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Arsenic Biosand Filter: Sustainable Implementation of an Appropriate Household Drinking Water Filter...
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Arsenic Biosand Filter: Sustainable Implementation of an Appropriate Household Drinking Water Filter for Rural Nepal
What Are The Problems/ Issues?
Technological Deficiencies:• Many previous aid projects have failed in rural
areas due to the use of inappropriate technologies.
• Many current point-of-use technologies treat pathogen and arsenic separately, resulting in complicated and time consuming treatments.
• Many current technologies have low flow rate, insufficient contaminant removal efficiency, complex production process, reliance on material unavailable in rural villages, high replacement cost.
Implementation Deficiencies:• Failure of many previous aid projects in rural
areas is also a result of non-sustainable implementation schemes.
• Problems include lack of user understanding of the technology, lack of user participation, inadequate long-term monitoring, inadequate co-ordination and transparency among participating parties, etc.
Unsafe Drinking Water:• 90% of the population in the rural Terai
depends on groundwater for drinking water. • 20+% of the Terai tube well water is
contaminated with arsenic, causing arsenicosis, vascular diseases, and cancer of the lungs, bladder, and kidney.
• 40+% of the Terai tube well water is contaminated by pathogens, causing diarrhea, intestinal worms, trachoma, cholera, stunting, etc.
Results:• Currently many villagers have no choice but to
drink contaminated water. Women and children are often most vulnerable to water-borne diseases, which are preventable.
Our Solution – Arsenic Biosand Filter
Lead Organization: Massachusetts Institute of Technology (MIT), Department of Civil and Environmental Engineering
Partner Organization 1: Environment and Public Health Organization (ENPHO), Nepal
Partner Organization 2: Rural Supply and Sanitation Support Programme (RWSSSP), Nepal
Team Leader: Susan Murcott ([email protected]), MIT - Team Members: Tommy Ngai ([email protected]), MIT - Sophie Walewijk, Stanford University - Roshan Shrestha, ENPHO - Heimo Ojanen, RWSSSP
Women are usually responsible for collecting drinking water for their
household
This coagulation-filtration technology is complicated to
use and time-consuming
Replacement parts for this U.S.-manufactured water treatment
system are unavailable in Nepal
This person suffers from skin diseases associated with arsenic
poisoning
Women and children are often most vulnerable to water-borne
diseases
Focus on Nepal
• Total population: 24 millions• Rural population: 20 millions• Population below poverty line: 11
millions• Annual per capita income: US220• 12th poorest country in world,
poorest in South Asia• Literacy rate for women: 24%• Children suffering from stunting due
to water-borne disease: 51%
(World Bank 2002; UNICEF 2003)
FilteredWater Fine Sand
Coarse Sand & Gravel
Iron Nails
Water
Contaminated Water In
• To provide safe water and health improvement for millions of poor in the Terai, MIT, ENPHO and RWSSSP developed an innovative, award-winning filter (the Arsenic Biosand Filter, or ABF) for simultaneous arsenic and pathogen removal.
• The ABF was designed based on iterative and multi-disciplinary thinking inherent in the sustainable development concepts.
• The design was optimized after five years of research, extensive field experiments, comparison with competing technologies available in Nepal, Bangladesh, India, Haiti, Nicaragua, and other countries, and field assessments of the social, economical, and political constraints of Nepal
• A 12-months pilot study showed very favorable performance and user acceptability.
• Simultaneous removal of arsenic and pathogens by combining the strength of two proven technologies: iron-hydroxide, and biosand filter.
• Robust removal processes based on simple chemistry• Aesthetically pleasing filtered water – removal of iron,
turbidity, color, etc. from raw water.• High flow rate – time savings for women to pursue other
productive work.• Easy operation and minimal maintenance – suitable for the
often illiterate women and children.• Simple construction, can be done by trained local
technicians, and using materials available in rural villages. • Low-cost
Large concrete version (left) and Plastic version (right) of the Arsenic Biosand Filter (ABF)
Features & Innovations:
Filter monitoring and user feedback are important parts of the iterative design process
Some villages are only accessible by foot
A cross-section diagram of an Arsenic Biosand Filter (ABF)
Project Scope• To provide safe drinking water to 25 rural villages, a population of about 10,000 • To educate and empower individuals toward safe water provision• Project duration = 8 months
Tube well water is contaminated by arsenic
and pathogens
ABF can be easily constructed by trained
technicians