Household Drinking Water Treatment Research Articles

Performance of traditional household drinking water treatment methods used in rural Amazon

Performance of traditional household drinking water treatment methods used in rural Amazon

Evidence of waste management impacting severe diarrhea prevalence more than WASH: An exhaustive analysis with Brazilian municipal-level data

Adequate housing protects from diarrhea, which is a substantial health concern in low- and middle-income countries. The purpose of this study was to quantify the relationship between severe diarrhea and housing features at the municipal level to help in public health planning.Regression analyses were performed on annual (2000–2012) datasets on Brazilian municipalities (5570) in six household feature categories (e.g., waste management) and four severe diarrhea outcomes (e.g., diarrhea deaths of under-5 children). Household data were not available elsewhere of this magnitude and granularity, highlighting the scientific value-add of this study. Municipalities were clustered prior to regression analysis because of data heterogeneity. The compositional household feature data were also subjected to principal component analysis to diminish feature variable multicollinearity.The highest explanatory power was found for diarrhea deaths of under-5 children (R2 = 10–22 %), while those in the over-5 population were the least best explained (R2 = 0.3–7 %). Household features predicted diarrhea outcomes more accurately in the “advanced” housing municipality cluster (R2 = 16–22 %) than in the “mid-level” (R2 = 7–20 %) and “basic” (R2 = 6–12 %) ones (over-5 diarrhea deaths excluded). Under-5 children's diarrhea death prevalence was three times higher in the “basic” cluster than in the “advanced” cluster. Importantly, the impact of waste management was overall the largest of all household features, even larger than those of WASH, i.e., water supply, sanitation, and household drinking water treatment. This is surprising in the context of existing literature because WASH is generally regarded as the most important household factor affecting gastrointestinal health.In conclusion, public health interventions could benefit from customizing interventions for diarrhea outcomes, municipality types, and household features. Waste management's identified stronger association with diarrhea compared to WASH may have important implications beyond the water field and Brazil.

Why do low-cost point-of-use water treatment technologies succeed or fail in combating waterborne diseases in the field? A systematic review

In a world where the consequences of inequalities in access to safe drinking water persist, Household Drinking Water Treatment Technologies (HDWT) remains the most readily available and promising alternative solution to prevent waterborne diseases. While successful cases of combating waterborne diseases with HDWT have been documented, there are also reports of failures in reducing water-related illnesses. Understanding the reasons behind these inconsistent results is crucial. This work aimed to identify and critically discuss barriers, enablers, and technology delivery strategies for HDWT-based interventions to improve drinking water safety. Data from 147 articles covering Solar Disinfection, Chlorination, Flocculation-Disinfection, BioSand Filter, and Ceramic Water Filter were extracted from a total of 11,982 systematically retrieved records. Among the identified factors, 77 barriers and 76 enablers were distributed across different domains: psychosocial (37.7, 47.4%), promotion (22.1, 26.3%), technology (28.6, 10.5%), economic (9.1, 14.5%), and environmental (2.6, 1.3%) for barriers and enablers, respectively. Technology delivery strategies primarily included water education and technology promotion, training for technology usage, provision of HDWT through donation or promotional sale, donation of safe water storage, technical assistance, and the use of a diarrhea control diary. All barriers and enablers affect the initial adoption, regular, and sustained use of HDWT and should be considered when planning and implementing interventions. The health impacts of interventions decreased over time since HDWT adoption. Adequate user training, HDWT donation, and high compliance are important predictors of success for HDWT-based interventions. In general, identifying and exploring the listed enablers can help overcome many of the reported limitations.

A challenge in washing water with the sun: 24h of SODIS fails to inactivate Acanthamoeba castellanii cysts and internalized Pseudomonas aeruginosa under strong real sun conditions.

Despite access to drinking water being a basic human right, the availability of safe drinking water remains a privilege that many do not have and as a result, many lives are lost each year due to waterborne diseases associated with the consumption of biologically unsafe water. To face this situation, different low-cost household drinking water treatment technologies (HDWT) have been developed, and among them is solar disinfection (SODIS). Despite the effectiveness of SODIS and the epidemiological gains being consistently documented in the literature, there is a lack of evidence of the effectiveness of the batch-SODIS process against protozoan cysts as well as their internalized bacteria under real sun conditions. This work evaluated the effectiveness of the batch-SODIS process on the viability of Acanthamoeba castellanii cysts, and internalized Pseudomonas aeruginosa. Dechlorinated tap water contaminated with 5.6 × 103 cysts/L, contained in PET (polyethylene terephthalate) bottles, was exposed for 8h a day to strong sunlight (531-1083W/m2 of maximum insolation) for 3 consecutive days. The maximum water temperature inside the reactors ranged from 37 to 50°C. Cyst viability was assessed by inducing excystment on non-nutrient agar, or in water with heat-inactivated Escherichia coli. After sun exposure for 0, 8, 16 and 24h, the cysts remained viable and without any perceptible impairment in their ability to excyst. 3 and 5.5 log CFU/mL of P. aeruginosa were detected in water containing untreated and treated cysts, respectively, after 3days of incubation at 30°C. The batch-SODIS process is unable to inactivate A. castellanii cysts as well as its internalized bacteria. Although the use of batch SODIS by communities should continue to be encouraged, SODIS-disinfected water should be consumed within 3days.

Household drinking water treatment in rural Indonesia: actual practice, determinants, and drinking water quality

Abstract Household water treatment (HWT) is a solution for households that do not have access to a safe drinking water supply. A cross-sectional study was conducted in Ende District, Province of Nusa Tenggara Timur (NTT), Indonesia. A total of 425 household respondents were interviewed and observed about the HWT practice and water storage condition and 143 household drinking water samples were collected for microbial water quality analysis. Results show that even though HWT is regularly performed, not all the water they drink has been treated. The ‘level’ of psychological factors risk, attitude, norms, ability, and self-regulation (RANAS) were high, indicating that regular HWT practice goes in hand with the underlying psychological factors. Psychological factor action planning was the most influential psychological sub-factor associated related with the frequency of drinking treated water. Drinking water is mostly stored in safe storage, but placed in a less hygienic surrounding environment. Though HWT results in better water quality, water quality was not significantly associated with HWT, drinking water handling, or storage. Finally, promoting always drinking treated water and then storing it in a safe and hygienic environment are still needed in areas where HWT is commonly practiced, so people can get the maximum health impact of HWT.

Environmental Factors Associated with Tyfoid Fever In Barru General Hospital

This study aimed to determine the relationship between the environment and the incidence of typhoid fever at the Barru Regional General Hospital, Barru Regency, in 2014. The type of research used was observational, with analytic characteristics and a cross-sectional study approach. The population in this study were all patients who were recorded in the medical records of the Barru Regional General Hospital in 2014 from January to June. There were 101 patients. The sample in this study was 80 people who became the object of research. The analysis was performed with the Chi-Square statistical test. The research results show the provision of clean water, disposal of feces, waste management, safeguarding of household waste, and processing household drinking water. There is a relationship between the provision of drinking water and the incidence of typhoid fever with a p-value = 0.000 <α 0.05; there is no relationship between the disposal of feces and the incidence of typhoid fever with a value of p = 0.058 > α 0.05, there is no relationship between waste management and the incidence of fever typhoid with a p-value = 0.725 > α 0.05, there is a relationship between household waste management and the incidence of typhoid fever with a p-value = 0.001 <α 0.05, there is no relationship between household drinking water treatment and the incidence of typhoid fever with a p-value = 0.568 > α 0.05.

Invited Perspective: Environmental Health Interventions Are Only as Good as Their Adoption.

Vol. 131, No. 1 Invited PerspectiveOpen AccessInvited Perspective: Environmental Health Interventions Are Only as Good as Their Adoptionis companion ofAdoption of Point-of-Use Chlorination for Household Drinking Water Treatment: A Systematic Review Karen Levy Karen Levy Address correspondence to Karen Levy, Department of Environmental and Occupational Health Sciences, University of Washington, Box 351618, 2980 15th Ave. NE, Seattle, WA 98195 USA. Telephone: (206) 543-4341. Email: E-mail Address: [email protected] https://orcid.org/0000-0002-0968-9401 Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA Search for more papers by this author Published:30 January 2023CID: 011303https://doi.org/10.1289/EHP11906AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit “I have not failed. I’ve just found 10,000 ways that will not work.” –Thomas EdisonScientists and engineers often come up with brilliant ideas, but in the end technology is only as good as its adoption and proper use. This is true for regardless of how complicated or simple the technology.Household water treatment, also commonly referred to as point-of-use (POU) water treatment, is a strategy to improve access to safe water that was introduced within the water, sanitation, and hygiene (WASH) field1 because many communities in lower- and middle-income country (LMIC) settings lack access to a full-scale water treatment plant. With POU treatment, residents can conduct at least some elements of treatment (coagulation and sedimentation, filtration, ultraviolet disinfection, or chemical inactivation) in their own homes, offering them the capacity to disinfect their own water. Treating water in the home also has the benefit of minimizing recontamination after collection, a well-documented phenomenon in locations where people fetch their water from locations outside the home.2,3Chlorination has been seen as a particularly promising POU approach because it leaves a residual disinfectant in the water to address microbial intrusion during storage.4 In LMICs, many studies have been carried out on the effectiveness of household drinking water chlorination for preventing diarrhea. A recent systematic review found that, compared with untreated drinking water from an unimproved source, risk of diarrhea was reduced by 44% with POU chlorination of water [lowercase italic n equals 25n=25 studies; 0.66 (0.56–0.77)].5However, although understanding the potential health impact of a technology is important, understanding whether and why people use, or do not use, a proposed technology is equally important. In their review in this issue of Environmental Health Perspectives, Crider et al. do just this, addressing barriers to the adoption of POU chlorination for household drinking water treatment by 46 target populations.6Considering users’ needs and interests is essential to adoption of a technology. For example, the authors found that bad taste, smell, or appearance of treated water was cited by a large percentage of households, as was lack of time to spend on disinfection (a time burden usually placed on women). Most of the intervention groups received chlorination products for free; households in the groups that did not cited price or availability of products as a barrier to repurchase and continued use.In addition to the identification of specific barriers to adoption two other aspects stood out in the review. First, the authors identified a sheer lack of information on barriers to adoption. “Much of the time, the reasons for low adoption are poorly understood simply because the relevant data are not systematically collected,” they stated. The authors excluded 27 of 63 otherwise-eligible studies because quantitative measures of adoption were not reported. Among those that did report a measure of adoption, there was no consensus definition of adoption, and several studies emphasized reasons for use rather than nonuse.Second, lack of attention in the field to user adoption as a signal of intervention success is also belied by the language that researchers use to describe it. Different words used in the literature to describe what Crider et al. appropriately refer to as “adoption” of water chlorination practices range from “adherence” or “compliance” to “use/usage” or “uptake.”6 Public health inherited the language of “compliance” and “adherence” from medicine, where it describes how often patients follow through with a medication regimen.7,8 Although subtle, this language is important because the medical words put the burden of failed adoption on the user, whereas “adoption,” “use/usage,” and “uptake” put this burden on the implementer.Time and again we see environmental health–based interventions fail because we are not focused enough on the actual uptake of a technology. This is also true for other areas of environmental health, such as household air pollution (HAP).9,10 The WASH and HAP fields are increasingly recognizing the importance of applying approaches from systems science and implementation science to increase the chances of success for environmental health interventions.10,11This work is critical. Our practices, and our language, must center on users’ needs and interests if we hope for adoption of new technologies to improve population health related to environmental conditions.

Application of the quorum sensing inhibitor to improve ARGs removal by membrane-based household drinking water treatment process

Antibiotic resistance genes (ARGs) have become an increasing threat to human health. Membrane-based technologies have been applied to address multiple concerns regarding the quality of household drinking water (HDW), including ARGs. However, the long-term operation of membrane-based HDW purifiers would inevitably lead to biofouling, making the membrane turn from cleaner to a secondary pollution source. This study proposed a strategy based on quorum sensing inhibitor (QSI) to control ARGs in the finished water of HDW purifiers. Three reported QSIs, vanillin (VL), cranberry extracts (CBETs), and tannic acid (TA), were selected to investigate their effects on the removal of ARGs by typical HDW purifiers, and the corresponding influencing mechanism was elucidated. The results indicated that ARGs leakage occurred in the absence of QSI but disappeared with the addition of VL, CBETs, and TA. The introduction of VL increased the guarantee rate of ≥ 3 log ARGs removal increased from 63.3 to 70% (control group) to 88.9–100%. The influencing mechanism of QSIs on ARGs removal by membrane filtration can be attributed to direct effect (direct inactivation of the ARGs host) and indirect effects (adjusting the physiochemical properties of the membrane surface and bioaccumulation). This study provides data on the regulatory mechanisms of biofouling induced by QSI and proposes a new strategy for ARGs control by membrane-based processes.

Evaluation of Rural Household Drinking Water Treatment: A Case Study of Rajaf Payam Central Equatoria State, Juba-South Sudan

The supply of clean drinking water is one of the most critical facets of primary health care, the main challenges of sustainable development in rural regions. However, Rajaf Payam experiences significant challenges in accessing clean and safe water. The study is designed to explore drinking water treatment methods in Rajaf Payam. Questionnaire was designed to conduct survey on sources of drinking water and drinking water treatment methods in the area, published articles included reports from the national government and some NGOs working in the rural drinking water sector were collected. So far 200 people participated in this study, from whom 60% were male, 40% female. However, 50 critical informant interviews and surveys were conducted, with 150 participants filling out questionnaires. The results show that 66% of the community use chlorine for drinking water treatment. Nonetheless, 19% are using boiling method, 10% using normal filtration (Water settling). At the same time, 5% know nothing about drinking water treatment. Therefore, this study recommending the Point-of-use (POU) of drinking water treatment technologies such as boiling, slow sand filtration, chemical disinfection, flocculation and coagulation, UV-C disinfection, and solar disinfection to the community of Raja Payam to enable them to access high quality drinking water and to avoid chronic drinking water related disease.

Assessment of low-cost cartridge filters for implementation in household drinking water treatment systems

In regions where houses are sparsely located, traditional centralized water treatment plants are not economically feasible, with household water treatment (HWT) systems commonly used to provide potable water for a range of household activities. Filtration prior to disinfection is essential, and due to their ease of use and small footprint, cartridge filters are commonly employed. In this work, readily available commercial filter types (spun, wound and pleated) of different micron ratings (10, 5 and 1) were tested for the removal of turbidity either alone or in series via simulated large volume pilot trials. Water with an initial turbidity of 40 ± 10 NTU was prepared using fine test dust (ISO 12103-1, A2) with the turbidity removal efficiency, pressure drop, total capacity and lifespan of the filters evaluated.To increase useable filter lifetime upon reaching the 1 bar pressure limit, a series of washing steps were employed to regenerate the filters. Whilst pleated filters could be efficiently cleaned, spun and wound filters could not, and were discarded after single use. In pilot trials, the volume of turbid water filtered varied from 0.85 m3 with a 1 micron wound filter to 6 m3, with 5 and 1 micron pleated filters in series, which following regeneration could be used for three filtration cycles. For pleated filters, turbidity removal efficiency improved over time as a cake built up resulting in the effluent turbidity reaching acceptable quality (<5 NTU). This criterion continued to be achieved with repeated cycles of washed pleated filters, thereby significantly reducing the cost and improving sustainability of the HWT system. Field trials were carried out with a similar HWT system (5 and 1 micron spun filters) installed in households of rural communities in Curiti, Colombia. Turbidity was effectively removed from natural water (reduction to <1.2 NTU) with improved efficacy in comparison to synthetic water samples due to the large particle size distribution observed in the natural water.

Optimization of a gravity‐driven membrane (GDM) system operated with simple manual cleanings for household drinking water treatment

AbstractManual cleaning protocols were developed for a gravity‐driven membrane (GDM) module. Such a module is a promising solution for household water treatment in low‐ and middle‐income countries. A filtration system equipped with the GDM module was tested in a batchwise manner using three different feed water solutions. Two types of manual cleaning protocols were performed to delay the permeability decrease, namely cleaning between batches and long‐term cleaning (every 15 batches). The optimized protocol for cleaning between batches consisted of 3 twisting and 10 vertical shaking movements; the optimized long‐term cleaning protocol consisted of 70 vertical shaking movements for both the middle region of the module and the module header. These cleaning protocols allowed the filtration system to produce sufficient water to meet the minimum requirements for a five person family using all three kinds of feed water solutions. The module produced water without Escherichia coli, even for the wastewater influent.

The effects of input materials on ceramic water filter efficacy for household drinking water treatment

Locally manufactured ceramic filters can improve drinking water quality and reduce diarrheal disease burden in developing countries; however, production methods and quality control protocols vary at the &amp;gt;50 factories. We manufactured filter disks with varied clay, burn-out material, burn-out material sieved with different mesh sizes, and burn-out material to clay ratios and calculated filter characteristics, including porosity, density, shrinkage, and flow rate. Water was run through filters daily for 4 weeks, and flow rate and Escherichia coli reduction, as measured by log reduction value (LRV), were tested twice weekly. Our results suggest: (1) the first and last LRV test results do not correlate strongly (R2 = 0.38, p &amp;lt; 0.010); (2) there is not a strong association between flow rate and first, average, or last LRV results (R2 = 0.17, p = 0.090; R2 = 0.30, p = 0.020; R2 = 0.24, p = 0.040); and (3) first and average LRV are associated with burn-out material (R2 = 0.68, p &amp;lt; 0.001; R2 = 0.60, p &amp;lt; 0.001), and last LRV is associated with burn-out material and mesh size (R2 = 0.54, p &amp;lt; 0.050). Recommendations for filter factories, are to: (1) verify filtration efficacy with repeated bacteria reduction tests when materials, processing, or filter characteristics vary; (2) carefully control production variables; and (3) continue flow rate testing each filter to evaluate within and across batch production consistency.

Continuation of Health Behaviors: Psychosocial Factors Sustaining Drinking Water Chlorination in a Longitudinal Study from Chad

Behavior that has changed following promotion campaigns is usually not maintained at its initial level. Psychosocial factors for initiating behavior are often not the same as for the continuation of health behaviors such as water treatment and are much less understood. Better knowledge of factors for behavioral continuation would help to improve programs, both in the design of strategies for sustainable behavior change and by defining stronger criteria for the evaluation of sustainability. This study compared the mindsets of caregivers who continuously performed household drinking water treatment over time with individuals that stopped doing so in a population sample from Chad. Several factors from health psychology based on the Risks, Attitudes, Norms, Abilities, and Self-Regulation (RANAS) model were used to compare the two groups and examine their differing development. Normative factors such as others’ behavior, personal obligation, social support and discourse, perceived self-efficacy convictions, action control, and intention best discriminated between the two groups and developed significantly more positively over time for continuers of water treatment. These factors should be considered when designing future interventions intended to lead to sustainable behavior change.

Accuracy, precision, usability, and cost of portable silver test methods for ceramic filter factories.

Locally manufactured ceramic water filters are one effective household drinking water treatment technology. During manufacturing, silver nanoparticles or silver nitrate are applied to prevent microbiological growth within the filter and increase bacterial removal efficacy. Currently, there is no recommendation for manufacturers to test silver concentrations of application solutions or filtered water. We identified six commercially available silver test strips, kits, and meters, and evaluated them by: (1) measuring in quintuplicate six samples from 100 to 1,000 mg/L (application range) and six samples from 0.0 to 1.0 mg/L (effluent range) of silver nanoparticles and silver nitrate to determine accuracy and precision; (2) conducting volunteer testing to assess ease-of-use; and (3) comparing costs. We found no method accurately detected silver nanoparticles, and accuracy ranged from 4 to 91% measurement error for silver nitrate samples. Most methods were precise, but only one method could test both application and effluent concentration ranges of silver nitrate. Volunteers considered test strip methods easiest. The cost for 100 tests ranged from 36 to 1,600 USD. We found no currently available method accurately and precisely measured both silver types at reasonable cost and ease-of-use, thus these methods are not recommended to manufacturers. We recommend development of field-appropriate methods that accurately and precisely measure silver nanoparticle and silver nitrate concentrations.

Understanding and improving water sanitation practices to improve health outcomes in Malawi

www.thelancet.com/lancetgh 27 Published Online April 8, 2016 Virginia Tech Carilion School of Medicine, Roanoke, VA, USA (P A Muelenaer MD); Virginia Polytechnic and State University, Blacksburg, VA, USA (K Redican PhD, S W Marmagas MPH); Mzuzu University, Mzuzu, Malawi (R H Holm PhD) Correspondence to: Penelope Muelenaer , 6736 Mallard Lake Drive, Roanoke, VA 24018-6931, USA pamuelenaer@carilionclinic. org Understanding and improving water sanitation practices to improve health outcomes in Malawi Penelope A Muelenaer, Kerry J Redican, Susan W Marmagas, Rochelle H Holm Abstract Background Sustainable Development Goals (SDG) for the universal provision of safe drinking water in the household focus on the need for sustainable, eff ective, and acceptable household water treatment. In this study we aimed to: understand baseline practices and knowledge related to household water supply, safety of drinking water, and hygiene and sanitation; and compare the effi cacy and acceptance of three diff erent point-of-use water treatment interventions.Background Sustainable Development Goals (SDG) for the universal provision of safe drinking water in the household focus on the need for sustainable, eff ective, and acceptable household water treatment. In this study we aimed to: understand baseline practices and knowledge related to household water supply, safety of drinking water, and hygiene and sanitation; and compare the effi cacy and acceptance of three diff erent point-of-use water treatment interventions. Methods We undertook a fi eld study of 30 households in a peri-urban neighbourhood adjacent to the city of Mzuzu, Malawi. We used a random number generator to assign households to one of three water purifi cation interventions: boiling, Waterguard chlorine solution (PSI/Malawi, Blantyre, Malawi) , or Tulip table-top ceramic fi lter. We analysed samples taken from a drinking-water storage container in each household at baseline and 2 weeks after baseline, and recorded total coliform and Escherichia coli count s. Participants completed an initial structured questionnaire about water sources used, sanitation, health, water consumption patterns, and socioeconomic variables in their household. Follow-up questionnaires at 1 week and 2 weeks after the intervention, focused on use and acceptance of the assigned treatment modality. We used WHO health risk standards, and correlated drinking water quality with the questionnaire responses. We used Fisher’s exact test for data analysis. Findings Final data analysis included 28 households: nine from the Tulip fi lter group, 10 from Waterguard chlorination, and nine from the group who boiled water. Two households had incomplete data and were excluded from analysis. Before the intervention, 29 of 30 households were not treating their water. The no-risk WHO standard of 0 CFU/100 mL Escherichia coli was met in eight (89%) samples from households assigned to the Tulip fi lter, four (40%) who used Waterguard , and fi ve (56%) that boiled water. Of the households that boiled water three (30%) met criteria for high, or very high risk. No statistical diff erences were noted between the treatment methods (p=0·081). Ratings of water appearance, smell, and taste were highest in the Tulip fi lter group and lowest in those who boiled water. All households that used the Tulip fi lter intervention expressed satisfaction with the method and wanted to continue to use the fi lter. Interpretation This study provides evidence to inform the development of public health educational programmes that promote household drinking water treatment, improved hygiene and sanitation practices for low-income and middleincome countries working to meet the SDGs. While not statistically signifi cant, there was a trend toward superior performance by the Tulip fi lter in eff ective treatment of household water. Future comparisons of these interventions in a larger study would need to be done to achieve the statistical power to detect a signifi cant diff erence in the three household water treatment methods studied. Funding The Pediatric Medical Device Institute. Copyright © Muelenaer et al. Open Access article distributed under the terms of CC BY. Declaration of interests We declare no competing interests.

Chitosan Coagulation to Improve Microbial and Turbidity Removal by Ceramic Water Filtration for Household Drinking Water Treatment.

The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters (CWFs) and evaluate the performance of this dual barrier water treatment system. Chitosan is a non-toxic and biodegradable organic polymer derived by simple chemical treatments from chitin, a major source of which is the leftover shells of crustacean seafoods, such as shrimp, prawns, crabs, and lobsters. To determine the effectiveness of chitosan, model test water was contaminated with Escherichia coli K011 and coliphage MS2 as a model enteric bacterium and virus, respectively. Kaolinite clay was used to model turbidity. Coagulation effectiveness of three types of modified chitosans was determine at various doses ranging from 5 to 30 mg/L, followed by flocculation and sedimentation. The pre-treated supernatant water was then decanted into the CWF for further treatment by filtration. There were appreciable microbial removals by chitosan HCl, acetate, and lactate pretreatment followed by CWF treatment, with mean reductions (95% CI) between 4.7 (±1.56) and 7.5 (±0.02) log10 for Escherichia coli, and between 2.8 (±0.10) and 4.5 (±1.04) log10 for MS2. Turbidity reduction with chitosan treatment and filtration consistently resulted in turbidities < 1 NTU, which meet turbidity standards of the US EPA and guidance by the World Health Organization (WHO). According to WHO health-based microbial removal targets for household water treatment technology, chitosan coagulation achieved health protective targets for both viruses and bacteria. Therefore, the results of this study support the use of chitosan to improve household drinking water filtration processes by increasing virus and bacteria reductions.

Chitosan Coagulation to Improve Microbial and Turbidity Removal by Ceramic Water Filtration for Household Drinking Water Treatment

Chitosan Coagulation to Improve Microbial and Turbidity Removal by Ceramic Water Filtration for Household Drinking Water Treatment

Microbiological Evaluation of Household Drinking Water Treatment in Rural China Shows Benefits of Electric Kettles: A Cross-Sectional Study.

BackgroundIn rural China ~607 million people drink boiled water, yet little is known about prevailing household water treatment (HWT) methods or their effectiveness. Boiling, the most common HWT method globally, is microbiologically effective, but household air pollution (HAP) from burning solid fuels causes cardiovascular and respiratory disease, and black carbon emissions exacerbate climate change. Boiled water is also easily re-contaminated. Our study was designed to identify the HWT methods used in rural China and to evaluate their effectiveness.MethodsWe used a geographically stratified cross-sectional design in rural Guangxi Province to collect survey data from 450 households in the summer of 2013. Household drinking water samples were collected and assayed for Thermotolerant Coliforms (TTC), and physicochemical analyses were conducted for village drinking water sources. In the winter of 2013–2104, we surveyed 120 additional households and used remote sensors to corroborate self-reported boiling data.FindingsOur HWT prevalence estimates were: 27.1% boiling with electric kettles, 20.3% boiling with pots, 34.4% purchasing bottled water, and 18.2% drinking untreated water (for these analyses we treated bottled water as a HWT method). Households using electric kettles had the lowest concentrations of TTC (73% lower than households drinking untreated water). Multilevel mixed-effects regression analyses showed that electric kettles were associated with the largest Log10TTC reduction (-0.60, p<0.001), followed by bottled water (-0.45, p<0.001) and pots (-0.44, p<0.01). Compared to households drinking untreated water, electric kettle users also had the lowest risk of having TTC detected in their drinking water (risk ratio, RR = 0.49, 0.34–0.70, p<0.001), followed by bottled water users (RR = 0.70, 0.53–0.93, p<0.05) and households boiling with pots (RR = 0.74, 0.54–1.02, p = 0.06).ConclusionAs far as we are aware, this is the first HWT-focused study in China, and the first to quantify the comparative advantage of boiling with electric kettles over pots. Our results suggest that electric kettles could be used to rapidly expand safe drinking water access and reduce HAP exposure in rural China.

Perception of drinking water safety and factors influencing acceptance and sustainability of a water quality intervention in rural southern India.

BackgroundAcceptance and long-term sustainability of water quality interventions are pivotal to realizing continued health benefits. However, there is limited research attempting to understand the factors that influence compliance to or adoption of such interventions.MethodsEight focus group discussions with parents of young children - including compliant and not compliant households participating in an intervention study, and three key-informant interviews with village headmen were conducted between April and May 2014 to understand perceptions on the effects of unsafe water on health, household drinking water treatment practices, and the factors influencing acceptance and sustainability of an ongoing water quality intervention in a rural population of southern India.ResultsThe ability to recognize health benefits from the intervention, ease of access to water distribution centers and the willingness to pay for intervention maintenance were factors facilitating acceptance and sustainability of the water quality intervention. On the other hand, faulty perceptions on water treatment, lack of knowledge about health hazards associated with drinking unsafe water, false sense of protection from locally available water, resistance to change in taste or odor of water and a lack of support from male members of the household were important factors impeding acceptance and long term use of the intervention.ConclusionThis study highlights the need to effectively involve communities at important stages of implementation for long term success of water quality interventions. Timely research on the factors influencing uptake of water quality interventions prior to implementation will ensure greater acceptance and sustainability of such interventions in low income settings.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-1974-0) contains supplementary material, which is available to authorized users.

High‐Content, Well‐Dispersed γ‐Fe2O3 Nanoparticles Encapsulated in Macroporous Silica with Superior Arsenic Removal Performance

Novel composites of iron oxide encapsulated in macroporous silica with excellent arsenic adsorption performance have been successfully developed. Macroporous silica foams with large pore sizes of ≈100 nm and a high pore volume of 1.6 cm3 g−1 are chosen as the porous matrix. Electron tomography technique confirms that γ‐Fe2O3 nanoparticles with an average particle size of ≈6 nm are spatially well‐dispersed and anchored on the pore walls at even a high γ‐Fe2O3 content of 34.8 wt%, rather than forming aggregates inside the pores or on the external surface. The open large‐pore structure, high loading amount, and the non‐aggregated nature of γ‐Fe2O3 nanoparticles lead to increased adsorption sites and thus high adsorption capacities of both As (V) and As (III) without pre‐treatment (248 and 320 mg g−1, respectively). Moreover, the composites can reduce the concentration of both As (V) and As (III) from 100 to 2 μg L−1. It is also demonstrated that the composites can be applied in a household drinking water treatment device, which can continuously treat 20 L of wastewater containing As (V) with the effluent concentration lower than the World Health Organization standard.