption by rural communities. The volume of water to be treated is 100 liters/day, average amount of water for services of a family of 6 people, including washing of kitchen utensils and food preparation. The selection of supply materials for the CPE manufacture was made considering the lifetime, low cost and availability in the Mexican industrial market. The main components of the CPC are: 1. the profile of the involute, made of galvanized steel sheet gauge 20 (0.9 mm) with bright chrome finish to achieve a reflective surface, 2. Hydraulic system, integrated by coupling elements between 6 lines of borosilicate glass tubes of 44 mm outside diameter and 1.6 mm thickness with PVC accessories and 3. Mechanical support structure of the CPC, which was designed with a variable angle, to adjust according to the latitude of the operation site, this was manufactured with industrial processes of pailería and reinforced tubular profile (PTR) of 14 gauge steel (1.9 mm thickness) was used.

HOUSEHOLD WATER BALANCE AND ASSESSMENT OF WATER VOLUME FOR IRRIGATION IN AGRO LANDSCAPES OF THE KYZYLSU-YUZHNAYA BASIN

2020 ◽  
pp. 102-109
Author(s):  
D.KH. DOMULLODZHANOV ◽  
◽  
R. RAHMATILLOEV
Keyword(s):  
Water Balance ◽  
River Basin ◽  
Water Use ◽  
Storage Systems ◽  
Low Cost ◽  
Field Studies ◽  
Water Volume ◽  
Land Productivity ◽  
Household Water ◽  
And Storage

The article presents the results of the field studies and observations that carried out on the territory of the hilly, low-mountain and foothill agro landscapes of the Kyzylsu-yuzhnaya (Kyzylsu-Southern) River Basin of Tajikistan. Taking into account the high-altitude location of households and the amount of precipitation in the river basin, the annual volumes of water accumulated with the use of low-cost systems of collection and storage of precipitation have been clarified. The amount of water accumulated in the precipitation collection and storage systems has been established, the volume of water used for communal and domestic needs,the watering of livestock and the amount of water that can be used to irrigate crops in the have been determined. Possible areas of irrigation of household plots depending on the different availability of precipitation have been determined. It has been established that in wet years (with precipitation of about 10%) the amount of water collected using drip irrigation will be sufficient for irrigation of 0.13 hectares, and in dry years (with 90% of precipitation) it will be possible to irrigate only 0.03 ha of the household plot. On the basis of the basin, the total area of irrigation in wet years can be 4497 ha, and in dry years only 1087 ha. Taking into account the forecasts of population growth by 2030 and an increase in the number of households, the total area of irrigation of farmlands in wet years may reach 5703 hectares,and in dry years – 1379 hectares. Growing crops on household plots under irrigation contributes to a significant increase in land productivity and increases the efficiency of water use of the Kyzylsu-yuzhnaya basin.

Triticum aestivum Assay - A Useful Tool for Environmental Monitoring and Toxicity Assessment

2019 ◽  
Vol 47 (4) ◽  
pp. 1005-1018
Author(s):  
Alexandra JITĂREANU ◽  
Ioana-Cezara CABA ◽  
Adriana TRIFAN ◽  
Silvica PĂDUREANU ◽  
Luminița AGOROAEI
Keyword(s):  
Triticum Aestivum ◽  
Higher Plants ◽  
Low Cost ◽  
Environmental Pollutants ◽  
Rapid Test ◽  
Toxicity Assessment ◽  
Pollution Monitoring ◽  
Present Review ◽  
Digital Object Identifier ◽  
Biological Assays

The present review summarizes the literature data regarding the application of Triticum aestivum assay as an alternative method for toxicity assessment of environmental pollutants or potential therapeutic agents. Plant bioassays present several advantages among other biological assays (simplicity, low cost, rapid test activation, a wide array of assessment endpoints). They present a good correlation with animal and human cells models, and are a reliable tool for genotoxicity assessment. Furthermore, in the context of toxicology guidelines that promote the substitution of assays using animal models with other bioassays, genotoxicity assays using higher plants models have gained in popularity. The present review focuses on three major aspects regarding Triticum aestivum assay - its utility in environmental pollution monitoring, its application in genotoxicity assessment studies, and its application in phytotoxicity evaluation of nanomaterials.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

scholarly journals Estimation of the Inhaled Dose of Pollutants in Different Micro-Environments: A Systematic Review of the Literature

Toxics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 140
Author(s):  
Francesca Borghi ◽  
Andrea Spinazzè ◽  
Simone Mandaglio ◽  
Giacomo Fanti ◽  
Davide Campagnolo ◽  
...  
Keyword(s):  
Systematic Review ◽  
Residence Time ◽  
Low Cost ◽  
Pulmonary Ventilation ◽  
Personal Exposure ◽  
Ventilation Rate ◽  
Atmospheric Pollutants ◽  
Active Commuting ◽  
Review Of The Literature ◽  
Future Studies

Recently, the need to assess personal exposure in different micro-environments has been highlighted. Further, estimating the inhaled dose of pollutants is considerably one of the most interesting parameters to be explored to complete the fundamental information obtained through exposure assessment, especially if associated with a dose-response approach. To analyze the main results obtained from the studies related to the estimation of the inhaled dose of pollutants in different micro-environments (environments in which an individual spends a part of his day), and to identify the influence of different parameters on it, a systematic review of the literature was performed. The principal outcomes from the considered studies outlined that (i) exposure concentration and residence time are among the most important parameters to be evaluated in the estimation of the inhaled dose, especially in transport environments. Further, (ii) the pulmonary ventilation rate can be of particular interest during active commuting because of its increase, which increases the inhalation of pollutants. From a methodological point of view, the advent of increasingly miniaturized, portable and low-cost technologies could favor these kinds of studies, both for the measurement of atmospheric pollutants and the real-time evaluation of physiological parameters used for estimation of the inhaled dose. The main results of this review also show some knowledge gaps. In particular, numerous studies have been conducted for the evaluation (in terms of personal exposure and estimation of the inhaled dose) of different PM fractions: other airborne pollutants, although harmful to human health, are less represented in studies of this type: for this reason, future studies should be conducted, also considering other air pollutants, not neglecting the assessment of exposure to PM. Moreover, many studies have been conducted indoors, where the population spends most of their daily time. However, it has been highlighted how particular environments, even if characterized by a shorter residence time, can contribute significantly to the dose of inhaled pollutants. These environments are, therefore, of particular importance and should be better evaluated in future studies, as well as occupational environments, where the work results in a high pulmonary ventilation rate. The attention of future studies should also be focused on these categories of subjects and occupational studies.

scholarly journals Investigations on arc brazing for galvanized heavy steel plates in steel and shipbuilding

2021 ◽  
Author(s):  
Philipp Andreazza ◽  
Andreas Gericke ◽  
Knuth-Michael Henkel
Keyword(s):  
Low Cost ◽  
Thin Sheet ◽  
Steel Structures ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Steel Plates ◽  
Galvanized Steel ◽  
Filler Materials ◽  
Static Tensile ◽  
Brazed Joints

AbstractArc brazing with low-melting copper-based filler materials, which has long been established and standardized in the thin sheet sector, offers numerous advantages in the processing of predominantly electrolytically galvanized steel structures. In steel and shipbuilding, on the other hand, equipment parts made of thick steel sheets are hot-dip galvanized at low cost and with good corrosion-inhibiting properties. Quality welding of such constructions is not possible without special precautions such as removing the zinc layer and subsequent recoating. With regard to greater plate thicknesses, arc brazing was analyzed in these investigations as an alternative joining method with regard to its suitability for practical use. Within the scope of the investigations, CuSi3Mn, CuMn12Ni2, and four different aluminum bronzes were examined on different sheet surface conditions with regard to the geometrical and production parameters. This was carried out by build-up and connection brazing, executed as butt and cross joints. Quasi-static tensile tests and fatigue tests were used to assess the strength behavior. In addition, metallographic analyses are carried out as well as hardness tests. The suitability for multi-layer brazing and the tendency to distortion were also investigated, as well as the behavior of arc brazed joints under corrosive conditions.

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