Tag Archives: Lulea University of Technology

Treating municipal wastewater and dirty industry byproducts with nanocellulose-based filters

Researchers at Sweden’s Luleå University of Technology have created nanocellulose-based filters in collaboration with researchers at the Imperial College of London (ICL) good enough for use as filters according to a Dec. 23, 2014 news item on Nanowerk,

Prototypes of nano-cellulose based filters with high purification capacity towards environmentally hazardous contaminants from industrial effluents e.g. process industries, have been developed by researchers at Luleå University of Technology. The research, conducted in collaboration with Imperial College in the UK has reached a breakthrough with the prototypes and they will now be tested on a few industries in Europe.

“The bio-based filter of nano-cellulose is to be used for the first time in real-life situations and tested within a process industry and in municipal wastewater treatment in Spain. Other industries have also shown interest in this technology and representatives of the mining industry have contacted me and I have even received requests from a large retail chain in the UK,” says Aji Mathew Associate Professor, Division of Materials Science at Luleå University.

A Dec. 22, 2014 Luleå University of Technology press release, which originated the news item, further describes the research,

Researchers have combined a cheap residue from the cellulose industry, with functional nano-cellulose to prepare adsorbent sheets with high filtration capacity. The sheets have since been constructed to different prototypes, called cartridges, to be tested. They have high capacity and can filter out heavy metal ions from industrial waters, dyes residues from the printing industry and nitrates from municipal water. Next year, larger sheets with a layer of nano-cellulose can be produced and formed into cartridges, with higher capacity.

– Each such membrane can be tailored to have different removal capability depending on the kind of pollutant, viz., copper, iron, silver, dyes, nitrates and the like, she says.

Behind the research, which is funded mainly by the EU, is a consortium of research institutes, universities, small businesses and process industries. It is coordinated by Luleå University led by Aji Mathew. She thinks that the next step is to seek more money from the EU to scale up this technology to industrial level.

– Alfa Laval is very interested in this and in the beginning of 2015, I go in with a second application to the EU framework program Horizon 2020 with goals for full-scale demonstrations of this technology, she says.

Two of Aji Mathews graduate student Peng Liu and Zoheb Karim is also deeply involved in research on nano-filters.

– I focus on how these membranes can filter out heavy metals by measuring different materials such as nanocrystals and nano-fibers to determine their capacity to absorb and my colleague focuses on how to produce membranes, says Peng Liu PhD student in the Department of Materials Science and Engineering at Luleå University of Technology.

I have been following the nanocellulose work at Luleå University of Technology for a few years now. The first piece was a Feb. 15, 2012 post titled, The Swedes, sludge, and nanocellulose fibres, and the next was a Sept. 19, 2013 post titled, Nanocellulose and forest residues at Luleå University of Technology (Sweden). It’s nice to mark the progress over time although I am curious as to the source for the nanocellulose, trees, carrots, bananas?

Nanocellulose and forest residues at Luleå University of Technology (Sweden)

Swedish scientists have developed a new production technique which scales up the manufacture of cellulose nanfibres and cellulose nanocrystals (CNC, aka nanocrystalline cellulose [NCC]) from waste materials. From the Aug. 30,2013 news item on Nanowerk (Note: A link has been removed),

Luleå University of Technology is the first in Sweden with a new technology that scales up the production of nano-cellulose from forest residues. It may eventually give the forest industry profitable new products, e.g. nano-filters that can clean both the gases, industrial water and even drinking water. Better health and cleaner environment, both nationally and internationally, are some possible outcome

“There is large interest in this from industries, especially because our bionanofilters are expected to be of great importance for the purification of water all around the globe,” says Aji Mathew, Associate Professor at Luleå University of Technology, who leads the EU-funded project, NanoSelect.

The Luleå University of Technology Aug. 28, 2013 news release, which originated the news item, briefly describe the process and the magnitude of the increased production,

On Tuesday [Aug. 27, 2013], researchers at Luleå University of Technology demonstrated before representatives from the Industry and from research institutes how they have managed to scale up the process of manufacture of nano-cellulose of two different residues from the pulp industry. One is from Domsjö in Örnsköldsvik in the form of a fiber product that is grinded down to tiny nano fibers in a special machine. Through this process, the researchers have managed to increase the amount of the previous two kilograms per day to 15 kg per day. Another byproduct is nanocrystals that have been successfully scaled up from 50 to 640 grams / day. The process is possible to scale up and therefore highly interesting for the forest industry.

As noted in the news item, this development is an outcome of the EU- (European Union) funded NanoSelect project, from the Project Details webpage,

NanoSelect aims to design, develop and optimize novel bio-based foams/filters/membranes/adsorbent materials with high and specific selectivity using nanocellulose/nanochitin and combinations thereof for decentralized industrial and domestic water treatment. NanoSelect proposes a novel water purification approach combining the physical filtration process and
the adsorption process exploring the capability of the nanocellulose and/or nanochitin (with or without functionalization) to selectively adsorb, store and desorb contaminants from industrial water and drinking water while passing through a highly porous or permeable membrane.

As the news release notes,

Nano Filter for purification of process water and drinking water is not the only possible product made of nano-cellulose since cellulose has much greater potential.

– Large-scale production of nano-cellulose is necessary to meet a growing interest to use bio-based nanoparticles in a variety of products, says Kristiina Oksman professor at Luleå University of Technology.

Nano filters is today developed at Imperial College, London, in close collaboration with the researchers at Luleå University of Technology.

– We have optimized the process to produce nano filters, we can control the pore size and thus the filter porosity. It’s actually just a piece of paper and the beauty of this piece of paper is that it is stable in water, not like toilet paper that dissolves easily in water, but stable, says Professor Alexander Bismarck at Imperial College.

Nice to hear more about CNC developments.

The Swedes, sludge, and nanocellulose fibres

According to a Swedish research team at Luleå University of Technology, it’s possible to create cellulose nanofibres from sludge. Well, it’s a particular kind of sludge. From the Feb. 16, 2012 news item on Nanowerk,

For example, at one single cellulose manufacturer, Domsjö Fabrikerna in Sweden, the producer of special cellulose, which is used to in the manufacturing of viscose fibers, causes one thousand tons of sludge as a residue each year.

A few years ago, cellulose industries in Sweden, disposed some of their waste as sludge into the ocean. It is now prohibited, and the sludge is stored in large tanks on land. This particular cellulose sludge makes it possible, to produce, so far, the most profitable production of cellulose nanofibres from bio-residue products.

The yield of the manufacture of cellulose nanofibres from the sludge is 95%, compared with cellulose nanofiber production from wood chips 48%, lignin residues 48%, carrot residues of 20%, barley 14% and grass 13%. [emphases mine] “The separation of cellulose nanofibres from bioresidues is energy demanding but when we separate the waste from Domsjö, the energy consumption is lower. The special cellulose from Domsjö has very small size and it also has high cellulose content and therefore the fibers do not need to be chemically pre-treated before the production of cellulose nanofibers,” says Professor Kristiina Oksman.

This is interesting news especially in light of the interview with Jean Moreau (president of CelluForce, a company which manufactures nanocrystalline cellulose [NCC] in Québec, Canada) that I heard yesterday where there was some discussion as to what type of wood is needed to produce it.

In an interview with Dr. Richard Berry (now with CelluForce but with FPInnovations at the time), I asked where the NCC comes from (my Aug. 27, 2010 posting),

Q: Does the process use up the entire log or are parts of it left over? What happens to any leftover bits?

A:         We are starting from the bleached chemical pulp which is, to a large extent, cellulose. The left over bits have actually been processed as part of the chemical pulp mill processes. The acid used is recovered and reused and the sugars are converted into other products; in the demonstration plant they will be converted into biogas.

I’m not sure when the ‘spiderphone’  interview took place but it seems to be prior to the manufacturing/demonstration plant’s opening earlier this year (2012). For the curious, here’s a link to the 48 min. interview (roughly 25 mins. Moreau and roughly 25 mins. of questions from callers), http://ccc.spiderphone.com/RealCast/9597937293/Flashcast.html. (Thanks again to David Rougley for dropping by to leave a comment and this link to the interview on an earlier nanocellulose fibre posting [March 28, 2011].)

Getting back to the main event, the Swedish research is part of a larger project called Bio4Energy and you can find out more about that here.

Bravo to the Swedes for making use of sludge!