scholarly journals Comparison of five point-of-use drinking water technologies using a specialized comparison framework

2019 ◽  
Vol 17 (4) ◽  
pp. 568-586 ◽  
Author(s):  
Stephen Siwila ◽  
Isobel C. Brink
Keyword(s):  
Water Treatment ◽  
Flow Rate ◽  
Low Cost ◽  
Ease Of Use ◽  
Fecal Coliforms ◽  
Ongoing Research ◽  
Produce Water ◽  
Point Of Use ◽  
Bacterial Removal ◽  
Comparison Results

Abstract Three novel and two commercially available low-cost point-of-use (PoU) water treatment technologies were comparatively evaluated using a specialized comparison framework targeted at them. The comparison results and specialized framework have been discussed. The PoU systems were evaluated principally in terms of performance, flow rate and cost per volume of water treated (quantitatively), ease of use, potential acceptability and material availability (qualitatively) with main focus on rural and suburban settings. The three novel systems assessed were developed in an ongoing research project aimed at developing a multibarrier low-cost PoU water treatment system. The comparative evaluation and analysis revealed that the commercially available systems may often produce water free of pathogens (with an apparent 100% removal for Escherichia coli and fecal coliforms) but may not be affordable for application to the poorest groups in much of the developing world. The novel systems, which were principally constructed from local materials, were more affordable, can supply relatively safe water and can be constructed by users with minimal training. Overall, bacterial removal effectiveness, ease of use, flow rate, material availability, cost and acceptability aspects of water were identified as key to potential adoption and sustainability of the evaluated low-cost PoU systems.

scholarly journals Comparative analysis of two low cost point-of-use water treatment systems

2018 ◽  
Vol 13 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Stephen Siwila ◽  
Isobel C Brink
Keyword(s):  
Water Treatment ◽  
Suspended Solids ◽  
Tap Water ◽  
Low Cost ◽  
Water System ◽  
Poor Quality ◽  
Fecal Coliforms ◽  
Point Of Use ◽  
Bacterial Removal ◽  
Made In

Abstract The study examined two low-cost point-of-use water treatment systems developed in respect of bacterial and particulate removal when exposed to surface water for three months. Bacterial removal efficiency was estimated using E. coli and fecal coliforms, while particulate reduction efficiency was estimated by determining turbidity and total suspended solids (TSS). The systems investigated were the Gift of Water System (GWS) made in USA and the Drip Filter System (DFS) Model-JW-PD-1-70 made in South Africa. The study included seasonal water quality changes. Both systems recorded 100% bacterial removal throughout the study. Although results show that DFS was slightly better in terms of particulate reduction, both systems removed large proportions of particles from the water. On average TSS removals were 89% and 95%, while turbidity removals were 87% and 94%, by GWS and DFS respectively. The treated water from the two systems compared well with good quality tap water supplied to Stellenbosch University. The results show that both systems can treat the poor quality water used to meet the SANS 241 and WHO guidelines with respect to bacterial and suspended solids content.

scholarly journals Use of ceramic pot filter (CPF) technology under pressure in an in-line pumping system

2017 ◽  
Vol 18 (3) ◽  
pp. 843-852
Author(s):  
Travis D. Gardner ◽  
Joe D. Guggenberger
Keyword(s):  
Water Treatment ◽  
Low Cost ◽  
Total Coliform ◽  
Fecal Coliforms ◽  
Coliform Bacteria ◽  
Limiting Factor ◽  
Water Production ◽  
Pumping System ◽  
Point Of Use ◽  
Logarithmic Reduction

Abstract Ceramic pot filters (CPFs) are an effective point of use water treatment device in developing nations due to their low cost and effectiveness. CPFs are gravity fed, typically making water production a major limiting factor to a CPF's lifetime and acceptability. Directly connecting CPFs to in-line pumping systems or systems with an elevated storage tank would allow filter usage for constant water treatment at increased pressures, increasing the quantity of treated water. Ceramic disks were manufactured for testing in a specially designed housing apparatus. Filters of varying thicknesses and clay to sawdust mass ratios were manufactured to fit tightly. Flowrate and microbiological removal efficacy (logarithmic reduction value (LRV)) were determined over the testing period at various pressures. Flowrate values ranged from 2.44 to 9.04 L per hour, significantly higher than traditional CPF technology. LRVs ranged from 1.1 to 2.0, lower than traditional CPF technology but still effective at removing most Escherichia coli and total coliform bacteria. Filters proved effective at removing total and fecal coliforms at pressures less than 70 kilopascals. The optimum filter had a thickness of 3.2 cm and clay to sawdust ratio of 6:1 by mass. Filters proved to be ineffective if flowrates were above 5 L/h.

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 Methods, Protocols, Guidance and Standards for Performance Evaluation for Point-of-Use Water Treatment Technologies: History, Current Status, Future Needs and Directions

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1094
Author(s):  
Emily S. Bailey ◽  
Nikki Beetsch ◽  
Douglas A. Wait ◽  
Hemali H. Oza ◽  
Nirmala Ronnie ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Enteric Bacteria ◽  
Current Status ◽  
Household Water Treatment ◽  
Produce Water ◽  
Point Of Use ◽  
Treatment Technologies ◽  
Injury And Repair ◽  
Testing Protocols

It is estimated that 780 million people do not have access to improved drinking water sources and approximately 2 billion people use fecally contaminated drinking water. Effective point-of-use water treatment systems (POU) can provide water with sufficiently reduced concentrations of pathogenic enteric microorganisms to not pose significant health risks to consumers. Household water treatment (HWT) systems utilize various technologies that physically remove and/or inactivate pathogens. A limited number of governmental and other institutional entities have developed testing protocols to evaluate the performance of POU water treatment systems. Such testing protocols are essential to documenting effective performance because inferior and ineffective POU treatment technologies are thought to be in widespread use. This critical review examines specific practices, procedures and specification of widely available POU system evaluation protocols. Testing protocols should provide standardized and detailed instructions yet be sufficiently flexible to deal with different treatment technologies, test microbe priorities and choices, testing facility capabilities and public health needs. Appropriate infectivity or culture assays should be used to quantify test enteric bacteria, viruses and protozoan parasites, or other appropriate surrogates or substitutes for them, although processes based on physical removal can be tested by methods that detect microbes as particles. Recommendations include further research of stock microbe production and handling methods to consistently yield test microbes in a realistic state of aggregation and, in the case of bacteria, appropriately physiologically stressed. Bacterial quantification methods should address the phenomenon of bacterial injury and repair in order to maximally recover those that are culturable and potentially infectious. It is only with harmonized national and international testing protocols and performance targets that independent and unbiased testing can be done to assure consumers that POU treatment technologies are able to produce water of high microbial quality and low health risk.

scholarly journals Point-Of-Use Drinking Water Treatment in the Developing World: Community Acceptance, Project Monitoring and Revision

2011 ◽  
Vol 6 (1) ◽  
pp. 14-32
Author(s):  
Temitope Adebimpe Ogunyoku ◽  
Daniel M. Nover ◽  
Erica R. McKenzie ◽  
Geetika Joshi ◽  
William E. Fleenor
Keyword(s):  
Water Treatment ◽  
Developing World ◽  
Drinking Water Treatment ◽  
Treatment Method ◽  
Ease Of Use ◽  
Particle Removal ◽  
Solar Disinfection ◽  
Community Acceptance ◽  
Point Of Use ◽  
One Year

Abstract - Project design and implementation of water treatment technologies in the developing world often overlooks potential pitfalls because: 1) technical experts focus on technologies without considering cultural acceptability and 2) projects lack monitoring, evaluation, and project revision. Over the past five years, Engineers Without Borders (EWB) at the UC-Davis partnered with the Rural Agency for Sustainable Development (RASD) in Nkokonjeru, Uganda, to implement sustainable point of use (POU) water systems. POU systems (i.e. Filtron clay pot filters, solar disinfection, chlorine treatment, and colloidal silver) were tested and implemented at RASD’s training center in Nkokonjeru. While all of the systems effectively removed pathogens, cultural appropriateness and education were the most important drivers of project acceptance. After a one-year assessment, it was determined that community preference was driven by transparency of treatment method, cost, stigma, and ease of use. Clay pot filters were preferred because of ease of use and physical particle removal capabilities. However, high cost, lack of local production and transportation difficulties dictated that their use was not sustainable. Biosand filters were introduced as an alternative and although originally deemed to be too complicated, they have been accepted by the community and continue to be manufactured by RASD in Nkokonjeru.

A novel low-cost multi-barrier system for drinking water treatment in rural and suburban areas

2019 ◽  
Vol 15 (1) ◽  
pp. 48-65 ◽  
Author(s):  
Stephen Siwila ◽  
Isobel C. Brink
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Granular Media ◽  
Low Cost ◽  
Water System ◽  
Drinking Water Treatment ◽  
Fecal Coliforms ◽  
E Coli ◽  
Suburban Areas ◽  
Novel Concept

Abstract A low-cost multi-barrier drinking water system incorporating geotextile fabric for pre-filtration, silver-coated ceramic granular media (SCCGM) for filtration and disinfection, granular activated carbon (GAC) as an adsorption media and a safe storage compartment for treated water has been developed and tested. The developed system offers a novel concept of point-of-use drinking water treatment in rural and suburban areas of developing countries. The system is primarily aimed at bacterial and aesthetic improvement and has been optimised to produce >99.99% E. coli and fecal coliforms removal. Although particular emphasis was placed on the elimination of bacteria, improvement of the acceptability aspects of water was also given high priority so that users are not motivated to use more appealing but potentially unsafe sources. This paper discusses key system features and contaminant removal performance. A system using SCCGM only was also tested alongside the multi-barrier system. Strengths and weaknesses of the system are also presented. Both the developed and SCCGM-only systems consistently provided >99.99% E. coli and fecal coliforms removal at an optimum flow of 2 L/h. The developed system significantly recorded improvements of aesthetic aspects (turbidity, color, taste and odor). Average turbidity removals were 99.2% and 90.2% by the multi-barrier and SCCGM-only systems respectively.

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.

A new generation low-cost biochar-clay composite ‘biscuit’ ceramic filter for point-of-use water treatment

2020 ◽  
Vol 185 ◽  
pp. 105409 ◽  
Author(s):  
Nhamo Chaukura ◽  
Robert Chiworeso ◽  
Willis Gwenzi ◽  
Machawe M. Motsa ◽  
Wisdom Munzeiwa ◽  
...  
Keyword(s):  
Water Treatment ◽  
Low Cost ◽  
Ceramic Filter ◽  
Point Of Use ◽  
New Generation

Continuous-flow high temperature and pressure water sterilizer

2015 ◽  
Vol 10 (1) ◽  
pp. 19-24
Author(s):  
Adrian Ponce
Keyword(s):  
High Temperature ◽  
Flow Rate ◽  
Continuous Flow ◽  
Low Cost ◽  
Water Flow Rate ◽  
Geobacillus Stearothermophilus ◽  
High Temperature And Pressure ◽  
Point Of Use ◽  
Pressure Water ◽  
Temperature And Pressure

Water sterilization at sterility assurance levels exceeding 10−6 has been achieved with a novel high temperature and pressure sterilization system (HAPSS) capable of continuous-flow sterilization. The tested sterilizer produces >2,000 L/day and does not require filters, moving parts, or regular maintenance and can operate for multiple years with only water and standard voltage/amperage electricity. Sterility assurance levels were determined using Geobacillus stearothermophilus spores with inactivation experiments as a function of temperature and flow rate (i.e., duration/dosage at given temperature). Sterility of 1.0 × 104 CFU/mL G. stearothermophilus spore suspensions was achieved at the highest water flow rate of 1.4 L/min at 140 and 130 °C. The low cost and maintenance-free operation of HAPSS is envisioned to impact water sterilization needs of developing nations, hospitals, and commercial point of use applications.

Carbon nanotube composite membranes for small ‘designer’ water treatment systems

2014 ◽  
Vol 14 (5) ◽  
pp. 917-923 ◽  
Author(s):  
Haiou Huang ◽  
Howard Fairbrother ◽  
Benoit Teychene ◽  
Gaurav Ajmani ◽  
Talia Abbott Chalew ◽  
...  
Keyword(s):  
Water Treatment ◽  
Membrane Filtration ◽  
Low Cost ◽  
Composite Membranes ◽  
Water Systems ◽  
Treatment Technology ◽  
Ongoing Research ◽  
Small Communities ◽  
Small Water ◽  
Filtration Cycle

Small water systems that serve fewer than a few thousand persons are often less safe and less sustainable than large drinking water systems due to lack of suitable technologies. This ongoing research aims to develop a novel water treatment technology for small communities. By layering structured, functional carbon nanotubes (CNT) onto low pressure membranes (LPMs), composite membranes were prepared to remove different organic and inorganic contaminants from water, including heavy metals, viruses, natural organic matter, and organic micropollutants. The removal efficiencies varied from over 99.9% (for cadmium) to above 60% (for humic substances). A low-cost CNT formed an antifouling layer that removed membrane foulants by depth filtration, thereby extending the membrane filtration cycle over five-fold. When the CNTs were layered inside hollow fiber membranes, superb backwashable properties were observed, allowing the operation of CNT-modified membranes under full-scale treatment conditions. Moreover, a systematic study of CNT rejection by LPMs found that commercially available LPMs efficiently prevented CNT breakthrough, thus ensuring nanosafety of the treated water. By varying the composition and structure of functional CNT layers, energy-efficient composite membranes may be economically produced for designer water treatment systems and applied in small communities.

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