Nepali Water Solutions Inc. Point-of-Use Water Treatment in Nepal Advisors: Susan Murcott, Harry Hemond Group members: Heather Lukacs Luca Morganti Chian Siong Low Barika Poole Hannah Sullivan Jeff Hwang Xuan Gao Tommy Ngai
Presentation Outline • Project Background • Project Goals • Arsenic Removal • Filtration • Chlorine Disinfection • Tubewell Maintenance • Conclusion
Project Background Population 24 million (88% rural) Average annual income: $ 210 Pop. below poverty line: 42% Access to safe water: 90% urban, 30% rural Infant mortality: 75/1000 birth (5/1000 in US) Diarrheal illnesses: 44000 child death/year Life expectancy: 58
Project Goals Main objective: To investigate appropriate technology to provide safe drinking water for rural Nepal population Criteria: 1. Technical performance 2. Social/cultural acceptability 3. Economic viable/sustainability
Introduction • Arsenic contaminated groundwater discovered in Terai region. • 4% of 5000 tubewells tested have arsenic contents greater than 50 ppb (18% have greater than 10 ppb). • Arsenic causes hyperpigmentation, skin and liver cancer, and circulatory disorder.
Goals • Evaluate & Test three different household arsenic removal technologies • Develop a comprehensive map to identify the extent of arsenic contamination within Nepal. • Water quality analysis to determine factors that affect arsenic presence and removal.
Evaluation Criteria • Effectiveness of unit to reduce arsenic concentration below 10 ppb (WHO Standard) • Appropriateness/Social Acceptability - Can it be made with local material by local labor? - Is it easy to operate and maintain? - Can it meet the water demand (40-50 liters per day per household)? • Cost - Is it affordable to average Nepali household?
Arsenic Removal withActivated Alumina (AA) • Promising household unit using AA developed by Bangladesh University of Engineering and Technology (BUET) • Adsorption by AA efficiently removes Arsenic (up to 98 % removal achieved) • Current cost per unit is $26 ($15 per unit possible with mass production)
Prototype Design • Features: - Oxidation-sedimentation unit - Sand filtration unit - AA adsorption column • Problems with the Current Design: - Flimsy frame - Too tall - Inadequate flow rate
Arsenic Removal with Iron Coated Sand • Iron oxide adsorbs arsenic from water • Iron coated sand is more porous and has a higher specific surface area than scrap iron • Can be regenerated and reused at least 50 times with out loss in treatment efficiency. • Has been effective in Bangladesh
System Design • Sand preparation: - Fe(NO3)3 is dissolved - NaOH is added, and iron oxide is formed - Sand is added to the colloid solution, mixed and baked for 15 hours • Cost ~ US$ 8 • Flow rate 6 L/h • 94-99% removal
Pepperell, MA • Well water analysis for arsenic contamination conducted 20 years ago • Sample collection and analysis on Industrial Test System Arsenic Test Kits • Arsenic still present in Pepperell, MA well water • Confirmation on Graphite Furnace Atomic Absorption Spectrometer • EPA has lowered the arsenic MCL to 10 ppb, and many households are over the new limit • We will test our technologies in Pepperell prior to field tests in Nepal
How to improve removal? • Both AA and Iron coated sand work best with As(V) instead of As(III) • Arsenic speciation in Nepal varies • Oxidation of Arsenic can improve removal efficiency
BP/I3 resin • Benzyl Pyridinium Triiodine • Developed by Aquatic Treatment Systems • 100% oxidation in 1 second • On-demand oxidant • Very stable, no by-products • Some ability to disinfect
Arsenic map of Nepal • Based on well info from ENPHO and Nepal Red Cross Society • Develop a map to show the extent arsenic contamination • Integrate information into GIS format
To develop arsenic map • Attend GIS class • Get relevant maps (scale, regions, details) • Get data from ENPHO/Red Cross • Obtain field data • Integrate all data into GIS format • Perform analysis on data • Print a big map
Water Quality Parameters • Want to investigate correlations between presence of arsenic and other parameters • Parameters of interest: pH, hardness, alkalinity, turbidity, conductivity, arsenic, iron, aluminum, sulfate, chloride, copper, phosphate, nitrate • Investigate the effects of these parameters on arsenic removal efficiency by our technologies • Can integrate these data on GIS
Current Progress • Accomplishments thus far - Literature review - Technology selection - Contacts made - Received some supplies and equipment - Test kit analysis - Arranged GFAAS analysis
Next Steps • Next steps: - Obtain supplies (e.g. buckets, pipes) - Build prototypes - Preliminary lab tests - GFAAS analysis - Field tests in Pepperell - BP/I3 Resin tests - Water quality analysis - Order digitized maps of Nepal
Terafil Terracotta Filter • Mixture of red pottery clay, river sand, wood sawdust • Designed by Regional Research Laboratory, India • Field tested in cyclone affected areas in Orissa, India (Oct 1999) • In-house test verification
MIT Massachusetts Institute of Technology Scope of Work In MIT, • Carry out lab tests on Terafil Filter and Potters for Peace Filter (PFP) (ongoing) • Terafil and PFP Literature Review • Compare effectiveness of Terafil and PFP Filter • Research into ceramic manufacturing process and local practices
MIT Nepal Massachusetts Institute of Technology Scope of Work In Nepal, • Carry out field tests on Terafil and/or PFP Filter • Get involved with local filter manufacture Back in MIT, • Wrap up test results into thesis • Possible research into other suitable filters for use in developing countries
Work in Progress • Lab familiarization completed with preliminary testing of Terafil filter • Devise comprehensive lab tests on filter with specific goals • Lab tests on PFP and improvised Terafil filter • Pre- and Post-Chlorination (Terafil only) • Colloidal silver coating (both)
Laboratory Testing • Physical parameter • Flowrate, turbidity, temperature • Chemical parameter • pH • Microbial parameters • H2S bacteria, Total Coliform/E.Coli (P/A tests) • Total Bacteria (Microscopic Direct Counts) • Total Coliform (Coliform Counts)
Biosand Filter Features • Slow sand filtration • Relatively fast flow rate • Made of local materials • Intermittent use • No chemical additives • Biofilm (Schmutzdecke) • Easy to clean • Economically sustainable
Biosand Filter Performance • Laboratory Studies • Parasite removal – 100% • Virus removal – 99.9% • Bacteria removal – 99.5% (Lee 2001) • Field Studies • Bacteria removal 60-99.9%
Biosand Project Goals • Expand 2001 MIT Biosand work • Slow sand literature review and applicability • Global Biosand usage • Methodology development • Maintain constant concentration input • Laboratory study of bacterial removal • After cleaning • Following pause time • Field study in Nepal • Quantification of fecal coliform removal (membrane filtration) • Turbidity, pH, Temperature
Chlorine Disinfection Investigated Fields • Household Chlorination (Hannah Sullivan) • Chlorine Generation (Luca Morganti)
Safe Water System (CDC) • Point-of-Use Treatment using locally produced and distributed sodium hypochlorite solution. • Safe Water Storage in plastic containers with narrow mouths, secure lids and dispensing spigots to prevent recontamination. • Behavior Change Techniques to influence hygiene behaviors and increase awareness about the dangers of contaminated water and waterborne disease.
Promising Results • Implemented World-wide • Kenya, Uganda, Zambia, Guatemala, Bolivia, Ecuador, Peru, Pakistan • Reduces levels of bacterial contamination • Low Cost • Annual cost of $1.17 - $1.62 per household Reduces incidence of waterborne disease
Lumbini Pilot Study Pilot Study of Household Chlorination March 2001 • Modeled after CDC’s Safe Water Systems • Experimental Group: 50 Families & 10 Schools • Control Group: 50 Families & 10 Schools
M.Eng Project • Review of CDC’s Safe Water System Program - History, Types of Programs, Costs, Sustainability • Evaluation of Lumbini Pilot Project - Point-of-Use Testing - Chlorine Residual, - Bacterial Analysis (H2S and MF) - Health Survey - Social Acceptability Survey • Recommendations for Lumbini and Nepal - Is the Safe Water Systems Approach Appropriate?
The Problem Chlorine is not readily available for disinfection Chlorine disinfectant (Piyush) is produced from imported bleaching powder (calcium chloride) • Dependence • Limited availability • Export of money
The Solution PRODUCE CHLORINE LOCALLY • Self-sufficiency • Easier supply • Generation of income for local people HOW ? Chlorine Generator (CG) (Nadine Van Zyl, M.Eng.2001)
Chlorine Generator Specs-1 • Electrolytic cell: NaCl +H2O -> NaClO + H2 • Batch system: easy regulation
Purpose of the study • Identify performance influencing factors (water and salt quality) • Define CG set-up procedure • Learn CG use and maintenance procedures • Test CG performance (concentration) • Train local personnel • Outline a micro-enterprise program
CG Sustainability • Economically: • Cost of materials, energy, labor • Reasonable price • Environmentally: • Energy source (solar energy) • Socially: • Actractive business? • Reliable business ? • Expanding market ?
Tubewell • Ground water is the main source in the most of the Terai areas • Ground water hand pump device • 5 to 10 households share 1 tube well • Tubewell water is better than dugwell water or surface water
Problem with Tubewells Past study has shown that over 70% of the tube well water in Lumbini is contaminated by bacteria.
Possible Causes of the Problem • Poor Sanitary Conditions • Sludge drilling which uses a slurry of cow dung • Inadequate sealing or protection of the well • Improper drainage that causes accumulation of wastewater in the pit nearby • Flooding during monsoon
Tubewell Maintenance Program • Determination of the sources of tubewell contamination • Development of a plan to eliminate the contamination and maintain the wells properly • A study of the suitability for shock chlorination of wells • One-time introduction of a strong chlorine solution into a well.