Researcher Mohammad Bhuyan: “Alkali-activated filter is the easiest way for people in poor rural areas to disinfect drinking water”

Erkki Paasikivi foundation grant recipient Mohammad Bhuyan is developing a new way for the treatment of drinking water in low-income countries. A novel filter helps to bring clean drinking water available to more and more people.

Every year, 1.7 million children under the age of 5 die of diarrhea caused by contaminated drinking water in low-income countries around the world. In poor rural areas, water purification is not done centrally in treatment plants, but the locals clean the water themselves.
The most popular method for water treatment is a ceramic silver-impregnated filter. Ceramic filter can remove even 99,88 percent of the bacteria in water, and its use has been observed to reduce the incidence of diarrhea. The ceramic filter is made of clay and impregnated with silver, which helps to kill bacteria and to prevent mold growth in the filter. The problem is that the manufacture of the filter requires as much as 1,000 degrees Celsius temperature, which makes manufacturing cumbersome.
Now, with the support of Erkki Paasikivi foundation, Bhuyan is developing a new kind of filter at the University of Oulu. The filter is equivalent to a ceramic filter but can be manufactured already at 60 Celsius degrees.

“If we are successful, this filter can be the easiest and simplest way to disinfect water for the local people living in rural areas”, Bhuyan says.

Safe drinking water available to more and more people

Bhuyan became interested in water technology research in his country of birth Bangladesh, where water used by industry and households flows untreated into water bodies and contaminates surface water.
Almost 80 percent of the water used by man is surface water, as groundwater is so difficult to access in many places. For example in Bangladesh, some people in rural areas drink surface water completely without purification or clean it just by boiling.

“I’m motivated by the fact that I can improve lives by making safe drinking water available for more people”, Bhuyan says.

Bhuyan graduated with a Master’s degree in chemistry in Bangladesh at the University of Chittagong, specializing in wastewater treatment. He moved to Finland in 2017 to do another Master’s degree in Materials Science at the University of Eastern Finland, and in 2020 he started postgraduate studies at the University of Oulu at Fibre and Particle Engineering Research Unit, where he is now developing the novel filter.

The Bhuyan filter uses blast furnace slag, which is a by-product of iron or steel production, and metakaolin made from clay. They contain reactive aluminosilicate, which reacts at high pH to form a ceramic-like texture. This reaction is called alkali activation, and it allows a low manufacturing temperature. In addition, the filter is impregnated with silver, which helps to remove bacteria.
“Alkali-activated materials have been previously used for wastewater treatment but not to disinfect bacteria from the water. I believe that this new filter also has commercial potential”, says Bhuyan.

Wastewater and drinking water treatment go hand in hand

There is still a lot of work to be done in the field of water technology to ensure that all the people around the world have clean and safe drinking water. As many as 2 billion people do not yet have access to clean drinking water, and the UN aims to halve this by 2050.
According to Bhuyan, in the future we must invest both in wastewater treatment and for disinfecting drinking water from bacteria and harmful microbes.
“For example in Bangladesh the industrialisation brings pollutants and chemicals, like dye from textile industry, into the waterbody. It is important to purify these wastewaters so that the chemicals won’t end up in the water stream and to the water that people drink”, says Bhuyan.

“Stories from water technology research” series of articles presents the work of researchers funded by the KAUTE Foundation and the Erkki Paasikivi Foundation. The foundations will organize a joint grant application focusing on water technology research on 16.8.–17.9.2021. The grants are primarily awarded for doctoral dissertations and for post-doctoral research. The foundations also encourage other organizations in the field of water technology to cooperate in the field of grant applications.