Current situation of process hygiene control in paper industry is relatively complicated.
No matter very effective control methods are already available (epifluorescence microscopy, ATP Assay, PCR, PMEU incubations) the roles of paper mills, biocide suppliers and raw material producers are not very clear.
Based on the experiences by Industrial Microbiologist since beginning of 80', it seems that paper mills prefer external services and this tendency is evergrowing today. Biocide suppliers have developed novel analyse methods which can be applied even at the mills, and many raw material suppliers know their response to deliver minerals, starches etc. with good hygienic quality for paper and board mills.
What should still be developed is the active role of paper mills themselves to control their machines. There is no more any need for expensive microbiological laboratories - in opposite, many methods could either be applied by wet end laboratories of the mills or be bought from external companies (ref. BIOTOUCH Service).
Wet end chemistry has already been controlled with ON LINE analyse units by certain institutes in Finland over years. ON LINE microbiological control is also coming soon, referring several current project proposals.
A combination of all parties - paper mills, biocide suppliers and raw material producers - would spare remarkable amount of money by optimizing biocide programs, by planning washing programs, by responsing immediately to hazardous situations and avoiding costs of returned products.
Wednesday, August 13, 2008
Saturday, August 2, 2008
Evaluation of slimicides for paper machine process waters.
Time series of steel coupons are the common method to evaluate the effects of biocides against slime-forming bacteria in paper machine processes.The installation of coupons inside the machine may not be the main problem. Two other aspects will limit the value of this method:* only one slimicide (= the current slimicide used in the machine) can be tested
* duration of the evaluation may take days...weeks
PMEU Incubator (by FINNOFLAG Oy) has been adopted into biocide and slimicide testing because it gives chance to
* evaluate several biocides/slimicides at the same time
* only hours to days are needed to have the results of evaluations
Picture (above) shows a bacterial population, attached on the surface of a PMEU test coupon, with fibres, minerals and starches. These bacteria stand washing of coupon with water after testing which means that they are "primary attachers" on the surface of steel when immersed in process water of a paper machine.
Friday, July 18, 2008
How to control the microbiological status of activated sludge?
There is one area of paper industry microbiology where active measures are needed to cultivate microbial flora: biological waste water treatment plants.
When focusing on activated sludge of aeration basin (anaerobic treatments will be discussed in another post), the roles of different microbes should first be understood.
The tasks of bacteria and protozoa - which are the beneficial microbial groups in the purification process - are different: bacteries are responsible for the transformations (mineralisation) of incoming organic compounds, Protozoa collects small particles (also bacteria) and acts as indicators of the activated sludge condition.
Bacteria shall also build up "flocs" which can settle down and be either returned backwards into the beginning of the purification process or totally removed from the plant. Significant amounts of nutrients will also be lead to the "sludge route" which is especially important for environmental reasons: no matter relatively low concentrations of nitrogen and phosphorus (compared with municipal waste water effluents), the volumes of P&P waste water effluents are huge.
Traditional parameters which are related to the microbiological status of activated sludge are C:P:R ratio, temperature, pH and oxygen concentration. In addition, the share of Protozoan indicator organisms are checked by microscopical methods.
ATP Assay is also a fast and reliable method to check the viability of activated sludge and control unfavourable sludge escape from secondary sedimentation basins (IM has written his second graduate work about this issue on 90's).
Incubations with PMEU equipment (FINNOFLAG Oy, Finland) have been very successful when the effects of low oxygen concentrations on the structure of flocs are the subject of the study. This method, in connection of bright field/dark field/phase contrast microscopy, gives also fast responses (even in hours) when the detrimental effects of toxic water fractions on activated sludge flora shall be checked.
There are many reasons for the bulking of activated sludge: nutrient supply, oxygen concentration, temperature etc. In all cases, a layer of activated sludge will rise on the surface of the basin and cannot be taken away from the water flow to sedimentation stages.
Measurements of redox potentials can give more information about the risks of anaerobic growth in biological waste water purification systems than sole oxygen concentration analyses(practical reslusts by IM). RO potential control may also work as a replacement/addition to traditional Respiratory Rate test, often used to check the viability of activated sludge.
Microbial activities continue also in sedimentation basins. IM has detected a significant rise of nitrogen concentration in certain basins in studies performed on 80's. The reason is obviously the activity of a coliform species, Klebsiella pneumoniae, which is able to fix nitrogen from atmosphere (nitrogen fixation). The routes of the pathogenic Legionella pneumophila in the purification process should also be investigated more deeply. Novel types of analytical methods to replace the traditional colony count methods (intended in the control of household water) shall be developed, however: L.pneumophila is very hard to "find" among other bacteria and fungi which are capable to grow extensively on selective nutrient media for Legionella.
ON LINE control has - until now - not got any role in HACCP of waste water treatment systems but promising technical solutions are already available for semi-continuous control of activated sludge microbiology.
When focusing on activated sludge of aeration basin (anaerobic treatments will be discussed in another post), the roles of different microbes should first be understood.
The tasks of bacteria and protozoa - which are the beneficial microbial groups in the purification process - are different: bacteries are responsible for the transformations (mineralisation) of incoming organic compounds, Protozoa collects small particles (also bacteria) and acts as indicators of the activated sludge condition.
Bacteria shall also build up "flocs" which can settle down and be either returned backwards into the beginning of the purification process or totally removed from the plant. Significant amounts of nutrients will also be lead to the "sludge route" which is especially important for environmental reasons: no matter relatively low concentrations of nitrogen and phosphorus (compared with municipal waste water effluents), the volumes of P&P waste water effluents are huge.
Traditional parameters which are related to the microbiological status of activated sludge are C:P:R ratio, temperature, pH and oxygen concentration. In addition, the share of Protozoan indicator organisms are checked by microscopical methods.
ATP Assay is also a fast and reliable method to check the viability of activated sludge and control unfavourable sludge escape from secondary sedimentation basins (IM has written his second graduate work about this issue on 90's).
Incubations with PMEU equipment (FINNOFLAG Oy, Finland) have been very successful when the effects of low oxygen concentrations on the structure of flocs are the subject of the study. This method, in connection of bright field/dark field/phase contrast microscopy, gives also fast responses (even in hours) when the detrimental effects of toxic water fractions on activated sludge flora shall be checked.
There are many reasons for the bulking of activated sludge: nutrient supply, oxygen concentration, temperature etc. In all cases, a layer of activated sludge will rise on the surface of the basin and cannot be taken away from the water flow to sedimentation stages.
Measurements of redox potentials can give more information about the risks of anaerobic growth in biological waste water purification systems than sole oxygen concentration analyses(practical reslusts by IM). RO potential control may also work as a replacement/addition to traditional Respiratory Rate test, often used to check the viability of activated sludge.
Microbial activities continue also in sedimentation basins. IM has detected a significant rise of nitrogen concentration in certain basins in studies performed on 80's. The reason is obviously the activity of a coliform species, Klebsiella pneumoniae, which is able to fix nitrogen from atmosphere (nitrogen fixation). The routes of the pathogenic Legionella pneumophila in the purification process should also be investigated more deeply. Novel types of analytical methods to replace the traditional colony count methods (intended in the control of household water) shall be developed, however: L.pneumophila is very hard to "find" among other bacteria and fungi which are capable to grow extensively on selective nutrient media for Legionella.
ON LINE control has - until now - not got any role in HACCP of waste water treatment systems but promising technical solutions are already available for semi-continuous control of activated sludge microbiology.
Thursday, July 17, 2008
Biofuels from pulp industry have a gret potential in future.
IM follows frequently the network site "The Paper Index Times" which has published this new post today:
"Monday, July 14, 2008
Paper and Pulp Mills Poised to Produce Biofuels
No other industry is so well suited to produce fuels from waste wood cellulose than the paper/pulp industry. By converting pulp by-products from waste to precious fuel, pulp mills can do a big favour to themselves, the environment, and the energy consuming public.
The pulp and paper industry has the scale to produce more than 9 billion gallons per year of biofuels, or as much as 20,000 MW of biomass power - as much as 16 Quads of cumulative fossil energy savings – realize net CO2 emissions reductions of more than 100 million tons annually, in the process generating financial returns, relative to continued investment in existing technology, with internal rates of return between 15-40% depending of fuel prices and incentives, according to a presentation given by Navigant Consulting’s Ryan Katofsky at the “Florida Farm to Fuel Summit,” which took place in St. Petersburg July last year....Gasifying rather than incinerating black liquor in soda furnaces – as is common practice - results in the production of a number of by-products, including synthesis gas. The bio-syngas can then be turned into a range of liquid fuels, such as methanol, dimethyl ester (DME), Fischer-Tropsch synthetic diesel and hydrogen gas. _SourcePulp mills could easily become energy self-sufficient by using the waste process heat of paper manufacture, and eventually supply energy to the outside in the form of electricity or fuels. The more productive uses that can be found for solid waste, waste sludge, waste exhaust gases, waste heat, and waste water, the cleaner the environment will become--land, air, and water.
Labels: cellulosic fuels, garbage energy
"Monday, July 14, 2008
Paper and Pulp Mills Poised to Produce Biofuels
No other industry is so well suited to produce fuels from waste wood cellulose than the paper/pulp industry. By converting pulp by-products from waste to precious fuel, pulp mills can do a big favour to themselves, the environment, and the energy consuming public.
The pulp and paper industry has the scale to produce more than 9 billion gallons per year of biofuels, or as much as 20,000 MW of biomass power - as much as 16 Quads of cumulative fossil energy savings – realize net CO2 emissions reductions of more than 100 million tons annually, in the process generating financial returns, relative to continued investment in existing technology, with internal rates of return between 15-40% depending of fuel prices and incentives, according to a presentation given by Navigant Consulting’s Ryan Katofsky at the “Florida Farm to Fuel Summit,” which took place in St. Petersburg July last year....Gasifying rather than incinerating black liquor in soda furnaces – as is common practice - results in the production of a number of by-products, including synthesis gas. The bio-syngas can then be turned into a range of liquid fuels, such as methanol, dimethyl ester (DME), Fischer-Tropsch synthetic diesel and hydrogen gas. _SourcePulp mills could easily become energy self-sufficient by using the waste process heat of paper manufacture, and eventually supply energy to the outside in the form of electricity or fuels. The more productive uses that can be found for solid waste, waste sludge, waste exhaust gases, waste heat, and waste water, the cleaner the environment will become--land, air, and water.
Labels: cellulosic fuels, garbage energy
Saturday, July 12, 2008
Features of sporeforming bacteria.
Sporeformers are certain bacteria which can transform themselves from vegetative (= growing) form to spores (= resting form). Best-known examples of these bacteria are aerobic sporeformers ("bacillus-type", inc. Bacillus sp. , Paenibacillus sp. and other Gram-positive, aerobic sporeformers) and anaerobic sporeformers (most common species belong to the genus Clostridium). These bacteria are very common in all environments, especially in soils.
Spores of bacteria are not intended in the reproduction of organisms (like fungal spores) but to keep bacteria alive in conditions where they cannot be metabolically active. Sporulation is caused by the lack of nutrients, and germination of spores takes place whenever environmental conditions turn better for the growth of the bacterial cells.
These bacteria are a problem for paper industry because their spores tolerate dryness, cleaning agents and biocides very well. Their main sources are mineral pigments and starches, especially when these raw materials are delivered to the mills as dry powders. Whenever they are slurried, an effective biocide program shall be applied in the total system of their storage and dosing into the machines.
Another problems are analytical ones. Spores can be detected after a simple pasteurization of the samples (vegetative cells get killed, only spores stay alive) but this procedure kills also vegetative sporeformes. An analysis called "Sporeforming bacteria" does therefore not show potential sporeformers which are in vegetative growth phase. In addition, germination of spores, like every other chances in the properties of bacteria, takes certain time. This slows the growth of spores on nutrient media significantly. Fastest germination times can be achieved by PMEU incubator but the outgrowth of spores into vegetative cells may take much longer periods on the agar plates.
Evaluation of biocides should also be done with equipments like PMEU which show the different effects of biocides in the original samples.
Last but not least: if the growth of certain aerobic sporeformers has been very active, starch-degrading enzymes can stay active after biocidic treatments. Amylases can be found even after heat treatments because many of them are thermotolerant ones.
Sporeforming bacteria of paper industry have been studied very actively in Helsinki University, Dep. of Applied Chemistry and Microbiology. IM recommends to read scientific articles, written by the research group of Professor Mirja Salkinoja-Salonen, in magazines like "Applied and Environmental Microbiology" and "Industrial Microbiology and Biotechnology".
This group of bacteria is always a target of HACCP activities of paper mills, especially when products with high hygiene quality are manufactured. Studies to understand their features is therefore continuing also in future.
Spores of bacteria are not intended in the reproduction of organisms (like fungal spores) but to keep bacteria alive in conditions where they cannot be metabolically active. Sporulation is caused by the lack of nutrients, and germination of spores takes place whenever environmental conditions turn better for the growth of the bacterial cells.
These bacteria are a problem for paper industry because their spores tolerate dryness, cleaning agents and biocides very well. Their main sources are mineral pigments and starches, especially when these raw materials are delivered to the mills as dry powders. Whenever they are slurried, an effective biocide program shall be applied in the total system of their storage and dosing into the machines.
Another problems are analytical ones. Spores can be detected after a simple pasteurization of the samples (vegetative cells get killed, only spores stay alive) but this procedure kills also vegetative sporeformes. An analysis called "Sporeforming bacteria" does therefore not show potential sporeformers which are in vegetative growth phase. In addition, germination of spores, like every other chances in the properties of bacteria, takes certain time. This slows the growth of spores on nutrient media significantly. Fastest germination times can be achieved by PMEU incubator but the outgrowth of spores into vegetative cells may take much longer periods on the agar plates.
Evaluation of biocides should also be done with equipments like PMEU which show the different effects of biocides in the original samples.
Last but not least: if the growth of certain aerobic sporeformers has been very active, starch-degrading enzymes can stay active after biocidic treatments. Amylases can be found even after heat treatments because many of them are thermotolerant ones.
Sporeforming bacteria of paper industry have been studied very actively in Helsinki University, Dep. of Applied Chemistry and Microbiology. IM recommends to read scientific articles, written by the research group of Professor Mirja Salkinoja-Salonen, in magazines like "Applied and Environmental Microbiology" and "Industrial Microbiology and Biotechnology".
This group of bacteria is always a target of HACCP activities of paper mills, especially when products with high hygiene quality are manufactured. Studies to understand their features is therefore continuing also in future.
Monday, July 7, 2008
Concepts of microbial ecology and biotechnology in process industry.
Coming back to the issues of microbial ecology and biotechnology:
Both of them have helped IM to understand the multitude of microbial activities which are typical for paper industry. Technical framework, beginning from the preparation of raw materials and ending to the waste water treatment plants can be regarded as fermentors or bioreactors where growth conditions vary a lot. Everlasting input of bacteria (and sometimes also fungal organisms) contain strains which can be adapted into these processes and live in them over very long periods - even tens of years. These topics, definitely, belong also to the research area of microbial ecology and its theories about adaptation, competition, synergisms...
These issues have been discussed by IM already in previous posts and shall be taken into account - in more detailled form - in near future.
By the way - what would be more interesting than to have shared net forum of paper industry engineers, environmental microbiologists, ecologists, biotechnicians and other specialists to discuss about similarities and analogies between natural environments and paper mills? Even limnology gives hints to understand certain microbial activities - like the growth of microbes in water flows as biofilm organisms. Another analogy can be found when observing the microbial populations of lake or ocean sediments and the microbial flora of different kind of depositions in paper mill machinery.
IM is looking forward to hear various multiscience views by biologists, biotechnical and environmental microbiologists, ecologists, limnologists and oceanologists about similarities between natural environments and paper machines!
Both of them have helped IM to understand the multitude of microbial activities which are typical for paper industry. Technical framework, beginning from the preparation of raw materials and ending to the waste water treatment plants can be regarded as fermentors or bioreactors where growth conditions vary a lot. Everlasting input of bacteria (and sometimes also fungal organisms) contain strains which can be adapted into these processes and live in them over very long periods - even tens of years. These topics, definitely, belong also to the research area of microbial ecology and its theories about adaptation, competition, synergisms...
These issues have been discussed by IM already in previous posts and shall be taken into account - in more detailled form - in near future.
By the way - what would be more interesting than to have shared net forum of paper industry engineers, environmental microbiologists, ecologists, biotechnicians and other specialists to discuss about similarities and analogies between natural environments and paper mills? Even limnology gives hints to understand certain microbial activities - like the growth of microbes in water flows as biofilm organisms. Another analogy can be found when observing the microbial populations of lake or ocean sediments and the microbial flora of different kind of depositions in paper mill machinery.
IM is looking forward to hear various multiscience views by biologists, biotechnical and environmental microbiologists, ecologists, limnologists and oceanologists about similarities between natural environments and paper machines!
Sunday, July 6, 2008
Why shall paper industry be moved to foreign countries from Finland?
IM was sitting with an old friend from Helsinki on the terrace of his summer cottage (no water lines, no electricity)on yesterday evening.
- (IM) Where are we going in near future?
- Basic production (agriculture, fishing etc.) will be respected after a while...
- Why we cannot continue P&P production in Finland?
- Labour costs are not the problem. Their share is under 10% of the costs of paper production.
- But..?
- Transport of the products and price of the raw material are the main problems.
IM has read from local newspaper "KESKISUOMALAINEN" about the problems of timber production. A manager of timber enterprise told that "the taxes are the problem. Price of the Finnish raw wood is too high today. Government should help to have wood with acceptable prices..".
This is economy.
- (IM) Where are we going in near future?
- Basic production (agriculture, fishing etc.) will be respected after a while...
- Why we cannot continue P&P production in Finland?
- Labour costs are not the problem. Their share is under 10% of the costs of paper production.
- But..?
- Transport of the products and price of the raw material are the main problems.
IM has read from local newspaper "KESKISUOMALAINEN" about the problems of timber production. A manager of timber enterprise told that "the taxes are the problem. Price of the Finnish raw wood is too high today. Government should help to have wood with acceptable prices..".
This is economy.
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