scholarly journals Impact of Low-Cost Point-of-Use Water Treatment Technologies on Enteric Infections and Growth among Children in Limpopo, South Africa

2020 ◽  
Vol 103 (4) ◽  
pp. 1405-1415 ◽  
Author(s):  
Courtney L. Hill ◽  
Kelly McCain ◽  
Mzwakhe E. Nyathi ◽  
Joshua N. Edokpayi ◽  
David M. Kahler ◽  
...  
Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1094
Author(s):  
Emily S. Bailey ◽  
Nikki Beetsch ◽  
Douglas A. Wait ◽  
Hemali H. Oza ◽  
Nirmala Ronnie ◽  
...  

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.


2017 ◽  
Vol 18 (3) ◽  
pp. 843-852
Author(s):  
Travis D. Gardner ◽  
Joe D. Guggenberger

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.


Author(s):  
Kathryn Gwenyth Nunnelley ◽  
James A Smith

With significant infrastructure investments required for centralized water treatment, in home treatment technologies, known as point-of-use, have become a popular solution in the developing world. This review discusses current filtration-based point-of-use water treatment technologies in three major categories: ceramics, papers and textiles. Each of these categories has used silver for added antimicrobial effectiveness. Ceramics have had the most development and market infiltration, while filter papers are a new development. Textiles show promise for future research as a cheap, socially acceptable, and effective method. Also, a new method of silver incorporation in ceramics is explored.


Author(s):  
Victor Odhiambo Shikuku ◽  
Wilfrida N. Nyairo

The search for efficient and sustainable wastewater treatment technologies is a subject of continuing research. This is due to the emergence of new classes of water contaminants that are recalcitrant to the conventional wastewater treatment technologies and the stringent allowable limits for contaminant levels set by environmental management authorities. The chapter discusses the developments in synthesis methods and application of polymer-metal oxides as emerging facile materials for wastewater treatment. The varying uses of polymer-metal oxides for different processes in water treatment under varying operational conditions and their performance for different pollutants are critically analyzed. Their strengths and inherent limitations are also highlighted. The chapter demonstrates that polymer-metal oxides are facile low-cost and efficient materials and can be integrated in wastewater and drinking water treatment systems.


2020 ◽  
Vol 185 ◽  
pp. 105409 ◽  
Author(s):  
Nhamo Chaukura ◽  
Robert Chiworeso ◽  
Willis Gwenzi ◽  
Machawe M. Motsa ◽  
Wisdom Munzeiwa ◽  
...  

2018 ◽  
Vol 17 (2) ◽  
pp. 266-273 ◽  
Author(s):  
D. Brown ◽  
C. Farrow ◽  
E. A. McBean ◽  
B. Gharabaghi ◽  
J. Beauchamp

Abstract Diarrheal illnesses and fatalities continue to be major issues in many regions throughout the world. Household water treatment (HWT) technologies (including both point-of-use (POU) and point-of-entry (POE) treatment solutions) have been shown as able to deliver safe water in many low-income communities. However, as shown herein, there are important inconsistencies in protocols employed for validating performance of HWTs. The WHO does not stipulate influent concentration as a parameter that could influence removal efficacy, nor does it indicate an influent concentration range that should be used during technology evaluations. A correlation between influent concentration and removal is evidenced herein (R2 = 0.88) with higher influent concentrations resulting in higher log-removal values (LRVs). The absence of a recommended standard influent concentration of bacteria (as well as for viruses and protozoa) could have negative consequences in intervention efforts. Recommendations are provided that regulatory bodies should specify an influent concentration range for testing and verification of HWT technologies.


2021 ◽  
Vol 7 (1) ◽  
pp. 36-54
Author(s):  
Manoj Kumar Karnena ◽  
Vara Saritha

Background: Purification and remediation of water remain to be a mammoth challenge for environmental engineers, continuously mounting pressure on providing safe water for consumers. Nevertheless, care has to be taken to avoid chemicals in treatment, which could prove to be toxic. One of the most prominent stages in treating water for human consumption is clarification through coagulation and flocculation to remove colloidal particles including silt, clay, precipitated iron or manganese oxides along with bacteria and algae. Objective: In order to achieve sustainability, the only possible way is to use innate materials in combination with inherent technologies. Considering this, the present review will appraise the efficiency of natural coagulants in treating surface water. Several researchers have tested numerous natural coagulants for clarification of water. Nevertheless, information on various natural coagulants and their efficiency has not yet been presented. Methods: Hence, an attempt is made to bring about a comprehensive account of various natural coagulants and also to understand their properties and efficiencies in treating water. Results: Cumulative information regarding natural coagulants presented in this review will add to the database of natural coagulants and can be adopted at various temporal and spatial levels according to the availability of these coagulants to treat water. Nevertheless, precise research on coagulation parameters and shelf life of treated water will enhance the opportunities for point of use water treatment technologies. Conclusion: The current review presents natural coagulants having the potential to treat surface water as sustainable alternatives to point of use treatment.


2020 ◽  
Vol 12 (17) ◽  
pp. 7017
Author(s):  
Hossain Md Anawar ◽  
Rezaul Chowdhury

Selection of appropriate river water treatment methods is important for the restoration of river ecosystems. An in-depth review of different river water treatment technologies has been carried out in this study. Among the physical-engineering processes, aeration is an effective, sustainable and popular technique which increases microbial activity and degrades organic pollutants. Other engineering techniques (water diversion, mechanical algae removal, hydraulic structures and dredging) are effective as well, but they are cost intensive and detrimental to river ecosystems. Riverbank filtration is a natural, slow and self-sustainable process which does not pose any adverse effects. Chemical treatments are criticised for their short-term solution, high cost and potential for secondary pollution. Ecological engineering-based techniques are preferable due to their high economic, environmental and ecological benefits, their ease of maintenance and the fact that they are free from secondary pollution. Constructed wetlands, microbial dosing, ecological floating beds and biofilms technologies are the most widely applicable ecological techniques, although some variabilities are observed in their performances. Constructed wetlands perform well under low hydraulic and pollutant loads. Sequential constructed wetland floating bed systems can overcome this limitation. Ecological floating beds are highly recommended for their low cost, high effectiveness and optimum plant growth facilities.


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