SHILLONG: Primitive and unscientific rat-hole mining and dumping of huge quantity of coal have polluted water bodies to a great extent in mining areas.
An assistant professor of University of Science and Technology, Meghalaya, has claimed to have come up with a possible solution to purify such polluted water by using an innovative “low-cost filtration technique using algal mat bags”.
Assistant professor Mautushi Das along with her students Monalisa Dutta, Zhodi Marak and Deepika Narah exhibited the filtration technique at the recently concluded Regional Innovators Conclave.
Talking to The Shillong Times, Das said the filter can be used in every household where people are facing tremendous fresh water scarcity due to acid mine drainage (AMD) from the mines which has polluted the fresh water bodies of the area.
She spoke of an acidophilic green alga, scientifically known as “Microspora quadrata”, which grows abundantly in most coalmine-impacted aquatic bodies covering almost the whole stream bed and can be used for filtering the water as it can remove harmful metals present in the liquid.
Giving details of the functioning of the low cost filter, she said that a multi-layer filter bed can be constructed using a bamboo or wooden frame and small buckets.
“The fourth bucket (from top) contains clean filter-sand and pebbles to remove bacteria and suspended particles, the third contains activated carbon (or alternatively charcoal) to remove dissolved organic matter and the top bucket contains the microbial mat (algae) that resists stress and remove metal,” she said.
Pointing to the ‘algae mats’ that have been packed like tea bags, she said, “(These are) Mat bags, a dried microbial mat can be packaged in bags designed like tea bags. The bags are added to a container and allowed to hydrate and sequester metals dissolved in the water.”
“After a prescribed period, the bags are removed from the treated water. Mats are non-toxic and do not produce offensive odours. They are grown using a standard technique that is inexpensive and can be accomplished with minimal training,” she added.
Das came up with this technique after eight years of research on algae in coal mining impacted areas of Jainita hills.
She observed that in case the government forms any plan to recover the acidic water bodies to reutilise the systems this filtration unit using acidophilic algae could be suggested.
“It can be useful in removing toxic metals from AMD impacted systems of the region with minimum expenditure,” she said.
