The safety and accessibility of drinking water is a global concern. The World Health Organization (WHO) reports that 80 percent of diseases are waterborne. Contamination from the geological formations (termed geogenic contamination) is the major source of groundwater contamination. Geogenic contaminants originate through weathering of rocks/formations deposited in the aquifer naturally, soluble in water. Arsenic and fluoride are such geogenic contaminants that possess a greater risk to human health (Ghosh, 2017). A major part of India suffers from fluoride and arsenic contamination in groundwater.
Groundwater plays a vital role in rural and urban domestic needs, industrial needs, and irrigation purposes in India. (Bhattacharya, et al., 2019). Arsenic (As) is a potent environmental pollutant and a silent toxic. Its concentration depends on local hydrology, geology, and geochemical characteristics of the aquifer. India is one of the largest countries struggling with geogenic contamination of arsenic. West Bengal, Jharkhand, Bihar, Uttar Pradesh, Assam, Manipur, Chhattisgarh, Haryana, Punjab, and Karnataka are the reported arsenic-affected states in India (Bhattacharya, et al., 2019). Jal Jeevan Mission (JJM), March 2022, reports that there are 1,657 arsenic-affected habitations in six states (Assam, Bihar, Jharkhand, West Bengal, Uttar Pradesh, and Punjab).
The Bureau of Indian Standards (BIS), has set the desirable limit of arsenic in drinking water to 10 ppb (parts per billion). The consumption of arsenic concentration above the desired limit affects health including respiratory and gastrointestinal systems along with an increase in the risk of cancer and skin diseases (Kushawaha and Aithani, 2021). The arsenic contamination can be removed from water through some conventional technologies such as adsorption, oxidation, membrane filtration, and ion exchange process (Kushawaha, et al., 2021).
WHO identifies household water treatment, and safe storage (HWTS) as a potential solution (WHO, 2019). The most promising technologies for household water treatment are filtration (biosand filter, ceramic pot filter, membrane filter, and candle filter) accompanied by disinfection (boiling, chlorine, UV, SODIS, and more) (Agrawal, et al., 2006). Household water treatment technologies hold an edge over community-level technologies as they reduce the chances of secondary infection (Sharma, 2018).
In groundwater primarily arsenic exists in two valence states, As (III) and As (V). As (III) is more toxic, mobile, and much more difficult to remove than As (V). However, As (III) can be easily oxidized into As (V), which is then easy to remove by the adsorption process. Biosand filter is one such technology that works under the force of gravity without using any form of energy. Sehgal Foundation innovated the sustainable biosand filter technology and named the innovated model JalKalp. Household water filter JalKalp is capable of addressing microbial, iron, and manganese contamination. Its design is also optimized for natural oxidation to oxidize As (III) into As (V). Integration of zero valent iron (ZVI) technology makes it perfect for removal of arsenic via adsorption of As (V) on hydrous ferric oxide (HFO) produced by ZVI placed in a diffuser.
Indian Institute of Technology, Kanpur, conducted a study on biosand filters to evaluate the performance and feasibility of a JalKalp biosand filter in providing potable water to rural households in India affected by chronic arsenic. The study proves that JalKalp removes arsenic by adsorption on rusted iron nails with an efficiency of 95–99 percent and microbial contamination through the addition of germicidal properties of copper. The study first took place under laboratory conditions and later community trials were undertaken in select villages of Bihar, India. The toxicity characteristic leaching procedure (TCLP) study indicated that the sludge generated was not hazardous and could be disposed of safely (Verma, et al., 2021). JalKalp biosand filter was efficient in lowering the concentration of arsenic from 1750 ppb to less than 10 ppb (safe for consumption) in the Buxar district of Bihar, India.
Considering the low affordability of the poorest of poor households, Sehgal Foundation is also promoting a ceramic pot filter technology (capable to remove microbial, iron contamination, and turbidity to improve water quality at the household level) and named it MatiKalp. So far the experiments have shown that this integration has brought down arsenic concentration from 600 ppb to less than 10 ppb. Experiments are continued to adapt MatiKalp for higher concentrations.
Simply the use of ZVI integrated into JalKalp and MatiKalp has worked wonders for the people affected by arsenic. With arsenic, JalKalp and MatiKalp were also able to reduce iron contamination from 5 ppm to less than 0.3 ppm.
The community has a positive response to the study conducted in their area in terms of health improvement and economic generation. The community members believed that the filtered water was as pure as a holy river and on the contrary, some also believed that drinking contaminated water would not cause any serious harm to their health. In this regard, Sehgal Foundation sensitized and built the awareness of the younger, formally educated children in the family intended to pass on the awareness and knowledge to the entire household.
The study has been a boon for community members as it has opened great doors in not only providing safe drinking water by improving health but in terms of education, economic generation, and entrepreneurial opportunities. For arsenic-affected Indian states, the use of low-cost biosand filters and ceramic pot filters such as JalKalp and MatiKalp with the integration of ZVI can be considered a sustainable solution to providing safe drinking water even in every household.
Put together, this low-cost innovation aimed at resolving one of the gravest developmental issues that decelerate the impact of other developmental solutions can be a game changer. Given its ease of use and the benefits it brings to its users, this innovation is scalable to regions affected by water contamination issues especially from the point of view of arsenic with iron, microbial contamination, and turbidity simultaneously. Sustenance of the impact however remains in the innovation of its implementation wherein the end user realizes its potential and impact and eventually becomes a champion to amplify the technology in their habitation zone. It is a combination of innovation both at the design and implementation stages that has made JalKalp and MatiKalp futuristic technological solutions to help countries like India accelerate their position in achieving SDG number six.
Authors: Lalit Mohan Sharma and Yashi Gautam,
(Lalit is principal scientist and Yashi is assistant program lead with Water, Research and Training, S M Sehgal Foundation)
Agrawal (Retd), Col V K, and Brig R Bhalwar. 2006. Household Water Purification: Low-Cost Interventions, MJAFI. 2009. 65: 260–263
Bhattacharya, Dr. A.K., Dr. R. Lodh, A.K Roy, D.M.P Karthik, Dr. A. Singh, and A.K Mishra. 2019. An Analysis of Arsenic Contamination in the Groundwater of India, Bangladesh and Nepal with a Special Focus on the Stabilization of Arsenic-Laden Sludge from Arsenic Filters” Electronic Journal of Geotechnical Engineering, 1–34.
Ghosh, N.C. 2017. Ground Water Hydrology Division, National Institute of Hydrology, Roorkee 247 667, India.
JJM., 2022. (https://pib.gov.in/Pressreleaseshare.aspx?PRID=1807847)
Kushawaha J. and D. Aithani. 2021. Geogenic Pollutants in Groundwater and Their Removal Techniques.
L.M. Sharma., 2018. “Promoting Community Health and Preventing Waterborne Diseases with The JalKalp Water Filter.” IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) 12.2: 16–22.
Verma, A., L.M. Sharma, G. Pahuja, J. J. Nilling, A. Kumar, and A. Singh. 2021. Modified Biosand Filter for Provisioning of Potable Water to Rural Households Affected by Chronic Arsenic Pollution in Groundwater, Environmental Engineering Science. Volume 00, Number 00.
WHO. 2019. Results of Round II of the WHO International Scheme to Evaluate Household Water Treatment Technologies, Licence: CC BY-NC-SA 3.0 IGO.