scholarly journals Chitosan Coagulation Pretreatment to Enhance Ceramic Water Filtration for Household Water Treatment

2021 ◽  
Vol 22 (18) ◽  
pp. 9736
Author(s):  
Collin Knox Coleman ◽  
Eric Mai ◽  
Megan Miller ◽  
Shalini Sharma ◽  
Clark Williamson ◽  
...  
Keyword(s):  
Water Treatment ◽  
Diarrheal Disease ◽  
Continuous Treatment ◽  
Water Filtration ◽  
Culture Methods ◽  
Household Water Treatment ◽  
Virus Removal ◽  
Treated Effluent ◽  
Life Years ◽  
Household Water

Viruses are major contributors to the annual 1.3 million deaths associated with the global burden of diarrheal disease morbidity and mortality. While household-level water treatment technologies reduce diarrheal illness, the majority of filtration technologies are ineffective in removing viruses due to their small size relative to filter pore size. In order to meet the WHO health-based tolerable risk target of 10−6 Disability Adjusted Life Years per person per year, a drinking water filter must achieve a 5 Log10 virus reduction. Ceramic pot water filters manufactured in developing countries typically achieve less than 1 Log10 virus reductions. In order to overcome the shortfall in virus removal efficiency in household water treatment filtration, we (1) evaluated the capacity of chitosan acetate and chitosan lactate, as a cationic coagulant pretreatment combined with ceramic water filtration to remove lab cultured and sewage derived viruses and bacteria in drinking waters, (2) optimized treatment conditions in waters of varying quality and (3) evaluated long-term continuous treatment over a 10-week experiment in surface waters. For each test condition, bacteria and virus concentrations were enumerated by culture methods for influent, controls, and treated effluent after chitosan pretreatment and ceramic water filtration. A > 5 Log10 reduction was achieved in treated effluent for E.coli, C. perfringens, sewage derived E. coli and total coliforms, MS2 coliphage, Qβ coliphage, ΦX174 coliphage, and sewage derived F+ and somatic coliphages.

scholarly journals Sodium hypochlorite dosage for household and emergency water treatment: updated recommendations

2017 ◽  
Vol 16 (1) ◽  
pp. 112-125 ◽  
Author(s):  
Natalie Wilhelm ◽  
Anya Kaufmann ◽  
Elizabeth Blanton ◽  
Daniele Lantagne
Keyword(s):  
Water Treatment ◽  
Sodium Hypochlorite ◽  
Diarrheal Disease ◽  
Microbiological Quality ◽  
Water Source ◽  
Field Studies ◽  
Household Water Treatment ◽  
E Coli ◽  
Log Reduction ◽  
Household Water

Abstract Household water treatment with chlorine can improve the microbiological quality of household water and reduce diarrheal disease. We conducted laboratory and field studies to inform chlorine dosage recommendations. In the laboratory, reactors of varying turbidity (10–300 NTU) and total organic carbon (0–25 mg/L addition) were created, spiked with Escherichia coli, and dosed with 3.75 mg/L sodium hypochlorite. All reactors had >4 log reduction of E. coli 24 hours after chlorine addition. In the field, we tested 158 sources in 22 countries for chlorine demand. A 1.88 mg/L dosage for water from improved sources of <5 or <10 NTU turbidity met free chlorine residual criteria (≤2.0 mg/L at 1 hour, ≥0.2 mg/L at 24 hours) 91–94% and 82–87% of the time at 8 and 24 hours, respectively. In unimproved water source samples, a 3.75 mg/L dosage met relaxed criteria (≤4.0 mg/L at 1 hour, ≥0.2 mg/L after 24 hours) 83% and 65% of the time after 8 and 24 hours, respectively. We recommend water from improved/low turbidity sources be dosed at 1.88 mg/L and used within 24 hours, and from unimproved/higher turbidity sources be dosed at 3.75 mg/L and consumed within 8 hours. Further research on field effectiveness of chlorination is recommended.

scholarly journals Antibacterial and antiviral effectiveness of two household water treatment devices that use monobrominated hydantoinylated polystyrene

2016 ◽  
Vol 14 (6) ◽  
pp. 950-960
Author(s):  
Kyle S. Enger ◽  
Emaly S. Leak ◽  
Tiong Gim Aw ◽  
Angela D. Coulliette ◽  
Joan B. Rose
Keyword(s):  
Developing Countries ◽  
Water Treatment ◽  
Diarrheal Disease ◽  
Human Adenovirus ◽  
Murine Norovirus ◽  
Household Water Treatment ◽  
Bacteriophage Ms2 ◽  
Household Water ◽  
Before And After ◽  
Antimicrobial Effectiveness

Many different household water treatment (HWT) methods have been researched and promoted to mitigate the serious burden of diarrheal disease in developing countries. However, HWT methods using bromine have not been extensively evaluated. Two gravity-fed HWT devices (AquaSure™ and Waterbird™) were used to test the antimicrobial effectiveness of HaloPure® Br beads (monobrominated hydantoinylated polystyrene) that deliver bromine. As water flows over the beads, reactive bromine species are eluted, which inactivate microorganisms. To assess log10 reduction values (LRVs) for Vibrio cholerae, Salmonella enterica Typhimurium, bacteriophage MS2, human adenovirus 2 (HAdV2), and murine norovirus (MN), these organisms were added to potable water and sewage-contaminated water. These organisms were quantified before and after water treatment by the HWT devices. On average, 6 LRVs against Vibrio were attained, as well as 5 LRVs against Salmonella, 4 LRVs against MS2, 5 LRVs against HAdV2, and 3 LRVs against MN. Disinfection was similar regardless of whether sewage was present. Polymer beads delivering bromine to drinking water are a potentially effective and useful component of HWT methods in developing countries.

Current practices in manufacturing locally-made ceramic pot filters for water treatment in developing countries

2013 ◽  
Vol 3 (2) ◽  
pp. 252-261 ◽  
Author(s):  
Justine Rayner ◽  
Brian Skinner ◽  
Daniele Lantagne
Keyword(s):  
Quality Control ◽  
Water Treatment ◽  
Best Practice ◽  
Diarrheal Disease ◽  
Microbiological Quality ◽  
Household Water Treatment ◽  
Production Methods ◽  
Household Water ◽  
Control Procedures

Locally produced ceramic pot filters have been shown to improve the microbiological quality of household drinking water and reduce the burden of diarrheal disease in users. They are considered one of the most promising household water treatment methods. However, overarching manufacturing and quality control guidelines do not exist for the 35 decentralized filter factories in 18 countries that currently produce filters. In this study, we conducted manufacturing process surveys with 25 filter factories worldwide to document production methods and identify areas where manufacturing and quality control guidelines are needed. Our results show that manufacturing processes vary widely both between and within factories, including the consistency of materials, manufacturing methods, and quality control practices. These variations pose concerns about the consistency and quality of locally produced filters in the absence of standardized quality control procedures. We propose areas where manufacturing guidelines are needed to assist factories in producing consistently high quality filters, and identify topics where further research is needed to refine manufacturing recommendations. These results guided the development of a best practice manual that described consensus-based recommendations to advance consistent, quality-controlled filter production world-wide.

Impact of repeated pressurization on virus removal by reverse osmosis membranes for household water treatment

2019 ◽  
Vol 5 (5) ◽  
pp. 910-919 ◽  
Author(s):  
Shotaro Torii ◽  
Takashi Hashimoto ◽  
An Thuan Do ◽  
Hiroaki Furumai ◽  
Hiroyuki Katayama
Keyword(s):  
Water Treatment ◽  
Reverse Osmosis ◽  
Dramatic Decrease ◽  
Household Water Treatment ◽  
Virus Removal ◽  
Household Water ◽  
Reverse Osmosis Membranes

Repeated pressurization caused integrity loss at the surface of reverse osmosis membranes resulting in a dramatic decrease in virus removal.

scholarly journals Cost and financial sustainability of a household-based water treatment and storage intervention in Zambia

2007 ◽  
Vol 5 (3) ◽  
pp. 385-394 ◽  
Author(s):  
Anyana Banerjee ◽  
Deborah A. McFarland ◽  
Ritu Singh ◽  
Robert Quick
Keyword(s):  
Water Treatment ◽  
Water System ◽  
Financial Loss ◽  
Household Water Treatment ◽  
Safe Water ◽  
Start Up ◽  
Household Water ◽  
Before And After ◽  
Program Costs ◽  
And Behavior

Providing safe water to >1 billion people in need is a major challenge. To address this need, the Safe Water System (SWS) - household water treatment with dilute bleach, safe water storage, and behavior change - has been implemented in >20 countries. To assess the potential sustainability of the SWS, we analyzed costs in Zambia of “Clorin” brand product sold in bottles sufficient for a month of water treatment at a price of $0.09. We analyzed production, marketing, distribution, and overhead costs of Clorin before and after sales reached nationwide scale, and analyzed Clorin sales revenue. The average cost per bottle of Clorin production, marketing and distribution at start-up in 1999 was $1.88 but decreased by 82% to $0.33 in 2003, when >1.7 million bottles were sold. The financial loss per bottle decreased from $1.72 in 1999 to $0.24 in 2003. Net program costs in 2003 were $428,984, or only $0.04 per person-month of protection. A sensitivity analysis showed that if the bottle price increased to $0.18, the project would be self-sustaining at maximum capacity. This analysis demonstrated that efficiencies in the SWS supply chain can be achieved through social marketing. Even with a subsidy, overall program costs per beneficiary are low.

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