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Nielsen AM, Garcia LAT, Silva KJS, Sabogal-Paz LP, Hincapié MM, Montoya LJ, Galeano L, Galdos-Balzategui A, Reygadas F, Herrera C, Golden S, Byrne JA, Fernández-Ibáñez P. Chlorination for low-cost household water disinfection - A critical review and status in three Latin American countries. Int J Hyg Environ Health 2022; 244:114004. [PMID: 35816847 DOI: 10.1016/j.ijheh.2022.114004] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/21/2022] [Accepted: 06/26/2022] [Indexed: 12/01/2022]
Abstract
Chlorination has historically provided microbiologically safe drinking water in public water supplies. Likewise, chlorine has also been introduced as a low-cost disinfection method in rural and marginalized communities, both at community and household level, as well as during emergencies. Although this practice is common and well established for use as a household water treatment technology in the Global South, several challenges in effective and efficient implementation still need to be addressed. Here, we explored these issues by a literature review and narrowed them to the status of three Latin American countries (Mexico, Colombia, and Brazil). Overall, it was found that although guidance on household-based chlorination includes information on health risks and hygiene, this may not create enough incentive for the user to adapt the method satisfactorily. Physicochemical quality of the water influences chlorination efficiency and it is found that variations in quality are rarely considered when recommending chlorine doses during implementation. These are far more often based on a few measurements of turbidity, thereby not considering dissolved organic matter, or seasonal and day-to-day variations. Other factors such as user preferences, chlorine product quality and availability also represent potential barriers to the sustainable use of chlorination. For chlorination to become a sustainable household water treatment, more focus should therefore be given to local conditions prior to the intervention, as well as support and maintenance of behavioural changes during and after the intervention.
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Affiliation(s)
- A M Nielsen
- School of Engineering, Ulster University, Northern Ireland, BT37 0QB, United Kingdom
| | - L A T Garcia
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense 400, São Carlos, São Paulo, Zip code 13566-590, Brazil
| | - K J S Silva
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense 400, São Carlos, São Paulo, Zip code 13566-590, Brazil
| | - L P Sabogal-Paz
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense 400, São Carlos, São Paulo, Zip code 13566-590, Brazil
| | - M M Hincapié
- School of Engineering, University of Medellin, Ctra 87, 30-65, Medellin, 050026, Colombia
| | - L J Montoya
- School of Engineering, University of Medellin, Ctra 87, 30-65, Medellin, 050026, Colombia
| | - L Galeano
- School of Engineering, University of Medellin, Ctra 87, 30-65, Medellin, 050026, Colombia
| | - A Galdos-Balzategui
- School of Engineering, Ulster University, Northern Ireland, BT37 0QB, United Kingdom; Fundación Cántaro Azul, Calzada Daniel Sarmiento 19, Los Alcanfores, 29246, San Cristóbal de Las Casas, Chiapas, Mexico
| | - F Reygadas
- Fundación Cántaro Azul, Calzada Daniel Sarmiento 19, Los Alcanfores, 29246, San Cristóbal de Las Casas, Chiapas, Mexico
| | - C Herrera
- Centro de Ciencia y Tecnologia de Antioquia, Carrera 46, 56-11,15. Ed. Tecnoparque, Medellin, Colombia
| | - S Golden
- Belfast School of Architecture and the Built Environment, Ulster University, United Kingdom
| | - J A Byrne
- School of Engineering, Ulster University, Northern Ireland, BT37 0QB, United Kingdom
| | - P Fernández-Ibáñez
- School of Engineering, Ulster University, Northern Ireland, BT37 0QB, United Kingdom.
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Freitas BLS, Terin UC, Fava NMN, Maciel PMF, Garcia LAT, Medeiros RC, Oliveira M, Fernandez-Ibañez P, Byrne JA, Sabogal-Paz LP. A critical overview of household slow sand filters for water treatment. Water Res 2022; 208:117870. [PMID: 34823084 DOI: 10.1016/j.watres.2021.117870] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/26/2021] [Accepted: 11/13/2021] [Indexed: 06/13/2023]
Abstract
Household, or point-of-use (POU), water treatments are effective alternatives to provide safe drinking water in locations isolated from a water treatment and distribution network. The household slow sand filter (HSSF) is amongst the most effective and promising POU alternatives available today. Since the development of the patented biosand filter in the early 1990s, the HSSF has undergone a number of modifications and adaptations to improve its performance, making it easier to operate and increase users' acceptability. Consequently, several HSSF models are currently available, including those with alternative designs and constant operation, in addition to the patented ones. In this scenario, the present paper aims to provide a comprehensive overview from the earliest to the most recent publications on the HSSF design, operational parameters, removal mechanisms, efficiency, and field experiences. Based on a critical discussion, this paper will contribute to expanding the knowledge of HSSF in the peer-reviewed literature.
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Affiliation(s)
- B L S Freitas
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense, 400, São Carlos, São Paulo, 13566-590, Brazil
| | - U C Terin
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense, 400, São Carlos, São Paulo, 13566-590, Brazil
| | - N M N Fava
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense, 400, São Carlos, São Paulo, 13566-590, Brazil
| | - P M F Maciel
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense, 400, São Carlos, São Paulo, 13566-590, Brazil
| | - L A T Garcia
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense, 400, São Carlos, São Paulo, 13566-590, Brazil
| | - R C Medeiros
- Department of Engineering and Environmental Technology, Federal University of Santa Maria, Linha 7 de Setembro, BR 386, Km 40, Frederico Westphalen, Rio Grande do Sul, 98400-000, Brazil
| | - M Oliveira
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense, 400, São Carlos, São Paulo, 13566-590, Brazil
| | - P Fernandez-Ibañez
- Nanotechnology and Integrated Bioengineering Centre, School of Engineering, Ulster University, Jordanstown, BT37 0QB, Northern Ireland, United Kingdom
| | - J A Byrne
- Nanotechnology and Integrated Bioengineering Centre, School of Engineering, Ulster University, Jordanstown, BT37 0QB, Northern Ireland, United Kingdom
| | - L P Sabogal-Paz
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-Carlense, 400, São Carlos, São Paulo, 13566-590, Brazil.
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3
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Andreoli FC, Sabogal-Paz LP. Household slow sand filter to treat groundwater with microbiological risks in rural communities. Water Res 2020; 186:116352. [PMID: 32916617 DOI: 10.1016/j.watres.2020.116352] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
Household slow sand filters (HSSFs) improve the quality of life in rural communities as they provide safe water. However, HSSFs require time for the growth of the biological layer (schmutzdecke) to achieve maximum performance, especially when groundwater is used as it normally has few nutrients. In this ripening period, pathogenic microorganisms can pass through the filter. In this context, this study reports the performance of two HSSF settings, intermittent (I-HSSF) and continuous (C-HSSF) flows followed by disinfection with sodium hypochlorite to treat groundwater with Escherichia coli, Giardia muris cysts and Cryptosporidium parvum oocysts. The weekly introduction of river water was tested as a filter-ripening agent and this procedure reduced the ripening time in approximately 80 days. Filtered water disinfection improved the water quality and inactivated protozoa. The costs and operational challenges addressed in this study can provide support to HSSF technology transfer in rural communities worldwide.
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Affiliation(s)
- F C Andreoli
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, 400 Trabalhador São-carlense Avenue, Zip code: 13566-590, São Carlos, São Paulo, Brazil
| | - L P Sabogal-Paz
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, 400 Trabalhador São-carlense Avenue, Zip code: 13566-590, São Carlos, São Paulo, Brazil.
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Medeiros RC, de M N Fava N, Freitas BLS, Sabogal-Paz LP, Hoffmann MT, Davis J, Fernandez-Ibañez P, Byrne JA. Drinking water treatment by multistage filtration on a household scale: Efficiency and challenges. Water Res 2020; 178:115816. [PMID: 32353612 DOI: 10.1016/j.watres.2020.115816] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
Universalising actions aimed at water supply in rural communities and indigenous populations must focus on simple and low-cost technologies adapted to the local context. In this setting, this research studied the dynamic gravel filter (DGF) as a pre-treatment to household slow-sand filters (HSSFs), which is the first description of a household multistage filtration scale to treat drinking water. DGFs (with and without a non-woven blanket on top of the gravel layer) followed by HSSFs were tested. DGFs operated with a filtration rate of 3.21 m3 m-2.d-1 and HSSFs with 1.52 m3 m-2.d-1. Influent water contained kaolinite, humic acid and suspension of coliforms and protozoa. Physical-chemical parameters were evaluated, as well as Escherichia coli, Giardia spp. cysts and Cryptosporidium spp. oocyst reductions. Removal was low (up to 6.6%) concerning true colour, total organic carbon and absorbance (λ = 254 nm). Nevertheless, HMSFs showed turbidity decrease above 60%, E. coli reduction up to 1.78 log, Giardia cysts and Cryptosporidium oocysts reductions up to 3.15 log and 2.24 log, respectively. The non-woven blanket was shown as an important physical barrier to remove solids, E. coli and protozoa.
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Affiliation(s)
- R C Medeiros
- Department of Engineering and Environmental Technology, Federal University of Santa Maria, 98400-000, Frederico Westphalen, Rio Grande do Sul, Brazil
| | - N de M N Fava
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Trabalhador São-Carlense Avenue, 400, São Carlos, São Paulo, 13566-590, Brazil
| | - B L S Freitas
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Trabalhador São-Carlense Avenue, 400, São Carlos, São Paulo, 13566-590, Brazil
| | - L P Sabogal-Paz
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Trabalhador São-Carlense Avenue, 400, São Carlos, São Paulo, 13566-590, Brazil.
| | - M T Hoffmann
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Trabalhador São-Carlense Avenue, 400, São Carlos, São Paulo, 13566-590, Brazil
| | - J Davis
- Nanotechnology and Integrated Bioengineering Centre, School of Engineering, Ulster University, Jordanstown, BT37 0QB, Northern Ireland, United Kingdom
| | - P Fernandez-Ibañez
- Nanotechnology and Integrated Bioengineering Centre, School of Engineering, Ulster University, Jordanstown, BT37 0QB, Northern Ireland, United Kingdom
| | - J A Byrne
- Nanotechnology and Integrated Bioengineering Centre, School of Engineering, Ulster University, Jordanstown, BT37 0QB, Northern Ireland, United Kingdom
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5
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Terin UC, Sabogal-Paz LP. Microcystis aeruginosa and microcystin-LR removal by household slow sand filters operating in continuous and intermittent flows. Water Res 2019; 150:29-39. [PMID: 30503872 DOI: 10.1016/j.watres.2018.11.055] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 11/13/2018] [Accepted: 11/19/2018] [Indexed: 05/26/2023]
Abstract
A household slow sand filter (HSSF) is a widely used water treatment technology recognized as one of the most effective and sustainable in reducing waterborne diseases. However, there is a lack of knowledge concerning its behaviour in the presence of cyanobacteria and cyanotoxins. In this context, the study aimed to evaluate HSSF ability to remove Microcystis aeruginosa cells (stain BB005) and microcystin-LR from water, among other parameters, when operated under continuous (C-HSSF) and intermittent (I-HSSF) flows. CHSSF was operated at a constant filtration rate (1.22 m3 m-2 day-1), while I-HSSF was operated at a variable filtration rate (starting at 2.95 m3 m-2 day-1 and finishing at zero). Each filter produced 60 L day-1. The influence of the pause period was also tested in the I-HSSF. The water from the study was prepared by inoculating M. aeruginosa culture in water from a well to a final cell density of ± 1 × 105 cells mL-1. M. aeruginosa removal rates were 2.39 ± 0.34 log and 2.01 ± 0.43 log by CHSSF and I-HSSF, respectively. Microcystin-LR concentration in studied water was 5.55 μg L-1, and both filters produced filtered water with microcystin concentrations below 1.0 μg L-1, the maximum value recommended by the World Health Organization (WHO), for most of the samples. Turbidity and apparent colour were also within WHO guidelines. Filters operating with different flow regimes and distinct residence times did not statistically influence treatment efficiencies. Both filters showed promising results in the M. aeruginosa and microcystin-LR removals from water; nevertheless, more research is needed to understand the mechanisms involved in the reduction of both cyanobacteria and cyanotoxin through household slow sand filtration.
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Affiliation(s)
- U C Terin
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Trabalhador São-Carlense Avenue, 400, São Paulo, 13566-590, Brazil
| | - L P Sabogal-Paz
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Trabalhador São-Carlense Avenue, 400, São Paulo, 13566-590, Brazil.
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6
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Maciel PMF, Sabogal-Paz LP. Removal of Giardia spp. and Cryptosporidium spp. from water supply with high turbidity: analytical challenges and perspectives. J Water Health 2016; 14:369-378. [PMID: 27280604 DOI: 10.2166/wh.2015.227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Giardia and Cryptosporidium species are a serious problem if present in water supplies. The removal of these protozoans and the adaptation of existing protocols are essential for supplying drinking water to developing countries. Considering this, the aim of this study is to evaluate, on a bench level, the removal of Giardia spp. cysts and of Cryptosporidium spp. oocysts from water with high turbidity, using polyaluminium chloride as a coagulant. Filtration using mixed cellulose ester membranes, followed, or not, by purification through immunomagnetic separation (IMS) was used for detecting protozoans. By evaluating the adopted protocol, without using IMS, retrievals of 80% of cysts and 5% of oocysts were obtained, whereas by using IMS, recoveries of 31.5% of cysts and 5.75% of oocysts were reached. When analyzing the coagulant performance, a dosage of 65 mg L(-1) showed contamination from protozoans in all the samples of filtered water. A dosage of 25 mg L(-1) presented protozoans in 50% of the filtered water samples. The results showed an improved performance for the 25 mg L(-1) dosage; therefore, the control of coagulation and adaptation of detection protocols must be evaluated according to the features of raw water and availability of local resources.
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Affiliation(s)
- P M F Maciel
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, 400 Trabalhador São-carlense Avenue, Zip code: 13566-590, São Carlos, São Paulo, Brazil E-mail:
| | - L P Sabogal-Paz
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, 400 Trabalhador São-carlense Avenue, Zip code: 13566-590, São Carlos, São Paulo, Brazil E-mail:
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