Rural water purifier hits the market in India

A low-cost water purification device that has been in development for more than three years was introduced on 7 December 2009 by India’s Tata Chemicals, which says the device is designed for use in rural households that have no electricity or running water..

The Tata Swach — Hindi for “clean” — also happens to meet US Environmental Protection Agency standards for removing microorganisms as well as off-color and off-taste, an AFP report claimed. AFP, quoting a newspaper report, said the device will be priced less than 1,000 rupees (US$21.75).  Tata Chemicals said it would cost 30 rupees  per month (US$ 0.64) for a family of five. The Pureit, a simlar device produced by Hindustan Unilever, retails for 2000 rupees ($42.92), with a replaceable battery kit that costs 365 rupees ($7.80).

The Swach combines low-cost ingredients such as rice husk ash with nanotechnology.  It uses ash from rice milling as a matrix, impregnated with nano-silver particles particles to kill the bacteria that cause 80 percent of waterborne disease, executives said in a report in Business Week.

While Tata’s device may be suitable for treating surface waters, it does not remove chemical contaminants like arsenic or fluoride, which are common in groundwater, used by 80 per cent of rural Indians.

The device has a 9.5-liter capacity and can filter 3,000 litres until the cartridge has to be replaced. A cartridge would last about 200 days for an average family of five,  Tata Chemicals managing director R. Mukundan.

Business Week reported that Tata executives plan to invest 1 billion rupees (US$21.6 million) in the project over the next five years. The initial production will be 1 million units a year from a Tata Chemicals plant in Haldia, West Bengal, with plans to increase production to 3 million units annually within five years.  Mukundan said the company would eventually look to sell the device in sub-Saharan Africa as well.

The Tata Group said it will distribute the device using distribution networks of Rallis, Tata’s agrochemical subsidiary with more than 30,000 retailers in rural India, and Tata Kisan Sansar, a farm services business run by Tata Chemicals, which reaches 2.5 million farmers.

Source: Tata Chemicals, 07 Dec 2009 ; WaterTech Online, 07 Dec 2009 ; Business Week, 07 Dec 2009

Roof-harvested rainwater for potable purposes : application of solar collector disinfection (SOCO-DIS)

Amin, M.T. and Han, M.Y. (2009). Roof-harvested rainwater for potable purposes : application of solar collector disinfection (SOCO-DIS). Water research ; vol. 43, no. 20 ; p. 5225-5235. DOI: doi:10.1016/j.watres.2009.08.041

Abstract

The efficiency of solar disinfection (SODIS), recommended by the World Health Organization, has been determined for rainwater disinfection, and potential benefits and limitations discussed. The limitations of SODIS have now been overcome by the use of solar collector disinfection (SOCO-DIS), for potential use of rainwater as a small-scale potable water supply, especially in developing countries. Rainwater samples collected from the underground storage tanks of a rooftop rainwater harvesting (RWH) system were exposed to different conditions of sunlight radiation in 2-L polyethylene terephthalate bottles in a solar collector with rectangular base and reflective open wings. Total and fecal coliforms were used, together with Escherichia coli and heterotrophic plate counts, as basic microbial and indicator organisms of water quality for disinfection efficiency evaluation. In the SOCO-DIS system, disinfection improved by 20–30% compared with the SODIS system, and rainwater was fully disinfected even under moderate weather conditions, due to the effects of concentrated sunlight radiation and the synergistic effects of thermal and optical inactivation. The SOCO-DIS system was optimized based on the collector configuration and the reflective base: an inclined position led to an increased disinfection efficiency of 10–15%. Microbial inactivation increased by 10–20% simply by reducing the initial pH value of the rainwater to 5. High turbidities also affected the SOCO-DIS system; the disinfection efficiency decreased by 10–15%, which indicated that rainwater needed to be filtered before treatment. The problem of microbial regrowth was significantly reduced in the SOCO-DIS system compared with the SODIS system because of residual sunlight effects. Only total coliform regrowth was detected at higher turbidities. The SOCO-DIS system was ineffective only under poor weather conditions, when longer exposure times or other practical means of reducing the pH were required for the treatment of stored rainwater for potable purposes.

Article Outline

1. Introduction
2. Materials and methods

2.1. SODIS and SOCO-DIS systems
2.2. Microbial analysis

3. Results and discussions

3.1. Sampling site and characteristics
3.2. Characteristics of different weather conditions
3.3. The effects of the collector’s base angle and different backing surfaces in the SOCO-DIS system
3.4. Comparison of the SODIS and SOCO-DIS systems

3.4.1. The effects of radiation and temperature effects on microbial inactivation
3.4.2. The effects of initial pH values on disinfection efficiency
3.4.3. The effects of initial turbidity values on disinfection efficiency
3.4.4. Microbial regrowth in SOCO-DIS system and comparison with SODIS

4. Conclusions
Acknowledgements
References

Contact:

• Assistant Professor, Department of Environmental Sciences, COMSATS Institute of Information Technology, Abbottabad, 22060, Pakistan, e-mail: muhammadamin [at] ciit.net.pk
• bProfessor, Civil and Environmental Engineering Department, Seoul National University, Shinrimdong, Kwanak Gu, Seoul, 151-742, Republic of Korea, e-mail: myhan [at] snu.ac.kr

Ceramic filters: Ugandan schools get CrystalPur kits

Uganda has been selected as the only country in Africa to pilot a project that provides cheap and pure drinking water to schools and clinics in rural Uganda. Appropriate Technology (AT) Uganda, together with Enterprise Works/ VITA, with funding from the Diageo Foundation’s Giving for Good programme, has introduced CrystalPur ceramic water filters. The filters remove bacteria and parasites from contaminated water, thus preventing water-borne-diseases.

“The gadget does not need electricity or chemicals and has no effect on the taste of water,” says Michael Oketcho, the project manager. Oketcho explains that Uganda was selected because of its high usage of open surface water.

“Most rural people use water from lakes, rivers, wells, rain water and swamps, while in urban areas, 95% of the wells and springs contain faecal matter,” says Oketcho.

The gadget filters between four and six litres of water per hour. It is suitable for schools, households, hotels, health centres, camping teams, and disaster and emergency hit areas. It weighs less than 500g and can filter up to 7,000 litres of water (350 jerrycans) before the filter is replaced. For less than the cost of one bag of charcoal, CrystalPur fllters can deliver 7,000 litres of safe drinking water.

The filter has been tested and approved by the Uganda National Bureau of Standards.

Diageo Foundation has donated 3,500 units which have been distributed in over 150 primary and secondary schools in Kampala and Wakiso districts. The water filter programme started in October 2008 and will end in October 2009.

Source: Patrick Jaramogi, New Vision, 8 Sep 2009

CrystalPur filter. Diageo/EnterpriseWorks/VIA

Solar disinfection: inventor unveils solar-powered water purifier

Photo: Solvatten

Swedish inventor, Petra Wadström, has unveiled Solvatten, a solar-powered water purifier, that she hopes will be used to provide household drinking water in developing countries.

Developed over a period of eleven years, the device resembles a standard jerrycan. It can be filled with up to 10 litres of water, opened out and left in the sun. A simple indicator uses a red or green face to show users when the temperature has reached 55°C and the water is safe to drink. It uses both thermal energy (heat) and UV radiation from sunlight, a created turbulence and a filter to treat water of up to 200 NTU. Water samples with more than 200.000 E. coli/100 ml have successfully been treated, the Solvatten web site claims.

Serving a family of five, a Solvatten device costs US$ 35 and lasts 5 years or more. The estimated cost per litre of water is 0.002 USD ( based upon 10 litres of water treated, 300 days per year).

The Solvatten company has already tested its device in Kenya and Nepal. In 2009 the first units of Solvatten will reach Nepal for a user study involving a number of families, schools and health centres. The programme is being implemented in collaboration with UN-HABITAT and ENPHO, the Environment and Public Health Organisation.

The Solvatten can also be used a solar water heater to produce hot water.

See videos below on Solvatten trials in Nepal and a product presentation by Petra Wadström.

Source: edie, 12 Jan 2009 : Solvatten web site

Terafil water filters: clay filters promise clean drinking water in villages in Jharkand, India

Terafil technology will not only ensure clean drinking water in villages but also turn the rural people into entrepreneurs.

Chakdoha and Chapri, two villages of Ghatshila in East Singhbhum district [of Jharkand state, India], will play host to the pilot project.

The initiative has been taken by the Rural Development Trust under the Art of Living Foundation, Bengaluru. Terafil water filters have been designed by S.K. Kuntia, the head of design and rural technology department at the Institute of Mineral and Material Technology (IMMT), Bhubaneswar, a wing of the Council of Scientific and Industrial Research (CSIR), New Delhi.

[...] The terafil would cost around Rs 350 to Rs 500. The foundation has planned to rope in the corporate sector to help donate the filters as a part of their corporate social responsibility.

The filters would encourage self-employment, too. The foundation would also arrange for resources to train the villagers and help them turn into entrepreneurs.

[...] The filters are being manufactured and would be distributed across the two villages from March 31 [2009].

Source: The Telegraph, 23 Dec 2008

The Terafil water filter is especially suited for water that is rich in sediments, suspended particles, iron and certain microorganisms, i.e. for areas where water from both surface & ground water sources like dug wells, ponds, tube wells and rivers is used for drinking water.

Terafil (red clay) filtration disc. Photo: IMMT

Terafil is a burnt red clay porous media [...] produced from mixture of red clay (silt clay), river sand and wood saw dust, without using chemicals. The dough of the mixture of these materials is sintered at high temperature in a low cost coal / wood fired furnace to make the terracotta disc porous.

About 99% of turbidity, 90-95% of micro-organisms, 80-95% of soluble iron,

Domestic Terafil filter. Photo: IMMT

colours etc. are effectively removed from the raw water during filtration process through the Terafil. 100% bacteria can be removed when a pinch (0.01 gm) of bleaching powder is added to a liter of filtered water. Rate of filtration is dependent upon turbidity and pressure of raw water over the Terafil.

Terafil filters are available for both domestic use and community-level use (gravity flow and on-line pressure flow models).

Read more technical specifications here (IMMT brochure, May 2008).

In 2007, IMMT had already licensed the technology for making and marketing Terafil discs to four parties in Orissa and had demonstrated the technology in several other states including Uttar Pradesh and Meghalaya. Over 50,000 water filters had been distributed. The domestic Terafil filter was used extensively in Orissa in 1999 when the state was severely hit by a cyclone.

Contact: S. Khuntia, Head, Design & Rural Technology, Institute of Minerals and Materials Technology, P.O. RRL, Bhubaneswar – 751013, India.  Tel (off) : 0674 2581635-39, Fax: 0674 2581637, 2581160. Email: khuntias [at] gmail.com, skhuntia [at] immt.res.in

Source: CSIR news, Oct 2007

Kanchan Arsenic Filter: verification update

Field testing of the Kanchan Arsenic Filter (KAF), a biosand filter modified to remove arsenic from contaminated raw water, is generating encouraging results in Cambodia and Bangladesh.

The KAF was found to be highly effective in Phase 1 testing, with average arsenic removals in the 95 to 97 per cent range. All of the 10 test filters consistently reduced levels from an average of 637ppb to less than 50ppb, which is the Cambodian standard for arsenic in drinking water.

Performance of the filters was consistent over the 30-week testing span, which produced 8,400 litres of filtered water.

Phase 2 testing, now underway, involves installing the filters in more challenging locations to determine if their arsenic removal capacity can be exhausted.

The tests will also examine hardness and pH levels, water usage patterns and include a social assessment.

Related news: Arsenic removal: field testing the Kanchan Arsenic Filter in Cambodia, Source Weekly, 22 Mar 2008

See also:

• MIT TechTV video “Arsenic Poisoning and the Kanchan Arsenic Filter”  here
• Centre for Affordable Water and Sanitation Technology (CAWST): Adapting the Biosand Filter for Arsenic Removal (10 Apr 2008)

Source: CAWST Newsletter [not yet online, but should become available here], Winter 2008

Arsenic removal: four years of development and field-testing of IHE arsenic removal family filter in rural Bangladesh

Petrusevski, B. … [et al.] (2008). Four years of development and field-testing of IHE arsenic removal family filter in rural Bangladesh. Water science and  technology : vol. 58, no. 1 ; p. 53-58. doi:10.2166/wst.2008.335

Abstract

UNESCO-IHE has been developing an arsenic removal family filter with a capacity of 100 L/day based on arsenic adsorption onto iron oxide coated sand, a by-product of iron removal plants. The longer term and field conditions performance of the third generation of eleven family filters prototypes were tested in rural Bangladesh for 30 months. All filters achieved initially highly effective arsenic removal irrespective of arsenic concentration and groundwater composition. Arsenic level in filtrate reached 10 mug/l after 50 days of operation at one testing site and after 18 months of continuous operation at other 3 testing sites. Arsenic level at other 7 sites remained below the WHO guideline value till the end of study. Positive correlation was found between arsenic removal capacity of the filter and iron concentration in groundwater. In addition to arsenic, iron present in groundwater at all testing sites was also removed highly effectively. Manganese removal with IHE family filter was effective only when treating groundwater with low ammonia. A simple polishing sand filter, after IHE family filter, resulted in consistent and effective removal of manganese. IHE family filters were easy to operate and were well accepted by the local population.

Contact: Dr. Branislav Petrusevski, UNESCO-IHE Institute for Water Education, Delft, The Netherlands, b.petrusevski [at] unesco-ihe.org

Ron Rivera, Potter Devoted to Clean Water, Dies at 60

Ron Rivera / Potters without Borders

Ron Rivera liked to call his ceramic water filters “weapons of biological mass destruction.” For 25 years he traveled to poor villages throughout Latin America, Africa and Asia teaching local potters to make what appears to be a big terra-cotta flower pot but is in fact an ingenious device for purifying water. In 1998 he joined Potters for Peace and became where he became Coordinator of Filter and International Projects.

[...]

Mr. Rivera died on Sept. 3 in Managua, Nicaragua, after contracting falciparum malaria, the most dangerous form, while setting up a water-filter factory in Nigeria, said Kathy McBride, his wife. He was 60.

Read more: William Grimes, New York Times, 14 Sep 2008

Potters for Peace and Potters without Borders have set up memorial pages here and here.

See a presentation video on ceramic filters by Mr. Rivera’s below.

Biological sand filters: low-cost bioremediation technique for production of clean drinking water

Lea, M. (2008).Biological sand filters : low-cost bioremediation technique for production of clean drinking water. Current protocols in microbiology ; suppl. 9 ; p. 1G.1 – 1G.1.28. DOI: 10.1002/9780471729259.mc01g01s9. Posted online May 2008

There is “conclusive evidence” that one low-cost household bioremediation intervention, biological sand filters, are capable of dramatically improving the microbiological quality of drinking water. This unit describes this relatively new and proven bioremediation technology’s ability to empower at-risk populations to use naturally occurring biology and readily available materials as a sustainable way to achieve the health benefits of safe drinking water.

This protocol provides guidelines for the selection, design, construction, operation and maintenance of biological sand filters. Options for pretreatment filtration and post-treatment disinfection (chlorination and solar disinfection (SODIS)) are provided, as well as a modified design for arsenic removal.

Solar pasteurisation: Kenyan project uses solar cookers to provide safe water

In November 2007, Solar Cookers International (SCI) began a two-year pilot project to increase water quality awareness and introduce [and train local staff to use] the Safe Water Package and the Portable Microbiology Laboratory to communities in western Kenya. The effort is led by SCI founder and board member Dr. Bob Metcalf, professor of Biological Sciences at California State University, Sacramento.

[...]

When used in conjunction with SCI’s Water Pasteurization Indicator (WAPI), simple solar cookers can safely

Solar CooKit

pasteurize drinking water and reduce incidence of waterborne diseases, while saving precious cooking fuel. The Safe Water Package (SWP) that families will receive provides all the necessary tools: a CooKit solar cooker, a black pot, a WAPI, and a water storage container.

[...]

[The project also distributes] the Portable Microbiology Laboratory (PML), a gallon-sized kit with materials for 25 water tests. Each PML contains Colilert® and Petrifilm^TM tests for Escherichia coli contamination, sterile plastic pipettes, collection bags, and a battery-operated UV lamp for reading Colilert® tests.

See the slide-show on Water testing & Pasteurization in Africa.

Read more