{"id":15512,"date":"2026-08-23T06:08:30","date_gmt":"2026-08-23T06:08:30","guid":{"rendered":"https:\/\/koshalsambada.in\/?p=15512"},"modified":"2026-08-23T06:08:30","modified_gmt":"2026-08-23T06:08:30","slug":"cost-effective-water-filter-delhi-ncr-twin-sisters-turn-okra-fenugreek-and-rice-husk-into-a-rs-100-electricity-free-water-filter-iit-delhi-tests-show-up-to-93-removal-of-pfas","status":"publish","type":"post","link":"https:\/\/koshalsambada.in\/?p=15512","title":{"rendered":"Cost-Effective Water Filter: Delhi-NCR twin sisters turn okra, fenugreek and rice husk into a Rs 100 electricity-free water filter; IIT Delhi tests show up to 93% removal of PFAS"},"content":{"rendered":"<p><br \/>\n<\/p>\n<div>\n<div class=\"e9jwa\">\n<div class=\"vdo_embedd\">\n<div class=\"GfdvZ\">\n<section class=\"_bIDB  clearfix id-r-component leadmedia undefined undefined  E9tg9 \" style=\"top:0px\">\n<div class=\"_bIDB\" data-ua-type=\"1\" onclick=\"stpPgtnAndPrvntDefault(event)\">\n<div class=\"ypVvZ\">\n<div class=\"WGttI\"><img src=\"https:\/\/static.toiimg.com\/thumb\/msid-133434362,imgsize-997334,width-400,height-225,resizemode-4\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg\" alt=\"Delhi-NCR twin sisters turn okra, fenugreek and rice husk into a Rs 100 electricity-free water filter; IIT Delhi tests show up to 93% removal of PFAS\" title=\"\u200bNaina and Nayantara Singh developed the low-cost plant-based water filter.\" decoding=\"async\" fetchpriority=\"high\"\/><\/div>\n<\/div>\n<\/div>\n<div class=\"Ta7d_ img_cptn\"><span title=\"\u200bNaina and Nayantara Singh developed the low-cost plant-based water filter.\">\u200bNaina and Nayantara Singh developed the low-cost plant-based water filter.<\/span><\/div>\n<\/section>\n<\/div><\/div>\n<\/div>\n<p>What if some of the ingredients sitting in a kitchen cupboard could help tackle pollutants that conventional water filters struggle with? For Delhi-NCR twins Naina and Nayantara Singh, that question became the starting point for a nearly year-long scientific experiment.<!-- --> The Class XII students have developed a plant-based water purification system that uses okra, fenugreek and rice husk to target two increasingly discussed contaminants in water- microplastics and PFAS, often referred to as \u201cforever chemicals\u201d.<span class=\"id-r-component br\" data-pos=\"3\"\/>The idea, which began as a school-level research project, eventually took the sisters to the biomass laboratory at <a href=\"https:\/\/timesofindia.indiatimes.com\/topic\/iit-delhi\" styleobj=\"[object Object]\" class=\"\" commonstate=\"[object Object]\" frmappuse=\"1\" target=\"_blank\" rel=\"noopener\">IIT Delhi<\/a>, where their prototype was developed and tested under the guidance of professor Vivek Kumar.<span class=\"id-r-component br\" data-pos=\"9\"\/>Their innovation, called <span class=\"strong\" data-ua-type=\"1\" onclick=\"stpPgtnAndPrvntDefault(event)\">Aqua Sattva<\/span>, is designed around a simple proposition: water purification need not always involve an expensive machine, electricity or complicated plumbing.<span class=\"id-r-component br\" data-pos=\"13\"\/><\/p>\n<div data-pos=\"0\" class=\"id-r-component iIpbx undefined  &#10;        \">\n<div><img decoding=\"async\" alt=\"The twin sisters developed Aqua Sattva using plant-based materials.&lt;br&gt;\" msid=\"133434376\" imgsize=\"798100\" resizemode=\"4\" width=\"\" title=\"The twin sisters developed Aqua Sattva using plant-based materials.\" placeholdersrc=\"https:\/\/static.toiimg.com\/photo\/83033472.cms\" offsetvertical=\"0\" placeholdermsid=\"47529300\" type=\"thumb\" class=\"\" src=\"https:\/\/static.toiimg.com\/photo\/imgsize-798100,msid-133434376\/the-twin-sisters-developed-aqua-sattva-using-plant-based-materials-br.jpg\" data-api-prerender=\"true\"\/><\/p>\n<p>The twin sisters developed Aqua Sattva using plant-based materials.<\/p>\n<\/div>\n<\/div>\n<p><span class=\"id-r-component br\" data-pos=\"15\"\/><\/p>\n<p><h2>From concern about groundwater to a science project<\/h2>\n<\/p>\n<p><span class=\"id-r-component br\" data-pos=\"17\"\/>The sisters began working on the idea while they were in Class XI. Their interest was sparked by concerns over groundwater quality and depletion in Delhi. \u201cWhen we came across a Delhi govt study highlighting groundwater depletion across all districts of the city, we felt it was a problem that deserved action,\u201d Nayantara said while speaking to TOI.<span class=\"id-r-component br\" data-pos=\"20\"\/>What started as a concern soon became an experiment. \u201cWe first began working on the idea when we were in Class XI, and it took nearly a year to reach meaningful results,\u201d Naina recalled.<span class=\"id-r-component br\" data-pos=\"22\"\/>The twins, who study at Step by Step School, Noida, eventually developed a filtration system using materials that are inexpensive, biodegradable and relatively easy to source. The system consists of sachets resembling tea bags. Inside are two key components: an okra-fenugreek polymer designed to help capture microplastics, and biochar made from rice husk to target PFAS. <!-- -->The estimated cost is around Rs 100 for a pack of 10 sachets.<span class=\"id-r-component br\" data-pos=\"26\"\/><\/p>\n<p><h2>How does the filter work?<\/h2>\n<\/p>\n<p><span class=\"id-r-component br\" data-pos=\"28\"\/>The process is based on two different mechanisms. First, water undergoes basic filtration to remove visible impurities. The next stage uses natural polymers derived from okra and fenugreek. These plant-based substances can help particles clump together through a process known as flocculation. In the sisters\u2019 system, this is intended to bind and trap microplastic particles, making them easier to separate from the water.<span class=\"id-r-component br\" data-pos=\"31\"\/>The second component is rice husk biochar. Rice husk is an agricultural residue that is often treated as waste, and biochar made from it has a porous structure capable of adsorbing certain contaminants.<span class=\"id-r-component br\" data-pos=\"33\"\/>In Aqua Sattva, the biochar is used to target PFAS- a large family of synthetic chemicals that have been widely used in products because of their resistance to heat, water and oil. Their persistence in the environment is also what has earned many PFAS compounds the label \u201cforever chemicals\u201d.<span class=\"id-r-component br\" data-pos=\"36\"\/>The combination gives the system a distinctly different approach from conventional household purification systems.<span class=\"id-r-component br\" data-pos=\"38\"\/><\/p>\n<div data-pos=\"0\" class=\"id-r-component iIpbx undefined  &#10;        \">\n<div><img decoding=\"async\" alt=\"Naina and Nayantara Singh\u2019s \u20b9100 filter targets microplastics and PFAS.&lt;br&gt;\" msid=\"133434379\" imgsize=\"798547\" resizemode=\"4\" width=\"\" title=\"Naina and Nayantara Singh\u2019s \u20b9100 filter targets microplastics and PFAS.\" placeholdersrc=\"https:\/\/static.toiimg.com\/photo\/83033472.cms\" offsetvertical=\"0\" placeholdermsid=\"47529300\" type=\"thumb\" class=\"\" src=\"https:\/\/static.toiimg.com\/photo\/imgsize-798547,msid-133434379\/naina-and-nayantara-singhs-100-filter-targets-microplastics-and-pfas-br.jpg\" data-api-prerender=\"true\"\/><\/p>\n<p>Naina and Nayantara Singh\u2019s \u20b9100 filter targets microplastics and PFAS.<\/p>\n<\/div>\n<\/div>\n<p><span class=\"id-r-component br\" data-pos=\"40\"\/><\/p>\n<p><h2>What did the testing show?<\/h2>\n<\/p>\n<p><span class=\"id-r-component br\" data-pos=\"42\"\/>The prototype was developed and tested at IIT Delhi\u2019s biomass laboratory. According to the project findings, independent laboratory testing showed up to 93% removal efficiency across 20 different PFAS compounds after basic filtration. Testing using stereomicroscopy also indicated a substantial reduction in the density of microplastics in treated water samples.<span class=\"id-r-component br\" data-pos=\"45\"\/>The results were significant enough for the project to move beyond a classroom experiment. The sisters are now awaiting a patent for the innovation. The system is not intended to simply replicate an RO purifier. Instead, the sisters say their aim is to create an affordable purification option that can be used without electricity or specialised technical knowledge.<span class=\"id-r-component br\" data-pos=\"47\"\/>\u201cMost effective solutions rely on RO systems, which are expensive, require electricity and also waste significant amounts of water,\u201d Nayantara said. <!-- -->\u201cWe wanted to develop something that could work for ordinary households. The objective was to make safe drinking water more accessible and affordable.\u201d<span class=\"id-r-component br\" data-pos=\"51\"\/><\/p>\n<p><h2>Why the low cost matters<\/h2>\n<\/p>\n<p><span class=\"id-r-component br\" data-pos=\"53\"\/>Household water purification can be expensive, particularly for families that cannot invest in sophisticated filtration systems or deal with recurring maintenance and electricity requirements.<span class=\"id-r-component br\" data-pos=\"55\"\/>Aqua Sattva has been designed around a much simpler model. The sachets do not require plumbing, electricity or technical expertise, according to the project description.<span class=\"id-r-component br\" data-pos=\"58\"\/>The estimated price- about Rs 100 for 10 sachets- is a fraction of the cost of many conventional RO systems. There is also an environmental dimension to the choice of ingredients. Okra and fenugreek are plant-based materials, while rice husk is an agricultural byproduct. Turning such materials into components of a purification system gives agricultural waste another potential use.<span class=\"id-r-component br\" data-pos=\"60\"\/>But the bigger challenge for any such innovation will be determining how consistently it performs outside controlled laboratory conditions and across different water sources. <!-- -->The sisters\u2019 work so far represents a promising prototype rather than a replacement for every form of household water treatment.<span class=\"id-r-component br\" data-pos=\"64\"\/><\/p>\n<div data-pos=\"0\" class=\"id-r-component iIpbx undefined  &#10;        \">\n<div><img decoding=\"async\" alt=\"The Class 12 twins developed their water filter after nearly a year of research.&lt;br&gt;\" msid=\"133434382\" imgsize=\"728064\" resizemode=\"4\" width=\"\" title=\"The Class 12 twins developed their water filter after nearly a year of research.\" placeholdersrc=\"https:\/\/static.toiimg.com\/photo\/83033472.cms\" offsetvertical=\"0\" placeholdermsid=\"47529300\" type=\"thumb\" class=\"\" src=\"https:\/\/static.toiimg.com\/photo\/imgsize-728064,msid-133434382\/the-class-12-twins-developed-their-water-filter-after-nearly-a-year-of-research-br.jpg\" data-api-prerender=\"true\"\/><\/p>\n<p>The Class 12 twins developed their water filter after nearly a year of research.<\/p>\n<\/div>\n<\/div>\n<p><span class=\"id-r-component br\" data-pos=\"66\"\/><\/p>\n<p><h2>A project built between school and laboratory<\/h2>\n<\/p>\n<p><span class=\"id-r-component br\" data-pos=\"68\"\/>Getting the science right was only one part of the challenge. The sisters had to work on their project while keeping up with Class XII studies. At one stage, they were travelling to the laboratory two or three times a week and also used their winter break to continue the research.<span class=\"id-r-component br\" data-pos=\"70\"\/>\u201cWhen one of us was tied up with academic commitments, the other would keep the project moving,\u201d the sisters said. <!-- -->Their mother, Gopika Kaul, said their curiosity about science had been visible since childhood. \u201cBoth of them have always been deeply inclined towards science and are endlessly curious,\u201d she said. \u201cThey have always wanted to understand why problems exist and how they can be solved.\u201d That curiosity appears to have shaped the project as much as the laboratory work did.<span class=\"id-r-component br\" data-pos=\"74\"\/><\/p>\n<p><h2>From school experiment to \u2018Water Champions\u2019<\/h2>\n<\/p>\n<p><span class=\"id-r-component br\" data-pos=\"76\"\/>The project has already received recognition beyond their school. <!-- -->Last month, Naina and Nayantara were named Water Champions 2026 at the Stockholm Junior Water Prize India competition, a student-focused contest centred on water sustainability. They competed against more than 350 teams and secured third place at the national finals held at IIT Madras.<span class=\"id-r-component br\" data-pos=\"81\"\/>They have also received recognition at the Conrad Challenge, an international entrepreneurship and innovation competition.<span class=\"id-r-component br\" data-pos=\"84\"\/>For the twins, however, the larger idea behind Aqua Sattva appears to be less about winning competitions and more about making water purification accessible.<span class=\"id-r-component br\" data-pos=\"86\"\/>Their experiment began with a question about a problem close to home. It has now grown into an attempt to show that solutions to complex environmental problems do not always have to begin with expensive technology. Sometimes, they can begin with something as ordinary as okra, fenugreek and rice husk- and two school students willing to ask what else those everyday materials might be capable of.<\/div>\n<p><br \/>\n<br \/><a href=\"https:\/\/timesofindia.indiatimes.com\/science\/delhi-ncr-twin-sisters-turn-okra-fenugreek-and-rice-husk-into-a-rs-100-electricity-free-water-filter-iit-delhi-tests-show-up-to-93-removal-of-pfas\/articleshow\/133434339.cms\" target=\"_blank\" rel=\"noopener\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u200bNaina and Nayantara Singh developed the low-cost plant-based water filter. What if some of the ingredients sitting in a kitchen cupboard could help tackle pollutants that conventional water filters struggle with? For Delhi-NCR twins Naina and Nayantara Singh, that question became the starting point for a nearly year-long scientific experiment. The Class XII students have [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":15513,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31],"tags":[],"class_list":["post-15512","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-31"],"magazineBlocksPostFeaturedMedia":{"thumbnail":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","medium":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","medium_large":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","large":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","1536x1536":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","2048x2048":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","blogsy-small":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","blogsy-small-tall":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","blogsy-small-square":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","blogsy-small-masonry":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","blogsy-medium":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","blogsy-medium-masonry":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","blogsy-large":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg","blogsy-wide":"https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg"},"magazineBlocksPostAuthor":{"name":"admin","avatar":"https:\/\/secure.gravatar.com\/avatar\/8709732a479614e7a8aa24d3eb1b239f30dc6d90c61464ed495001e7a469d856?s=96&d=mm&r=g"},"magazineBlocksPostCommentsNumber":"0","magazineBlocksPostExcerpt":"\u200bNaina and Nayantara Singh developed the low-cost plant-based water filter. What if some of the ingredients sitting in a kitchen cupboard could help tackle pollutants that conventional water filters struggle with? For Delhi-NCR twins Naina and Nayantara Singh, that question became the starting point for a nearly year-long scientific experiment. The Class XII students have [&hellip;]","magazineBlocksPostCategories":["\u0b26\u0b47\u0b36 \u0b2c\u0b3f\u0b26\u0b47\u0b36"],"magazineBlocksPostViewCount":1,"magazineBlocksPostReadTime":6,"magazine_blocks_featured_image_url":{"full":["https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg",400,225,false],"medium":["https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg",300,169,false],"thumbnail":["https:\/\/koshalsambada.in\/wp-content\/uploads\/2026\/08\/naina-and-nayantara-singh-developed-the-low-cost-plant-based-water-filter.jpg",150,84,false]},"magazine_blocks_author":{"display_name":"admin","author_link":"https:\/\/koshalsambada.in\/author\/admin"},"magazine_blocks_comment":0,"magazine_blocks_author_image":"https:\/\/secure.gravatar.com\/avatar\/8709732a479614e7a8aa24d3eb1b239f30dc6d90c61464ed495001e7a469d856?s=96&d=mm&r=g","magazine_blocks_category":"<a href=\"#\" class=\"category-link category-link-31\">\u0b26\u0b47\u0b36 \u0b2c\u0b3f\u0b26\u0b47\u0b36<\/a>","_links":{"self":[{"href":"https:\/\/koshalsambada.in\/index.php?rest_route=\/wp\/v2\/posts\/15512","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/koshalsambada.in\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/koshalsambada.in\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/koshalsambada.in\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/koshalsambada.in\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=15512"}],"version-history":[{"count":0,"href":"https:\/\/koshalsambada.in\/index.php?rest_route=\/wp\/v2\/posts\/15512\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/koshalsambada.in\/index.php?rest_route=\/wp\/v2\/media\/15513"}],"wp:attachment":[{"href":"https:\/\/koshalsambada.in\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15512"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/koshalsambada.in\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15512"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/koshalsambada.in\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15512"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}