The need of paper machine biocides?

IM is wondering: are there any other sector of process industry, where microbes are allowed to grow like in paper industry?

Biotechnological processes, of course. But their populations are carefully selected and controlled. And they are employers of the company, not criminals trying to cause harm to the company.

Some significant changes in paper industry processes have taken place after the rise of active environmental care. Both the closure of water circulation and the cancelling of biocides having mercury as an active incredient are favorable for the environment, of course. But the microbial growth inside the paper machines has activated at the same time.

The beginning of neutral paper production led to an "ecocatastrophe" inside paper machines. The rise of pH value (as well as the rise of temperature, caused by the extended recirculation of water) was fatal for slow, acid-loving fungal growth. New mineral additives are an important source of certain types of bacteria, causing severe problems like production of slime, spoiling of the process compounds and hygiene faults of the products.

IM has published an article "Paper Machine: an Ecosystem and a Bioreactor" (INOCULA 1/2007. Helsinki, Finland). Many readers agree: paper machines offer ecological niches for bacteria, and the controlled environments of wet end circulations are very much similar with those of biotechnical processes, based on chemostatic fermentors.

A lot could be do to make paper machines more unfavorable growth environment for microbial contaminants. Very good results have been achieved in some projects where ecological aspects have been taken into account. These issues will be discussed later in this blog.

But the main question is: how much biocides we still need to control the microbial growth in all regions of a paper machine?

Incoming raw materials, sorry to say, may be very contaminated: the highest value of total count during IM's career has been over 100 000 000 cfu/g in a mineral slurry (which was fortunately replaced by a fresh lot by the supplier!). It is therefore obvious that a continuous control - both analytical and practical - is needed for starches, mineral pigments and other contaminated raw materials. This does not mean that all lots are spoiled: there are suppliers which know their response to deliver pure products to the mills but all kind of errors in biocidic pre-treatment, transport and storage of these products may happen.

Certain sites of paper machines also need biocidic treatments all the time. Chosing proper solutions for biocide programs (type of biocide, active compound, dosing sites, timing etc.) of a paper machine is a challenging tasks. In best cases, both the paper mill and biocide personnel are sitting down and discussing of the individual problems of the paper process hygiene.

When specified laboratory services, having tools like PMEU and biofilm microscopy, are included, the final result can be optimal one. Paper industry microbiologists can also help significantly by declaring the effects of process parameters on the growth of planktonic and biofilm bacteria.

The more competence is included, the better solution will be find.

Checkpoints of a paper machine.

Imagine yourself as a bacterium.

You are coming to the paper mill - maybe waterborne, maybe as a bug or as a spore in a lot of starch or mineral pigment.

What will happen to you?

Do you find an ecological niche inside the machine?

I am sure, you will find.

You will find a wet surface, some of your genes will be activated for the living inside a biofilm.

You have fellow bugs there. You could even communicate chemically.

And, after a period of lush life inside the biofilm, you get older and will be released into the water current.

And you wish, that there are no detectives, controlling your movements inside the paper machine: wet end systems, pulp and broke systems, mineral slurry and starch size routes...

The detectives belong to HACCP. They know where you will hide...

- This is my dream. Tools for this kind of HACCP are already available.

Some practical views into the future of biotechnology.

I will come back to the future of biotechnology.

The economical figures of traditional industries seem to be awful. We will see, what is the condition of such branches like paper, automobile and communication enterprises in 2010.

The optimistic view into biotechnology, presented by Osmo Kuusi in 1991, should be reviewed soon.

Another positive attitude has been presented by Tom Abate in "The Biotech Investor", published in 2003 and found by me under a layer of dust in the library of Jyväskylä University (Tom Abate 2003. The Biotech Investor: how to profit from the coming boom in biotechnology. Owl Books, New York).

Tom Abate tells about sectors of biotechnology like the previous authors, discovering this area. He calls them "The Genomics Wave", "The Proteomics Wave" , "The Biotech Toolmakers", "Green Genes", "The New Factories", "Brave New Worlds" and "The Biotech Clusters".

What these titles include, I'll try to explain whenever I have red this interesting book.

Before that, I have good news:

The leading newspaper in Central Finland, Keskisuomalainen, tells about the manufacturers of small-scale waste water treatment plants. Finnish legislations says that all small houses shall update their ww treatment systems before the end of 2013.

The count of these households is est. 300 000 in Finland!

Not to name the individual enterprises, there are a couple of small companies manufacturing/importing batch-type activated sludge systems in a small scale in our country. Two larger companies, having Finnish background, also exists.

Novel ideas to control the effluents of these mini-plants already exist, but the questions of evaluation, standardization etc. will have a sever effect on the application of these methods.

I think that it is now time for the Finnish government to accept these analytical methods to be applied by small-scale treatment plant producers.

Colony counts, developed in the beginning of 20th century, are valuable. But what we are needing today are the rapid methods for the control of both activated sludge itself and the effluents of these equipments.