Nano filter made of microalgae

A team of researchers and scientists from the University of Dhaka and Uppsala University, Sweden have jointly invented paper sheets made of microalgae, locally known as 'shewla' in Bangladesh, that can filter virus and bacteria in water.

An article published in the International Scientific Journal (ISJ) shows, this invention can be used in providing fresh water to thousands of people in Bangladesh leading to the prevention of waterborne disease eventually. It will take time to make it available for wide use though.
Professor of the botany department in Dhaka University, Mohammed Almujaddade Alfasane found this particular type of pond weed. It is called pithophora algae which was later processed in a laboratory in Sweden and made into paper sheets. Albert Mihranyan, senior lecturer of nanotechnology and functional materials at Uppsala University leaded the process. Honorary professor of the biomedical physics and technology department of Dhaka University, Khondkar Siddique-e-Rabbani, has been the coordinator of the project in Bangladesh.

After the filter paper was made, its effectiveness was tested in the department of microbiology, under the supervision of Anwara Begum. He was accompanied by Sharmin Zaman, a research scientist at the Centre for Advanced Research in Sciences.

Background

Dhaka University has jointly conducted a number of research projects with Uppsala University. This is how Khondkar Siddique-e-Rabbani was linked with the research.
“Albert Mihranyan first told me about making paper filter with microalgae to purify water in a developing country like Bangladesh,” said Khondkar Siddique.
“I came to know that Almujaddade Alfasane has been studying and working on various types of pond weeds,” he added. Khondkar Siddique then contacted Almujaddade.

Incidentally, Almujaddade Alfasane has developed 14 types of new pond weeds that he along with late professor AKM Nurul Islam gave different names. They have ensured that Bangladesh is somehow or the other included in the names of these pond weeds. One such pond weed is Trachelomonas Barishalika, the genus he found in Barishal.

Almujaddade recommended pithophora algae to Albert for making paper filter. Albert was not very sure in the beginning that pithophora could be made into paper filter. Almujaddade was confident and brought pithophora to the Dhaka University laboratory from Sylhet.

“Its growth was super fast. It grows twice in three days. It can be grown in soil, water and cow dung compost,” Almujaddade told Prothom Alo.

Pithophora was then sent to Sweden and Albert Mihranyan started processing algae into paper filter.

It seems to be merely white paper. But scrutinised under a microscope, it has hundreds of pores.

Professor Siddique said the filter contains hundreds of nano filters. The size of those pores are 17 nanometre and these prevent all kind of virus and bacteria. The size of the waterborne germs ranges from 30 to 100 nanometre in general.

“If the pore sizes were less than 17 nanometre it would filter the salt in the water which destroy the standard quality of the water,” Almujaddade added.

In Sweden, researcher created plastic virus to test the newly invented nanofilter and it was successful.

After if had been sent back to Dhaka University lab, the researcher tested the filter with the water from Dhanmondi Lake and river Turag.

“It can filter 100 percent germs from the water and the water looks very clear as well. The kit is in the primary stage now. It can be improved further,” Anwara Begum told Prothom Alo.

Siddique-e-Rabbani said, the filter requires high force to process water and takes time.

Many technical improvements are needed to make it available for wider use, admits Albert Mihranyan over an email to the Prothom Alo correspondent.

“With proper technical support and funding the filter can be developed for commercial use. A user friendly machine can be made as well,” Albert wrote.

The nano filter made from pithophora algae has also received international recognition as a successful research finding. The research paper was published in the American Chemical Society's (ACS) Sustainable Chemistry and Engineering Journal (Impact Factor 6.97) on 6 August.

Uppsala University told a press conference about the algae of Bangladesh. ScienceDaily.com has published a report titled, "Paper filter made from local microalgae can save millions of lives in Bangladesh".

This nano filter made from pithophora algae in Bangladesh can cleanse the river or reservoir water. Now it neds to be made available for all.

*The piece, originally appearing in ‘Chhutir Diney’ a weekly supplementary of Prothom Alo, has been rewritten in English by Farjana Liakat